NORTH ATLANTIC NUDIBRANCHS OF THE CHROMODORTS CLENCHI COLOUR GROUP (OPISTHOBRANCHIA: CHROMODORIDIDAE)

The correct identity of three chromodorid nudibranch species,Chromodoris clenchi, C. neona and C. binza is established onthe basis of material from the Caribbean Sea. These three speciesare compared with C. britoi, from the northeastern Atlanticand the Mediterranean Sea. All four species have a colour patternof cream with red (or yellow) lines and blue spots. (Received 30 March 1993; accepted 20 November 1993)     

RELATIONSHIPS BETWEEN PATELLA FERRUGINEA GMELIN, 1791 AND THE OTHER TYRRHENIAN SPECIES OF PATELLA (GASTROPODA: PATELLIDAE)

The external morphology of soft parts of the rare Patella ferrugineaGmelin, 1791 is described, and its relationships with P. caerulea,P. rustica and P. ulys-siponensis are investigated on both morphologicaland electrophoretic grounds. Soft part morphology is a gooddiscriminative tool, but of little help in detecting affinities.Electrophoretic data on 19 presumptive loci suggest that P.rustica is the closest species to P. ferruginea, whereas P.caerulea and P. ulyssiponensis are clustered separately. Meanobserved heterozyg-osities arc higher in P. ferruginea and P.rustica. It is concluded that in case of subdivision of thegenus Patella L., 1758, P. ferruginea and P. rustica shouldbe placed together in the subgenus Patellastra Mon-terosato,1884. (Received 6 January 1993; accepted 23 February 1993)     

THE ANATOMY OF CYLINDROTIS QUADRASI FORM OKINAWA ISLAND, JAPAN AND THE SUBFAMILIAL POSITION OF THE GENUS CYLINDROTIS MOLLENDORFF, 1895 (ARCHAEOPULMONATA: ELLOBIIDAE)

Cylindrotis quadrasi Mollendorff, 1895, the type species ofthe ellobiid genus Cylindrotis, was collected from Okinawa Island,southwest Japan. This is the first record of C. quadrasi inJapan and the third in the world. The anatomical charactersof this species, i.e. shell, head-foot, pallial cavity, radula,stomach, reproductive system, and central nervous system, aredescribed in detail for the first time. The significance ofthese observations is discussed and the subfamilial positionof Cylindrotis is reconsidered. Cylindrotis was included inthe Pythiinae, the most primitive group of the Ellobiidae, basedon the conchological characters alone. However, the male andfemale tracts of the reproductive system are entirely separated,and other internal organs exhibit highly derived conditions.Accordingly, Cylindrotis is transferred from the Pythiinae tothe Ellobiinae. Among the genera of the latter subfamily, Cylindrotisseems to be allied to Blauneria Shuttleworth, 1854 and LcucophytiaWinckworth, 1949. (Received 1 February 1993; accepted 7 June 1993)     

蝗虫微孢子虫病在草原蝗虫优势种种群及空间的分布

在采用蝗虫微孢子虫Nosema locustae防治过的草场中进行抽样调查,研究了草原蝗虫优势种类、混合种群平均密度与蝗虫微孢子虫疾病分布之关系,以及该疾病的空间分布。在防治后的当年,蝗虫微孢子虫疾病的感染率随着混合种群平均密度及靶标蝗虫亚洲小车蝗Oedaleus asiaticus的感病率的下降而降低。但是,次靶标蝗虫如宽须蚁蝗Myrmeleotettixpalpalis(一种中后期发生的种类)其感病率呈上升趋势,表明该疾病可在不同发生期种类蝗虫之间进行有效地传播。病蝗虫在防治后第7d其空间分布呈随机分布(Poisson),第28d 则是聚集分布,第40d时也呈聚集分布。于1993年、1994年对1988年(样区Ⅱ)、1989 年(样区Ⅲ)采用微孢子虫防治过的草场进行抽样调查。结果表明,在二个样区中,二年混合种群平均虫口密度与混合种群的平均感病率呈正相关(相关系数分别为r=0.289, r=0.479)。蝗虫微孢子虫病在主要优势种,如亚洲小车蝗、宽须蚁蝗、白边痂蝗Bryode maluctuosumluctuosum、皱膝蝗Angaracris /I>spp.、毛足棒角蝗Dasyhippus barbipes均有分布。二个样区中的混合蝗虫种群的平均感病率在1994年显著低于1993年。混合蝗虫种群的种类组成也有所变化,与1993年相比,1994年宽须蚁蝗及白边痂蝗的比例上升较大,而亚洲小车蝗的比例下降。经过5—7年的扩散,蝗虫微孢子虫病至少可扩散距防治区1 000m,其扩散方向可能与风及地势等有关。     

