A MONOGRAPH OF THE EXISTING CRINOIDS 397 



description of the types at Paris); Proc. U. S. Nat. Mus., vol. 43, 1912, p. 382 (specimen from 

 Koombana Day in U. S. N. M.), p. 384 (includes dorcadis), p. 404 (southwestern Austrah'a; 

 Dirk Hartog Island, 7 fms.); Crinoids of the Indian Ocean, 1912, p. 9 (confined to southern 

 Australia), p. 30 (=Comatula macronema 3. Miiller), p. 34 [ — Anledon macronema P. H. Car- 

 penter, 1888, in part), p. 189 (synonymy; range); Smithsonian Misc. Coll., vol. 61, No. 15, 

 1913, p. 42 (published references to specimens in the B. M.; localities). — Alexander, Rec. 

 Western Australian Mus., vol. 1, pt. 3, 1914, p. 108 (off Geraldton).— A. H. Clark, Rec. Western 

 Australian Mus., vol. 1, pt. 3, 1914, p. 115 (collected by the Endeavour in Western Australia; 

 southern Australian species), p. 131 (off Geraldton, 25-40 fms., very abundant; characters); 

 Die Crinoiden der Antarktis, 1915, p. 167 (range); Internat. Rev. gesamt. Hydrobiol. und 

 Hydrogr., 1915, pp. 226 and following (detailed account of the distribution).— H. L. Clark, 

 Biol. Results Fishing E.xper. F. I. S. Endeavour, 1909-14, vol. 4, pt. 1, 1916, p. 5 (characteristic 

 of South Australian subregion), p. 23 (new localities). — Hart.meyer, Mitt. Zool. Mus. Berlin, 

 vol. 8, No. 2, 1916, p. 236 (southwestern Australia, No. 5959; Dirk Hartog, No. 2964). — A. H. 

 Clark, Proc. Biol. Soc. Washington, vol. 31, 1918, p. 42 (listed from Tasmania).— H. L. Clark, 

 Rec. South Australian Mus., vol. 3, No. 4, May 9, 1928, pp. 362, 368 (Encounter Bay, St! 

 Vincent Gulf, Spencer Gulf, off Althorpe Island, and specimens without locality). — H. L. Clark, 

 Echinoderm fauna of Australia, 1946, p. 55 (in key), p. 56 (records). 

 Ptdomelra dorcadis A. H. Clark, Proc. Biol. Soc. Washington, vol. 22, 1909, p. 39 (description; 

 Turtle Bay, Dirk Hartog Island, 7 fms.); Zool. Anz., vol. 34, No. 11/12, 1909, p. 368 (same 

 locality); Die Fauna Sudwest-Australiens, vol. 3, Lief. 13, 1911, p. 437 (history; synonym of 

 macronema); Proc. U. S. Nat. Mus., vol. 43, 1912, p. 384 (synonym of macronema). 



Diagnostic features. — In its general appearance this species is more robust than 

 P. australis; the centrodorsal is thicker and more columnar, the cirri are stouter basally 

 and longer with the longest segments as long as or slightly longer than broad instead 

 of from twice as broad as long to about as long as broad; and the proximal 

 pinnules are more enlarged and longer than in P. australis with longer segments of 

 which the central are from half again to twice as long as broad instead of broader 

 than long, or at least not longer than broad. In the middle pinnules the third and 

 following segments are always longer than broad, and the distal are considerably 

 elongated. The cirrus sockets are arranged in three or sometimes four columns on 

 the centrodorsal. Both this species and P. australis are variable and most of the 

 differential characters show more or less overlapping. 



Description. — The centrodorsal is columnar, 6.5 mm. in diameter at the base and 

 3 mm. high, with the sides slightly convex and the large bare polar area flat, 5 mm. in 

 diameter. The cirrus sockets are closely crowded, arranged in 15 columns of two or 

 three each, the sockets in each column tending to alternate with those in the neigh- 

 boring columns. 



The cirri are XXXV, 93, from 55 mm. to 60 mm. in length, stout basally but 

 tapering distally. The first segment is very short, about four times as broad as 

 long, and those following gradually increase in length to about the eighth to thir- 

 teenth, which is about as long as broad, then remain similar or become very slightly 

 longer than broad until about the thirty-fifth, after which they very gradually de- 

 crease in length, the terminal 40 or so being about twice as broad as long. The 

 proximal segments are smooth, without dorsal or ventral spines. At about the thirty- 

 fifth the median portion of the distal dorsal border begins to become prominent, this 

 feature gradually becoming more pronounced resulting in high carinate dorsal spines 

 on the later segments. The opposing spine is large, prominent, and blunt, directed 

 distally, arising from the entire dorsal surface of the penulthnate segment and in 



