636 



PROCEEDINGS OF THE NATIONAL MUSEUM. 



VOL. 41. 



The first pair of legs have the basis about half as long again as the 

 distal segments together, and not distinctly spinous; the propodus 

 is a little longer than the carpus and about equal to the dactylus. 

 In the legs of the second pair the carpus is only a little longer than 

 the last two segments together. 



The legs of the third and fourth pairs bear each a vestigial exopod 

 of two segments. 



The peduncle of the uropods has a row of small spines on the inner 

 edge. The endopod is about half as long as the peduncle and slightly 

 longer than the exopod; its three segments well defined, the first much 

 longer than the other two together. The inner edges of both rami 



41 42 



Figs. 41-44.— DiASTYLis dalli, immature female. 41, Carapace from above; 42, first leg; 43, 



THIRD leg; 44, LAST SOMITE, TELSON, AND UROPOD. 



bear series of short spines ; the terminal spines are broken off in all 

 the full-grown specimens examined, but in younger specimens they 

 are quite short. 



Remarks. — Although bearing a striking general resemblance to 

 D. scorpioides, this species is at once distinguished from it by having 

 only four in place of five oblique ridges on the carapace. The 

 presence of vestigial exopods on the third and fourth legs, while they 

 are absent in the closely allied D. scorpioides, shows that this character 

 can no longer be regarded as of generic value. 



It seems likely that this species or the next is that referred to by 

 Stuxberg as "en vackert rod- och gulfargad Diastylis (lik Diast. scor- 

 pioides),'' taken by the Vega at East Cape.^ 



1 Bihang Kgl. Svenska Vet. Akad. Ilandl., vol. 5, 1S80, No. 22, p. 29, and Vega Exped. Vetensk. lakttag- 

 elser, vol. 1, 1882, p. 715. 



