492 DR. J. E. GRAY ON SPONGES. [May 9, 



ciirvatis, elongatis, in valva sinistra diqiUcibus ; maryarita ar- 



gentea, iridescente. 

 Long. 49, alt. 4], lat. 24 mill. 

 Hab. Shanghai, North China {Lamprey and Harland). 



Anodonta harlandi, nob. (PL XXVI. figs. 3, 3 a.) 



A. testa transversa, elonyato-ovata, incequilateraJi, tenuiuscida, 

 injiata, concentrice striata; maryine dorsali postice arcuato, 

 antice excavato ; maryine ventrali convexo ; latere antico ro- 

 tundato ; latere postico oblique subtruncato, declivitate vmbo- 

 nali obtuse anyulato ; umbonibus antemedianis, inconspicuis, 

 sulcatis ; epidermide fusco-olivacea ; maryarita cceridea, callo 

 sitate apicali livido tincta. 



Long. 70, alt. 45, lat. 33 mill. 



Hab. Shanghai, North China {Harland and Lamprey). 



Specimens of this interesting species from China were first sent 

 over to the British Museum by the late Dr. Harland, to whose me- 

 mory we have dedicated this shell. 



DESCRIPTION OF PLATE XXVI. 



Figs. 1, 1«. Uiiio {Lamp.silis) su/iforfus, p. 491. 



2, 2a. (Bi/snom/a) /fn/qji-cj/cnius, p. 491. 



3, 3a. Anodonta har/andi, p. 492. 



G. Notes on the Arrangement of Sponges, Avitli the Descrip- 

 tion of some New Genera. By Dr. J. E. Gray, F.R.S., 

 V.P.Z.S., F.L.S., &c. 



(Plates XXVIL, XXVin.) 



Dr. Solander, nearly a century ago, well observed that some 

 sponges are " composed wholly of interwoven reticulated fibres, 

 while others are composed of little masses of straight fibres of dif- 

 ferent sizes, from the most minute spicula to strong elastic shining 

 spines, like small needles of one-third of an inch long ; besides these 

 there is an intermediate sort between the reticulated and the finer 

 fasciculated kinds, which seems to partake of both sorts." — Zoo- 

 phytes, p. 182. 



In the 'Annals of Philosophy,' n. s. vol. ix. p. 431, 182.0, I pub- 

 lished a short notice on the "Chemical Composition of Sponges," in 

 which I pointed out from chemical analysis, I believe for the first 

 time, that the spicules of several sponges consist almost entirely of 

 pure silica. 



This paper was very shortly followed by two papers by Dr. Ed- 

 mmid Grant, entitled, 1st, "On Calcareous Sponges," 2nd, "On 

 Siliceous Sponges," published in the ' Edinburgh New Philosophical 

 Journal,' i. pp. 166 & 341, for 1826. 



Since the publication of my paper and his. Dr. Grant has pro- 



