32 G. W. Lamplugh — BeUmnites of Faring don Sponge-gravels.. 



VII. — Belemnites of the Faeingdon 'Sponge-gravels.' 

 By G. W. Lamplugh, F.G.S. 



^URING a preliminary traverse of the Lower Cretaceous outcrop- 

 in the Midlands last June, I visited Faringdon for the first 

 time, and examined the famous sections in the ' Sponge-gravels.' 

 My chief aim was to obtain some evidence by which the relative 

 position of these beds in the Lower Cretaceous series might be 

 determined. The greater part of the fauna was so anomalous and 

 peculiar that it afforded little or no assistance towards this purpose, 

 and the only common fossil which gave definite promise of service 

 was the fragmentary Belemnites, which I found in unexpected 

 abundance. It is true that I had previously noticed a few specimens 

 among the Faringdon fossils in the Natural History Museum (from 

 the Caleb Evans' Collection) and in other public collections, and 

 had seen references to Belemnites in descriptions of the ' Sponge- 

 gravels '; but I went with the impression that its occurrence was 

 rare and exceptional, whereas I found that it could be collected 

 plentifully from every pit, though always in a more or less worn 

 and fragmentary condition, and generally encrusted with small 

 oysters, serpulge and polyzoa, and perforated by marine borers. 

 The scant attention which the fossil has hitherto received is 

 probalaly due to the prevalent opinion that it is dei'ivative from 

 the Jurassics, but this opinion is almost certainly erroneous, as 

 I shall now try to show. 



In the large number of specimens which I obtained only one 

 species appears to be represented, and this species cannot, I think, 

 be matched among Jurassic Belemnites. A careful comparison of 

 the form with my large collection of Lower Cretaceous Belemnites 

 from Speeton and Lincolnshire has satisfied me that all the specimens 

 collected or seen by me may be referred to the species figured and 

 described by Professor Pavlow ("Argiles de Speeton," pi. vii, figs. 13 

 and 14, and p. 88) as Belemnites Speetonensis. This species occurs 

 abundantly in the ' zone of Bel. Brunsvicensis ' at Speeton and in 

 Lincolnshire, and is indeed probably an offshoot or extreme variety of 

 the zonal species. In fragments of the thicker portion of the guard 

 the Faringdon specimens might be mistaken for Bel. lateralis, which 

 occupies a well-marked zone at or below the base of the Lower 

 Cretaceous in the north-east of England ; but when the pointed end 

 is preserved, the tapering outline, depth and slight grooving strongly 

 distinguish the species. The Speeton fossils are in a different state 

 of preservation ; but specimens of Bel. Speetonensis in my collection 

 from the Tealby Limestone of Lincolnshire so closely resemble the 

 best examples from Faringdon that if mixed without identifying 

 mai-ks they would be very difiicult to separate. 



I noticed a difference in the average size of specimens from 

 different pits at Faringdon which I thought at first might be of 

 import ; but a simple explanation of this distribution soon presented 

 itself. The Faringdon ' gravels ' have clearly been heaped together 

 as a current-swept bank on the old sea-floor ; and materials of 



