212 A. E. Verrill — Mevision Genera and Sj)ecies of IStarfishes. 



The lower marginal plates extend much farther back from the 

 margin than the dorsal ones, but they have the same line spinulation; 

 there are distinct marginal fascioles between them ; most of the 

 distal and some of the proximal plates also have a central spine, like 

 those of the dorsal series, but rather longer. 



The apical plate is relatively large, elongated, ovate, with a large 

 proximal notch. 



The abactinal paxillae are numerous, very small, round, nearl}' uni- 

 form in size; when rubbed the plates are convex and elevated, well 

 separated ; three or four rows continue even to the apical plate. 

 There is no distinct median dorsal series; each plate bears a group of 

 four to eight (usually six) very small, slightly elongated, divergent 

 spinnles, forming regular stellate clusters, without any evident larger 

 central spine. 



The actinal plates are rather numerous, forming triangular areas; 

 they are similar to the abactinal plates, but rather larger; each 

 usually bears six to eight small, rough, divergent spinules, in a 

 stellate group. They extend to about opposite the fourth or fifth 

 adambulacral plates, and do not form evident radial rows. 



The adambulacral plates are relatively large ; the inner or furrow 

 margin is convex and along the middle portion of the groove of each 

 plate four or five slender, elongated, rough, terete furrow-spines on 

 its convex edge, and six to eight shorter and smaller, divergent 

 spinules on its actinal surface, foi'ming two or three irregular trans- 

 verse rows, or else an irregular roundish cluster. 

 , The dentary plates are rather prominent, sub-carinate, and are 

 covered with numerous small, slender spinules on the actinal surface; 

 on the furrow margin there are numerous small slender spinules and 

 about six larger, convergent, apical ones. No pedicellariae could be 

 found. 



Although this is evidently the young of some large species, it 

 differs decidedly from the young of Dytaster insignis and D. gran- 

 dis, of the same size, with \vhich I have compared it directly. It 

 has shorter rays; single' marginal spines; much smaller and more 

 finely spinulose dorsal paxillae ; more numerous actinal plates, with 

 finer and more numerous spinules ; more numerous spinules on the 

 dentary plates ; more nearly equal and regular and more slender 

 furrow spines on the adambulacral plates ; the edge of the latter is 

 less prominent, so that the furrow-series is less broken. In these 

 characters it agrees better with Plutonaster than with Dytaster. 



It should probably be referred to Plutonaster^ as has been done 

 by Perrier (1894), but it does not agree with the young of either of 

 the adult forms known from the American coasts. 



