1901.] NATURAL SCIENCES OF rHILADELPIIIA. 171 



Station 52. Robertson Bay, 5-15 fathoms. 4 specimens. 



Station 61. Battle Harbor, Labrador, 1 fathom. 83 specimens. 



The series of 101 specimens, ranging from 5 mm. to 58 mm. in 

 <liameter, shows considerable variation among themselves and from 

 the typical form, as has been noted by Duncan antl Sladen in 

 their report on the Echinoderms of the Nares Expedition.^ The 

 height in two specimens of approximately the same diameter may 

 differ by as much as 10 mm. — as 55 : 35 and 52 : 25 mm. 



The specimens on the whole are more depressed than specimens 

 of similar size collected on the Massachusetts coast, and the spines 

 are shorter and less numerous, the cleaned test showing only com- 

 paratively few large tubercles. 



Distribution. — IS^umerous stations on the west coast of Green- 

 land: Discovery Bay (jSTares Ex.), Assistance Bay (Penny's 

 voyage) ; Great Britain, Scandinavia, Spitzbergen, Xova Zembla, 

 north coast of Siberia, Ochotsk Sea, Kamschatka, Bering 

 Strait. 



An Arctic and Sub- Arctic form, extending as far south on the 

 North American coast as off Chesapeake Bay. A circumpolar 

 form, being found both in the north Atlantic and north Pacific. 

 Its extreme depth is given by YerriU as 640 fathoms. 



ASTEROIDEA. 

 4. Asterias polaris (M. andT.). 



Asteracnnthion polaris Miiller and Troschel, System der Asterideu, p. 



16, 1842. 

 Asterias polaris Yerrill, Proc. Boston Society Natural History, X, p. 



356, 1866. 



Station 1, Domino Run, Labrador, 1 fathom. 4 specimens (3 

 dry). 



Station 2. Godhavu, Discc Island, 8 fathoms. 2 specimens 

 (juventi). 



Station 61. Battle Harbor, Labrador, 1 fathom. 12 specimens 

 (4 dry). 



A six- armed species. The size of the sixteen adult specimens 

 averages from 100-200 mm. in total diameter. The smallest of the 

 young specimens has a radius of 10 mm. Four of its six arms are 

 in the form of buds. 



Distribution. — Greenland, Torske Beach, and at 65° N., 



^Annals of Natural History (IV), Vol. XX, p. 453, 1877. 



