I8OPODS OF NORTH AMERICA. 7l 



the terminal abdominal segment, and arching over the telson. Inner 

 branch with posterior margin widety rounded and extending beyond 

 telson. Both branches have the margins smooth, entire. 



First gnathopods with small hand. Dactylus short. Free inner 

 margin of propodus furnished with hairs. Second gnathopods and 

 first periopods similar in shape to, but smaller in size than first pair 

 of gnathopods. The free inner margin of the propodus is beset with 

 two spines, the carpus with one spine. The remaining periopods 

 have a single spine at the distal margin of the propodus and two 

 spines on the carpus. 



One specimen, a female, was collected by Prof. A. E. Verrill at the 

 Bermudas in 1901. 



Type in Peabody Museum of Yale University. Cat. No. 3349. 



This species differs from A. elongata Norman, in the shape of the 

 outer branch of the uropoda; in the length of both branches, as com- 

 pared with the terminal abdominal segment, and in the fact that the 

 margins of the outer branch in this species are smooth and not cren- 



ulate, as in A. elongata. 







16. Genus CALATHURA Norman and Stebbing. 



Abdomen short with the segments not very distinctly defined in the 

 male, but distinct in the female. Both pairs of antennae in both sexes 

 with multi-articulate flagella. Buccal mass projecting, cone-shaped. 

 Anterior lip terminating in an obtusely conical point. Posterior lip 

 slightly bifid at the tip. Anterior maxillae simple, spear-like; termi- 

 nal part armed with recurved teeth. Maxillipeds with the basal part 

 narrow, oblong; palp composed of three articles; epignath small, 

 rounded. Mandibles terminating in an acutely-pointed lancet-like 

 organ. 



ANALYTICAL KEY TO THE SPECIES OF THE GENUS CALATHURA. 



a. Eyes not conspicuous. First pair of antennae with flagellum twelve jointed, not 

 longer than the length of the head. Second pair of antennge with the flagellum 

 twelve jointed. First three segments of thorax bounded laterally by carin. 

 Terminal segment of body triangular, acute at apex, margin not crenulate. 

 Superior or outer branch of uropoda oval in form, slightly dentated. Inner 

 branch acutely triangular Calathura brancldata (Stimpson) 



of . Eyes conspicuous. First pair of antenme with flagellum seventeen jointed, more 

 than twice as long as the length of the head. Second pair of antennae with the 

 flagellum twenty-three jointed. First three segments of thorax not bounded 

 laterally by cariiue. Terminal segment of body linguate, rounded posteriorly, 

 with crenulate margin. Superior or outer branch of the uropoda narrow, elon- 

 gated, not dentated. Inner branch rounded. 



Calathura crenulata Richardson 



See Sars, Crust, of Norway, II, 1899, pp. 44-45, and Norman and Stebbing, 

 Trans. Zool. Soc. Lond., XII, 1886, Ft. 4, p. 122, for characters of genus. 



