AMPHIPOD GENUS PARATHEMISTO BOWMAN 377 



and has a high comb of setae on its anterior margin. P3-4 carpus 

 (fig. 6) arc of the form typical for P. gaudichaudii forma bispinosa 

 (=antarctica), in which the carpus is wide proximally and narrows 

 distally; the posterior margin is convex in the proximal part and be- 

 comes straight or slightly concave distally. A tendency toward (his 

 form is evident in the New Zealand specimens illustrated by Hurley 

 (1955, text-fig. 9, Nos. 155-156). According to Stephensen, there 

 are no fine teeth along the posterior margin between the long setae in 

 the female, hut these are present in both the New Zealand and Korean 

 specimens. 



Yamada (1933) illustrates a "Parathemisto sp. (12)" which he found 

 to be widely distributed in the Yellow Sea. Although he did not 

 identify it specifically, he stated that using Barnard's key (1930) the 

 specimens keyed out to P. gaudichaudii. This statement implies that 

 the inner margin of the inner ramus of uropod 3 appeared smooth to 

 him. In my Korean "long-legged" P. gracUipes, the serrations of this 

 margin are quite weak, and it is possible that they escaped Yamada's 

 notice. If so, his "Parathemisto sp. (12)'' is P. gracUipes rather than 

 P. gaudichaudii, for in other respects "Parathemisto sp. (12)" agrees 

 reasonably well with my" long-legged" P. gracUipes. Yamada's speci- 

 mens attained a length of 7-8 mm.; this length is short for P. gaudi- 

 chaudii, but about right for P. gracUipes. Moreover, on the basis of 

 the temperatures at which they live in other regions, P. gracUipes, 

 rather than P. gaudichaudii, would be expected to occur in the East 

 China and Yellow Seas. 



Although it thus seems probable that Yamada's "Parathemisto sp. 

 (12)" is P. gracUipes, the possibility remains that his tentative identi- 

 fication of it as P. gaudichaudii was correct. This problem cannot be 

 solved until extensive collections from the Yellow Sea are available. 



Distribution: Figure 15 shows the known distribution oiP.gracvr 

 lipes. It is evident that much remains to be learned about its distri- 

 bution, especially in the southern hemisphere. The record of Stewart 

 (1913) from off Brazil is probably erroneous, since members of the 

 genus Parathemisto are not known to inhabit tropical waters. Steph- 

 ensen (1949) regarded his identification of specimens from Tristan da 

 Cunha as doubtful. 



The collections of the U.S. National Museum contain 7 specimens 

 of P. gracUipes collected in the vicinity of the Juan Fernandez Islands 

 by the yacht Vagabondia. Comparable in size to Hurley's New Zea- 

 land specimens, these specimens range from 7.9-8.5 mm. in length 

 and agree well with Hurley's description. 



P. gracUipes lives in warmer water than P. gaudichaudii. This 

 preference is clearly shown in the distribution of the two species in 

 the north Atlantic (see figs. 15 and 17; see also Stephensen, 1923 and 



540580—60 1 



