SHALLOW-WATER STARFISHES 95 



Stout, mostly blunt or truncate and striated at the tip ; but close to 

 the bases of the rays they become longer. Some are acuminate and 

 subacute. On the distal third of the rays there are only three rows, 

 besides the superomarginals, there being but one row of actinals 



distally. 



The inferomarginal ossicles are rather large, thick and convex, 

 roundish on the outer end, and usually bear two or three divergent 

 spines, which are mounted on low mammillae with a central pit. The 

 peractinals are similar in form externally, and mostly bear but one 

 spine, but sometimes two proximally. The principal row of sub- 

 actinal plates, proximally, are large and transversely broad in their 

 internal part, but show only a rounded exterior surface, smaller 

 than the other plates and bearing a single spine. Between these, 

 proximally, there are a few smaller wedge-shaped or irregular sub- 

 actinal ossicles, interpolated irregularly and mostly without spines. 

 The inferomarginal and actinal plates are closely crowded together. 



There is a rather wide naked channel between the synactinal and 

 adambulacral plates, due to the great transverse length of the latter 

 externally to the single spine that stands on the inner edge. 



The adambulacral spines are slender and tapered, mostly 5 mm. 

 to 7 mm. long, becoming still longer near the mouth. 



Large major pedicellariae, like those of the type, occur among the 

 actinal adambulacral spines and along the inner edge of the grooves. 

 These are long-ovate or lanceolate, with acute or subacute jaws, 

 often toothed. With these there were others of various smaller 

 sizes, of nearly the same forms. 



THE YOUNG. 



A small specimen, from Sitka, has the radii 10 mm. and 45 mm. ; 

 ratio, 1 : 4.5. 



The dorsal spines are few and sparse, except along the median 

 radial rows, where they form pretty close and nearly regular simple 

 rows. A very imperfect, irregular row also occurs on each side, 

 about midway between the median and superomarginal rows. Ten 

 small groups of about two or three spines each form a central 

 pentagon, with three central spines. Elsewhere dorsal spines are 

 mostly lacking. All these spines are short, cylindrical or slightly 

 clavate, with obtuse, sulcated tips. The dorsal ossicles are rather 

 large and broad; even those that are without spines are often 

 lozenge-shaped ; those that bear spines are convex centrally, with a 

 mammilla and pit. The superomarginal spines form a regular simple 



