ISOPODS OF NORTH AMERICA. 



131 



Localities. West Indies; Gulf of Mexico; Caribbean Sea; Mouth 

 of Exuma Sound; Bay of Bengal. 



Depth. 955 fathoms; 740 fathoms. 



Body oblong-ovate, nearly two and a half times longer than wide, 

 38 mm. : 90 mm. 



Head wider than long, 12 mm. : 21 mm., with the anterior margin 

 produced in a median point which meets the apex of the triangular 

 frontal lamina. The eyes are 

 large, composite, and are situ- 

 ated on the inferior side of the 

 head. The first pair of antenna 1 

 have the basal article large, 

 about as wide as long; the sec- 

 ond is about as long as the first; 

 the third is half as long as the 

 second; there is a small scale 

 articulated to the end of the 

 third article of the peduncle; 

 the flagellum is composed of 

 forty-six articles and extends 

 one-fourth the length of the 

 first thoracic segment. The sec- 

 ond pair of antennae have the 

 first article short; the second is 

 almost at right angles to the first 

 and is about 2 mm. long; the 

 third is about as long as the sec- 

 ond; the fourth is about 3 mm. 

 in length; the fifth is -t mm. long. 

 The flagellum is composed of 

 about sixty-six articles and ex- 

 tends to the middle of the fourth thoracic segment. The maxillipeds 

 are composed of seven articles. The frontal lamina is triangular in 

 shape, with the apex contiguous with the median point of the frontal 

 margin of the head. 



The first segment of the thorax is the longest, being 10 mm. in 

 length. The second and third are subequal, and each is 6 mm. long. 

 The fourth and fifth are each 5 mm. in length. The sixth and seventh 

 are each 4 mm. long. The epimera are distinctly separated on all the 

 segments with the exception of the first, and are large plates with the 

 outer post-lateral angle produced in the last four beyond the posterior 

 margin of the segments. 



The six segments of the abdomen are distinct, the first five being 

 subequal in length. The sixth or terminal segment is wider than 



FIG. 112. BATHYNOMl'S GIGANTEITS (AFTER EDWARDS 

 AND AGASSIZ). DORSAL VIEW. 



