ASTEBOIDEA OF NOETH PACIFIC AND ADJACENT WATEEiJ — KbiUtB. 299 



HENRICIA LONGISPINA Flaher. 

 PI. 7G, figH. 1, 2; pi. Ill, figH. 3, 3a. 

 Henricia lonffispina Fisher, Zool. Anz., vol. 3.5, Jfarch 29, 1910, p. 572. 



Diagnosis. — Rays five, moderately robust, fonstricted at ba.sc, cylindricul, 

 taperiiig gradually to a very blunt, recurved extreiuity ; disk small, siightiy inflated; 

 skeleton forming fairly coarse me.sli work with stout plates, and irregidar, mostly 

 quadrate or roundish, though often irregular, papular areas, with rather numerous 

 papulje to an area; spinelets in well-defined, spaced fasciculate groups of two to nine 

 (usually five to seven) and 1 to 1.5 mm. long; extensive intennarginal .series of plates; 

 adambulf-cral armature consisting of a zig-zag series of six or seven long bristling 

 spinelets decreasing in size from furrow edge, and in addition one spinelet deej) in 

 furrow; actinal intermediate plates extending only about half length of raj-. 



Description.— Type, R = 47 mm., r=9 mm.; R = 5.2 to 4.5 r; rays unequal. 

 Breadth of ray at ba.se, 10 mm. ; slightly beyond base, 12 mm. Abactinal and lateral 

 skeleton forms a fairly coarse meshwork with stout plates which at frequent and 

 fairly uniform intervals bear on a shght elevation fasciculate groups of two to nine, 

 usually five to seven, unequal sharp radiating spinelets. Tlio groups are largest 

 usually at the intersection of the skeletal ridges of plates. Between two such nodes 

 there is usuall}' one smaller intermediate fascicule of two or three spinelets. These 

 spinelets, wliich are skin-covered ami tliicker in hfe than when drieil, are finely 

 denticulate, sharp, and long for this genus (1 to 1.5 nun.), and much longer an<l 

 stouter than in any other s])ecies. Papular areas irregidarly quadrate or roundish, 

 often broken up by a few isolated plates bearing one or two, or less often, more, 

 smaller spinelets than those of the regular plates. ^Vs viewed from the outside the 

 papular areas arc irregular on account of the smaller secondary plates. PapuliB 

 usually five or six to an area on proximal half of raj", but groups of two or tliree are 

 sometimes found, and rarely as many as eight or nine. On disk the pseudopaxillje 

 are closer together and papula? range from about tliree to ten to an area. Anus 

 surrounded by several pseudopaxilla\ one probably representing the central plate, 

 having twelve spinelets. 



A fairly regular series of pseudopaxilla; extending from interbrachial line, 

 about midway between abactinal and actinal surfaces, reaches tip of arm, and 

 represents the superomarginal plates. About midway between this and edge of 

 furrow is a similar series of inferomarginal i)lates wlxich are a trifle larger than 

 superomarginals. The plates of both series bear sLx to nine or ten spinelets, and are 

 somewhat transversely ehmgatcd at base of ray. Between supenv and inferomar- 

 ginal series is a scries of small pseudopaxillav with one or two to five smaller s])inelets, 

 extending one-half to two-thirds lengtli of ray, and at base of ray one or two addi- 

 tional incipient intermarginal series are added to the above. In the small papular 

 spaces between superomarginal and intermarginal series and between latter and 

 inferomarginal are about one to tliree good-sized papula;. Just external to adam- 

 bulacral plates is a series of very small actinal intermediate pseudtipaxilla^ extending 

 about one-half length of ray, each having two, tliree, or four spinelet.s. Between 

 this series and adambulacral plates is a series of single papula-, and another series 

 between inferomarginal and actinal intermediate plates. After the actinal inter- 



