VerriU.] 350 



the lateral plates, each bearing a prominent slender spine, forming a 

 regular row, which curves upward at the base of the ray. Between 

 the prominent, median, dorsal row, and the lateral, there are usually 

 but two longitudinal rows of small, rather scattered spines. The 

 blunt, dorsal spines are placed on somewhat tumid prominences of 

 the plates, and are surrounded at base by close wreaths of minor ped- 

 icellariEe, which also form thick clusters on the outer sides of the lat- 

 eral and ventral spines. The major pedicellari^ are lanceolate and 

 pointed, about twice as long as broad, and are numerous on the dorsal 

 and lateral surfaces between the spines, and on the inner edges of the 

 ambulacral groove ; a few are attached singly to the interambulacral 

 spines, one or two are placed in the angles of the rays beneath, and 

 the madreporic plate is surrounded by a circle of spines alternating, 

 irregularly with major pedicellarias. The spines of the disk are nu- 

 merous, and concentrically arranged. The texture is firm, owing to 

 the rather stout, imbricated plates which form the dorsal frame-work. 

 Diameter of the largest specimen observed 2.5 inches. 



Color reddish purple above, yellow beneath. Eastport, Me., 

 twenty fathoms, stony bottom, not uncommon. 



This species is allied to A. Miilleri Sars, but differs from a typical 

 specimen sent by Dr. Llitken, in having less slender, and more de- 

 pressed rays, and in having two rows of interambulacral spines in- 

 stead of a single series, one to each plate, as in the latter. The spines 

 in A. Miilleri are, also, more slender and translucent, and are 

 arranged differently on the dorsal surface. The pedicellarias, also, 

 are less numerous. 



The two preceding species, together with A. compta Stimp., and A. 

 Miilleri^ present so great differences in structure from the typical 

 species of Asterias, that it seems to me desirable that they should be 

 separated as a distinct genus, or at least as a natural subgenus, which 

 I designate as follows : 



Leptasterias gen. nov. 



Type Asleracantldon Miilleri Sars. 



Small starfishes allied to Asterias^ but having comparatively 

 large papulae ("water tubes") placed singly (or sometimes in groups 

 of two or three) along the sides and on the back of the rays, where 

 in Asterias they are very small, and in crowded clusters. The plates 

 are usually stout and imbricated. The madreporic plate is surrounded 

 by a circle of spines in most, if not all, of the species. 

 ' From the observations of Prof Sars on the typical species, and of 

 Prof Agassiz upon another species, probably one of those here men- 

 tioned, the mode of reproduction differs from that of Asterias, the 

 eggs and embryos being carried by the parent until the peculiar meta- 

 morphoses have been passed through. 



