Etude Ultrastructurale du CiliéKuklikophrya dragescoi gen. n., sp. n.*

SYNOPSIS The cortical infraciliature of Kuklikophrya dragescoi gen. n., sp. n. is composed of double kinetosomes. Each kinetosome has transverse fibers. The anterior transverse fibers are associated with a sheet of dense material and the posterior transverse fibers are directed toward the posterior part of the body. The posterior kinetosome of a pair has only a short protuberance in the position of the kinetosomal fiber. The cortex has a well developed alveolar layer and a thick ecto-endoplasmic boundary. A distinctive characteristic of the buccal ciliature is the circumoral ciliature whose infraciliature is made up of pairs of cilia-bearing kinetosomes. The antero-posterior polarity of the paroral segment is in inverse relationship to that of the remaining ciliature of the organism. The adoral and preoral ciliary organelles consist of 2 rows of kinetosomes, each of which bears postciliary fibers. A frame of nematodesmata surrounds the cytopharynx which is supported by microtubular bands which impart to it a very specific laminated appearance. The “phagoplasm” is formed by “vermicelli”-like vesicles. The micronucleus is found in the perinuclear area of the macronucleus.     

Etude Ultrastructurale de la Sporulation de Paramarteilia orchestiae gen. n., sp. n., Parasite de l'Amphipode Orchestia gammarellus (Pallas)

RESUME. L'individualisation de 2 spores bicellulaires à partir d'un měme pansporoblaste caractérise la sporulation du parasite de l'Amphipode Orchestia gammarellus (Pallas) précédemment décrit sous le nom de Marteilia sp. Cette sporulation le distingue des espèces du měme genre parasite d'Hutres qui sont toutes caractérisées par la production de spores tricellulaires. Les conditions semblables dans lesquelles les pansporoblastes paraissent se differencier à partir d'une cellule souche dans laquelle ils poursuivent leur évolution vers la sporogenèse ainsi que divers caractères cytologiques communs, nous incitent à maintenir tous ces parasites dans une měme famille mais à placer celui de l'Amphipode dans un genre différent. Nous proposons de le nommer Paramarteilia orchestiae gen. n., sp. n.
Ces parasites ne peuvent ětre maintenus dans les Protozoaires en raison de leur évolution vers la pluricellularité et de l'individualisation de ces éléments somatiques que représentent la cellule souche primaire, les pansporoblastes et cellules sporales (à l'exception des sporoplasmes). Il semble logique de les inclure dans l'embranchement des Myxozoaires créé par Grassé pour les Myxosporidies et Actinomyxidies qui différencient également des spores pluricellulaires et des éléments somatiques. Les centrioles à 9 singlets de P. orchestiae ainsi que les cellules primaires uninucléées, quel que soit le nombre de pansporoblastes qu'elles contiennent, peuvent ětre considérés comme des caractères résiduels d'Unicellulaires.     

Ormiersia carcini gen. n., sp. n., microsporidian of the Mediterranean crab, Carcinus mediterraneus Czerniavsky, 1844: developmental cycle and ultrastructural study]

A microsporidan parasite, Ormieresia carcini gen. n., sp. n., was found in the crab, Carcinus mediterraneus Czerniavsky. Its development and fine structure are the subject are the subject of the present study. The life cycle begins with a schizont surrounded by a unit membrane and containing a diplokaryon. The entire process of sporogony takes place in the host musculature. The sporogonic stages are enclosed in the pansporoblastic membrane. In each pansporoblast, sporogony gives rise to 8 sporoblasts; the octonucleate sporogonial plasmodium is lacking. In the course of schizogonic and sporogonic divisions, each kinetic center consists of 2 plaques, one located within and the other outside the nuclear envelope. The dividing sporonts and sporoblasts sevrets "metabolic" substances (granules, tubules) which are depostied in the pansporoblast. The uninucleate spore is long and cylindrical, measuring 19.1 X 2.4 micronm. A rectilinear manubrium traverses the spore. Its posterior end attenuates abruptly into a polar filament with 4 or 5 coils; its anterior end is attached to the polar cap, which is compressed by a double polar ring. The anterior part of the manubrium is surrounded by a polaroplast consisting of a "spongy" (vesicular) and a lamellar zone.     

Étude de Pseudanogmius maiseyi gen. et sp. nov., poisson marin (Teleostei, Tselfatiiformes) du Crétacé supérieur du Kansas (États-Unis)

The osteology of Pseudanogmius maiseyi gen. and sp. nov., a marine teleost of the Upper Cretaceous of Kansas, is studied. This fish belongs to the order Tselfatiiformes and more particularly to the group with a more or less flat skull roof and with large, quadrangular and joined parietals. Pseudanogmius maiseyi, formerly named Anogmius sp. by Hay (1903), differs from Bananogmius and the other genera known in the order by three autapomorphies: an elongated and very narrow vomer, a peculiar relief of the toothed part of the parasphenoid, and transverse processes on the caudal vertebrae. Within the order, it shows a few evolved characters, such as the loss of the preural 1 hemal arch and of the sixth autogenous hypural and by the shortening of the preural 1 neural spine.     

