Mr. J. S. Bowerbank on the Structure of Sponges, 1 29 



breadth, rather narrower behind than before, the posterior angles 

 obtuse ; dorsal channel indistinct, the posterior fovea on each side 

 in the form of a long narrow groove, which extends to the hinder 

 margin ; no punctures on the thorax : elytra elongate, striated, the 

 striae impunctate, those nearest the suture the most deep, the others 

 rather faint : antennae scarcely reaching beyond the hinder margin 

 of the thorax, and of a red colour, as well as the palpi ; legs pitchy 

 red ; mandibles pitchy. In one specimen, the thorax is pitchy 

 black, and the elytra pitchy ; in the other two specimens, the thorax, 

 as well as the head, is black ; in all the specimens the outer mar- 

 gins of the elytra are pitchy, and the reflected portion is pitchy 

 red. 



This species is considerably larger than either of the preceding, 

 being equal in size to the Calathus piceus. 



Sp. 21. Feronia (Argutor) Chilensis, Dejean, Spe. gen. des Co- 

 leop., torn. iii. p. 251. 



Of this species there are three specimens, two of which are from 

 Valparaiso, and the third is from S. Chiloe. 



[To be continued.] 



XVII. — Observations on a Keratose Sponge from Australia. 

 By J. S. Bowerbank, Esq., F.G.S. 



To the Editors of the Annals and Magazine of Natural History. 



Gentlemen, 



I AM not aware that modern naturalists have published the 

 results of any examination of the structure of the Keratose or 

 Horny Sponges while in that state of perfect preservation, 

 such as they would be if alive, or immediately after their re- 

 moval from their native element. The skeletons of these cu- 

 rious animals are familiarly known to every naturalist, but in 

 this state they have undergone decomposition of the softer 

 parts of their substance ; and the descriptions handed down to 

 us by former w^'iters, based upon the examination of such 

 specimens, have unavoidably led to the propagation of erro- 

 neous ideas of their true nature and structure. In a paper 

 read before the Microscopical Society, January the 27th, 1841, 

 I have shown that even in this state they possess a much 

 higher and more complex form of organization than they had 

 hitherto been supposed to exhibit, and that, contrary to re- 

 ceived opinions, they are furnished with siliceous spicula, which 

 are imbedded in considerable abundance in some of the larger 

 fibres of their solid horny skeletons. 



Since the publication of these facts, I have had the oppor- 

 tunity afforded me by the kindness of Mr. J. E. Gray, of 

 examining a specimen of this class of Sponges which was 



Ann. ^ Mag. N. Hist. Vol. vii. K 



