RADIATES. 



By a. E. Vekrill. 



ECHINODEEMATA. 



Pentacta froudosa Jaeger (Gunner, sp.). 



Cucumaria frondosa Forbes, Brit. Starfishes, 1841. — Duben and Koren, 1844. 

 One large specimen, Godthaab, Greenland, August 11, 1878. 



Strongylocentrotus Drobachiensis A. Agassiz. 



Penny Harbor, Gulf of Cumberland, reef at low- water, October, 4, 1877, 

 lot 420. 



Leptasterias Gronlandica Verrill. 



Asieracanthion Gronlandicus Steexst. — Lutken, Oversigtover GronlandsEchiuo- 

 dermata, p. 29, 1857. 



Head of Gulf of Cumberland, Niantilic Harbor, lot 144 ; low- water, 

 September 25, 1877, lot 179; Arctic Island, lot 06; Penny Harbor, lat. 

 66°, at low- water, October 4, 1877, lot 224 ; also same locality, lot 290. 



Leptasterias Mulleri Verrill, 1866. 



Asteracanthion Mulleri Sars, Fauna Litt. Norveg., i, p. 56, f. 38,39; Oversigt af 

 Norges Echinodermer, p. 88. 



Annanactook Harbor, 4 fathoms, May 19, 1878, lot 580. 



Stephanasterias albula Verrill. 



Asteracanthion albulus Stimpson, Invert, of Grand Manan, p. 14, fig. 5, 1853. 

 Aster acantliion prohlema Steenstrup. — LtJTKEN, op. cit. p. 30. 



Common in Cumberland Gulf. Gravel beach at the head of the gulf, 

 etc. Tbe only lot with the date remaining is 649, May 30, 1878. With 

 lot 725 is the following note : " Dull lilac above, yellowish white beneath." 



All the specimens are young, with the rays irregular in length and 

 variable in number. 



Ihe genus Stephanasterias, ijroposed by me for this species several 

 years ago, is characterized by a peculiar structure of the skeleton and 

 spines as well as by its remarkable method of fission, so well elucidated 

 by Dr. Liitken. Wnen adalt, there are usually six regular equal rays, 

 such specimens becoming four or five inches in diameter. But in smaller 

 specimens, still undergohig self division, there are usually two to four 



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