A MONOGRAPH OF THE EXISTING CRINOIDS 559 



Dichrometra afra A. H. Clark, Proc. Biol. Soc. Washington, vol. 26, 1913, p. 144 (listed); Smith- 

 sonian Misc. Coll., vol. 61, No. 15, 1913, p. 31 (Zanzibar); Unstalkcd crinoids of the Siboga 

 Exped., 1918, p. 105 (in key; range); Journ. Linn. Soc. (Zool.), vol. 36, 1929, p. 641 (Zanzibar). — 

 Gisl£n, Kungl. Fysiogr. Sallsk. Handl., new ser., vol. 45, No. 11, 1934, p. 25; John Murray 

 Exped. 1933-34, Sci. Reports, vol. 4, No. 4, 1936, p. 104. 



Li-parometra multicirra H. L. Clark, Ann. South African Mus., vol. 13, pt. 7, 1923, p. 232 (descrip- 

 tion; Pieter Faure, 12157). — A. H. Clark, John Murray Exped. 1933-34, Sci. Reports, vol. 4, 

 No. 4, 1936, p. 100 (synonym of afra). — Gisl£n, Kungl. Svenska Vet. Akad. Handl., ser. 3, 

 vol. 17, No. 2, 1938, p. 4 (synonym of afra). 



Diagnostic features. — The cirri are XX-XLIII, 23-36, 15-18 mm. long; the long- 

 est earlier cirrus segments are slightly longer than broad, and the distal segments 

 are slightly broader than long and bear prominent, though blunt, dorsal spines; 

 the lower pinnules are moderately stout and do not differ greatly in size ; P; is 8-10 mm. 

 long, with 17-25 segments; P 2 is 9.5-13 mm. long, with 22-26 segments; P 3 is 10-13 

 mm. long, with 22-24 segments; the 20-50 arms are 75-85 mm. long. Except for 

 the greater equality of the lower pinnules and the lesser development of the rugosity 

 of the division series and arm bases this species does not differ in any essential feature 

 from D. flagellata. 



Description. — The centrodorsal is low hemispherical, 4 mm. in diameter at the 

 base, with the dorsal pole flat 2.5 mm. in diameter. The cirrus sockets are arranged 

 in two irregular marginal rows. 



The cirri are about XX, 23-29, from 15 to 18 mm. in length. The first segment 

 is very short, and those following gradually increase in length to the fifth or sixth, 

 which is about as long as broad, and the sixth-ninth or seven-tenth, which are the 

 longest, slightly longer than broad; the succeeding segments gradually decrease in 

 length, those in the distal half of the cirri being slightly broader than long. The 

 ninth or tenth and following segments bear prominent blunt dorsal spines of moderate 

 size. 



There are in the type specimen 29 arms about 85 mm. long. IIIBr series are 

 developed externally. The division series are broad with the ventrolateral edges of 

 the component ossicles extended laterally as a thin narrow border the outer edge of 

 which is parallel to the axis of the division series. Synarthrial and articular tubercles 

 are not developed. 



Pj is 8 mm. long, delicate and flagellate, with 21-25 segments, of which the first 

 is twice as broad as long, the third is about as long as broad, and those in the distal 

 half are twice as long as broad. The pinnule tapers rather rapidly in the first four 

 segments, more gradually from that point onward. P 2 is 9.5 mm. long, with 22-25 

 segments, similar to Pj but stouter and tapering more evenly. P 3 is 10 mm. long, 

 with 22-24 segments, similar to P 2 and about of the same size. The following pinnules 

 are small. The distal pinnules are very slender, 8 mm. long, with 20 segments. The 

 enlarged lower pinnules are slender and flagellate as in D. flagellata. 



Notes. — The preceding description is based upon the type specimen from Mada- 

 gascar in the collection of the Hamburg Museum. 



The two specimens from Cape St. AndrS, Madagascar, are young. One of them 

 has exactly 20 arms, one IIIBr series being present and one IIBr series absent. The 

 other has about 20 arms. I originally recorded these as representing a species of 

 Dichrometra close to D. palmata {—Lamprometra klunzingeri) . In my paper on the 



