ISOPODS OF NORTH AMERICA. 



233 



much larger and long-cr than the sixth pair, being extreme!}" long. 

 The last three pairs have the basis furnished with a low carina. 



Fig. 235. — Olencika PR.EcirsTATou. o, Mandible, x 27|. h, Mandible without palp, x 51|. 

 c, Maxilliped. X 27^. d, Second ma.xilla. x 27f. e, First maxilla, x 27j. 



37. Genus CERATOTHOA Dana." 



Body oblong. 



Head but little immersed or set in the first thoracic segment. E3"es 

 small. The tirst pair of antenn;^ are dilated, contiguous at the base. 

 The second pair of antennw are compressed. 



Anterior margin of the tirst segment of the thorax rounded. Epiin- 

 era of the tirst thoracic segment in the female with a carina produced 

 in the form of a spoon or a tubercle and directed anteriorl}'. The 

 anterior epimera do not reach by a great but gradually decreasing 

 distanc(^ the posterior angle of the segment. The posterior epimera 

 almost reach or extend a little beyond the posterior angles of the 

 segments. 



The abdomen is deeply immersed or set in the thorax. Terminal 

 segment transverse. The legs are rather long, with the exception of 

 the tirst and second pairs. The unguhie are long and strongly curved, 

 those of the third pair in the female being the longest of all. and 



"See Schioedte and Meinert for characters of genus, Nat. Tidsskr. (3), XIII, 

 1881-83, pp. 299-300. 



