170 Miss H. Richardson on the Isopods of the 



13. Rocinela tuberculosa^ Richardson. 



Rocinela tuberculosa, Richardson, Proc. Ain. Phil. Soc. xxxvii. 1898, 

 p. 16, fig. 10. 



Hah. Southern part of Gulf of California. 



Fig. 6. 



Rocinela belliceps (Stimpson). x 2f . 



14. Rocinela aries, Schiodte & Meinert. 



Rocinela aries, Schiodte & Meinert, Naturhistorisk Tidsskrift, xii. 

 1879-80, pp. 401-403, pi. xiii. figs. 7, 8. 



Hah. Mazatlan ; Lower California ; Panama Bay, 



Family VI. Cymothoidge. 



Analytical Key to the Genera o/ Cymothoidae. 



Head deeply immersed or set in the first thoracic seg- 

 ment, whose antero-lateral angles project forward. 



b. Abdomen deeply immersed. 



First pair of antennae more often dilated, rarely 

 compressed. First four or five segments of body 

 long, subequal in length, except the first, which 

 is a little longer; last two or three segments 

 abruptly shorter, very often decreasing gradually 

 in length. Terminal segment of abdomen sub- 

 triangular or semicircular, often bilobed. Body 

 oblono' : 8. Meinertia. 



v. Abdomen scarcely immersed. 



First pair of antennae very much compressed. Seg- 

 ments of thorax either equal in length or the 

 first segment abruptly longer than the others and 

 the last segment abruptly shorter than the others. 

 Terminal segment of the abdomen varying in size 

 and form. Body suboval, more or less contorted. 9. Livomca. 



