334 BULLEllN 100, UNITED STATES NATIONAL MUSEUM. 



brachium, 43 mm. ; disk very large with open, arcuate interbrachia 

 and short, tapering, bluntly pointed rays; whole surface overlaid by 

 soft membrane, obscuring the underlying plates, especially the abac- 

 tinals, which are covered with spaced granules larger than in epix- 

 anthus; marginal plates covered all over with spaced granules, coars- 

 est on outer part of plate, and more numerous than in A. epixanthus ,' 

 no marginal spines ; actinal intermediate granules coarse and numer- 

 ous; furrow spines slender, compressed, G to 9, the adoral end of the 

 plate with a large, slender, foi*cipiform pedicellaria, and 1 to 3 more 

 on the actinal surface ; subambulacral spines, 1 to 4, according to the 

 number of pedicellariae, which they partly replace; oral spines 13 

 to 15, with several suboral pedicellariae and numerous suboral 

 granules. 



Description. — This species so closety resembles A. epixanthus 

 (Fisher) of the Hawaiian Islands that the description will be in the 

 form of a comparison. The entire animal is overlaid by a soft, 

 fairly thick, membrane, obscuring the outlines of the abactmal plates 

 (which are arranged as in epixanthus). The membrane is thrown 

 into fine wrinkles and reticulations, partly due to the numerous un- 

 equal spaced granules beneath. These granules are much more 

 numerous and much larger than in epixanthus and become visible 

 when the membrane is partly or wholly dried. They increase in 

 size from the center of disk toward the periphery, and the central 

 granules of each plate (especially near margin) are larger than the 

 peripheral. The number of granules to a plate is between 15 and 20. 

 In A. epixanfJms the granules are practically microscopic (as in 

 A. peircei) uniform in size and scarcely a tenth the size of an average 

 granule in granulosv.s. They are so small that the membrane is 

 smooth even when dried, while in granulosus it is very rough. Scat- 

 tered over the abactinal plates are numerous small pedicellariae about 

 the size of largest granules, with 2 curved truncate jaws as wide as 

 high, or wider than high. They resemble split granules. 



Papulae frequently very dark brown (as in epixanthus)^ con- 

 fined to petaloid radial areas, confluent at center of disk. As is 

 usual in this genus, there are smaller secondary plates on the proxi- 

 mal radial regions. The secondary plates are lobed, and partly or 

 wholly surround the carinal, and 1 or 2 parallel series, to either side. 

 They extend on each side of the carinal series nearly one-half K, 

 while the proximal plates of the same series may be entirely encircled 

 by 6 or 8 secondary plates. The secondary plates do not extend very 

 far distad on the lateral portions of the area. The primary plates 

 become Smaller and also incipiently lobed at the center of disk so that 

 they are indistinguishable from the secondaries. Over the papular 

 areas, even where there are no secondary plates, the primaries are 

 roundish or broadly elliptical with 5 or 6 incipient lobes, sometimes 



