A new species, Ishikawatrechus bidilatatus sp. nov., is described from the northwestern part of the Ishizuchi Range, Shikoku, Japan. The structure of the everted internal sac of the aedeagus in a fully inflated condition is observed and the taxonomic significance is discussed by comparing with a related species, I. ishiharai Uéno, 1994.

Mesothoracic wings have been examined and compared in 32 species representing 20 genera of Afrotropical Scutelleridae. Morphological characters of the corium are described. Three main types of mesothoracic wing venation patterns can be recognized. The taxonomic significance of forewing characters in Scutelleridae is briefly discussed.

The ability of Yersinia to digest polypectate may be of some value in differentiating Y. enterocolitica and Y. pseudotuberculosis from some of the other fermenting gram-negative bacilli, such as Enterobacter agglomerans, with which they can be confused. Pectolytic activity in Yersinia may also have some teleologic or taxonomic significance about which we do not care to speculate.

Bairdoppilata scaura, n. sp. and five species of Bairdoppilata and Paranesidea in open nomenclature are described from encrusting communities on French Frigate Shoals and Kane'ohe Bay, Oahu, Hawaiian Islands. Some poorly documented anatomical traits (carapace setae, hingement, antennal claws, genitalia) are examined for their potential taxonomic significance, in order to confirm the coherence o...

During the post-Darwinian history of taxonomy, the Linnaeän hierarchy has maintained its role as a means for representing hierarchical taxononaic relationships. During the same period, the principle of descent has tallen on an increasingly important role as the basis for reformulated versions of fundamental taxonomic concepts and principles. Early in this history, the principle of descent provi...