236 DISCOVERY REPORTS 



Anasterias pedicellaris (Koehler) 



(Plate XIX, fig. 3) 



Sporasterias pedicellaris Koehler, 1923, p. 18, pi. 5, figs. 1-6; pi. 6, figs. 1-5, 7-10. 

 Sporasterias antarctica Koehler, 1920, p. 78, pi. 18, fig. 4. 

 Anasterias pedicellaris Fisher, 1930; p. 225; 193 1, p. 8. 



St. 5v Port Stanley, East Falkland Island, 10-16 m., 2 specimens. 



St. WS81. 8 miles north, 11° W of North Island, West Falkland Island, 81-82 m., sand, 10 

 specimens. 



St. WS 84. 7!- miles south, 9° W of Sea Lion Island, East Falkland Island, 75-74 m., shells and 

 stones, 13 specimens. 



St. WS 85. Falkland Islands, 52° 09' S, 58° 14' W, 79 m., sand and shell, 14 specimens. 



St. WS 221. Off Argentina, 48" 23' S, 65° 10' W, 76-91 m., i specimen. 



St. WS 576. 51° 35' S, 57° 50' W, 34-24 m., I specimen. 



St. WS 823. 52° 14!' S, 60° 01' W, 80-95 m-- I specimen. 



Koehler has described in detail this form which is very variable in respect to the 

 robustness of skeleton and the number of both sorts of pedicellariae. The rays are longer 

 and narrower than in antarctica, the abactinal skeleton usually weaker, the abactinal 

 spinelets more delicate (and sometimes much more numerous) and the crossed pedicel- 

 lariae (of about the same size) less numerous. In typical antarctica the superomarginal 

 spines are surrounded by numerous crossed pedicellariae, but in pedicellaris as in 

 studeri these are scarce or absent on the proximal half of ray. The characteristic 

 lanceolate straight pedicellariae are found abundantly only in large specimens ; in small 

 ones they are scarce or absent. In general, such small specimens differ from small 

 antarctica in having more numerous abactinal spinelets, with not many more crossed 

 pedicellariae than spinelets scattered over the abactinal surface. Without accompanying 

 adults it is questionable if one can be certain of the identification of these young. 



A characteristic feature of the species is the variability of the abactinal skeleton, 

 already described and figured by Koehler. When at its weakest it is no better developed 

 than in the type specimen of Perrier's Anasterias minuta (see Koehler, 1923, pi. 5, fig. 5). 

 But I am not sure that Koehler's pi. 6, figs. 3 and 10 are not mimita rather th?Ln pedicel- 

 laris. They are quite unlike young pedicellaris from St. WS 85, at which typical adults 

 were taken. These young have narrow convex rays with a reticulate skeleton and 

 numerous delicate spinelets. But adults may have a skeleton obviously weaker than in 

 typical " Sporasterias'' (Koehler, pi. 5, fig. i). I have such specimens from St. WS 85. 

 It is futile therefore to base genera upon the " more or less " development of the abactinal 

 skeleton, where one species exhibits such instability. 



The integument is soft and rather thick but not pustulated in the ordinary sense. The 

 abactinal, intermarginal, and actinal pedicellariae are large, the last usually 2 or 3 to an 

 area. 



This seems to be a shallow water form, whereas studeri is found in much deeper water 

 and differs inter alia in having shorter and broader, more triangular, straight pedicellariae. 



Distribution. Tierra de Fuego, Falkland Islands, north to 48° 23' S, 7-95 m. 



