Vol. XXII, pp. 39-42 March 10, 1909 



PROCEEDINGS 



OK THE 



BIOLOGICAL SOCIETY OF WASHINGTON 



TWO NEW AUSTRALIAN CRINOIDS. 

 BY AUSTIN H(3BART CLARK. 



The collections made by the German steamship Gazelle in 

 the Australian seas included a number of unstalked crinoids 

 taken on the zoologically little known coast of West Australia. 



Through the courtesy of Drs. W. Weltner and R. Hartmeyer 

 of the Konigliche Zoologisches Museum at Berlin, and of Dr. 

 Th. Studer of Berne, these crinoids have been submitted to me 

 for study. There are among them two interesting new species, 

 both belonging to characteristic littoral East Indian genera. 



Ptilometra dorcadis sp. nov. 

 Antedon macronema 1889. Studer, Die Forschungsreise S. M. S. Gazelle, 



III Thiel, p. 185. 



Type. — Cat. No. 2,964 (part), Kt5nio;liche Zoologisches Museum, Berlin. 



Centro-dorsal columnar, 6.5 nun. in diameter at the base by 3 mm. 

 long, the sides slightly convex, the large polar area flat, 5 mm. in diame- 

 ter; cirrus sockets closely crowded, arranged in fifteen columns of two or 

 three each, the sockets in each column tending to alternate Avith those in 

 the neighboring columns. 



Cirri xxxv, 93, 55 mm. to 60 mm. long, stout basally, but tapering 

 distally; first joint very short, about four times as broad as long, the 

 following gradually increasing in length to about the eighth to thirteenth, 

 which is squarish, then remaining similar or bec(jming very slightly 

 longer than broad, until about the thirty-fifth, then very gradually 

 decreasing in length, the terminal forty or so being about twice as broad 

 as long; proximal joints smooth, without dorsal or ventral spines; at 

 about the thirty-fifth the median distal dorsal border begins to become 

 prominent, this feature gradually becoming more pronounced, resulting 

 in dorsal spines on the later joints resembling those of P. macronema; 

 opposing spine large, prominent, blunt, directed anteriorly, arising from 

 the entire dorsal surface of the ])enultimate joint, equal in length to the 

 anterior diameter of that joint; terminal claw nearly as long as the two 

 preceding joints, slender, slightly curved. 



4— Proc. Biol. Soc. Wash., Vol. XXII, 1909. (39) 



