202 BULLETIN 82, UNITED STATES NATIONAL MUSEUM 



Chlorometra (part) A. H. CLARK, Proc. Biol. Soc. Washington, vol. 22, 1909, p. 22. F. W. CLARKE 

 and WHEELER, U. S. Geol. Surv. Prof. Pap. 90-L, 1915, p. 195 (inorganic constituents of the 

 skeleton); Prof. Pap. 102, 1917, pp. 23 and following (same); Prof. Pap. 124, 1922, p. 20 (same). 



Chondromelra A. H. CLARK, Journ. Washington Acad. Sci., vol. 6, No. 17, 1916, p. 608 (diagnosis; 

 genotype Chlorometra robusta A. H. Clark, 1911; range; included species). A. H. CLARK, 

 Unstalked crinoids of the Siboga-Exped., 1918, p. 172 (in key; range), p. 187 (key to the included 

 species). GISLEN, Kungl. Fysiogr. Sallsk. Hand!., new ser., vol. 45, No. 11, 1934, p. 18. 



Diagnosis. A genus of Charitometridae in which the genital pinnules taper evenly 

 from the more or less broadened earlier segments to a delicate tip, the portion beyond 

 the gonad being much longer than the gonad itself; the division series and arms are 

 V-shaped in cross section, rising evenly to a more or less sharp median keel, the keel 

 on each of the outer brachials forming a high overlapping spine or tubercle; the cen- 

 trodorsal is conical or columnar with the cirrus sockets in 5 or 10 definite columns; 

 and the arms are 75-211 mm. long. 



Geographical range. From Timor northward to the southern Philippines. 



Bathymetrical range. From 520 to 1,334 meters. 



Thermal range. From 4.77 to 13.55 C. 



Remarks. The laterally compressed and carinate arms make the species of this 

 genus easy to recognize. Of the three species herein referred to Chondrometra one, 

 ru-gosa, seems to be quite distinct; the other two, robusta and aculeata, are separated 

 on characters that may prove to be due merely to differences in the degree of maturity. 



History. The first known species of this genus, aculeata, was described by Dr. 

 P. H. Carpenter in 1888 under the generic name of Antedon. In 1907 I transferred it 

 to the new genus Charitometra. In 1909 I assigned it to the genus Chlorometra of which 

 the genotype was Antedon garrettiana A. H. Clark, 1907. In 1916 I established the 

 genus Chondrometra with the genotype Chlorometra robusta A. H. Clark, 1911, and 

 including also Chlorometra rugosa (a nomen nudum, described in 1918 as Chondrometra 

 rugosa) and Carpenter's Antedon aculeata. 



KEY TO THE SPECIES IN THE GENUS CHONDROMETRA 



a 1 . Centrodorsal very large, truncated conical or more or less columnar, with the cirrus sockets 

 arranged in 10 regular columns, two, more or less widely separated in the midradial line, in 

 each radial area; cirri short, one-sixth of the arm length, XXX, 18-19, 35 mm. long; arms 210 



mm. long (Celebes southward to the East Timor Sea; 520-871 meters) rugosa (p. 206) 



a 2 . Centrodorsal small or of medium size, sharply conical, with the cirrus sockets arranged in 5 more 

 or less regular columns, one in the midline of each radial area; cirri longer, from one-fourth to 

 one-third the arm length. 



6'. Size large, the arms 170-211 mm. long; cirri numerous with numerous segments, XX-XXV, 

 26-28, 55-60 mm. long (southern Philippines southward to the East Timor Sea; 520-1,334 



meters) robusta (p. 202) 



h 2 . Size small, the arms 75 mm. long; cirri less numerous with fewer segments, XV, 18, 27 mm. 

 long (Meangis Islands; 914 meters) aculeata (p. 204) 



CHONDROMETRA ROBUSTA (A. H. Clark) 



PLATE 19, FIGURE 60 

 [See also vol. 1, pt. 1, fig. 207, p. 239.] 



Chlorometra robusta A. H. CLARK, Proc. U. S. Nat. Mus., vol. 39, 1911, p. 558 (description; Albatross 

 station 5348; also station 5349; comparison with Ch. aculeata}; Crinoids of the Indian Ocean, 

 1912, p. 225 (synonymy; locality). 



