478 BULLETIN 54, UNITED STATES NATIONAL MUSEUM. 



Caudal segment regularly rounded, with two small incisions at the 

 place where the uropoda are attached, between which is a rounded 

 lobe. Uropoda are extremely small, short, nodiform. 

 Legs simple, similar in structure, with bi-unguicu- 

 late dactyli. 



Two specimens from Monterey Bay, California, 

 were sent by Mr. Heath. 



Type. Cat. No. 22583, U.S.N.M. 

 This species is very close to Jseropxt* krevicomis, 

 but differs in the following points: The coloring of 

 the body, which in J. brevicornis is perfectly trans- 

 ' > parent and colorless, with the exception of the head, 



} which is marked with a large brown spot, while in 



r~ r ~ \ our species the head is dark, as are 



* ' also the entire second, third, fourth, 



and seventh thoracic segments and 

 the terminal abdominal segment, 

 the other segments being colorless; 

 in the shape of the terminal seg- 

 ment, which is perfectly rounded in 

 J. hrevicornis and fringed with hairs, 

 while in our species there are two 

 posterior incisions for the reception 

 of the uropoda, and an absence of 

 hairs; in the larger median lobe on 



the anterior margin of the head; in the acuteness of the antero-lateral 

 angles of the head, which are rounded in J. brevicornis; in the more 

 angular post-lateral angles of the head, and in the more angular antero- 

 and post-lateral angles of the thoracic segments. Other differences 

 are noticed from a comparison of both pairs of antennae. 



J^ROPSIS RATHBUN^ Richardson. 



Jseropsis rathbunae RICHARDSON, Trans. Conn. Acad. Sciences, XI, 1902, p. 298, 

 pi. XL, figs. 53-55. 



Locality. Bermudas. 



Body elongate, depressed; segments loosely articulated; surface 

 smooth ; color uniformly light, almost white. 



Head with a median excavation, on either side of which the frontal 

 margin is produced into angulations. On either side of these angula- 

 tions is another excavation, on the outside of which are lateral angula- 

 tions. A rounded lobe is placed in the median excavation. The eyes 

 are small and are situated near the lateral margins about halfway 

 between the anterior and posterior margins. The first pair of antennae 

 consist of five joints, the two first joints being large, the three follow- 



F I G . 535. J^KOPSIS 

 LOB AT A. X20. 



FIG. 536. J,EROPSIS 

 LOBATA. ANTENNA. 



