58 BULLETIN 76, UNITED STATES NATIONAL MUSEUM 



Superomaxginal series turns upward near base of raj reaching the abactinal 

 end of the interbrachial or axillary sines: beyond n iddh i I ray intermarginal chan- 

 nel is narrow. E imes at bas< oi ray, most of the superomarginals allor- 



with a secondarj ossicle (pi. 12, fig. 9) winch persists for about three-fourths 



length of r.-.y. A similar ossicle is present, bul less regularly, between the 

 inferomarginal plates. Thej arc present probably only in fully adult animals since 

 none are present in a specimen with R '27 nun.. 



There is generally but one superomarginal spine to a plate, cylindrical and 

 slightly tapered, of the genera] form of the slenderer inferomarginal spines, but a 

 little shorter. There is a single series of stout inferomarginal spines, decidedly 

 more robusl than the superomarginals, and a single series of similar actinal spines 

 which extends about half the length of the ray. The spines of these two series are 

 1.5 to 1.6 mm. long, robust, cylindrical, slightly tapered as a rule, and round-tipped. 



The adambulacral plates are diplacanthid at the base of the ray, then mona- 

 canthid but with the spine alternaterj i o tie furrow margin and set slightly back. 

 In the largest specimen sent by Doctor Djakonov the spines alternate fairly regu- 

 larly one and two as described by Brandt (K 40 mm.). The spines are about 1.5 

 mm. long, slender, terete, round-tipped, sometimes slightly tapered. The first and 

 second pairs of adambulacral plates are in contact interradially, or the second pair 

 simply touch: the first plate is conspicuously longer than the second. The first 

 three are monacanthid. 



The mouth plates are rather short and broad, the length of the median suture 

 being less than that of the first two pairs of adambulacrals. There are two apical 

 and one suboral spine, the latter a little longer and stouter than the first few adam- 

 bulacral spines. (PI. 12, fig. 10.) 



Straight pedicellariae of a characteristic subtriangular form are very abundant 

 among the abactinal spines, in the intermarginal furrow, actinally, and along the 

 furrow face of the adambulacral plates. They are less numerous on the oral and 

 adambulacral spines. The abactinal vary in size from 0.22 to 0.4 mm. in length 

 and occur on the surface of the plates between the spines, the largest being in the 

 neighborhood of the marginal plates. The lateral (intermarginal) are 0.5 or 0.6 

 mm. long, while the largest axial ones are 0.7 mm. long by 0.5 mm. broad at the 

 base. The adambulacral are 0.25 to 0.3 mm., and the largest oral 0.4 and 0.5 mm. 

 long. (PI. 12, figs, 5, 6, 7.) 



Crossed pedicellariae occur in circles around the dorsal and superomarginal 

 spines, and in clusters on the outer side of the inferomarginal, actinal, and adam- 

 bulacral spines. Thej are apparently not very abundant abactinally. The abac- 

 tinal pedicellariae are 0.22 to 0.25 mm. long, the terminal toothed part being about 

 0.055 to 0.08 nun. long. The adambulacral are 0.26 to 0.28 mm. long, while, the 

 terminal toothed part, in profile, is 0.12 to 0.15 mm. long. The difference in the 

 two sorts is shown on Plate 12, figures 1 and 2. 



Madreporic plate convex, surrounded by a circle of spines, and located at 

 mid r. The striae are coarse and irregular. 



Papulae few to an area, and similar to those of other small Li jitasieiius. 



The ovaries of the specimen examined are compact, with subglobose lobules 

 containing relatively large ova. The duct is attached to the interbrachial septum 



