144 Clark — -New Recent Indian Crinoids. 



Radials short, trapezoidal, four or five times as broad as long; i Bri and 

 2 united by syzygy, the syzygial pair being al)!)ut twice as broad as long; 

 I Bn almost entirely or quite united laterally ; i Br2 free laterally. 



Ten arms 50 mm. to 65 mm. long, resembling, with the pinnules, those 

 of C. pectinala. 



Gentjs eOMASTER L. Agassiz.* 

 Comaster parvus sp. nov. 



Type. — Cat. No. Z. E. V. ^^, Indian Museum; Andaman Islands; 

 53 fathoms. 



Cirri xiii-xvin, 10-11, 8 mm. long, arranged in a single or partially 

 double row on a rather thick discoidal centro-d((rsal. 



Ends of the basal rays visible as prominent tubercles in the angles of 

 the calyx ; radials projecting slightly l)eyond the edge of the centro-dorsal ; 

 I Bri very short and band-like, just in contact liasally but widely diverg- 

 ing so tiiat their lateral edges are separated by a Ijroad shallow U-shaped 

 gap; I Brn (axillary) triangular, twice as broad as long, the anterior 

 angle very acute; ii Br 4 (8 -1- 4), widely separated; in Br 2 (1 -f- 2); 

 IV Br 2 (1 -f 2), developed interiorly in reference to the ii Br series, bnt 

 seldom present. 



Forty arms 60 mm. to 70 mm. long resembling, with the pinnules, 

 those of the other small species of the genus. 



Mouth central or sub-central; anal tube small, sub-central or marginal; 

 disk naked. 



Family HF\IER0METRID/E. 



Mariametra gen. nov. 



Genotype. — Himerotnetra subcarinata A. H. Clark, 1908. 



The form which 1 described under the name of Himerometra subcari- 

 nata differs markedly from all the other sjiecies in the genus Dichrometra, 

 where I had tentatively jjlaced it, in having a delicate narrow carinate 

 line in the middle of tlie dorsal surface of the division series and first two 

 brachials, and iu having the sides of the division series thickly covered 

 with fine granulations forming a triangular figure in each interradial area, 

 witii the apex at about the level of the last axillary, something similar to 

 the ornamentation found in certain species of Crinometra. There are 

 also ditt'erences in tlie, cirri and in the pinnules, and the surface of the 

 disk adjacent to the anil)ulacra is strongly i)lated. It did not seem wise 

 ' to create a genus for this single aberrant species, as it was then im])ossi- 

 V)le to judge of the value of the characters exhibited, they not being met 

 with in any other species of the HimerometridtT". The Indian collection, 

 however, contains another species possessing the same general features 

 which scjiarate Kulirarinata. from the remaining species of Dlchro)iietra, 

 tliougli (liU'ering widely in its details, and I have now no hesitation in 

 creating a genus for these two peculiar forms, which I propose to call 

 Mariametra. 



* ( 'f. 'iiiira, p. ST. 



