NO. 2063. NORTH AMERICAN PARASITIC COPEPODS— WILSON. 663 



named Naobrancliia cygniformis. Kr0yer's specimen undoubtedly 

 belonged to this same genus, and hence must be called Naobranchia 

 lizae. In 1877 Kurz in his Studien der Lernaeopodiden ^ described 

 a new genus and species which he designated Cestopoda amplectens. 

 He was thoroughly familiar with Kr0yer's paper and made several 

 quotations from it, and concluded that his specimens and Kr0yer's 

 "certainly belong, if not to the same species, at least to the same 

 genus." He added that the data with reference to Kr0yer's species, 

 which are necessary to enable us to tell whether the two are identical, 

 are lacking. If he could have had the data here presented he would 

 have seen at once that the two species are distinct. However, he 

 seems to have entirely overlooked Hesse's paper, and since Hesse's 

 species is a third one belonging to the same genus, the name which he 

 gave to that genus must stand, and "Cestopoda," given by Kurz, 

 becomes a synonym. The distinctive characteristics of the present 

 species are the comparatively great width of the second maxillae, the 

 elongation of the trunk, and the form and position of the egg strings. 

 In the other species some of the eggs are carried in front of the 

 opening of the oviduct, but the great majority are behind it, and the 

 egg strings taper posteriorly; here only a few of the eggs are carried 

 behind the opening, while the great majority are in front of it, and the 

 egg strings taper anteriorly. The male also, which is here described 

 for the first time, serves to distinguish the species. The large and 

 prominent genital process is especially noteworthy, as well as the 

 similarity in size and structure between the second maxillae and the 

 maxillipeds. 



NAOBRANCHIA OCCIDENTALIS, new species. 

 Plate 44, figs. 136 to 139. 



Host and record of specimens. — Five adult females and one male 

 were obtamed from the gills of the Pacific cod, Gadus macroceplialus, 

 at Chignik Bay, Alaska, August 7, 1903, by the Bureau of Fisheries 

 steamer Albatross during the Alaska salmon investigations. The 

 best female has been selected as the type and numbered 43579, 

 U.S.N.M. The remaining specimens with the male become paratypes 

 and have been numbered 39567, U.S.N.M. 



Specific cliaracters of female. — Cephalo thorax about the same length 

 as the trunk, much enlarged and wrinkled at the base, tapering toward 

 the head, where it is considerably smoother; head not enlarged, but 

 covered with a minute and smooth dorsal carapace; neck distinctly 

 separated from the trunk by a deep dorsal groove and shallower ones 

 on the sides; trunk triangular, much flattened dorso-ventrally, the 

 posterior corners of the triangle projecting over the egg strings; pos- 

 terior margin inclined on either side toward the genital segment; the 



1 Zeit. fur wiss. Zool., vol. 29, p. 407. 



