294 VERRILL 



coarser and fewer. Madreporite is large. Ambulacral feet have 

 large terminal suckers. 



It was known to me only from the Bering Sea and Siberia. The 

 type (U. S. Nat. Mus.) was from Bering Island (N. Grebnitsky, 

 1899). 



Fisher (1911&) records it from the Commander Islands, Shumagin 

 Islands, Aleutian Islands; and Kadiak, Alaska, from low tide to 

 102 fathoms. 



Genus Amphiaster Verrill. 



Amphiaster Verrill, Trans. Conn. .A.cad. Sci., i, part 2, p. 372, February, 1878. 

 Stellate, with short, stout rays and large disk. Dorsal surface 

 covered with large, stout, conical spines mostly one to a plate. 

 Similar spines are borne by most of the marginal plates in both 

 series. The marginal plates are unequal, few, large, convex or 

 swollen, and naked in the middle, granulated around the edges. 

 Dorsal abactinal plates are granular, polygonal, tesselated, sur- 

 rounded by papulae. Interactinal plates tesselated; each usually 

 bears a spine. Adambulacral plates have a short row of marginal 

 spines and a single larger spine on the actinal side. Only one 

 species is known. 



AMPHIASTER INSIGNIS Verrill. 

 Plate xcviii, figure 2 (type). 

 Amphiaster insignis Vermll, Trans. Conn. Acad. Sci., i, part 2, p. 372, pi. rv, 

 fig. 10, 1878. 



A well grown specimen has the radii 50 mm. and 24 mm. ; ratio, 

 about 1 : 2. The marginal plates are alternately unequal ; alternate 

 ones bear a large, conical spine. There are about ten to twelve 

 lower marginal plates and eight or nine upper ones, in adult 

 specimens. 



Three pretty regular, radial rows of spines on each ray, one to 

 each of the principal dorsal plates ; some may be lacking. Each of 

 the interactinal plates usually bears a large central spine, elsewhere 

 they are coarsely and evenly granulated. 



Lower California; La Paz; Gulf of California. The types were 

 from La Paz (Yale Museum). 



Subfamily MEDIASTERIN^ Verrill, 1899. 

 Stellate, depressed, in form resembling Ccramaster. Dorsal radial 

 plates paxilliform, or parapaxillae, with circular or nearly circular 

 bases, united together by radiating internal ossicles, about six to 



