120 ]\Ir. W. S. Kent on a new Genus of Madrej^oraria. l)c-twoon tlio ?i)on.i;vs and the otluM-Ca'lentcrata. Tliis Ixmn-darv a|)]K'ars to be very artificial, it" we consider that hoth among-the Vermes and among tlie ^lollusea tliere are parti-euhir forms -with m-ticating organs. It is, however, still further weakened when we take a general view of the whole of the conditions of histological differentiation in the sponges and corals, and become convinced that in both classes a wide scope is given to the degree of differentiation. Not a few of the more highly dcvelo])ed sponges, with regard to histological differentiation, ])erhaps occuin' a higher grade than many corals, or at least than the lljidnv among the Acalephs. On the other liand, a very important and thoroughgoing difference between the Acalephs and Sponges would result from the confirmation of the supposition expressed by me above, that zoospermia and consequently sexual differentiation do not occur among the sponges, and that the su])poscd " ova " of the sponges are agamic spores. The further explanation and establishment of all the parti-culars here brought forward I reserve for my detailed mono-graph of the Calcispongiffi, and, in conclusion, beg all readers of this preliminary communication who may be in possession of dried or spirit specimens of Calcispongia? to be kind enough to transmit them to me for examination and comparison, in order to render tlie systematic part of that work as complete as possible. The Calcispongiaj have hitherto been so sparhigly represented in zoological collections almost everywhere, and their classification is so imperfect, that the following Prodro-mus of a system of the Calcispongiaj must commence quite afresh. Moreover many Calcispongiaj are so very different in their internal stnicture, Avhilst their sober exterior aj)])ears almost the same, that the most accurate microscopic examina-tion of all the forms hitherto discovered is quite indispensable for the establishment of their classification. XIV. — On a netv Genus of the Madreporaria or Stony Corals (Stenohelia). By Wm.'S. Kent, F.Z.S., F.R.M.S., of the Geological Department, British Museum. In the ' Proceedings of the Zoological Society for 1862,' p. 196, J. Y. Johnson described as a new species oi Allopora a small branching coral, of the family Oculinida?, taken by himself in the vicinity of Madeira. There are, however, f-everal points of structure connected with it, seemingly over-looked by ]Mr. Johnson, which render it perfectly essential that a new genus should be created for its reception.
BioStor
