32 PBOCEEDINGS OP THE GEOLOGICAL SOCIETY. [Apr. 6, 



one of the most persistent fossiliferous bands in the coast-section, 

 and may be traced continuously from Cloughton Wyke to Peak Point, 

 as we sail along the shore. It forms an anticlinal at the south side 

 of Cayton Bay and at Eed Bock Point. At Cloughton Wyke it is 

 well exposed, where it measures about 10 feet. The lower portion 

 is shelly and ferruginous, and emits a sulphurous odour ; and from 

 this part of the rock Mr. Leckenby has collected the following species 

 of Mollusca. 



Fossils from, the Millepore-bed in Mr. LecJcenby's Cabinet. 



Natica adducta, Phil. 

 Nerita pseudocostata, d' Orb. 

 Chemnitzia yetusta, d! Orb. 

 Turritella quadrivittata, Phil. 

 Alaria Phillipsii, Lye. 8f Mor. 

 Turbo elaboratus, Bean. 

 Actseonina glabra, Phil. 

 Cerithium Leckenby i, Wr., sp. n. 



Pecten Saturnus, d' Orb. 



demissus, Phil. 



Lima duplicata, Sow. 

 Gervillia lata, Phil. 



Hartmanni, Goldf. 



Pinna cancellata, Phil. 

 Mytilus tumidus, Lye. 8f Mor. 



Modiola irabricata, Sow. 



cuneata, Sow. 



Leckenbyi, Mor. 



Trigonia angulata, Sow. 

 Cardium striatulum, Phil. 

 Astarte minima, Phil. 

 Pullastra recondita, Phil. 

 Unicardium gibbosum, Lye. 

 Pholadomya Heraulti, Ag. 



Ssemanni, Lye. 8f Mor. 



Myacites oblonga, Wr., sp. n. 



decurtata, Phil. 



Ceromya Bajociana, d' Orb. 

 Gresslya adducta, Phil. 

 Pholas costellata, Lye. 8f Mor. 

 Goniomya literata, Sow. 



The Millepore-bed attains a considerable development at Crome- 

 beck and Whitwell, near Castle Howard station, on the York and 

 Scarborough railway, where it is a thick-bedded oolitic limestone, 

 resembling the freestones of the Inferior Oolite in Gloucestershire. 

 The rock has long been worked at Cromebeck for economic purposes, 

 and is admirably exposed in an extensive range of quarries. The 

 limestone of the Inferior Oolite is here overlain by a soft greyish 

 sandstone, about 6 feet thick, which forms the uppermost bed ; 

 beneath this is an extremely hard, siliceous, slaty sandstone, 18 inches 

 thick, which represents part of the " Block-sandstone," No. 3 of 

 the Peak, and caps the thick-bedded oolitic limestone, which is the 

 inland representative of the Millepore-rock of the coast-section. 

 The cream-coloured oolitic limestone dips to the north at an angle 

 of 2°, and is in some parts composed of large grains, in others of 

 small, and in others it is soft and fine-grained. In lithologieal 

 character, the rock and its bedding resemble the thick-bedded 

 freestones of the West of England. Its upper beds, from 10 to 12 

 feet thick, are quarried for building- stone, and burned for lime ; and 

 the lower portion is a grey oolitic limestone, which is largely quar- 

 ried for road-material. It attains a thickness of 10 feet, and rests 

 upon a hard dark-blue shale, No. 2 of the Boring- section. I have 

 prepared the following list from a series of specimens obtained from 

 this rock by my friend W. Peed, Esq., of York, and contained in his 

 collection. I found several of the species in situ during the excur- 

 sion which I made to the quarries in August last. 



