NO. 1876. ON THE CRUSTACEAN ORDER CUMACEA—CALMAN. 637 



This fine species, one of the largest of the Cumacea, may be appro- 

 priately associated with a name famous in the history of the scientific 

 exploration of Alaska, that of Dr. W. H. Dall. 



Localities.— Bering Strait; W. H. Dall, 1880; U.S.N.M. 13379; 1 

 female (holotype). 



Ofl' Cape Sabine; 13 fathoms; W. H. Dall; U.S.N.M. 44046; 5, 

 female and young. 



Off Cape Sabine; 13 fathoms; W. H. Dall, August 24, 1880; 

 U.S.N.M. 44044; about 10, female and young. 



Off Point Plope, Alaska; 25 fathoms; U. S. R. S. Corwin, Capt. 

 M. A. Healy, 1884; U.S.N.M. 44049; about 20, female and young 

 male. 



Albatross station 2841 ; lat. 54° 18' 00"N. ; long. 165° 55' 00"W. ; 56 

 fathoms, U.S.N.M. 44045; 1 immature male. 



Ridge, Captains Harbor, Alaska; 80 fathoms; W. H. Dall, 1874; 

 U.S.N.M. 13364; 1 immature male. 



Alaska; W. H. Dall; 1 immature female. 



Albatross station 5023; off Cape Patience, Sakhalin Island; 75 

 fathoms; bottom temperature 30.9° F.; U.S.N.M. 44048. 



DIASTYLIS BIDENTATA, new species. 



Adult female (with empty brood-pouch). — Total length, 11.5 mm. 

 Resembling D. scorpioides (Lepechin) in general appearance; sur- 

 face of carapace smoother, the ridges very finely crenulated. There 



Fig. 45.— Diastylis bidentata, immatxtre female, from the sroE. 



are only four oblique ridges on each side of the carapace; the first is 

 short and runs forward on the side of the pseudorostrum; the others 

 are very strong and run from the dorsal surface to the lower margin 

 parallel to each other; just at the lower margin the fourth ridge curves 

 forward to meet the third. The second ridge is produced, a little 

 way from its lower end, into a strong acute tooth directed outward 

 and forward. The longitudinal ridges unitmg the upper ends of the 

 three posterior oblique ridges on the dorsal surface are distinct but 

 not very prominent and approach each other anteriorly. The pseu- 

 dorostrum is much as in D. scorpioides, the lateral plates meeting for 



