128 ECHINODERMA OF THE INDIAN MuSETTM, PART VII. 



HETEROMETRA ASPERA. 



Heterornetra aspera 19U9. A. H. Clark, Vidensk. Medd. fra den naturhist. 

 Forening i Kobenhavn, 1909, p. 162. 

 Habitat.— Singapore. 



HETEROMETRA SINGULARIS. 



Heterornetra singuJari.s 1909. A. H. Clark, Proc. U. S. Nat. Mus., vol. 36, 

 p. 638. 



Description. — Centrodorsal discoidal, the bare polar area flat, 1'5 mm. in 

 diameter; ciri'us sockets arranged in a single crowded, more or less irregular 

 marginal row. 



Cirri XVII, 21-25, 12 mm. long : first segment short, second about twice as 

 broad as long, third somewhat longer, fourth about as long as broad, next two 

 slightly longer than broad, the following; gradually decreasing in length, the 

 terminal fifteen being one third or one half again as broad as long ; at the 

 seventh subterminal dorsal spines begin to develop which soon become long and 

 prominent; opposing spine large and long, much larger than the spines on the 

 preceding segments, triangular, the apex terminal, arising from the whole surface 

 of the penultimate segment and about equal to the diameter of that segment in 

 height; terminal claw nearly twice as long as the penultimate segment, slender, 

 abruptly curved proximally, becoming nearly straight distally. 



Disk with a few calcareous granules in the anal area, especially on the anal 

 tube. 



Radials short, oblong, the dorsal sui'face with numerous prominent rounded 

 tubercles; IBr, short, oblong, slightly over four times as broad as long, in close 

 lateral apposition; IBr, broadly pentagonal, almost triangular, twice as broad 

 as long, the lateral edges shorter than those of the IBr,; IIBr 4 (3 4-4); .seg- 

 ments up to and including the second brachial exteriorly and fourth interiorly, as 

 well as the first two segments of the first three pinnules, in close apposition and 

 sharply flattened, the lateral edges somewhat produced. 



Eleven arms 40 mm. long; first two brachials subequal, wedge-shaped, 

 about twice as broad as the exterior length, the first interiorly united ; third and 

 fourth (syzygial pair) slightly longer interiorly than exteriorly, nearly three 

 times as broad as the interior length ; next four brachials oblong, nearly four 

 times as broad as long, then becoming almost triangular, about three times as 

 broad as long, then gradually lengthening (though remaining almost triangular) 

 to about twice as broad as long , and at a point somewhat beyond the proximal 

 third rather quickly becoming wedge-shaped, almost oblong, about two and one 

 half times as broad as long. From about the ninth onward the brachials have 

 prominent distal ends, though they do not overlap the bases of the succeeding 

 segments. Syzygies occur between the third and fourth, ninth and tenth, and 



