THE RECENT CRINOIDS OP AUSTRALIA — CLARK. 769 



Family STEPHANOMETRID^, A. B Clark. 

 Genus STEPHANOMETRA, ^. i/. Clark. 



JStephanometra, 1909, A. H, Claik, Proc. Biol. Soc. Washington, 

 vol. 22, p. 9 (Antedon monacantha, Hartlaub, 1890). 



Dijfferential Characters. — In the genus Stephanometra the 

 pinnules of one or more of the lower pinnule pairs are enlarged, 

 with less than eighteen segments, greatly stiffened, and very 

 sharply pointed, becoming spine-like in character. The division 

 series are all 2, each of their component ossicles with a rounded 

 ventro-lateral process supporting the visceral mass. 



Range. — Stephanometra ranges from Mauritius and the Red 

 Sea to northern Australia, Fiji, Tonga, and the Philippine 

 Islands. 



It is represented in the Caribbean Sea by Analcidometra. 



STEPHANOMETRA MONACANTHA (Hartlaub). 



Antedon monacantha, 1890, Hartlaub, Nachr. Ges. Gottingen, 

 Mai, 1890, p. 179 (Mortlock Island; Torres Strait). — 

 1891, Nova Acta Acad., vol. 58, No. 1, p. 59, pi. 3, figs. 33, 

 2)d) {Mo7'tlock Island ; Torres Strait). 



Dij^erential Characters. — Stephanometra tnonacantha usually 

 has from twenty to thirty arms; the cirri are without dorsal 

 spines, and the second pinnule, in abrupt contrast to the others, 

 is much enlarged, stiff and spine-like, with 12-14 (rarely as many 

 as 20) .segments, of which the outer are very long. 



Australian Record. — This form was recorded at the time of its 

 description from Torres Strait. 



Distribution. — This well marked species occurs from the 

 Nicobar Islands and Singapore to the Philippines, the Carolines, 

 and the Tonga Islands, and on the northern coast of Australia, 



Family MARIAMETRID^, A. H. Clark. 

 Genus D I C H R O M E T R A, ^. //. Clark. 



Michrometra, 1909, A, H. Clark, Proc. Biol. Soc. Washington, 

 vol. 22, p. 12 {Alecto flagellata, J. Miiller, 1841). 



Difere7itial Characters. — The proximal pinnules of Dichrometra, 

 though enlarged, are slender and flagellate distally and are com- 

 posed of more than twenty-four segments ; the division series are 

 ^11 2, and are in lateral apposition, sometimes being considerably 

 fattened against each other. 



