266 



J. F. BLAKE AND W. H. HTJDLESTON ON 



Chernnitziaheddingtonensis ( Sow.). 

 Phasianella Buvignieri {D'Orb.). 

 Natica corallina {Damon). 



clytia {D'Orb.). 



Opis corallina {Damon). 



Phillipsi {Mor.). 



Lucina Moreana {Buv.). 

 Trigonia clavellata {Sow.). 

 Hudlestoni {Lye). 



Sowerbya triangularis {Ph.). 

 Tancredia planata {M. Sf L.). 



disputata {Bl. §• H.). 



curtansata {Phil.). 



Cucullaea contracta {Ph.). 

 Lima subantiquata {Rom.). 

 Pecten qualicosta {Et.). 

 Echinobrissus scutatus {Lam.). 



The Phasianella, Sowerbya, Tancredia, Lima, and Pecten are the 

 most noteworthy fossils in this list, as being very characteristic of 

 these beds, and yet recalling the facies of more ancient oolites. 



The series which follows and concludes, in an ascending order, 

 the more calcareous portion of the Corallian beds iD this district 

 is one of extreme importance, no less by the abundance of its 

 fossils than by the lithological characteristics which approximate 

 it most nearly to that class of rock which might fairly be called 

 " Coral Rag." On account of the abundance of Trigonia clavellata, 

 we have called these the " Trigonia-beds " of Weymouth. Although 

 they present no very constant lithological characters throughout 

 the range, there is no difficulty in identifying the equivalent bed, 

 especially as it is almost everywhere overlain by at least some 

 recognizable thickness of more argillaceous beds. In descending 

 order, we may describe the section exposed on the coast near Wey- 

 mouth as follows : — 



Section of Trigonia- beds near Weymouth. 



ft. 



1 . Rubbly gritty limestone, formed of a mass of shells, 



chiefly Trigonia clavellata and Gervillia avicu- 

 loides, but witb many others, in several beds with 

 hummocky irx'egular surfaces and marly partings, 

 becoming less fossiliferous below 9 



2. Strong limestone band with a few Trigonioe only... 1 6 



3. Harsh suboolitic grits, showing, on weathering, 



ramose projections in moderate relief. Myacites 

 numerous, A Nerin(sa-hed about 7 ft. down. 12 



4. Numerous irregular, blue-weathering, rather im- 



pure limestones in hummocky masses, full of 

 shell-structure 6 



28 6 



The following fossils have been found by us in the Trigonia- 

 beds of Weymouth or Osmington. 



Fossils from the Weymouth Trigonia- beds. 



Ammonites cordatus {Sow.). 



, sp. (cf. eupalus, D'Orb.). 



Belemnites (narrow form). 

 Chemnitzia heddingtonensis {Sow.). 



, sp. {cf. rupellensis, D'Orb.). 



Nerinaea Groodhallii {Sow.). 



fasciata ? ( Voltz.). 



Desvoidyi {D'Orb.). 



Cerithium muricatum {Sow.). 

 Alaria Deshayesea {Buv.). 



seminuda {Heb. cf Desl.). 



Natica corallina {Damon). 



clytia {D'Orb.). 



Nerita lninuta {Sow.). 

 Littorina pulcherrima {Do/If.). 

 Turritella jurassica {Qu.). 



