A MONOGRAPH OF THE EXISTING CRINOIDS 309 



India [A. H. Clark, 1912] (3, I. M.). 



?India [A. H. Clark, 1912] (8, U.S.N.M., 35090 [original No. 34H], 35093 [original 

 No. 9H], 35105 [original No. 10H], 35214 [original No. 30H]; I. M.). 



Investigator; ?India (probably Ceylon) [A. H. Clark, 1912] (2, U.S.N.M., 35215 

 [original No. 55H], 35217; I. M.). 



Geographical range. — From the Maldive Islands and Ceylon northward along 

 the western and northern shores of the Bay of Bengal and south along the eastern 

 shore as far as Borongo Island, near Akyab, Burma. 



Bathymetrical range.— From the shoreline down to 62 (?69) meters. Most of the 

 records are littoral or sublittoral. 



History. — It is probable that the Alecto horrida described by Dr. W. E. Leach in 

 1815 is in reality this species. Leach's description is very short. He says "Rays 

 simple; tentacules of the back smooth, with the joints moderately long and produced 

 internally. Locality unknown. British Museum." 



Carpenter noted that Schweigger's figure of the disk of Alecto horrida shows 

 clearly enough that the five trunks of the ambulacral grooves converge toward the 

 center of the disk as in Antedon bifida and that Alecto horrida is therefore a true Antedon 

 in the modern (1879) sense of the term, although belonging to that division of the 

 genus in which the repetition of the bifurcation of the 10 primary arms is carried to a 

 great extent. 



Leach's figure shows a comatulid with 25 very flexible, slender, and slowly taper- 

 ing arms about 90 mm. long. The drawing is sufficiently detailed to indicate that it 

 represents, without any question, a species with the IIBr series 4(3+4) and the IIIBr 

 series 2. The cirri are numerous, slender, and rather long, all of them being shown 

 incurved over the centrodorsal. They are the structures referred to as the "tenta- 

 cules of the back," and the expression "produced internally" indicates that the seg- 

 ments carry dorsal processes. 



This specimen cannot belong to a species of Comasteridae, for no member of that 

 family has such long and slender many jointed cirri and such evenly tapering and flex- 

 ible arms. Nor do the four enlarged brachials and three enlarged pinnules shown 

 suggest those of any species of Comasteridae. It is evidently an example of a species 

 of Himerometridae belonging to the genus Heterometra. Among the species of Hetero- 

 metra it agrees perfectly, so far as the details of the figure will permit us to form an 

 opinion, with H. reynaudi of Ceylon, but not with any other species. 



There can be little doubt that Leach's Alecto horrida, described in 1815, is the same 

 species as Muller's Comatula (Alecto) reynaudi, although definite proof of the identity 

 of the two is lacking. 



This species was first recognizably described in 1846 under the name of Comatula 

 (Alecto) reynaudi by Prof. Johannes Miiller from a specimen that he had studied in 

 the Paris Museum and that had been collected during the cruise of the Chevrette by M. 

 Reynaud in Ceylon in 1829. It was redescribed by Professor Miiller in 1S49, and this 

 redescription was translated and published in French by Dujardin and Hup6 in 1862. 

 In all three of these descriptions there is a curious omission of part of a sentence (see 

 page 304), which renders them quite obscure. 



In the autumn of 1876 Dr. P. H. Carpenter examined Muller's type specimen in 



