Mr. IT. J. Carter 07i the Spongozoon. 45 



the resemblance between the different groups of reptiles, for 

 instance, is a correspondence of homologous parts, and no 

 evidence of the orders having had an immediate parentage in 

 common. Such a doctrine invites investigation. Here I can 

 but state it, and try to show hereafter in what way such por- 

 tions of it as practically concern the student of reptile bones 

 may be profitably studied. 



IV — Proposed Name for the Sponge-animal^ viz. " Spongo- 

 zoon ;''"' also on the Origin of Thread-cells in the SpongiadcB. 

 By H. J. Caeter, F.R.S. &c. 



As it has now been satisfactorily determined that the Spon- 

 giada3 are animals and not plants, and the form of the animal 

 which produces them has also been determined, it becomes 

 necessary to give that form a specific name, and to define the 

 animal, in order that henceforth both may not only be used 

 by the zoologist, but by the comparative anatomist, wliose 

 lectures without such additions now cannot be considered 

 complete, the time having passed for the comparative anato- 

 mist and the botanist to dispute respecting the kingdom to 

 which this class of beings may belong.- 



The name that I would propose for this purpose is " spon- 

 gozoon," which is only the Greek rendering of " sponge- 

 animal," but retaining " sponge" for the root will ever ally it 

 to the Spongiada?, and thus aid the memory by associations 

 Avhich any other term differently compounded would not do. 



Spongozoon, or the sponge-animal, then, I first pointed out 

 in Spongilla^ in 1857 (Annals, vol. xx. p. 28, pi. 1. fig. 4), 

 wherein it is shown that it is a granuliferous polymorphic 

 body possessing a nucleus and one or more contracting vesi- 

 cles (p. 30), that it exists in communities of a spherical form 

 with a common circular aperture (figs. 2, 3, 5), in countless 

 numbers, in the sarcode of the sponge (fig. 1), and that it is 

 capable of taking into its body crude material and of dis- 

 charging the undigested portions after the manner of Amooha ; 

 lastly, that the circular aperture opens and closes itself as 

 required. 



Then, in 1859 (Annals, vol. iii. p. 14, pi. 1. fig. 12), the 

 same monociliated body is described and figured with two 

 ear- or spine-like points of its sarcode, one on each side the 

 cilium, which, I might also add, noio stands in my journal as 

 it was figured " Aug. 12, 1854," although not published until 

 1859 ; and that I had been previously acquainted with the 

 existence of the spines may be seen by the following passage 

 in the paper to which I have last referred, viz. : — " But there 



