A New Species of Lima from the English Chalk. 311 



limited, strongly marked with eighteen radiating grooves. 

 The grooves are uniformly distinct throughout. 



Surface of shell with pronounced lines of growth forming 

 fairly distinct peripheral grooves. Throughout the surface 

 fine linear striae with pits occur, though these are more pro- 

 nounced on the margins of the valves. The striae are slightly 

 wavy, occasionally discontinuous, and are deeper near the 

 posterior margin. The pits average four to the millimetre. 



Measurements : — Length, 50mm., height, 33 mm. 



Affinities : — This species appears to be very markedly 

 distinct in shape from any other of the Cretaceous Limidae, 

 and seems most nearly to resemble Lima hoperi, which has 



Lima (Plagiostoma) middletonensis n.sp. 



a wide range in the south of England, and is found in the 

 same quarry as that from which the new species was obtained. 

 L. middletonensis is distinguished at once from L. hoperi by its 

 extreme anterior development and by its much more oval 

 contour. 



Type : — In the Hull Municipal Museum. 



Distribution : — Base of the Micraster cor-anguinum zone, 

 Middleton-on-the-Wolds, East Riding of Yorkshire. 



-: o 



Thecosmilia sp. in the Millepore Oolite of South Cave. 



— Some weathered slabs of Millepore Oolite recently obtained 

 from the cutting west of South Cave railway station were 

 covered by a large coral. Mr. Lang, of the British Museum, 

 has kindly examined these and refers the species to Thecosmilia, 

 though specific determination was difficult on account of the 

 condition of the specimens. In any case, this seems to be an 

 addition to the fauna of the Yorkshire Millepore bed. — 

 T. Sheppard. 



3 917 Oct. 1. 



