spiculifera. 



Abactinal plates not closely crowded, much leea 

 80 than in kviuscula. 



Abactinal platea crescentic or irregularly 

 rounded. 



Papular areas eubequal to or larger than plates. 



Actinal intermediate series of plates extend.s to 

 tip of ray. 



Adambulacral plates with one spinelet in fur- 

 row, and with actinal spinelets (twentj'-five to 

 thirty) in six or seven series parallel to furrow. 



ASTEROIDEA OF NORTH PACIFIC AND ADJACENT WATEBS FISUEB. 297 



In a general way, spiculifera and multispina resemble each other. Doctor 

 Clark examined several of tlie extreme variants of muHisinna and expressed his 

 opinion that none of them represented his species. 



The following are the principal differences between njnculifira and ntultispina: 



muUlspina. 



Abactinal plates closely crowded, much more so 

 than in Uviuscula. 



Abactinal plates rounded or irregular, not 

 crcHcentic. 



Papular areas smaller than plates, and smaller 

 than in typical leviuscula, as the platea are more 

 crowded. 



Actinal intermediate series of plates extends only 

 half to three-quarters length of ray. 



Adambulacral plates with two spinelets in fur- 

 row on outer half to fourth of ray and with actinal 

 spinelets (twenty-five to fifty) not arranged in 

 series parallel to furrow. 



The form of spinelet is highly characteristic in multispina and probably differs 

 from that of spiculifera, although it would not be safe to make comparisons without 

 specimens. 



HENRICIA ASTHENACTIS Fisher. 

 PI. 77, fig. 1; pi. Ill, figs. 4, 4a. 

 Henricia asthenacM Fisher, Zool. Anz., vol. 35, March 29, 1910, p. 572. 



Diagnosis. — General appearance somewhat like tliat of young asperc, but tlie 

 abactinal and lateral skeleton more open and weaker, the papular areas being pro- 

 portionateh' mucli larger and the spinelets scattered, few, and conspicuously longer; 

 adambulacral spinelets long, and in a single transverse series (four to six in numl>er 

 counting the spinelet in furrow); two regular series of plates adjacent to adambu- 

 lacrals separated by a row of single papulae. 



Description.— B.&ys, five. Tj-pe: R = 2'2 mm. : r = 5mm; R = 4.4r. Breadtii 

 of ray at base 6mm. The rajs taper from a broader base than in aspcra to a sharper 

 point and are more depressed. Tlie skeleton consists of a more open mesh work 

 even than in aspera, the ridges being narrow, and surmounted by a single row of 

 slender well-spaced spinelets about as long as the heigiit of tlie calcareous ridges 

 above level of intervening integument. There appears to be only one or two 

 spinelets to each plate. Tiic large meshes which constitute the papular areas are 

 often squarish, and freciuently arranged in fairly regular longituduial rows, so 

 that three or four rows ma}- be seen wlien the ray is regarded from above (or six 

 from superomarginal across ray to superomarginal). It so happens that there is also 

 sometimes, but not always, a distinguisiiable median row of ossicles. The papular 

 areas, especially on disk, may contiiin one to three small isolated plates bearing one 

 or two spinelets. Tliere are commonly upwanl of ten papuhp abaci inally to each 

 area. While the papular areas are always large, tiiey vary considerably in shape 

 and regularity and are largest on the median area of ray and on disk. It is not 

 possible to appreciate tlieir extent accurately until specimen i>i dry. 



