454 



PKOCEEDINGrS OP THi; GEOLOGICAL SOCIUTY. [May 24, 



as seventeen pipes may be counted, as shown 

 in jfig. 4. They vary in width from 6 feet to 

 50 feet. Some of them in the quarry are seen 

 to be 30 feet deep ; and of course as no signs 

 of their ending off are seen, they go down 

 deeper : one has been proved to be at least 50 

 feet deep. 



In the Iguanodon-quarry, belonging to Mr. 

 Bensted, some good examples of small pipes 

 are seen, one of which is shown in fig. 5. 



The organic remains found in the brick- 

 earth resemble those obtained from the gravel. 

 Eemains of the following Mammalia have been 

 found * : — 



Elephas primigenius, 



Rhinoceros tichorhinus, 



Cervus, 



Equus. 

 The brick-earth t has also been found to 

 contain the following shells, kindly determined 

 by Mr. Etheridge : — 



Helix fulva (MuUer), 



hispida (?), Linn. 



Pupa muscorum, Pfeiffer. 



Succinea oblonga, Brap. 



Zua subcylindrica, Limi. 



Pisidium or Cyclas. 

 This Pisidium or Cyclas was found by our 

 colleague, Mr. T. M^K. Hughes. 



Pipes similar in character to those of our dis- 

 trict are of frequent occurrence in limestone 

 strata. To account for them, two theories 

 have been brought forward. Mr. Trimmer, in 

 numerous papers in the Society's Journal, 

 argued that the pipes had a mechanical origin. 

 Dr. Buekland, Sir Charles Lyell, Mr. Prest- 

 wich, Mr. Kirkby, and others have upheld the 

 notion that the pipes were produced by the 

 slow dissolving action of water charged with 

 carbonic acid. This view is now so generally 

 adopted, and is so entirely consistent with ob- 

 served facts, that it is unnecessary for us to 

 enter very minutely into the matter. We will 

 therefore content ourselves with referring for 



* Mr. Bensted (' Geologist ' for 1862) mentions 

 Hippopotamus as occurring in the brick -earth; and 

 Prof. Owen gives Hycena upelma (Brit. Fos. Mam. 1846, 

 p. 151). 



t See also the paper by Prof. Morris, Mag. Nat. 

 Hist. vol. ix. 1836, p. 593, where lists of fossils are 

 given. 



&i 



