131 



abound, while they have only been met with sparingly at Half 

 Way House and Bradford Abbas. 



These sinistral examples from Coker are accompanied by a 

 large series of dextral univalves, which are common at Bradford, 

 such as species of Amberlya, Pleurotomaria, Turlo, and others, 

 whilst the bivalves can all be referred to our Dorsetshire 

 sections. 



DESCRIPTION OF SINISTRAL SHELLS. 



CIBBTJS LEACHI, Plate of Sinistral Shells, f. 1 and 2. 

 ,, LEACHI, Miller's M.S.S. 



Shell conical, longitudinally striated, whorls many, with 

 several rows of tubercles crossed by numerous small carina ; upper 

 row of tubercules spinif orm, compressed.* 



The lower whorl of this shell, though larger than the spire 

 whorls, has not that disproportion which occurs in the C. nodosus. 

 The spire consists of six whorls, in which it diifers from C. inter- 

 medius, which has as many as nine upper whorls, forming an 

 acute spire upon only a slightly enlarged lower whorl. 



This fossil occurs occasionally at Bradford Abbas, but is some- 

 what common at Coker, near Yeovil. Sometimes it has long 

 spiniform tubercles as figured by Sowerby, but we have not met 

 with a specimen with the spines so pronounced. Fig. la, probably 

 has the spines a little worn- 



CIKETJS NODOSTJS, pi. f 3 and 3a. 



Shell conical, acuminated, or discoid with an acuminated 

 spiral umbo : spire reversed ; whorls many ; with two rows of 

 longitudinally extended tubercles, crossed by numerous small 

 carinse.f 



This shell has a equat spire of about six whorls proceeding 

 from a much enlarged outer whorl a character which, when 

 united with the extended tubercles reaching down the sides from 



* See Sowerby's Min. Conch., vol. 3, p. 36. 

 f Ibid, vol. 3. p. 35. 



