228 Notices of Memoirs'— Brief Abstracts. 



IV. — Brief Abstracts. 



Davey, E. 0. The " Sponge-Gravel " Beds at Coxwell, near 

 Faringdon ; with an Appendix on Cole's Pits. Paper con- 

 tributed to the Newbury Field Club. 8vo. pp. 14. 19 photo- 

 graphic illustrations (18 of fossils). Wantage, [1874]. 



The " Sponge-Gravel " (Neocomian) crops out over a space of 

 about a mile by a quarter of a mile, and is from 25 to 40 feet thick, 

 forming a plateau based on Kimmeridge Clay, and capped in places 

 by dark ironsand. The bed is a conglomerate of sand and fossils, 

 mostly hardened by a ferruginous cement, and according to some 

 authorities must have been accumulated in a deep clear sea, with 

 currents ; whilst others take it to have been deposited in a shal- 

 lower and more sheltered sea. 



There are two large and three small pits, some of which have 

 been worked for a great time, being mentioned by Llwyd (who 

 collected fossils from them) in 1698. In later times they have been 

 the subject of much controversy, having been classified as Lower 

 Greensand, Upper Greensand, and top Chalk (= Maestricht Chalk). 

 The author thinks that Sharpe was led to take this last view from 

 the abundance of Polyzoa ; but he finds that of the half hundred 

 species found at Coxwell, not half a dozen occur at Maestricht. He 

 questions also whether there is a single species of Sponge common 

 to the two beds, believing that the Manon peziza and M. pulvinarium 

 of each are really distinct. 



It is now allowed that these fossiliferous gravels belong to the 

 Lower Greensand, or Upper Neocomian, and on these grounds : 1. 

 Similarity with Lower Greensand, at Seend, Godalming, Upware, 

 and Potton. 2. Presence of Lower Greensand Brachiopoda and 

 Echinodermata. 3. Infraposition to the Lower Greensand iron- 

 sand of Furze Hill. 4. Dissimilarity from Upper Greensand, 

 which is fairly developed. in the neighbourhood. 



The fossils are of two sorts — those that lived on the spot, and 

 those derived from beds of Oolitic age. The latter can be dis- 

 tinguished by colour and condition, and they are chiefly the remains 

 of vertebrates ; the former are Sponges, Polyzoa, Echinoderms, and 

 bivalve Molluscs, the absence of univalves being remarkable. The 

 Sponges are most important, both as forming a large part of the 

 gravel and from their good preservation. Sharpe names 16 species; 

 but the author would eliminate from his list Manon Fanngdonense 

 and Spongia Trigeris, adding Scyphia multidigitata, Mich., and Manon 

 marginatum, Goldf. [Porospongia, D'Orb.), and altering the name of 

 Manon pidvinarium. Chenendopora fungiformis is also questionable. 

 These 16 species differ much in form and size ; some -are funnel- 

 shaped, some are single cylinders, some clusters of slender pipes, and 

 some are solid, etc. Five characteristic sorts are illustrated, by de- 

 scriptions of Verticellites anastomosans, Tragos Faring donensis, Manon 

 marginatum, M. macropora, and M. porcatum. 



By the name of " Cole's Pits " is known a number of old over- 

 grown excavations in sand and conglomerate (Neocomian), extending 



