284 Dr. J. E. Gray on the Arrangement of Sponges. 



expected to trust out of ray possession valuable preparations, 

 which, if lost or injured, I might never be able to replace. 

 But I am quite willing to give time and trouble to enable 

 those who wish to make the " comparison of the actual speci- 

 mens " for themselves, to do so, without any " verbal argu- 

 ments " or " prolonged disputations." 



If the so-called Eozoon be really an Organic structure, 

 whether Foraminiferal or any thing else, it is time that it should 

 be generally acknowledged as such. But if it can be shown to 

 be a Mineral pseudomorph, I quite agree with ]\lr. Carter that 

 the sooner it is exploded as a sham, the better it will be for 

 Geology. I ti'ust that my scientific career has given sufficient 

 evidence of my having " loved truth better than system," to 

 justify my assertion that I shall be quite ready to surrender 

 it, if I can be proved to be mistaken (as I have been before 

 now) by the examination of my own specimens, and that I 

 shall even thank any one Avho will set me right. No one, 

 however, of the many eminent scientific men who have ex- 

 amined and compared these specimens, has as yet pointed out 

 to me any error in my interpretation of the appearances they 

 present; and nearly all of them have expressed their unreserved 

 acceptance of it. 



XXXVII. — On the Arrangement of Spoyiges. 

 By Dr. J. E. Geay, F.R.S. &c. 



I PROPOSED an arrangement of sponges in the '■ Proc. Zool. 

 Soc' 1867, p. 502, of which I suggested a modification in the 

 'Ann. & Mag. Nat. Hist.' 1868,"i. p. 165, and 1872, ix. p. 440, 

 and especially in a paper which I wrote on the division of the 

 spicules of sponges into types (Ann. & Mag. Nat. Hist. 1873, 

 ' xii. p. 203). 



The continued study of the structure of sponges and of their 

 spicules has induced me to propose an alteration in their 

 arrangement, as a sequel to tlie last quoted paper, wliich I 

 believe will make it more natural and facilitate their study. 



I would divide tlie Porifera, or sponges, into four 

 orders : — 



Order I. Arenospongia (Ann. & Mag. Nat. Hist. 1872, ix. 

 p. 448, enlarged) . The sponges strengthened by particles 

 of sand, fragments of spicules, and other siliceous bodies, 

 which they collect from the sea. 



Order II. ThALASSOSPONGIA (Ann. & Mag. Nat. Hist. 1872, 



