SHALLOW-WATER STARFISHES 327 



It resembles L. arcticus of the North Atlantic in form and size, but 

 is a more robust species, with thicker disk and rays and larger and 

 fewer marginal plates. 



The marginal plates are about twenty-two on each side of a ray, 

 finely spinulated, prominent, the lower ones projecting beyond the 

 upper ones, and separated from them by a deep groove ; they 

 become somewhat oblique distally. The fasciolate grooves between 

 the plates are deep and often nearly as wide as the ventral plates, 

 proximally. The lower marginal plates are high, compressed, wedge- 

 shaped. The dorsal paxillae are small, close, and covered with 

 numerous fine, slender spinules. When the spinules are removed 

 the columns are small, unequal, round, slender, with small capitate 

 tips. 



The actinal plates are prominent, subimbricated, with deep 

 grooves between ; their summits are oblique, elliptical, covered with 

 numerous elongated, slender spinules. 



The adambulacral plates project into the grooves, which are very 

 narrow, and have deep fasciolate notches between them. They bear 

 a furrow-series of about five or six small, slender, subequal, rather 

 short spines, and an actinal group of about nine smaller, divergent 

 spinules. No pedicellarise were found. Madreporite is small and 

 sunken between the paxillae. 



The two specimens here described were taken at Departure Bay. 

 British Columbia, by C. H. Young, 1908 (Canadian Geological Sur- 

 vey). Unalaska to Straits of Georgia (Fisher), in 56 to 238 

 fathoms. 



Although this species resembles L. arcticus of the North Atlantic, 

 it is quite different in some respects. The adambulacral spines of 

 the latter are larger, fewer, much more unequal ; the spinules of the 

 marginal plates and dorsal paxillae are coarser ; the marginal plates 

 smaller, less prominent and more numerous, about forty to forty- 

 four, while in this, when adult, they are from twenty-two to about 

 thirty-five. The specimen figured was the type of L. millespina 

 Verrill. 



Genus Glyphaster Verrill. 



Glyphaster Verrill, Amer. Naturalist, xliii, p. 553, 1909. Fisher, op. cit., 

 191 1 &, pp. 39, 53. 



Disk broad ; rays very short. Marginal plates thick and squarish, 

 scarcely oblique. The upper ones encroach on the upper surface. 

 Each inferomarginal corresponds to two adambulacrals on the rays, 

 and nearly three in the interradial areas. The marginal plates are 



