Mr. W. S. Kent on Dorvillia agariciformis. 37 



IV. — Note on Dorvillia agariciformis. By W. Saville 

 Kent, F.Z.S. &c., of the Geological Department, British 

 Museum. 



At the November meeting of the Royal Microscopical Society, 

 I described, under the above title, a new deep-sea sponge re- 

 cently purchased for the British Museum by Dr. Gray, which 

 description, with a plate (pi. Q>Q) illustrative of its structure, 

 has subsequently appeared in the December Number of the 

 * Monthly Microscopical Journal.' 



At the time, I observed that some of the spicules figm'ed 

 greatly resembled those of Pheronema ; and being derived 

 from so great a depth, it was not unreasonable to suppose 

 that spicules of that last-named form had become asso- 

 ciated with it. Fuller examination has further strengthened 

 me in this idea ; and I now feel satisfied that none of the hex- 

 radiate forms, in addition to figs. 12 & 14, are referable to 

 Dorvillia^ having simply become entangled with it during 

 contact with examples of other species. 



Making these deductions, it will become evident that Dor- 

 villia is a representative of the true Tethyidse, its afiinities 

 with which have already been recognized in consequence of the 

 highly developed triradiate character of the spicules and the 

 remarkably firm consistence of its sarcode. 



Since the publication of its description I have seen the yet 

 unpublished plates of a form Prof. Wyville Thomson pro- 

 poses to name Tisij)honia agariciformis^ taken in one of the 

 earlier expeditions of the ' Porcupine,' which plates have been 

 sent by that gentleman to Dr. Gray only within the last few 

 days. Dorvillia and this will probably prove to be identical ; 

 and had I been favom*ed with a sight of these plates in time, 

 I should certainly have withheld its description. I would 

 nevertheless remark that a brief but speedy notice of the most 

 interesting forms collected, preparatory to the excellent and 

 elaborate monographs in course of construction, would serve 

 to efface the present feelings of fear and trembling with which 

 one proceeds to describe any new accessions, while at the 

 same time it would conduce greatly to satisfy the hopes long 

 deferred with which zoologists on all sides are expectantly 

 awaiting an account of the immense amount of material the 

 late expeditions have afforded. 



The plates of Tidplionia here alluded to seem to include, 

 as its young condition. Prof. Perceval Wright's Wyville- 

 Thomsonia Walli'chii, described in the ' Quarterly Journal of 

 Microscopical Science ' for Jan. 1870 ; and though Dorvillia 

 is the first full account published. Prof. Wright's name, in the 



