SHALLOW-WATER STARFISHES 233 



HENRICIA SANGUINOLENTA, Var. RUDIS Verrill, nov. 

 Plate Lxxxvi, figures 5, 5a (details). 



Rays five, large, thick, tapered to small tips. Disk large, swollen. 

 Radii of the type, 22 mm. and 80 mm. ; ratio, i : 3.14 ; breadth of rays 

 at base, 25 mm. to 30 mm. 



Dorsal surface covered with a multitude of very small, distinct 

 parapaxillse, forming a close reticulation, in which the small papular 

 pores are mostly placed singly. The larger parapaxillae bear a com- 

 pact cluster of about five or six slender, tapered, acute, rough and 

 rather long spinules ; many of the smaller ones have three or four 

 spinules. These give the surface a finely spinulose but rough 

 appearance. There may be six to eight pseudopaxillae to a square 

 millimeter. 



The adambulacral armature consists of a single or partially double 

 transverse row, mostly of spatulate spinules. There are five to seven 

 larger spinules in each group, and two or three outer ones that are 

 much smaller, slender, and not flattened. The odd one on the inner 

 angle, which is the largest one, is stout, wide at the truncate and 

 grooved tip ; up to 2.3 mm. long ; the rest decrease gradually in size 

 and amount of distal expansion to the most external ones. Adoral 

 and oral spines are similar in size and form. The furrow-spine is 

 single, small and slender. 



The two rows of marginal pseudopaxillre are small and scarcely 

 distinguishable in the crowd of adjacent ones, all of which are spinu- 

 lated like the dorsals. The inferomarginals are a little larger than 

 the others and somewhat transversely elongated, bearing a trans- 

 verse and slightly pectinate two-rowed group of slender spinules, 

 about eight to twelve on the larger plates. The superodorsals are 

 similar, when they are distinguishable, but in many places they are 

 as small as the dorso-laterals. The peractinals are small and round- 

 ish. The type is from ten miles west of Point Franklin, Arctic 

 Ocean, off the north coast of Alaska in 13^/^ fathoms, sand (coll. 

 Murdoch, Point Barrow Expedition, No. 7623, U. S. Nat. Mus.). 



This, though quite peculiar in respect to its adambulacral spinules, 

 seems to be only an extreme variation of H. sanguinolenta, perhaps 

 only an individual variation. I have seen no others like it, though 

 some approach it to some extent. 



