268 



Antediluvian %oology and Botany, 



the 



but 



properly 



On ac- 



crag 

 have 



Consistently with our plan of supplying illustrations of the 

 principal departments of fossil zoology, rather than a perfect 

 classification, we commence with the lowest in the scale of 

 animated nature, arranged under the class 



Sponges. — This tribe, whose structure approaches so closely 

 to that of vegetables, is by no means abundant in the early fer- 

 ruginous strata. It occurs plentifully in the ferruginous sand of 

 Farringdon. {Jig. 53.) The upper green sand contains a few 



species ; the chalk 

 53 formation abounds 



with them ; and some 

 spongiform varieties 

 appear in 

 of Suffolk, 

 not been 

 examined. 



count of the delicate 

 texture of these bo- 

 dies, and the filling 

 up of their cellular 

 cavities by the matter 

 of their matrices, it 

 is not often that they 

 are sufficiently dis- 

 tinct to admit of ready 

 examination. 



The recent sponges, which are classed by M. Lamouroux 

 under seven principal divisions, comprise 161 species. We 

 have given two figures in this work, of S. oculata and S. flu- 

 viatilis. (Vol. I. p. 278.) 



Siphbnice are distinguished by their resemblance to flowers 

 (whence their original name of Tulip Alcyonia), and consist of 

 bundles of tubuli, derived from a pedicle, and passing through 

 a spongious substance. Several species have been noticed by 

 Mr. Townsend, Mr. Parkinson, and Miss Bennett. (Vol. II. 

 p. 295. fig. 82., supra, represents a Siphonia from the green 

 sand of Blackdown.) They are associated in the upper green 

 sand, and their principal localities are the Vale of Pewsey, 

 Warminster, the Isle of Wight, and Devonshire. Mr. Web- 

 ster traced them in the limestone of Portland, and in the 

 sandstone between the chalk and the gault on the south coast 

 of the Isle of Wight. A beautiful series of illustrative draw- 

 ings, by this writer, occurs in the Trans, Geol, Soc, whence 

 the following figure is derived (vol. ii. 1st series, pi. 28. fig. 3.). 

 (Jg^ 54.) 



Sponges from Farringdon. The same species are figured 

 in British Mineralogy under the name of 5p6ngia pezizSides, 

 pi 482. Green Sand. 



