Vol. 69.] TWO DEEP BOEINGS AT CALVEET STATION. 321 



zone of the Itadstock district. Terebratula radstockensis and some 

 of the species of Rhynchonella tabulated below are no less charac- 

 teristic ; and, although the Spiriferina comes nearest to one which 

 is said to occur in the striatum zone of Cheltenham, and Hh.rimosa- 

 multiplicata is placed by Mr. Buckman as striatum-valdani, the 

 balance of evidence is decisive for the jamesoni zone. 



But the most interesting discovery in this basement-bed was 

 a derived fragment of Echioceras microdiscus (Quenstedt), a rari- 

 costatum-zone ammonite. That it is derived was shown by the 

 following facts, determined during extraction : — (1) It is the internal 

 cast of the body-chamber only, and as it lay in the rock there were 

 portions of the shell adherent in some parts and not in others ; 

 (2) the matrix of the cast was not the same as that of the rock 

 around; (3) it was standing vertically. AVe have here, then, con- 

 ditions very similar to those known at various places near Badstock r 

 where derived raricostatum-zone ammonites are found at the base 

 of the armatum zone. 



It is important to notice that the small thickness of Lias in this 

 boring is due to the absence of many zones, not to the thinning of 

 those that are present. The thickness of the zones represented is- 

 normal; indeed, it is if anything greater than might have been 

 expected — greater than that of the same zones at Lyme liegis, for 

 example. 



List of Fossils from the Lias — Domerian* and Ciiarmoutiiian — 

 algotiaxvm to jamesoni zones. 



[* Iii the collection of H.M. Geological Survey. 1" In the collection of 

 Dr. A. M. Davies.] ' 



From an unknown depth, probably between 203 and 210 feet (algovianivm 

 zone) : — 



\Cristellaria sp. , fNucula cordata (?) Goldfuss. 



*\Chlamys sp. (immature, maximum *\Nttculana cf. quenstedti (Tate). 



length =5\o mm., showing abrupt *Amaltheus sp.cf.de-/rresstts (Simp- 

 change from smooth to costate son) and clevelandicus (Young & 

 at 33 mm. from the umbo). Bird). 

 * Goniomya hybrida (Munster), or 

 Gr. heteropleura Agassiz. 



At 210 feet ? (algovianum or capricornus zone ?) : — 



'[Area or Cucullcea 9p. 

 t Goniomya hybrida (Munster) or 

 67. heteropleura (Agassiz). 



\Nuculana cf. quenstedti (Tate). 

 iPseudomelania (!) sp. (young). 

 '[Turbo sp. (young). 



At 230 feet (probably capricornus zone) :— 

 fNucula cordata (?) Goldfuss. ] •\Xuculana cf. quenstedti (Tate). 



At about 300 feet (striatum zone) : — 



flsocrimis, columnals. 

 fNuculana cf. quenstedti (Tate). 

 •\Androgynoceras hybrida (d'Orbigny), 

 Capricorn stage. 



\Belemnites, phragmocone of a hir; 

 species. 