THE REPRODUCTIVE ANATOMY OF PAROPEAS ACHATINACEUM AND A NEW CONCEPT OF PAROPEAS (PULMONATA: ACHATINOIDEA: SUBULINIDAE)

The majority of subulinid land snails are known only as shellsand generic groupings need to be revised on the basis of theirinternal anatomy. Paropeas achatinaceum (new combination) isa synanthropic subulinid that is widely distributed around theIndo-Pacific region. Features of the genital anatomy and radulademonstrate that Paropeas should be rejected as a subgenus ofProsopeas and be recognised as a distinct genus. The radulaof Paropeas is more typical of a subulinid than is that of Prosopeaswhich proves to be highly modified for a carnivorous diet. Thespermatophore of Paropeas is inserted directly into the oviductwhere it releases sperm through its porous tail before beingdigested in the bursa copulatrix. (Received 23 September 1992; accepted 11 November 1993)     

THE IMPORTANCE OF MUCUS AS A DEFENCE AGAINST CARABID BEETLES BY THE SLUGS ARION FASCIATUS AND DEROCERAS RETICULATUM

The effect of mucus exudation on the survival of Arion fasciatusand Deroceras reticulatum was studied by exposing mechanicallystimulated and control slugs to Carabidae beetles for 24 hours.A light stimulation, lasting three minutes, exhausted the copiousflow of mucus for one day. A generalist, Pterostichus niger,significantly preferred stressed D. reticulatum over controlones. Similarly, P. niger exclusively ate stressed individualsof A. fasciatus. Two beetles which specialize in gastropods,Cychrus caraboides and Carabus violaceus, consumed an equalnumber of stressed and control D. reticulatum and A. fasciatus.The susceptibility of the slug species to predation was different:for each beetle species, the proportion of available D. reticulatumpreyed upon was significantly higher than that of A. fasciatus.The differences in the behaviour of A. fasciatus and D. reticulatumin defending themselves against attacks is described. The mainreason why specialist beetles are able to hunt slugs successfullyis their ability to prevent the slugs from exuding large amountsof mucus. This may succeed by different means: C. violaceustargeted their killing strokes against the posterior part ofthe mantle while C. caraboides hit the head of the slug. Inboth case the strokes seemed to paralyze the slugs. (Received 31 March 1993; accepted 1 October 1993)     

背展恙螨亚科一新属(蜱螨亚纲：恙螨科)

1993年6月16日从西藏错那县贡日的锡金松田鼠（Pitymyssikimensis）体上采到1只背展恙螨亚科（Gahrliepiinae）的恙螨,其盾板近五角形,后缘钝圆,具2根后侧毛（2PL）,板上尚具很多副毛,有的副毛位于两感毛基之间,此特征与现有的各属均不同,经研究后认为系该亚科中的一新属。为了表示对吴厚永教授的敬意,特将此新属命名为吴氏恙螨属Wuella新属。属模标本保存于军事医学科学院微生物流行病研究所医学昆虫标本馆。吴氏恙螨属Wuella新居背展亚科的中小型螨类。盾板近五角形,后下角钝圆,具1对前侧毛AL和2对后侧毛PL。感毛叶片状。盾…     

HYDROBIIDAE (GASTROPODA: HYDROBIOIDEA) FROM THE RIBEIRA VALLEY, S.E. BRAZIL, WITH DESCRIPTIONS OF TWO NEW CAVERNICOLOUS SPECIES

Potamolithus karsticus n. sp. and Potamolithus troglo-bius n.sp., two Brazilian aquatic cavesnails (Gastropoda: Hydrobiidae),are described. P. troglobius is blind and depigmented, and isthe first stygobiontic snail to be described from Brazil Additionally, specimens of Potamolithus ribeirensis Pilsbry,1911 were collected near the type locality for comparison withthe new cave species (Received 2 December 1993; accepted 20 June 1994)     

