Clark — Six New Starfishes frovi the Gulf of California. 61 



Type.— Cat. No. 36,893, U. S. N. M., from "Albatross" Station 3021, 

 Gulf of California, 14 fathoms. 



Cyllaster new genus. 



Genotype. — Cyllaster seminuda, new species. 



The disk is very small. 



The rays are slender (R=6r to 8.3r), usually subcylindrical, very 

 flexible, usually arising somewhat abruptly from the disk; that is, there 

 is usually a more or less straight, though short, interbrachial border. 



The abactinal skeleton is more or less open, or aborted. 



The papulae are isolated, very large and conspicuous. 



The marginal plates are more or less imperfectly developed and irreg- 

 ular, or absent altogether. 



The adambulacral plates have from two to six sabre-shaped spines on 

 the furrow face; the actinal surface is densely packed with from twenty 

 to forty spines or spinules, all long, or one or two rows bordering the 

 furrow long, the remainder short. 



This genus is very closely related to Henricia; it includes, in addition 

 to the type, Cyllaster polyacantha (Fisher), C. clarki (Fisher), and C. 

 pauperrima (Fisher), all of which were originally described as Henricia. 



Cyllaster seminuda new species. 



Five arms; R=about 50 mm. ; r=6 mm. ; R:r=8.3: 1. 



The arms are very long, slender, approximately cylindrical, and very 

 flexible; there are no marginals in either series. 



The abactinal skeleton is very greatly reduced. A continuous line of 

 very narrow elongate plates runs along the mid-dorsal line from the 

 base of the arms to the tip; it does not extend onto the disk. Between 

 this median line and the region normally occupied by marginals is a 

 widely open, exceedingly irregular, meshwork of narrower and smaller 

 plates; within the spaces between the narrow lines forming this mesh- 

 work are numerous granules. Exteriorly the plates and the granules 

 bear numerous fine spines, those on the granules being usually one or 

 two in number, though sometimes more, according to their size, those on 

 the plates being irregularly distributed, on the mid-dorsal line showing 

 a tendency to grouping. The skeleton becomes somewhat more dense at 

 the arm tips. The disk and arm bases carry a few small detached plates 

 and numerous spiniferous granules. 



The interradial areas of the disk actinally have an irregular median 

 column of very narrow plates which resembles the line of plates running 

 down the midline of the arms, and numerous relatively large widely 

 spaced granules, which become suddenly smaller and more numerous 

 toward the abactinal surface. 



Between the adambulacrals and the outer (actinal) border of the dorsal 

 meshwork, covering the region normally occupied by the marginals, is a 

 band occupied solely by very numerous minute spiniferous granules. 



The madreporite is large, oval, with a few coarse irregular striae situ- 



