2O6 CONNECTICUT GEOL. AND NAT. HIST. SURVEY. [Bull. 



1899. Mga psora, G. O. Sars. Crust. Norway, vol. 2, p. 59, 

 pi. 24. 



1905. Mga psora, Richardson, Bull. U. S. Nat. Mus., No. 

 54, p. 168. 



The following description is abbreviated from Harger's. I 

 have not personally seen this species. 



Body oval, broadest at fourth and fifth thoracic segments 

 where the breadth is about half the length ; dorsal surface mod- 

 erately convex and smooth except for minute and scattered 

 punctations, which occur also on the legs, first antennae, uropods 

 and pleopods. Head transverse and subtriangular, salient in 

 front between the bases of the first antennae. Eyes very large 

 and reniform covering nearly all the upper surface of the head. 



First antennae when bent backward attaining anterior margin 

 of first thoracic segment; first two segments. large and flattened; 

 third joint cylindrical; flagellum tapering, made up of about a 

 dozen segments. Second antennae when reflexed extending 

 beyond first thoracic segment ; first two segments short and com- 

 pressed; third somewhat longer; fourth and fifth longer and 

 nearly cylindrical, followed by a tapering flagellum which is about 

 as long as peduncle and composed of fifteen to twenty segments. 



First thoracic segment at anterior margin scarcely broader 

 than head, expanding rapidly backward, excavated in front some- 

 what for the accommodation of the eyes. Second, third, and 

 fourth segments each a little shorter than first ; fifth and sixth 

 somewhat longer; seventh shorter than sixth. Coxal plates dis- 

 tinctly demarcated from segments except the first one ; those of 

 second, third, and fourth segments rounded behind but those of 

 succeeding segments becoming acute and extending backwards. 

 First three pairs of legs short and armed with strong, hooked 

 dactyls ; fourth to seventh legs of different form, slender ; seventh 

 pair only slightly developed in young but never quite as large 

 as sixth which is the largest. 



Abdomen scarcely narrower than last thoracic segment and 

 scarcely tapering to the fifth segment. Last segment triangular, 

 with sides but little dilated and pointed at the tip. Uropods 

 scarcely exceeding the abdomen; peduncle with inner angle long 

 and spiniform, extending whole length of inner margin of inner 

 ramus and ciliated toward tip ; rami flattened, outer one elongate 