TWO NEW SPECIES OF THE GENUS ISLAMIA RADOMAN, 1973 FROM ITALIAN ISLANDS (PROSOBRANCHIA, HYDROBIIDAE)

Two new Italian species of the genus Islamia (Prosobranchia:Hydrobiidae), one living in eastern Sicily (I. cianensis), andone on Elba Island (Tuscan Archipelago, Italy) (I. gaiteri)are described. The two species are distinguished on the basisof shell and anatomical characters, mainly those of the malegenitalia. I. cianesis n. sp. is characterized by a valvatoidshell and a penial lobe with internal band of glandular tissuenot distinct in its lower portion from the penis body but bulgingapically as a small knob. I. gaiteri n. sp. is characterizedby a planispiral shell and a small lateral penial lobe withoutinternal glandular tissue. (Received 20 December 1993; accepted 27 June 1994)     

Organization of the psaH Gene Family of Photosystem I in Nicotiana sylvestris

The PSI-H subunit of photosystem I has two isoforms of differingmolecular mass in Nicotiana sylvestris [Obokata et al. (1993)Plant Physiol. 102: 1259], and is encoded by a nuclear gene,psaH. We identified three structurally distinct psaH genes inthe nuclear genome of N. sylvestris, designated psaHa, psaHb,and psaHc, and all three genes are expressed in young leaves.Each gene has two introns: one between sequences encoding atransit peptide and the N-terminal acidic domain, and one betweenthe N-terminal domain and a central hydrophobic domain. Thededuced amino acid sequences are identical in the mature proteinsand differ only in the transit peptides. Since PSI-H is presentin two isoforms in N. sylvestris, the psaH products may be subjectedto post-translational modifications. (Received November 8, 1993; Accepted December 28, 1993)     

DEVELOPMENT OF ACCESSORY SEXUAL ORGANS IN BIOMPHALARIA GLABRATA (PLANORBIDAE) IN RELATION TO TIMING OF INFECTION BY SCHISTOSOMA MANSONI: CONSEQUENCES FOR ENERGY UTILIZATION PATTERNS BY THE PARASITE

The growth rates of ovotestis and individual accessory sexualorgans (ASO) of Biomphalaria glabrata snails were studied forcontrols and for immature and mature snails infected with Schistosomamansoni. The infection of immature B. glabrata strongly delaysgrowth of the ovotestis and inhibits the development of theaccessory sexual organs. There is no significant differenceup to 2 weeks post infection in the volume of the ovotestisand the ASO between mature infected B. glabrata and controlsnails. From 3 to 4 weeks post infection there was a reductionin the volume of the ovotestis and the ASO of infected matureB. glabrata; then growth of the ovotestis, albumen gland andfemale organs was stopped, but the effect of infection was lessconsistent for the male organs. For a parasite, immature andmature snails have to be considered as two different resourceenvironments, each having at infection time a particular patternof resource allocation, towards growth for juvenile and towardsreproduction for adult snails, changing the possible energyutilization patterns which can be used by the trematode. (Received 29 January 1993; accepted 22 April 1993)     

SEASONAL FLUCTUATIONS IN POPULATION DENSITES OF BULINUS SENEGALENSIS AND B. TRUNCATUS (PLANORBIDAE) IN TEMPORARY POOLS IN A FOCUS OF SCHISTOSOMA HAEMATOBIUM IN NIGER: IMPLICATIONS FOR CONTROL

Annual and seasonal changes in population densities of Bulinussenegalensis Müller 1781 and B. truncatus (Audouin, 1827)were studied in temporary pools of the west sahelian zone inNiger in relation to environmental factors. B. senegalensisis present in the temporary pools whatever their duration, whereasB. truncatus inhabits only the more persistent pools. B. senegalensispopulations develop mostly during the rainy season when thewater temperature is warm. B. truncatus is most abundant afterthe rainy season when the water temperature is cooler, but thissnail may increase when the water temperature is warmer duringunusual rainy seasons with low and intermittent rainfall. Fieldobservations suggest that interspecific competition is exceptionallyoccurring in the pool colonized by both B. senegalensis andB. truncatus. The implications of these observations on treatmentand retreatment schedules for schistosome infection in peopleand on snail control in temporary pools are discussed. (Received 4 May 1993; accepted 22 July 1994)     

