ISOPODS OF NOKTH AMEEICA. 



163 



four have the outer post-lateral angle acutely produced beyond the 

 posterior margin of the segments. 



All six segments of the abdomen are distinct, although the first is 

 partly covered at the sides 

 by the last thoracic segment. 

 The sixth or terminal segment 

 is wider than long, 3 mm.: 

 2 mm., and is rounded pos- 

 teriorly with margins dis- 

 tinctly crenulate and has a 

 slight median emargination. 

 The inner branch of the uro- 

 poda reaches the extremity of 

 the terminal segment of the 

 abdomen. It is broad and 

 truncate posteriorly, with mar- 

 'gins distinctly crenulate and 

 furnished with spines. The 

 outer branch is shorter than 

 the inner branch, is narrower 

 and more pointed at its ex- 

 tremity. It is also distinctly 

 crenulate and furnished with 

 spines. 



Two specimens of this spe- 

 cies were collected by the U. S. 



Bureau of Fisheries steamer Albatross at station -1117, S. W. Rock, 

 Santa Barbara Islands, latitude 8 north, longitude, 6.3' west. 



Depth. 29 fathoms. 



29. Genus NALICORA Moore. . 



"Clypeus small, peduncle of second antennte long; mandible weak, 

 with bidentate cutting edge and three-jointed palp; first maxillae very 

 large, robust, and conspicuous in situ, outer joint stout, hooked, and 

 terminated by a strong, curved spine in the male, continuous in con- 

 tour with the rest of the part, and with a knob-like process at its base; 

 inner joint with its tip covered by a quadrate, curve-faced cap covered 

 with papillae; second maxilla? four- jointed, first two joints stout, short, 

 third joint stout and subconical, terminal joint slender and conical, with 

 a tuft of setae near tip; palp of maxillipeds five-jointed, slender. "- 

 MOORE. a 



/ \ 



FIG. 145. TRIDENTELLA VIRGINIANA. a, MAXILLIPED. 

 x 5l|. 6, MANDIBLE, x 51|. c, PALP OF MANDIBLE. 

 x 51|. d, SECOND MAXILLA, e, FIRST MAXILLA 

 (OUTER LOBE) . x 61|. /, FRONTAL. LAMINA, x 27}. 



a Bull. U. S. Fish Commission, XX, Pt. 2, 1902, p. 169. 



