The crenellate lining of the Dufour gland in the genus Aenictus: a new character for interpreting the phylogeny of Old World army ants (Hymenoptera, Formicidae, Dorylinae)

The Dufour gland epithelium in Aenictus has a crenellate appearance, a condition previously found only in the primarily African genus Dorylus . This character, taken alone, strongly suggests that these two genera share a common ancestry, as is presently reflected in their placement in the subfamily Dorylinae, and that an independent, convergent origin for them, as has been proposed in the triphyletic hypothesis for army ant evolution, is incorrect.     

Iterative evolution of Middle Jurassic ammonite faunas

The phenomenon of iterative evolution of homeomorphs in identical temporal sequences is exhibited by Aalenian and Bajocian ammonite faunas in the south German depositional basin. Within each evolutionary cycle, inflated, evolute, and ornamented shells with complex suture lines are successively replaced with discoidal, involute, smooth shells with simpler sutures. Three distinct and identical cycles of morphological change occur, and involve ammonites belonging to four different familial/subfamilial groups: the Leioceratinae, Graphoceratinae, Hammatoceratidae, and Sonniniidae. Geometric and statistical analyses of morphological change within each of these higher taxa reveal remarkable iteration in both the pattern and proportion of change with time. The iterative morphological cycles were not driven by orthogenesis or anagenetic transformation within lineages, as has been previously suggested. A clear correlation exists between the successive ammonite faunas and repeated cyclical changes in the physical marine environment of the depositional basin. D Ammonoidea, Aalenian, Bajocian, south Germany, iterative evolution.     

Four New Recent Genera of Foraminiferida

SYNOPSIS. Four new genera of Foraminiferida are described. Phlegeria , type species P. hyalina sp. nov. and Tomaculoides , type species T. lucidum sp. nov. belong to the family Glandulinidae, and both were obtained from the Gulf of Mexico. Francesita , type species Virgulina ? advena Cusbman is found in the North Atlantic and the Gulf of Mexico, and belongs to the Caucasinidae. Montfortella , type species M. bramlettei sp. nov. occurs in Pleistocene strata and is living on the coast of California, and belongs to the Cibicididae.     

Spores of a New Microsporidan Species Parasitizing Molluscan Neurons

Synopsis.
A new species of Microsporida was observed in neurons of the marine mollusc Aplysia californica and the ultrastructure of its spores was investigated. The spores were ˜ 1.3 m long and had a thick 3-layered coat. An anchoring disc and polar aperture were present. The polaroplast occupied most of the anterior half of the spore. The vesicular portion included lengths of loosely packed lamellar structures as well as the usual vesicular profiles embedded in fibrillar material; it was entirely surrounded by tightly packed, electron-dense lamellae. The polar tube had 5 or 6 coils. In this stage of the life cycle (mature spores), the parasites did not appear to be disturbing the host cells. The organism was named Microsporidium aplysiae sp. n.