Sarsicopia polaris gen. et sp.n., the first platycopioida (Copepoda: Crustacea) from the Arctic Ocean,and its phylogenetic significance

A new genus of Platycopioida is described from a boxcore sample taken at a depth of 534 m in the ArcticBarents Sea. This is the deepest record ofPlatycopioida so far. Sarsicopia gen. n. is thesistergroup of a taxon comprising Platycopia and Nanocopia; the sistergroup ofthese is Antrisocopia. Sarsicopia gen. n.is the only platycopioid to retain 2 inner setae onthe second endopod segment P2–P4, and 8 setae in thethird endopod segment of P2. The male antennnule isremarkable in having a geniculation located betweenancestral segments XX and XXI. It is suggested thatthis flexure zone was already present in thegroundpattern of Copepoda. Platycopia and Nanocopia have secondarily lost thisgeniculation.     

Isonema papillatum sp. n., a New Colorless Marine Flagellate: A Light- and Electronmicroscopic Study

SYNOPSIS. Isonema papillatum sp. n. is described from observations with the light and electron microscope. It has 2 short emergent subapical flagella without appendages, a specialized ingestion apparatus, and a nonrigid naked cell body capable of pronounced changes in shape similar to euglenoid movements. It lacks a stigma and flagellar swelling and does not form paramylon granules. The nucleolus persists throughout nuclear division.     

Morphological conservatism in the foreleg structure of cicada hatchlings,Burmacicada protera n. gen., n. sp. in Burmese amber,Dominicicada youngi n. gen., n. sp. in Dominican amber and the extant Magicicada septendecim (L.) (Hemiptera: Cicadidae)

Two cicada hatchlings (Hemiptera: Cicadidae) in Burmese and Dominican amber are described as Burmacicada protera n. gen., n. sp. and Dominicicada youngi n. gen., n. sp., respectively. Although very similar in appearance, the two species can be separated by body contour, the nature of the process on the terminal antennomere and the shape and size of protrusions, teeth and spines on the forelegs. A comparison of the forelegs of the fossil hatchlings with those of an extant hatchling of the periodical cicada, Magicicada septendecim (L.), reveals a remarkable degree of morphological conservatism over 100 million years. A brief review of fossil cicadas is presented.     

Cryptosporidium anserinum sp. n. (Sporozoa) in a Domestic Goose Anser anser L., from Iowa

SYNOPSIS. Cryptosporidium anserinum sp. n. is described in the large intestinal mucosa of a domestic goose, Anser anser L., from Iowa. Ultrastructural studies revealed schizonts containing 4 merozoites and macrogametes and schizonts with characteristic attachment zones and double membranes. The only lesion associated with infection was shortening of the intestinal microvilli.     

Thalassomermis megamphis n. gen., n. sp. (Mermithidae: Nemata) from the Bathyal South Atlantic Ocean

Thalassomermis megamphis n. gen., n. sp. (Mermithidae: Nemata) was extracted from sediment collected off the coast of Brazil at a depth of approximately 1,000 m. Although the food of this new nematode is unknown, the reduction of the stoma and esophagus and presence of a trophosome indicate that it is parasitic in its juvenile stages. Thalassomermis megaraphis n. gen., n. sp. is assigned to Mermithidae because of its similarity to that family in the appearance of the cephalic sensory receptors, the long and tubular vagina, and copulatory muscles of the male extending posteriorly throughout most of the length of the tail. Thalassomermis megamphis n. gen., n. sp. differs from all other members of Mermithidae by the large, lenticular, intracuticular amphidial fovea with coiled, emergent terminal filaments as well as the small amphidial aperture situated over the center of the fovea.     

Colpoda spiralis sp. n., a Colpodid Ciliate Found Inhabiting Treeholes (Colpodida,Ciliophora)*

SYNOPSIS A new species of the family Colpodidae, genus Colpoda O. F. Müller, Colpoda spiralis sp. n. is described. This organism has been found only in treehole fluid. Its species status is based on the possession of a unique and prominent preoral protuberance, multimicronuclearity, and the preference for a treehole habitat. Its range is known to include the tri-state area of Arizona, New Mexico and Utah, and the mixed-deciduous forests of Maryland. This species prefers treehole fluids with a pH > 7 and is naturally limited to tree species which possess these alkaline treeholes. It encysts as a treehole dries and excysts when the treehole is again filled by fluids from the tree, or rainwater.     

