332 Correspo7idence — Mr. C. Callaicay. 



End to Weston-super-Mare the raised beaches are more or less 

 covered with " Head," which often contains large and undoubtedly 

 ice-borne boulders. Under the raised beaches of the W. coast of 

 Cornwall and Devon, traces of an older deposit with ice-borne 

 boulders may occasionally be seen, as I have been informed by Mr. 

 Whitley of Truro, who has had very extensive opportunities of ob- 

 serving these phenomena. The raised beaches themselves sometimes 

 contain very far transported erratics (washed out of an older 

 glacial deposit ?). 



In answer to H. E. H., it ought to be remembered that, in Sir H. 

 de la Beche's day, the effects of glacial action were but little under- 

 stood, and it is probable that he never saw sections of curved 

 laminae like those which of late years have been exposed by exten- 

 sive quarrying and mining operations. 1 would refer H. E. H. to 

 the very able defence of the glacial origin of persistently curved 

 laminae by Mr. Tiddeman in the Q. J. G. S. vol. xxviii. p. 480. 



D. Mackintosh. 



ON THE FAUNA AND AGE OE THE SHINETON SHALES. 

 Sir, — I was glad to see in your April issue a letter by Dr. Lin- 

 narsson on the Trilobites of the Shineton Shales, as I am desirous 

 that my conclusions should be tested in every possible way. I have 

 carefully reviewed every detail to which he has suggested exception, 

 and beg to submit a brief reply to his criticisms. His statements 

 are the following. 



1. Conocoryphe monile is more nearly related to Angelin's genus 

 Euloma than to Conocoryphe striata. 



To this I demur. Euloma is described by Angelin as covered with 

 a smooth crust, and with pJeurce acute, and bent back at the ends. C 

 monile has a granular surface and blunt pleuree. I submit that these 

 are more important characters than the " strongly-lobed glabella 

 and the dotted marginal furrow," in which C. monile is supposed to 

 resemble Euloma. C. striata is larger than C. monile, has the glabella 

 more conical, and with a third pair of side furrows, and has the 

 frontal margin undotted, but on the whole the two species are of the 

 same type. 



2. Lichapyge is more closely allied to Bemopleurides than to 

 Lichas. 



To this also I cannot agree. Dr. Linnarsson assumes that in my 

 genus the " two hindermost thoracal segments " are united with 

 the pygidium. If he were to examine my specimen, he would see 

 that it consists of one undivided piece, and is therefore a pygidium 

 only. This being so, it cannot be related to Bemopleurides. It re- 

 sembles Lichas in the number of segments (three), and in the shape 

 of the pleuree ; but differs in the telson, which in Lichas ends in two 

 denticles, while in Lichapyge it forms a broad sword-like blade with 

 a central point. 



3. Platypeltis is more nearly related to Niobe than to the typical 

 Asaphi. 



I myself called attention to this point on page 659. 



