THE ANNALS 



AND 



MAGAZINE OF NATURAL HISTORY. 



[FOURTH SERIES.] 

 No. 71. NOVEMBER 1873. 



XLIV. — On iAe Hexactinellid^ and JjYvni^TmM generally^ 

 and particularly on the Aphrocallistidas, Aulodictyon, and 

 Farreae, together with Facts elicited from their Deciduous 

 Structures^ and Descriptions respectively of Three New 

 Species. By H. J. Carter, F.R.S. &c. 

 [Plates XIII.-XVII.] 



This paper was commenced with observations on some deciduous 

 specimens of the Hexactinellidge from the deep sea, in which 

 the influence of an absorbing process (to be mentioned here- 

 after) had rendered the sexradiate spicules, on which the 

 vitreous fibre had originally been deposited, again recognizable. 

 It was then found necessary to study the Hexactinellida3 and 

 Lithistidje (that is^ Dr. J. E. Gray's Coralliospongia exparte) 

 generally for a better understanding of this process, and par- 

 ticularly tlie Aphrocallistidoe^ Atdodictyon^ and the Farrece^ as 

 it was in the deciduous fibre of such sponges that the facts 

 desired were, if possible, to be ascertained. During this study 

 much information hitherto unknown has been oljtained, and 

 three new species of vitreous sponges discovered. 



I shall first, therefore, give the results of my investigations 

 of Dr. Gray's Coralliospongia &c., under the heads respectively 

 of "Hexactinellidaj" and " Lithistid^e " — afterwards an ac- 

 count of the specimens respectively to which I shall have to refer 

 when the spicules of the AphrocalUstida'^ Aidodictyon, and 

 the Farreoi in the living state have been described and I 

 come to the identifying of them in the deciduous structures — 

 and, lastly, a short summary of what these stmctures have 



Ann. & Mag. N. Hist. Ser. 4. Vol xii. 24 