Nothacrobeles,n. gen., with Descriptions of Four New Species (Nematoda: Cephalobidae)

A new nematode genus, Nothacrobeles, is proposed in the subfamily Acrobelinae. Four new species are described and one new combination made. The five species exhibit a progression from short-to-long, bifurcate, elaborately fringed labial probolae, the longest probolae resembling those of species of Acrobeles.     

Stempellia milleri sp. n. (Microsporida: Nosematidae) in the Mosquito Culex pipiens quinquefasciatus Say*

Stempellia milleri sp. n. was found in blood cells and the adipose tissue of field-collected larvae of Culex pipiens quinquefasciatus Say. Its development is different from other Stempellia species described in that it is dimorphic, producing two types of spores in adipose cells. Both were studied with the electron microscope. One spore is thin-walled and uninucleate; the other is thick-walled and binucleate. The latter spores are produced from sporonts that are somewhat similar to those of Nosema. Sporoblasts and spores of S. milleri were compared to those of Stempellia magna Kudo, and Stempellia lunata Hazard and Savage in both light and electron microscope preparations. S. milleri was transmitted experimentally to Culex pipiens pipiens, C. p. quinquefasciatus, C. salinarius, C. tarsalis, and C. territans. Transmission of S. magna to its host and other mosquito species was not possible. Although, generally low numbers of test larvae became infected with the pathogen, heavy infections were seen occasionally in individual specimens of its natural host, C. p. quinquefasciatus. Species of Aedes, Anopheles, Culiseta, Psorophora, and Uranotaenia exposed to spores of S. milleri were not susceptible to the disease.     

<Emphasis Type="Italic">Pleuroxus</Emphasis>-like chydorids (Crustacea: Anomopoda) from South Africa,with the description of <Emphasis Type="Italic">Dumontiellus africanus</Emphasis> gen. n., sp. n.

Five species of Pleuroxus-like chydorids are found in new material from South Africa or are known from the literature. One species is here described as Dumontiellus africanus gen. n., sp. n., endemic to South Africa. Handling editor: K. Martens     

Eimeria crotalviridis sp. n. from Prairie Rattlesnakes, Crotalus viridis viridis, in New Mexico with Data on Excystation of Sporozoites and Ultrastructure of the Oocyst Wall

SYNOPSIS Oocysts of Eimeria crotalviridis sp. n. are described from prairie rattlesnakes, Crotalus viridis viridis in New Mexico on the basis of light and electron microscopy and in vitro excystation of sporozoites. Sporulated oocysts of E. crotalviridis are elliptical, 26.4 × 22.3 (23–29 × 20–24) μm with ovoid sporocysts 11.7 × 8.1 (11–13 × 7–9) μm. A micropyle, micropyle cap and polar bodies are absent, but oocyst and sporocyst residua and Stieda and substieda bodies are present. Excysted sporozoites are 12.4 × 2.8 (11–13 × 2–3) μm and have 1 large posterior refractile body and a nucleus with a prominent nucleolus. Ultrastructurally, the oocyst wall has 2 layers, a thick, electron-dense, highly sculptured outer layer composed of a fine granular matrix and a thin, granular, osmiophilic inner layer, separated from the outer layer by at least one unit membrane. These layers are 441 (353–510) and 21.6 (19–29) nm thick, respectively. Within 15 min after exposure to a trypsin-sodium taurocholate fluid, sporozoites of E. crotalviridis excysted from 5-month-old sporocysts.     

Sphaeromyxa maiyai sp. n. (Protozoa: Myxosporidea), Coelozoic Parasite of the Pacific Tomcod,Microgadus proxiimus*

SYNOPSIS. Sphaeromyxa maiyai sp. n. (Myxosporidea: Myxiidae) is described from the gall bladder of the Pacific tomcod Microgadus proximus Girard, from Newport, Oregon. The plasmodial stage is discoid averaging between 1 and 2 cm. The spore averages 27.6 × 5.6 μm in breadth, with pyriform polar capsules measuring 9.3 × 3.7 μm. Scanning electron microscopy reveals the presence of numerous longitudinal striations.     

Nosema parkeri sp. n., a Microsporidan from the Argasid Tick, Ornithodoros parkeri Cooley

SYNOPSIS. Nosema parkeri sp. n. is described from nymphs and adults of the argasid tick, Ornithodoros parkeri Cooley, from a laboratory colony. Schizogonic and sporogonic stages are described from various tick tissues. Spores are binucleate, measuring 3.2 (3–4) × 1.9 (1.8–2.5) μm. Transmission is transovarial and transstadial. The parasite does not appear to affect adversely the development or reproduction of the tick. Dermacentor andersoni Stiles was experimentally infected. Attempts to infect Swiss mice by tick feeding or by injection of infected tick suspensions were unsuccessful. The microsporidan differs in structure from Encephalitozoon ixodis Weiser) and Nosema slovaca Weiser & Reháček, the only other microsporidans known from ticks.