498 BULLETIN 54, UNITED STATES NATIONAL MUSEUM. 



Family XX. BOJ^YRID.E.« 



Body of female dUtinctly seo^mented and somewhat asymmetrical. 



Both pairs of antenna' rudimentary. Maxillipeds composed of two 

 articles, and very frequently with a small terminal article, the palp; 

 two curved lanceolate appendages at the ])ase represent the epignaths. 



Coxal plates usually detined. 



There are live pairs of incubatory lamelhv; the tirst pair is composed 

 of two segments. 



Abdomen more or less distinctly detined. Pleopoda simple, bira- 

 mous, or triramous; sometimes obsolete. Uropoda, when present, 

 simple, lanceolate. 



Legs usually in seven pairs, sometimes absent on one side with the 

 exception of the first; all are similar in structure, short, prehensile. 



Male S3'mmetrical. Head rounded in front. All seven segments of 

 thorax distinct. Segments of abdomen sometimes distinct, sometimes 

 united. Legs similar in structure, all prehensile. 



Parasitic on decapods. 



ANALYTICAL KEY TO THE GENERA OF THE FAMILY* BOPYRID.E. 



a. Body of female with one .side greatly .swollen and much longer than other side. 

 Abdomen composed of only five segments. Only first leg present on larger 

 side; others absent. Coxal plates only visible on shorter side. Marsupial 

 plates largely developed on longer side of body, and inclosing the entire 

 incubatory cavity; incubatory lamell;e of shorter side small. 



Genus Phryxus Rathke 



(/. Body of female with neither side swollen. iVbdomen usually composed of six 



segments. All the legs of both sides present. 



b. Abdomen of female with the lateral parts or pleural lamella' elongated, digitate. 



c. All six segments of the abdomen with the jdeural parts elongated, digitate. 



Male with the lateral parts of the segments of the abdomen or pleural 



lamellae elongate < ienus lone Latreille 



K. Only the five anterior segments of the abdomen with the pleural parts 



elongated, digitate. Male with the lateral parts of the segments of the 



abdomen not elongate. 



d. Female without median dorsal tu]>ercles on sixth and seventh segments of 



tliorax. Exopods present on all seven pairs of legs. Uropoda of male 



filiform Genus Leidya Cornalia and Panceri 



d^. Female with median dorsal tubercle on sixth and seventh thoracic seg- 

 ments. Exopods not developed on any of legs. Uropoda of male rep- 

 resented by two bunches of stiff hairs. 



Genus (rrapsicepon Giard and Bonnier 

 //. Abdomen of female with the lateral parts or pleural lamellte not elongated 

 or digitate. 

 c. Lateral parts or pleural lamelhc of al)domen of female produced lamellariy. 

 d. Uropoda in female doul)le-l)rauched. Alxlomen in male with segments 



fused Genus Munidioii Hansen 



d' . Uropoda in female single-branched. Abdomen in male with segments 

 distinct. 



« See Sars for characters of genus, Crust, of Norway, II, 1899, pp. 195-196. 



