380 BULLETIN 100, UNITED STATES NATIONAL MUSEUM. 



&. Abactinal plates not ordinarily oriented transversely and in specimens 

 with R about 70 mm. there are 7 to 10 rows of primary abactinal 

 plates (always more than 5). The plates are smaller and roundish, 

 but conspicuously larger than the papular areas, and those of distal 

 third of ray are markedly small and close-set. Adamhulacral armature 

 in 3 series. 

 cZ\ Abactinal plates in 7 rows on basal third of ray, but fewer and ir- 

 regular distally ; no intermarginal or actinal papulae ; abactinal 

 papular ai*eas with granules conspicuously larger than the rest; 



furrow spines about 6 squamulosa, p. 383. 



d'. Abactinal plates 7 to 10, counting across ray, much larger than pap- 

 ular areas (whose granules are subequal to or smaller than those of 

 plates) ; an intermarginal series of papulae and an incomplete series 

 of actinal intermediate papulae; furrow spines 3 or 4. 

 e*. Rays longer, slenderer, tapering to an attenuate, rather sharp, ex- 

 tremity; R=about 6 to 7 r; abactinal plates nearly plane, or only 

 faintly convex, their contour excavated by the papular areas, 

 forming short irregular lobes (which can be seen only when the 



plates are denuded) lemonnieri, p. 382. 



e*. Rays shorter and thicker, not especially attenuate at the tip; R. 

 variable, but about 5 r; abactinal plates markedly convex, the 

 primary plates without lobes or with only very faint lobing. 

 f. Abactinal plates a little larger and more convex, especially on 

 disk; granules relatively larger on the convex part of the ab- 

 actinal plates, and abruptly larger, by 4 or 5 times, than 

 granules of interstices betvreen plates ; adamhulacral armature, 

 3, 8, 3, or 4, 3, 3; contour of plates of type, unknown (see foot- 

 note) " gamopliia " Perrier.^ 



f. Abactinal plates by direct comparison a little smaller and a little 

 less convex; rays slightly longer and a little more attenuate 

 distally ; granules of the convexity of plates smaller and grading 

 more gradually into the smaller granules of margins of plates 

 and papular areas novae-caledoniae Perrier.* 



1 The differences between gomophia and novae-caledomae are rather difficult to express 

 In a key, being somewhat subtle. I have, of course, relied upon the correctness of the 

 label which designates Perrier's type in the British Museum — or, rather, upon the 

 authenticity of the specimen. Perrier compares his specimen to Nardoa aegyptiaca in 

 the following manner (1875, p. 167) : 



" II existe dans la collection du British Museum un bel 6chantillon d'une espfece de 

 Scytaster trfes volsine par ea forme et eon aspect g^n^ral des indlvldus de grande taille 

 de I'espfece pr^c^dente [aegyptiaca] ; nous proposons de lui donner le nom de Scytaster 

 gomophia en souvenir du nom de genre cr66 par Gray pour celle-ci." 



But the type does not particularly resemble N. aegyptiaca. It Is, on the contrary, 

 very close to the specimens of N. novae-caledoniae mentioned by Perrier (1875, p. 164) 

 as being in the British Museum. I think the names refer to a single species. 



The type of gomophia measures: R=71 mm., r=13 mm., breadth of ray at base, 16 

 or 17 mm. The Mer Island specimen measures : 11=79 mm., r=13 mm., breadth of ray 

 at base, 14 or 15 mm. 



The type-locality of both species Is New Caledonia. 



1 have figured (pi. 108, fig. 2) a specimen taken by Dr. H. L. Clark at Mer (Murray) 

 Island, Torres Strait. I do not feel at all sure that this is really N. novae-caledoniae, but 

 It seems at least pretty close to that species. As will be seen from the figure, it resembles 

 vaHolata, but the abactinal plates are round instead of elliptical, and those of the distal 

 half of the ray are much smaller and close-set. The primary abactinal plates show a 

 very faint lobing, although a few plates are nearly entire. The adamhulacral armature 

 is 3, 3, 3, or 4, 3, 3, and a series of actinal Intermediate papulae extends a little over 

 half the length of the ray. 



2 The chief differences between the type of " N. gomopliia" and the British Museum 

 specimens of novae-caledoniae are mentioned in the key. In gomophia the rays are a little 



