A MONOGRAPH OF THE EXISTING CRINOIDS 327 



has made a careful search for them; and the identity of his Alecto carinata with the 

 Comatula carinata from Mauritius which was described by Lamarck in the following 

 year must therefore remain uncertain. He said that Lamarck referred to Antedon 

 gorgonia de Fre"minville as a possible synonym of his species, and from this one may 

 perhaps conclude that he had been unable to get access to de Freminville's type. 

 He remarked that we have seen that he had ignored de Freminville's generic name 

 Antedon, which had five years' precedence over Comatula, and that his definition of 

 the latter type differed but little from that of Antedon which had been previously 

 given by do Freminville. But the latter author gave no figure or formal description 

 of Antedon gorgonia as distinguished from his definition of the genus; and if Lamarck 

 was unable to see de Freminville's original specimen we can understand his uncer- 

 tainty respecting the possible identity of Comatula carinata and Antedon gorgonia. 



He regarded the specimens from Rio de Janeiro that had been distributed by 

 Lutken under his manuscript name Antedon braziliensis, and those from Brazil doubt- 

 fully referred by Verrill to Antedon diibenii, as conspecific with carinata. The differ- 

 ence, he said, seems to be chiefly in the coloration, and it is now practically certain 

 that VerrilFs and Liitken's types alike are identical with the species from the Indian 

 Ocean (carinata). He said that in this species the lower pinnules are all of tolerably 

 equal length, and only differ in the proportions of their component segments. The 

 stoutness of the segments increases up to the third outer pinnule (Ps), and the next 

 two or three pinnules are most frequently almost equally stout, but in a few cases 

 the size of the pinnule segments decreases from this point onward. In full-grown 

 individuals the width of the arm remains uniform until the second syzygial pair (com- 

 posed of brachials 9+10), after which the brachials become more triangular, and the 

 width begins to decrease, while the median keel or crest becomes more distinct. This 

 varies greatly in the extent of its development, and is so slight in some individuals 

 that he has seen from Mauritius, the locality of Lamarck's original specimen, that 

 he would most assuredly never have given them the specific name carinata. 



Carpenter said that there is always more or less of a tubercular elevation on 

 the junction lines of the elements of the IBr series and the two lowest brachials, and 

 from the second of these onward the median dorsal line of the arm is more or less 

 sharply indicated, owing to the way in which the dorsal surface of each brachial falls 

 away from it, so that the arm has somewhat the appearance of having been compressed 

 laterally. The bases of many arms show little more than this ; but in others the middle 

 of the distal edge of each brachial is distinctly raised, and a sharp forward-projecting 

 crest or keel is gradually developed upon it, and continues for some way out on the 

 arms, till it becomes less and less distinct in their terminal portions. He said that 

 in the few specimens that he had seen from Muscat and from the Red Sea this charac- 

 ter, and also the tubercular elevations on the radials and lowest brachials are con- 

 siderably less distinct than in those from the Indian Ocean (that is, Mauritius and 

 more or less adjacent islands, and the southeast African coast), Brazil, or the Carib- 

 bean Sea; while both hi the African and in the Red Sea variety the terminal portions 

 of the arms have stiffer pinnules and a less feathery appearance than in the Brazilian 

 examples. He remarked that the sacculi are extremely abundant in this species, 

 and occur in considerable quantity at the sides of the ambulacra both on the disk and 

 on the arms. He said that the ambulacra are often supported by delicate rods and 



