82 VERRILL 



spines. On the disc, there is a central tubercle, but scarce any indi- 

 cations of a pentagon. Around tlie bases of the dorsal spines there 

 are regular wreaths of minor pedicellarise. The major pedicellariae, 

 which are of the short, conical or sub-globular form, with broad 

 valves, are scattered between the spines as in A. ochracea. Papulae 

 in groups. 



" Color in life purple, according to Dr. Newberry. The spines 

 are probably white, or at least of a lighter color. Diameter, five and 

 a half inches. 



"This very pretty species differs from A. ochracea in its larger 

 dorsal spines, which are not arranged in a reticulating pattern ; and 

 from A. Lutkenii in its shorter and more numerous ventral spines, 

 as well as in the presence of major pedicellariae on the back. 



" Habitat, San Diego, Cal. Colorado Expedition. Dr. J. S. New- 

 berry." 



The photographs of the type, sent by Dr. R. Rathbun, are six 

 inches in longest diameter; radii, i8 mm. and 80 mm.; ratio, nearly 



i:4-5- 

 Little need be added to Stimpson's description of the type. The 



adambulacral spines are often flattened. The ventral spines are 



unequal ; those of the inner or synactinal row are distinctly smaller 



than the others, and the outer or peractinal are largest. Most of 



these spines are stout and clavate, rather than capitate, the tips being 



mostly obtusely conical or ovoid and strongly striated ; only a part 



are grooved ; distally they become much more slender and distinctly 



clavate. 



The superomarginal spines are considerably stouter than the 

 ventral ones, but not much longer. They form a regular simple row 

 of rather widely spaced spines, each one on the raised node of a 

 marginal ossicle. The dorsal spines are mostly quite similar to the 

 laterals in size and form. The larger ones have large, rounded, 

 capitate, and strongly striate tops ; but those toward the ends of the 

 rays become longer and more slender, cylindrical or clavate, rather 

 than capitate, but striated in the same way. 



The spines are distantly spaced, generally one on each raised 

 node of the reticulating ossicles. Usually, in our specimens, five or 

 six ridges, indicating the lobes of the ossicles, radiate out from the 

 base of each spine, so that the skeleton has a pretty regularly reticu- 

 lated structure. The spines usually form more or less evident 

 median, radial rows, and sometimes two less distinct rows can be 

 traced, between the median and marginal rows. 



