ISOPODS OF NORTH AMERICA. 187 



thoracic segment; in Dana's species they are shorter than the basal 

 part (peduncle) of the external or second pair of antennae; in the larger 

 eyes, which are narrow and elongate instead of being round and very 

 small; in the longer uropoda, the branches in A. microphthalma 

 scarcely surpassing the abdomen; in not having the apex of the inner 

 branch "faintly arcuate obliquely" and in having all six segments of 

 the abdomen visible in a dorsal view, only five being apparent in A. 

 microphthalma. 



This species differs from ^Ega longicornis Hansen in the shorter 

 second antennae, which extend only to the middle of the third thoracic 

 segment, while in A. longicornis the}^ extend to the middle of the fifth 

 thoracic segment; in having the first three pairs of legs furnished with 

 a greater number of spines than in Hansen's species; in having both 

 branches of the uropoda terminating ki a bifid extremity, while in A. 

 longicornis the extremities of the uropoda are acute, and in having the 

 apex of the terminal abdominal segment bifid instead of acutely pointed. 



A specimen from off Santa Cruz Island, California, agrees with the 

 specimens from Alaska, with the exception that the second antennae 

 have fourteen instead of sixteen articles to the flagellum. They are, 

 however, just as long, extending to the middle of the third thoracic 



segment. 







JEGA VENTROSA M. Sars. 



JEga ventrosa M. SARS, Chr. Vid. Selsk. Forh., 1858-59, pp. 154-156. SCHICEDTE 



and MEINERT, Natur. Tidsskr. (3), XII, 1879-80, pp. 375-377, pi. ix, figs. 7-8. 

 jEgiochus nordenskidldii BOVALLIUS, Bihang Sv. Vet.-Akad. Handl., X, 1885, 



No. 9,, p. 5, pi. i-n. 

 JEga loveni BOVALLIUS, Bihang Sv. Vet.-Akad. Handl., XI, No. 17, 1886-87, pp. 



3-6, pi. i, figs. 1-10. 

 jEgiochus rentrosus BovALLitfs, Bihang Sv. Vet.-Akad. Handl., XI, No. 17, 1886- 



87, pp. 8-9. 

 JEga nordenskioldii HANSEN, Vidensk. Meddel. Naturh. Foren. i Kj0bh., 1887-88, 



pp. 184-187. 

 JEga ventrosa G. O. SARS, Crust. Norway, II, 1899, p. 64, pi. xxvi, fig. 3. 



RICHARDSON, American Naturalist, XXXIV, 1900, p. 218; Proc. U. S. Nat. 



Mus., XXIII, 1901, p. 522. NORMAN, Ann. Mag. Nat. Hist. (7), XIV, 1904, 



p. 432. 



Localities. Greenland; latitude 59 33' north, longitude 43 25' 

 west; also coast of Norway; Finland. 



Depth. 120 fathoms; 203-312 fathoms (Norman). 4 



Body oblong-ovate, about two and one-third times longer than 

 wide, 13 mm. : 30 mm. 



Head twice as wide as long, 3 mm.: 6 mm. In the median line the 

 front is produced in a process which arches over the antennas, separat- 

 ing the basal articles, and meets the frontal lamina or interantennal 

 plate at its upper end. The eyes are large, irregularly oval, com- 

 posite, situated in the lateral angles of the head and extending along 



