./ 



155 



Lima pectenoides, Sow. TJnicardium cardioides, Phil. 



Liinea acuticosta, Gold/. Cardium tinincatum, Phil. 



Pinna folium, Phil. Cj^iricardia cucullata, Goldf. 



Pholadomya ambigua, Sow. Modiola scalpinim, Sow. 



Homomya (?) Ai-com5"a elongata, Roem. 



Pleuromya unioides, Poem. Cardinia crassissima, Sow. 



II rotundata, Goldf. Goniomya capiicomi, Wright 



II donaciforme, Goldf. Solen (?) 



Ceromya lineata, Williamson 



BRACHIOPODA. 



Terebratula punctata, Sow. Rhynchonella acuta, Soia. 



II resupinata, Sow. n tetrahedra, Sow. 



II comuta, Soiv. m variabilis, Schloth. 



ECHINODERMATA. 



Hemipedina Jardinii, Wright Pentacrinus subangularis. Mill. 



II quadrifida, LamcJc. Spii'ifera rostralis, Schloth. 



In the Sands above and below the Marlstone several thin seams of 

 fossiliferous bands occur ; some of those above the marlstone are highly 

 ferruginous, and full of the casts of small shells, of the same species as 

 many in our list. Cardium truncatum is found small, and in abundance, in 

 blocks obtained from the highest point of the marlstone on Dumbleton Hill. 



Zone of Ammonites sjiinatus. 



The Zone of Ammonites spinatus is here so closely united with the marl- 

 stone, that it appears to form its upper portion, lithologically, it is a light 

 coloured friable bed, containing many fossiliferous nodules. Arnmonites 

 spinatus, Brug. ; Belemnites brevlformis, Ziet. ; Lima Hermanni, Voltz. ; 

 Terebratula punctata and Spirifer rostratus, Schloth., are the prevailing 

 forms. 



THE UPPER LIAS. 



The Upper Lias caps the summits of Alderton and Dumbleton hUls, and 

 attains a thickness in these localities of 150 feet; the lower part of this for- 

 mation is exposed in the marlstone quarries, where it consists of beds of 

 stiff clay, about 30 ft. in thickness, divided by a band of large light-coloured 

 argillaceoiis nodules, containing many species of fishes and insects in 

 fine preservation, and called the Fish-bed. The fossils of this formation 

 are all specifically distinct from those of the marlstone on which it rests 

 conformably. The Ammonites of the group Capricorni are all absent 

 from these beds ; and in their stead have appeared gi-eat numbers of the 

 groups Falciferi and Plaijulati ; from the prevalence of one species 

 of tlie latter I have named this diA-ision of the LTpper Lias the Zone of 



