236 CONNECTICUT GEOL. AND NAT. HIST. SURVEY. [Bull. 



are exclusively branchial and not covered by an operculum. 

 Parasitic forms. 



These are the most degraded forms of Isopoda; in some 

 instances the fully-grown female represents merely a simple sac 

 filled with ova, and without any trace of segmentation or of limbs. 

 In all cases the male is much smaller than the adult female and 

 is generally found clinging to the genital region of the female 

 like a parasite. 



BOPYRID^. 



Body of female distinctly segmented and somewhat asymmet- 

 rical. Eyes, when present, dorsal. 



Both pairs of antennze rudimentary. 



Legs, seven pairs, sometimes obsolete on one side, all of 

 same structure, short prehensile. Coxal plates obsolete or distinct. 

 Marsupial plates five pairs; of which the first pair is made up of 

 two segments. 



Abdomen more or less distinctly defined. Uropods, when 

 present, simple, lanceolate. 



Male, symmetrical. Head rounded in front. Thoracic 

 segments distinct. Legs similar, prehensile. Segments of abdo- 

 men sometimes distinct, sometimes united. 



Parasitic on decapods. 



Stegophryxus hyptius Thompson. 



1902. Stegophryxus hyptius, Thompson, Bull. U. S. Fish. 

 Com., vol. 21, p. 53-56, pis. 9, 10. 



1905. Stegophryxus hyptius, Richardson, Bull. U. S. Nat. 

 Mus., No. 54, p. 532. 



A species of Bopyrid which is parasitic on the gills of 

 Pagurus longicarpus (hermit crab), collected at Woods Hole, 

 Hadley Harbor, Naushon, Edgartown, Massachusetts, and War- 

 wick, Rhode Island. 



Probopyrus pandalicola (Packard). 



1881. Bopyrus palcemoneticola, Packard, Zoology for High 

 Schools and Colleges, p. 288. 



1905. Probopyrjts pandalicola, Richardson, Bull. U. S. Nat. 

 Mus., No. 54, p. 554. 



