ISOPODA 381 



Family 14. TKICHONISCIDAE. 



Body elliptical, elongate; first antennae minute; second antennae end- 

 ing with 3 or 5 small segments ; abdomen not pointed behind, but truncate 

 or indented ; the 2 branches of each uropod of about the same length : 4 

 American species; terrestrial or in fresh water. 



Trickoniscus Brandt. Head rounded in front; eyes small, composed 

 each of 3 ocelli; second antennae long; abdomen abruptly narrower than 

 thorax: 2 species. 



•T. pusillus Br. (Fig. 612). Length 3 mm.; width 1 

 mm.; body smooth: entire North America; Europe; 

 under moss, in the woods. 



Family 15. BOPYEIDAE. 



Parasites of decapods; male and female animals 

 dissimilar, the female being asymmetrical and broad, and 

 sometimes much deformed, the male more slender and 

 symmetrical; antennae rudimentary; legs prehensile: 35 

 species, 29 American. 



1. Probopyrus Giard and Bonnier. Segments of „ P§- ^}^ 



^ Trichomscus 



abdomen distinct in female, but fused, except at the (Ri^b^'d"^n) 



edges, in the male; 5 pairs of abdominal appendages; 



uropods wanting : parasites in the gill chamber of decapods ; 5 American 



species. 



P. pandalicola (Packard). Body (of female) 5 mm. long, white in 

 color with black markings; the female lies against the body of the host, 

 the ventral side of the thorax having the brood pouch with the eggs, 

 the much smaller male is usually found clinging to the female: entire 

 Atlantic coast, on Palcemonetes, producing large tumors under the 

 carapace. 



2. Phryxxjs Rathke. Body of female veiy asymmetrical, one side 

 being greatly swollen; 5 abdominal segments; the legs of the longer side 

 of the body wanting, except on the first thoracic segment, on the shorter 

 side very small; antennae and uropods iiidimentary; abdomen of male 

 composed of a single triangular segment, without appendages: parasitic 

 on the abdomen of decapods; 1 species. 



P. abdominalis (Kroyer). Body of female 9 mm. long, 7 mm. wide; 

 of male 3 mm. long and 1 mm. Avide : circumpolar, extending to Vineyard 

 and Puget Sounds; on the abdomen of Pandalus and other prawns. 



3. BoPYROiDES Stimpson, Body of female somewhat asymmetrical, 

 with 6 abdominal segments and 7 pairs of legs, without abdominal ap- 

 pendages; abdomen of male forming a single piece without appendages; 

 antennae rudimentary: 1 species. 



