860 



PROCEEDINGS OF THE NATIONAL MUSEUM. 



Legs simple, similar in structure, with biunguical&te dactyli. 

 Two specimens from Monterey Bay, California, were sent by Mr. 

 Heath. 



Type.— No. 22583, U.S.N.M. 



This species is very close to Jceropais hrevicornis, but differs in the 

 following points: the coloring of the body, which in J. hrevicornis is 



perfectly transpar- 

 ent and colorless, 

 with the exception of 

 the head, which is 

 marked with a large 

 brown sjiot, while in 

 our species the head 

 is dark, as are also 

 the entire second, 

 third, fourth, and 

 seventh thoracic seg- 



FlG. 31.— MXXILLIPPED AND MANDI- 

 BLE OF J.T.ROPSIS LOB ATA. 



FlO. 32.— J^EEOPSIS LO- 

 BATA. X 20. 



Fig. 33.— Antennae op 

 j^ropsis lobata. 



ments and the terminal abdominal segment, the other segments being 

 colorless; in the shape of the terminal segment, 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. hrevicornis ; 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. 



V. ONISCOIDEA. 



ANALYTICAL KEY TO THE FAMILIE.S OF ONLSCOIDEA. 



a. Flagellum of outer antennae not niultiarticulate. Buccal mass not very promi- 

 nent below. First maxillc-B have two plumose set;e on the inner plate. Mandi- 

 bles with molar expansion obsolete, without any triturating surface, it being 

 replaced by brushlike recurved seta?. Maxillipeds with terminal part three- 



