RADIATES. 



By a. E. Vekrill. 



ECHINODERMATA. 



Pentacta frondosa JiBger (Gunner, sp.j. 



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

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



Strongylocentrotus Drobachiensis A. Agassiz. 



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

 lot 420. 



Leptasterias Gronlandica Verrill. 



Asteracanthion Gronlandicus Steexst. — Lutken, Oversigtover GronlandsErhiuo- 

 dermata, p. 29, 1857. 



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

 September 25, 1877, lot 179 ; Arctic Island, lot 66 ; 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 at" 

 Norges Echinoderiner, p. 88. 



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



Stephanasterias albula Venill. 



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

 Asteracanthion prohJcma Steenstrup.— LUtkex, op. cit. p. 30. 



Common in Cumberland Gulf. Gravel beacb at the bead of the gulf, 

 etc. The 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. 



'J he genus Stephanasterias, moito^vd l)y iik^ 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 eliu-idated 

 by Dr. Lutken. Wiien adult, there are usually six regular equal rays, 

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

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



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