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. 