NOTES ON SOME IBERO-MOROCCAN AND MEDITERRANEAN TRICOLIA (GASTROPODA, TRICOLIIDAE), WITH DESCRIPTIONS OF NEW SPECIES

Three new species hitherto confused with Tricolia tingitanaGofas, 1982 are described, one from Corsica and Sicily and twofrom the Strait of Gibraltar. Distinctive characters seen onliving animals and on radulae are discussed. (Received 26 August 1992; accepted 4 January 1993)     

NOTOLIMEA CLANDESTINA A NEW SPECIES OF NEOTENOUS BIVALVE (BIVALVIA: LIMIDAE) ENDEMIC TO THE STRAIT OF GIBRALTAR

Notolimea clandestina new species (Bivalvia: Limidae) is describedfrom the littoral of the Strait of Gibraltar. The small size(1 mm) and the persistence of the larval hinge suggest a neotenousspecies. Its area of distribution is likely to be restrictedto the Strait of Gibraltar. (Received 7 July 1993; accepted 2 December 1993)     

TAXONOMIC REVIEW OF THE TREE SNAIL AMPHIDROMUS ALBERS, 1850 (PULMONATA: CAMAENIDAE) IN THAILAND AND ADJACENT AREAS: SUBGENUS AMPHIDROMUS

Extensive series of Amphidromus Albers, 1850 were collectedfrom low-altitude areas (30–500 m above sea level)in Thailand, Laos, Malaysia, Singapore and Indonesia between1993 and 2004. Data on shell colour, genital and spermatophoremorphology, and radular structure are presented. Five speciesof Amphidromus (Amphidromus) are reviewed, of which four occurin Thailand. Intraspecific variation between populations ofAmphidromus (Amphidromus) atricallosus (Gould, 1843) is considered;three subspecies are accepted and a new subspecies described.Subspecies of A. (A.) inversus (Müller, 1774) and A. (A.)schomburgki (Pfeiffer, 1861) are reconsidered, and a new subspeciesof the latter is described. A dichotomous key to the speciesand subspecies of Amphidromus (Amphidromus) in Thailand is provided. (Received 7 May 2004; accepted 31 March 2005)     

DISTRIBUTION AND POPULATION DYNAMICS OF THREE POPULATIONS OF SIPHONARIA ON ROCKY INTERTIDAL SHORES IN HONG KONG

The pulmonate limpets Siphonaria japonica and Siphonana siriusoccur over a wide range of local habitat types in terms of exposureto wave action and salinity. This is a study of these two specieson three different shore types in Hong Kong, ranging from anextremely exposed, high salinity (32–35) shore at Caped'Aguilar to a sheltered, low salinity (16–33) shore atTai Lam Chung. Both species are restricted to the low shore,year round. S. japonica is a winter breeder and recruitmentoccurred between October and January. The recruitment of S.sirius could not be recognised from the size-frequency histograms.The algal standing crop at Tai Lam Chung was higher than atWu Kwai Sha during the winter period, i.e., between Octoberand April. Seasonal fluctuations in growth rate were recordedfor both Siphonaria species with the time of fastest growthoccurring in winter. S. japonica grew faster at Tai Lam Chungthan at Wu Kwai Sha. Food availability is thought to be an importantfactor affecting growth. (Received 17 September 1993; accepted 16 June 1994)     

YOLDIELLA SEGUENZAE, A NEW SPECIES OF NUCULANIDAE (BIVALVIA; NUCULOIDA) FROM THE MEDITERRANEAN SEA

A new species, Yoldiella seguenzae (Bivalvia, Nucu-loida), froma deep sea community off the north east coast of Sardinia (MediterraneanSea), is described. Morphometrical and statistical comparisonwith the very similar Yoldiella philippiana (Nyst, 1845), andgeneral morphological comparison with other Mediterranean andAtlantic species support the distinc-tivness of Y. seguenzaewhich is distributed in deep waters of the Central MediterraneanSea, Alboran Sea and the Atlantic Ocean. (Received 21 October 1993; accepted 1 July 1994)