REPORT ON THE CRINOIDEA. 5 



the calyx of Comatuke which was prevalent at the time of Goldfuss, and that Comaster is 

 in reality nothing but a large Antedon or Actinometra. 



Apart from Phanogenia and Comaster, therefore — one, if not both, of which are 

 merely synonyms — no other Comatulid genera except Eudiocrinus, Antedon, and 

 Actinometra were known, to science before the collections of the Challenger and of the 

 United States Coast Survey ships came into my hands for examination. But one species 

 of Eudiocrinus was known, and only about twenty each of Antedon and of Actinometra 

 had been described, though many others were awaiting description in various museums. 

 Now, however, the number of recent species of Comatula is probably nearly four hundred, 

 and three new genera have been established, thus doubling the number known at the time 

 the Challenger returned. One of these generic types, Atelecrinus, was actually obtained so 

 long ago as 1868, during the earliest explorations of the Gulf Stream by Count Pourtales ; 

 but the single specimen dredged was so small and mutilated that its very striking 

 peculiarities escaped notice at the time. Equally imperfect and isolated examples of two 

 other species were dredged by the Challenger ; and it was not until several less mutilated 

 individuals were obtained by the " Blake " in the Caribbean Sea, that I was able to 

 realise that a new Comatula genus had been discovered. 1 It presents so many larval 

 characters that I have called it Atelecrinus, as will be explained subsequently. 



Atelecrinus can hardly be considered as a new genus discovered by the Challenger ; 

 but with P romachocrinus and Thaumatocrinus the case is altogether different. The 

 former genus 2 differs from all other Crinoids in the composition of the calyx, which has 

 ten primary radials instead of five only, as is normally the case ; and it is represented by 

 three distinct species, one from the North Pacific, one from Kerguelen, and one from a 

 depth of 1800 fathoms at Station 158 in the Southern Sea. At this Station too, there 

 was obtained a single specimen of another Comatula which I have no hesitation in 

 regarding as by far the most remarkable of all the Crinoids that have been dredged of 

 late years, viz., the extraordinarily archaic form TJiaumatocrinus, which presents certain 

 characters only to be found in some of the Palaeocrinoids. Its peculiarities were fully 

 described in the Report on the Stalked Crinoids, 3 and I do not propose therefore to say 

 much about it here. 



1 Report on the Results of Dredging under the Supervision of Alexander Agassiz, in the Gulf of Mexico, and in the 

 Caribbean Sea, 1877-79, and along the Atlantic Coast of the United States during the summer of 1880, by the 

 United States Coast Survey steamer " Blake," Lieutenant-Commander C. D. Sigsbee, U.S.N., and Commander J. R. 

 Bartlett, U.S.N., commanding. XVI. Preliminary Report on the Comatula?, Bull. Mus. Comp. ZooL, 1881, vol. ix. 

 No. 4, p. 16. 



2 Preliminary Report upon the Comatuhe of the Challenger Expedition, Proc. Roy. Soc, 1879, vol. xxviii. p. 385. 



3 Zool. Chall. Exp., part xxxii., 1884, p. 370. 



