NO. 1G73. RECENT CRINOID8 FROM THE PHILIPPINES— CLARK. 403 



Arms ten, but all broken off near the base; first two brachials 

 externally, and second and third internally, sharply flattened later- 

 ally ; first brachials interiorly united ; second brachial large, shield- 

 shaped, deeply incising the very narrow first brachial ; first two 

 brachials with more or less everted and coarseh^ spinous edges; arms 

 with a very narrow% sharp, and moderately high median carination. 



The i^innules are essentially as in S. hana. 



Color. — Chrome yellow. 



Type.— Cd^t. No. 25470, U.S.N.M., from Albatross station 5154; 

 off Tawi-Tawi (between Simaluc and Tawi-Tawi) ; 12 fathoms. 



A much mutilated specimen found in a jar Avith a specimen of 

 ATrhphimetra discoidea (and therefore probably taken in shallow 

 water) , from Port Denison, Australia, certainly belongs to this genus, 

 and i^ossibly to this species. It is slightly smaller than the type, with 

 the keels less produced, and with the spinous edges of the low^er joints 

 less pronounced, differences which are in all probability due to im- 

 maturity. 



The occurrence in the East Indian region of a littoral species of 

 Thalassometrida^, a family there and elsewhere especially character- 

 istic of the deep-w\ater " Oceanic '' faunal division, is a fact of very 

 considerable interest. 



CROTALOMETRA, new genus. 



Centro-dorsal large, conical, as long as or longer than broad, the 

 cirrus sockets large, arranged in two columns of usually two each in 

 each radial area. 



Cirri X-XX, CO-80, very long and strongly flattened; first five 

 joints short, then longer than broad, becoming short again distally; 

 distal joints with the distal dorsal edge produced; all the joints with 

 the edge all around somewhat prominent. 



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

 calyx ; radials short and bandlike, of uniform height, or concealed ; 

 I Br of moderate length, rounded dorsally, in close lateral apposition 

 and strongly w^all sided, the lateral edges everted. 



Ten to twenty arms; II Br 4(3+4) ; first two brachials in close 

 lateral contact, and sharply flattened, the lateral edges everted; first 

 four brachials in close apposition and sharply flattened interiorly; 

 arms stout and, rugged; first nine or ten brachials oblong, about twice 

 as broad as long, tubercular; following brachials triangular, about 

 as long as broad, becoming wedge-shaped and somewhat longer than 

 broad terminally. Syzygies occur between the third and fourth 

 brachials, again betw^een the fourteenth-fifteenth to seventeenth- 

 eighteenth, and distally at intervals of four to ten (usually six or 

 seven) oblique muscular articulations. 



