A MONOGRAPH OF THE EXISTING CRINOIDS 137 



Syzygies occur between brachials 3+4, again between brachials 14+15, and 

 distally at intervals of 3 or 4 muscular articulations. 



PI is larger than P 2 ; its lower segments are relatively stout with somewhat flattened 

 outer sides, and the inner edges of the third to the fifth segments are slightly carinate. 

 P, and P 2 are small, and those following increase slowly in length, the later ones some- 

 times showing a faint expansion of the two basal segments. 



The color in alcohol is light brownish white. 



Notes. The preceding description is adapted from the original description by 

 Carpenter, to which are added a few notes taken from his figure. I examined three of 

 the five original specimens in London in 1910. This is a curious small and delicate 

 species, with curiously long cirrus spines. 



Prof. Torsten Gislen examined these specimens in August 1925. He noted that 

 the synarthrial pah's are triangular and carinate and slender; the arms are otherwise 

 smooth and in rather close lateral contact. He remarked that in my key to the genera 

 of the subfamily Thalassometrinae (that is, the family Thalassometridae as now under- 

 stood) published in the Siboga report the section referring to Stiremetra should be altered 

 to "arms distally of Br 2 [the second brachial] without carination." 



Locality. Challenger station 164; near Sydney, M'ew South Wales (lat. 3408' S., 

 long. 15200' E.); 1,737 meters; bottom temperature 2.28 C.; green mud; June 12, 

 1874 [P. H. Carpenter, 1888; Hartlaub, 1895; A. H. Clark, 1907, 1909, 1911, 1912, 1913, 

 1918; Gislen, 1928] (3, B. M.). 



History. This species was first described by Dr. P. H. Carpenter in 1888 under 

 the name of Antedon spinicirra from five specimens, two of which were much mutilated, 

 that had been dredged by the Challenger at station 164 off Sydney, New South Wales. 

 In 1895 Dr. Clemens Hartlaub discussed its systematic and bathymetrical relationships. 



In my first revision of the genus Antedon published in 1907 spinicirra was assigned 

 to the new genus Thalassometra, and in my revision of the family Thalassometridae 

 published in 1909 it was transferred to the new genus Stiremetra. In my memoir on the 

 Recent crinoids of Australia published in 191 1 I listed it as one of the species known from 

 the waters about Australia, and in my memoir on the crinoids of the Indian Ocean 

 published in 1912 I listed it and gave the range. In a paper on the crinoids of the 

 British Museum published in 1913 I gave a short note on the three specimens I had 

 examined during a visit to that institution in 1910. In my report upon the unstalked 

 crinoids of the Siboga expedition published in 1918 I again listed it and gave its range. 



In 1928 Prof. Torsten Gislen published additional notes on the type specimens in 

 the British Museum he had examined in 1925. 



Genus OCEANOMETRA A. H. Clark 



Thalassometra (part) A. H. CLARK, Proc. U. S. Nat. Mus., vol. 34, 1908, p. 214. 



Crotalometra (part) A. H. CLARK, Proc. U. S. Nat. Mus.. vol. 36, 1909, pp. 406, 642. 



Oceanomelra A. H. CLARK, Journ. Washington Acad. Sci., vol. 6, No. 17, 1916, p. 606 (diagnosis; 

 genotype Thalassometra gigantea A. H. CLARK, 1908; range; included species); Unstalked crinoids 

 of the Siboga-Exped., 1918, p. 146 (in key; range), p. 150 (key to the included species). GISLN, 

 Kungl. Fysiograf. Sallsk. Handl., new ser., vol. 45, No. 11, 1934, p. 22. 



Diagnosis. A genus of Thalassometridae in which the arms are rounded dorsally 

 to the tips; there is no appreciable expansion of the proximal segments of the genital 



