132 



THE VOYAGE OF H.M.S. CHALLENGER. 



Section TIL Siphonostom a, Tliorell. 



Family I. Caligina. 



Lepeophtheirus, Nordman n. 



Lepeophllidru*, Nonlmann, Mikr. Beit. 

 Fourth pair of feet slender, of only one branch, and serving the animal for walking. 

 Thorax exhibiting only two distinct articulations. Frontal plates destitute of sucking- 

 discs or lunules on their under surface (Baird). 



Lepeophtheirus suhmi, n. sp. (PI. LV. fig. 2). 



Length, 16-100ths of an inch (4 mm.). Cephalothorax about twice as long as the rest 

 of the animal, scarcely longer than broad, and not much narrowed in front; frontal region 

 not emarginate in the middle. Antennas short, first joint of the anterior pair stout and 

 densely setose towards the anterior margin, second joint bearing several short setae at the 

 extremity ; posterior pair directed backwards and having the last joint abruptly hooked 

 at the apex. Furcula deeply cleft, segments slender and curved. Fourth pair of feet 

 reaching to the distal extremity of the genital segment, long, flexuous, and slender, four- 

 jointed, armed with two small lateral and three apical spines, one of which is very long and 

 curved. Genital segment much broader than long, armed with a small spine at each 

 posterior angle. Last abdominal segment and caudal stylets about equal in length, and 

 together equalling only about one-half the genital ring. 



The segment to which the third pair of feet is attached is rounded and squamous, and 

 has a small spine at the base of each pair of feet. Between the rostrum and the base of 

 the first foot-jaw, on each side, is a small forked appendage (fig. 2, a), in shape very much 

 like the " furcula," — apparently homologous with the "palp" of some authors, but which 

 I cannot perceive to have any organic connection with either foot-jaw or rostrum. 

 Nearer the margins of the carapace, outside of the first foot-jaws, are two minute hooked 

 appendages (fig. 2, b), which enclose in somewhat dilated bases two objects which have 

 the appearance of very small sucking discs. 



Found on a Scams taken at St. Vincent, Cape Verde, July 1873. 



Echthrogaleus, Steenstr. and Lutk. 



Echthrogaleus, St. & Ltlc, Snyltekrebs og Lernaeer, 1861. 

 Dinematura, M.-Edw., Dana, not of Latreille nor Kroyer. 



First two body segments coalescent ; genital segment broad and flat (never long or 



slender), and deeply emarginate behind ; dorsal laminge large, and covering half of the 



