12 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 122 



form, considered a new species, C. kincaidi, by Thorsteinson, is 

 distinguished by its larger size, more produced pereonite 1 (higher 

 cyphos index) and a longer process on pereopod 3 than populations 

 from Revillagigedo Channel and Lynn Canal, Alexander Archipelago. 

 The two inshore forms are morphologically more similar to each 

 other than to the oceanic form. 



We are now faced with the problem of whether Thorsteinson's 

 C. kincaidi should be reestablished as a species distinct from C. 

 challengeri. First, however, we must consider to which form Steb- 

 bing's C. challengeri belongs. Unfortunately, Stebbing's single type 

 specimen was so immatiu^e (about 5 mm) that morphological charac- 

 ters cannot be relied upon. Concerning the type-locality Stebbing 

 states: "The label on the mounted specimen states that it was taken 

 400 miles north of the Sandwich [= Hawaiian] Islands; probably near 

 station 256." Miu-ray (1895) lists it as a constituent of the surface 

 plankton of Station 256, located at 30°22'N, 154°56'W. At oiu- 

 request Mr. E. C. Jones, Bm*eau of Commercial Fisheries Biological 

 Laboratory, Honolulu, examined a niunber of plankton samples 

 collected near the type-locality, but none of these samples contained 

 Cyphocaris. Mr. Jones agrees with us that C. challengeri is a sub- 

 arctic species and woidd not be expected to occm* in Central Water. 

 It is not unreasonable to suspect that the type specimens of C, 

 challengeri may have been collected farther north than Station 256. 

 perhaps dui'ing the traverse of H.M.S. Challenger across the North 

 Pacific from Japan. 



Despite the uncertainty of the exact position of the type-locality, 

 it must be presumed that C. challengeri is the oceanic form, with 

 the more produced pereonite 1. But, as we have seen, Thorsteinson 

 described the oceanic form as a new species, C. kincaidi, and assigned 

 the Puget Sound form to C. challengeri. Hence, C kincaidi is a junior 

 synonym of C. challengeri, and, if the inshore form {C. challengeri 

 sensu Thorsteinson) should be considered to be specifically or sub- 

 specifically distinct, a new name v\^oidd be required. 



Because the differences between the oceanic and coastal forms are 

 much less than those separating the known species of Cyphocaris 

 from one another and because these differences vary from one coastal 

 population to another, we have chosen not to consider the two forms 

 as distinct species. For the present it seems most convenient to 

 refer to "oceanic" and "coastal" forms and to fiu-ther designate the 

 coastal form popiJations by locality. 



