STARFISHES OF THE PHILIPPINE SEAS. 



149 



has these plates conspicuously broader than long on the rays. 

 D. sladeni has larger inferomarginal spines which tend, at least 

 proximally, to form transverse series, and differs in this respect 

 from the other four. In addition to the differential characters men- 

 tioned in the diagnosis. D. imperialis has more subambulacral 

 spines than sladeni (in which there are 12), and the latter has more 

 elevated actinal intermediate plates. According to the description 

 " each plate has the appearance of a veiy large, compact, and beauti- 

 fulh^ expanded glomerular paxilla, owing to the fact that the 

 central carina of the plate bears a" multitude of stiff, radiating spine- 

 lets arranged like the florets of a composite flower." In imperialis 

 the elevated portion of the plate is too broad and the spinelets are 

 too short to give this appearance; rather the mostly four-cornered 

 plates look as if covered with squamiform granules. 



In D. laetmophilus the rays are broader, with a distally wider 

 paxillar area. The superomarginals are narrower, with deeper 

 fascioles, and thej^ correspond to the inferomarginals on the outer 

 part of the ray (as in sladeni). The adambulacral furrow spines 

 are 7, thinner and more bladelike. 



The principal differences between this species and grandissimiis 

 are contrasted below in parallel columns. 



D. grandissimus. 



D. imperialis. 



Kays shorter and blunter, with a 

 subangnlar interbrachuim. R=2.5 r ; 

 in figiire a little less. 



Superomarginals from near middle 

 of ray outward nearly twice as broad 

 as long. 



Inferomarginals uniformly covered 

 with a thick coat of very fine, some- 

 what flattened spines of a silky ap- 

 pearance. 



One of the larger paxillae near mid- 

 die of disk witli 4.") spinolets. 



Aciiiial iiilernicdiate plates 18.j to 

 cncli of ilic ." areas; actinal spinelets 

 very small, exactly like those of the 

 inl'eromarginal plates. 



Rays longer and sharper, with wide 

 arcuate interbrachia ; hence rays are 

 narrower a short distance above base ; 

 fv=less than 3 r. 



From proximal fifth of ray outward 

 plates only slightly broader (1.2) than 

 long. 



Actinal surface of inferomarginals 

 covered with very small, sharp, sub- 

 conical and slightly squamiform, spine- 

 lets directed toward the ambitus and 

 increasing in size tow-ai'd the outer 

 tumid margin where a tuft is enlarged 

 on the aboral border. At the base of 

 ra.v 5 to 8 tapering sharp spinelets are 

 obviously of predominant size. 



One of the larger paxillae from disk 

 with 8.5 spinelets (some with fewer, 

 some with more). 



Actinal intermediate plates (in 

 slightly larger specimen) 260± ; actinal 

 spinelets swollen, papilliform. bent to- 

 ward the ambitus, and more or less 

 squamiform, with a broad, lanceolate 

 contour and a rounded or pointed tip. 



1. •',4.^,4— 1 •.nil. 100— in- 



-11 



