DEVELOPMENT OF ANTEDON (COMATULA, LAMK.) EOSACEUS. 689 



mata, according to '•• the nioditications of theii- organs and modes of progi'ession." He 

 does not enter into any explicit justification of the claims either f)f the CRI^'oiDl:A or of 

 the Ophiukida to the ordinal rank here first assigned to them ; but contents himself 

 with remarking that " as an explanation of th(^ true nature and relation of the l^thiiio- 

 dermatous tribes, I prefer it to any arrangement at present used, and have accordingly 

 followed it throughout this work." There can now be no doubt that Professor Foube.s 

 was completely justitied in separating the CRlxoiBEA from the Stellerida with which 

 they had been previously associated ; since they differ entirely fiom the Asterida and 

 the Ophiunda in the conformation both of tlieir digestive and of their generative appa- 

 ratus ; whilst theii- resemblance to those groups is only such as springs from the general 

 disposition of the parts of their skeletons, the fundamental homologies of Avhich are 

 altogether divei'se. And in accordance with his views, a rank corresponding to that of 

 EcHixiDA and Asteruda has been assigned to the Crinoidea by the general consent of 

 subsequent systematists ; as D'Orbigxy', \x:i der Hoeven% PICTET^ Bronn\ De 

 KoNi:ycK and Le HoN^ and Dujardin^. 



The account which Professor Edward Forbes gave of Comatula rosacea appears to 

 have been written without any knowledge of the previous anatomical investigations of 

 Heusixger, and Avas issued before those of Professor Muller had been communicated 

 to the Berlin Academy. It is for the most part confined to the external characters of 

 the animal, which are in general correctly described, though not with the minuteness 

 which could only be attained by a more elaborate microscopic investigation than Pro- 

 fessor Forbes seems to have bestowed upon the details of its structure. He rightly 

 apprehended the relative characters of the mouth and anus ; and with respect to the 

 latter he remarks, " This curious vent has been mistaken by many authors for the 

 mouth, and has greatly puzzled others ; and M. de Blaixville suggested that it might 

 be connected with the functions of respiration or generation : but any one who examines 

 the Comatula alive, or dissects a specimen well preserved, will not doubt it is a true 

 vent." He made, however, a most extraordinaiy mistake in regard to the ovaries ; for 

 notwithstanding the very explicit statement of Mr. J. V. Thompsox (which he quotes) 

 as to the liberation of the ova from conceptacles formed by the swelling of the pinnae, 

 he aflfinns that only spermatozoa are formed in these conceptacles, and that the real 

 ovaries are certain " round bro^vn dots, placed in regular rows and at regular distances 

 along the margins of the canals, on the body, tlie arms, and the pinure." What is the 

 true nature of these spots, is a question which will be considered hereafter ; it may be 

 positively affirmed, however, that they are not the ovaries, since the production of the 



' Cours Elementaire de Paleontologie et de Geologie Stratigraphiques. Paris, 1849. 

 ' Handbook of Zoologj-, translated by Professor Cl.\iik. London, 1S50. 



• Traite de Palt'ontologie, ^if""^' Ed. Paris, 1857. 



* Die Klassen und Ordnungcn des Thier-Eeichs. Zweiter Band. Leipzig und Heidelberg, 1860. 

 ' Eecherehcs sur Ics CrinoYdcs dii Terrain Carbonifi-re de la Belgique. BnixeUes, 1854. 



' Histoire XatiireUe des Zoophytes Echinodermes. Paris, 18G:i. 



5b2 



