254 DISCOVERY REPORTS 



typical specimen of meridionalis (St. MS lo) has 4 out of 50 young with only 5 rays. 

 Possibly in deeper water near South Georgia there may be typical brucei, of which these 

 6-rayed specimens constitute a shallower water form. 



A specimen of typical brucei (St. 371) is carrying 65 young about 6 mm. in diameter 

 and all are 5 -rayed. 



Distribution. South Georgia (6-rayed form) ; South Sandwich group, South 

 Orkneys, South Shetlands; Graham Coast; Antarctic Coast from 92^ E to 166^ 12' E 

 and 77° 32' S (McMurdo Sound, South Victoria Land); probably circumpolar; 

 0-581 m. 



Diplasterias octoradiata (Studer) 



(Fig. M, i-if ; Plate XXI, figs. 1-3 ; Plate XXII, fig. 2) 



Pedicellaster octoradiatus Studer, 1885, p. 147, pi. i, figs. la-d. 



Anasterias octoradiata Koehler, Broolilyri Institute Museum, Sci. Bull., 11, no. 4, 1914, p. 64, pi. 14, 



figs. 1-7; 1923, p. 14, pi. 6, fig. 6.— Fisher, 1922, p. 595.— Grieg, 1929a, p. 7. 

 Koehleraster octoradiatus Fisher, 1930, p. 234. 



St. 145. Stromness Harbour, South Georgia, 26-35 m., i specimen, typical, 8 rays. 

 St. 1941. Leith Harbour, South Georgia, 55-22 m., i specimen, f. euuota, 8 rays. 

 St. WS 25. Undine Harbour (North), South Georgia, 18-27 n^-' mud, sand, i specimen, f. euuota, 

 9 rays. 



St. WS 62. Wilson Harbour, South Georgia, 15-45 n"*' ^ specimen, typical, 8 rays. 



St. MS 6. East Cumberland Bay, South Georgia, 27 m., typical, 3 specimens, 8 rays; one, grays. 



St. MS 10. Same, 26 m., 10 specimens, typical, 3 (7r), 5 (8r), i (gr). 



St. MS 67. Same, 38 m., i specimen, juv., 8 rays. 



St. MS 74. Same, 22-40 m., i specimen, subtypical, 7 rays. 



Undine Harbour, South Georgia, 20 m., 2 specimens, f. eunota, 9 rays. 



Cumberland Bay, South Georgia, 1 specimen, typical, 8 rays. 



Heretofore only 3 specimens have been known : two recorded by Koehler (1914, 1923) 

 and one by Grieg (1929), all from South Georgia. The number of rays in these was 8 

 and 9. 



The present collection affords an altered picture of the species. The number of rays 

 varies from 7 to 9 among adult specimens and young large enough to fend for themselves. 

 But a tally of young carried by the mother indicates the astonishing range of from 5 to 10 

 rays with the greatest frequency 8, then 7, 9, 6, 10, 5. 



The typical form as described by Koehler has the thickest skin and most swollen 

 welts around the spines, and the latter do not protrude much if at all beyond the broad 

 collar. It is this swelling of the spine collars which hides the large madreporite that 

 escaped both Koehler and Grieg. The madreporite is subcircular, flat, 5 mm. in 

 diameter, and its inner border is at mid-r. The typical form has the weakest abactinal 

 skeleton, and (in large specimens) the best development of hidden actinal plates, the 

 series of which extends far along ray. There is in mature specimens an actinal series of 

 conspicuous papulae, extending nearly three-fourths length of ray measured on side. 

 The skeletal intervals for these papulae alternate with the actinal plates. In this actinal 



