92 Miscellaneous. 



and a Ctcuophore (pi. iii. fig. 25) with its lateral tubes on the 

 sides of the digestive cavity (_</), leading into the chymifcrous 

 pouches («'), branching into the chyniilcrous tube. The coeliac 

 openings (pi. iii. fig. 4.5, rn) of the funnel he looks upon as repre- 

 senting the raadrcporic body, Avhile I look upon them as the anal 

 openings. In this view of the case, the Clenophore is rather more 

 in the embryonic condition of the Ecliinoderni larva, when the 

 actinostome leading into the digestive cavity should perform at the 

 same time the function of mouth and anus, whidi it occasionally 

 does, although at other times tlie coeliac ojjcning of the funnel seems 

 to be the true anal opening, while, according to Metschiiikoff, it is 

 the madreporic body which perfurms the part of an anal opening. 

 He says it only acts to introduce water into the system, which is 

 contrary to my observations. 



I may here recall former statements* concerning the affinities of 

 the Ctenophora, when describing some of the younger stages. It 

 could only be after a careful comparison of Ctenophorous and 

 Echinoderm embryos that undoubted evidence of their identity of 

 plan might be obtained. The Ctenophora retain the permanently 

 embryonic features of Echinoderm embryos, in which the water- 

 system is still connected with the digestive cavity. The formation 

 of a funnel as a sort of alimentary canal, opening externally through 

 the coeliac apertures at the abactinal pole, corresponds to the exist- 

 ence of a short alimentary canal in Echinoderm larva). The Cteno- 

 phora are, from their embryology, more closely related to the Echino- 

 derms than to the other Acalephs ; and it seems natural to separate 

 the Acalephs into two orders — the Ctenophora, characterized by the 

 presence of locomotive flappers, and the Medusida), including the 

 Discophora and Hydroids. — From the Memoirs of the American 

 Academy of Arts and Sciences, vol. x. no. iii., August 1874. 



Notice of Papers on Embryology by A. Kotvalevshy. By A. Agassiz, 



A. Kowalevsky has published, unfortunately in Kussian, two 

 capital papers on embryology. The one continues the investigations 

 he had been carrying on regarding the existence of an ectoderm and 

 entoderm layer in the early embryonic stages of Invertebrates. In 

 the present paper he has given a sumniary of the early stages of a 

 Cam/)rt?u</orjrt, confirming the observations of Wright and A. Agassiz. 

 For lihizostoma and Cassiopea he shows that the digestive cavity is 

 formed by the invagination of the ectoderm. This is contrary to 

 the results of previous observers, except ISchneider. Eor I'eJagia he 

 shows a direct development from the v'^\i remarkably similar to 

 that of the Gcryonidoe as we know it from Htickel, Fol, and Metsch- 

 iiikoff. He adds nothing to the embryolog}' of Actinia not 

 already known from the magnificent monograph of Lacaze-Duthiers. 

 He then passes on to the development of Ahyoniuin, of which he 

 gives an extremely interesting sketch supplemented by fragments 

 on the embryology oi Astrcea, Goryonia, and Cerianthus : the deve- 

 lopment of the latter is strikingly .similar to that of Edivardsia, as 

 we know it during its passage from Arachnactis to Edwardsia. He 



* Alexander Agasf-lz. 111. Cat. M. C.Z. n... 1', p. li>, 1865. 



