142 ECHINODERMA OF THE InDIAN MUSEUM, PART VII. 



almost or quite triangular, two and one half or three times as broad as long, in 

 apposition laterally ; IIBr 2 ; radials and portion of centrodorsal above the proxi- 

 mal row of cirrus sockets evenly and thickly covered with higli small tubercles 

 resembling those on the dorsal pole of the centrodorsal, this tubercular modifica- 

 tion of the dorsal surface of the segments extending distally in the interradial 

 angles, occupying the lateral third of the IBr, and the IBr^ and of the IIBr 

 series, thence diminishing in width and disapiiearing on the second brachial ; 

 inner edges of the IIBr series similarly modified ; IBr series with a low and nar- 

 row, but prominent, tubercular keel or row of tubercles ; this is much less 

 marked or absent altogether on the IIBr series and first two brachials, thougli 

 sometimes traceable to the lowest of the triangular brachials : IBr and IIBr 

 series and proximal oblong brachials with prominently everted dentate proximal 

 and distal ends; as the brachials become wedge-shaped and triangular the 

 everted dentate ends become gradually lower, transforming into a rather promi- 

 nent finely spinous overlap which slowly dies away distall}'. 



Eighteen arms (in the type) apparently 30 mm. to 35 mm. long, the propor- 

 tions of the brachials being approximately as in M. subcarinata. 



Pi 4 mm. long, moderately stout basally but tapering rather rapidly in the 

 proximal lialf and slender distally, with twelve segments, the first three squarish, 

 the following increasing in length and becoming three or four times as long as 

 broad distally ; P.^ 6 mm. long, slender, but stouter than P, and somewhat stif- 

 fened, with about sixteen segments, at first squarish, but becoming three or four 

 times as long as bi'oad distally ; P.^ similar to P.^ and about the same size ; follow- 

 ing pinnules 3 mm. long, small and weak : distal pinnules delicate, 5 mm. long. 



The colour in spirits is white, the division series and arms with a narrow 

 median dorsal line of deep purple. 



Locality. — Two miles off Great West Torres Island. — One broken specimen. 



MARIAMETRA VICARIA. 



Antedon vicaria 1894. Bell, P. Z. S. , 1894, p. 400. 

 Antedon ? variispina 1894. Bell, P. Z. S., 1894, p. 39*3. 



Description. — Cirri XXIII ; 29-31 (usually 29), slender, 2(i mm. long: long 

 sharp dorsal spines are developed from the ninth or tenth segment onward ; the 

 longest cirrus segment (just before the development of the spines) is about twice 

 as long as broad. 



The disk is covered with small calcareous plates. 



The twenty-four arms are 00 mm. long. When IlIBr series are developed 

 they are always external ; the ornamentation resembles that seen in Mariaiiwtra 

 subcarinata^ and occupies exactly the same areas, but it is much more prominent 

 and more irregular ; instead of having a finely tuberculated surface the sides of 

 the rays are converted into a sort of spongy-looking mass, causing the edges of 

 the segments to appear denticulate ; the median keel on the division series and 

 brachials is much higher than in M. subcarinata. 



