28 THE INDIGENOUS EAUNA. 



The full number of species known is 2G, 18 from Upware and 

 8 from Brickhill. 



Annelida. Amongst the Worms fine species of the Genus 

 Serpula are common, and the Vermicularia Phillipsii occurs both 

 at Upware and Brickhill. The Serpula articulata (Sowerby) is 

 the representative of the S. vertebralis of the Oxford Clay. 



Echinodermata. The Echinoderms are few but interesting. 

 A single specimen of Peltastes Wrightii has occurred at Upware, 

 and at Brickhill it flourished in good numbers, but its full de- 

 velopment was realized still further south, at Farringdon. The 

 Pseudodiadema are fine and abundant from Brickhill. 



Sponges. This group was nobly represented in the Neoco- 

 mian formation at Upware. Beautiful cup sponges of the group 

 Catagmidce (the old Manon) flourished around the Upware Coral 

 Bank, belonging to the genera Catagma, Elasmostoma, Verticillites 

 and others ; altogether they number eight species. Eleven species 

 have occurred at Brickhill. The Upware sponges were remark- 

 ably limited in their distribution, all the good specimens having 

 been found within the area of some two or three fields; — unless 

 indeed it be that they have been destroyed elsewhere by the 

 percolation of water, which is improbable. 



The curious septate and siphuncled sponge Verticillites reached 

 its greatest development in these deposits, three distinct species 

 (two of them new) having lived at Upware ; and the strange- 

 looking fragments of the coarse mesh-work of Pachytiloda are also 

 worthy of note. At Brickhill most of the species are the same 

 as at Upware, but two new forms appear with narrow elongated 

 cloacal cavities, which I refer to the genus Peronella (Zittel). 



All these sponges belong to the group of Vermiculata (O.Schmidt), 

 the " Schwamme mit Wurmformigen Gewebe " of Roemer, so 

 named from the vermiculate appearance of the anastomosing fibres 

 of which these sponges are composed ; but at Brickhill another 

 species belonging to the beautiful group of Hexactinellidce or Vitrea 

 has also been found, namely Plocoscyphea pertusa, a species de- 

 scribed by Geinitz, and occurring in the Quader Sandstein, near 

 Dresden. 



The classification of sponges is now undergoing a complete 



