Correspondence — Mr. Lydekker — Dr. Callaway. 45 



were in the most confidential communication relative to our various 

 works on the Crinoids, especially the one now in progress. We 

 always interchanged advance sheets of our publications, and some- 

 times sent each other manuscript for examination and criticism. 

 Carpenter was always the soul of honour in regard to information 

 derived from these private communications, and was generous to the 

 last degree in giving information from his great store of learning, 

 whose value none could estimate higher than we. I should be very 

 glad to know of any publications in England in recognition of his 

 merits. 



Hoping this will find you very well, believe me always, very 

 sincerely yours, 



Las Vegas, New Mexico, Frank Springer. 



November I5th, 1891. 



"ANiSrALS OF BRITISH GEOLOGY" FOR 1890. 

 Sir, — It is not my intention to make any comments on the criticisms 

 which the compiler of the volume bearing the above title has thought 

 fit to introduce into the notices of my papers, as those who have 

 even the most superficial acquaintance with the subject therein 

 treated will be able to appreciate the value of such criticisms. 

 When, however, I am deliberately charged with making a blunder, 

 which exists only in the mind of the compiler, it is time to say 

 something. In noticing the fourth part of my " Catalogue of Fossil 

 Eeptilia and Amphibia," the compiler of the work in question goes 

 out of his way to state that I have changed the names Orthocorta to 

 OrtJiopleurosaurus without giving any reason for so doing. Now 

 (without commenting on the circumstance that he had the reason for 

 this change staring him in the face), if the compiler had taken the 

 trouble to look at the notes at the bottom of the page, he would 

 have seen after the reference to the name Orthocorta, the word 

 "Hybrid." E. Lydekker. 



UNCONFORMITIES BENEATH THE CAMBRIAN QUARTZITES IN 

 SHROPSHIRE. 



Sir, — In the Geological Magazine (1891), p. 485, is a paper by 

 the Rev. J. F. Blake, in which he challenges some of my criticisms 

 on his work in Shropshire. His chief assertions are the following : 



(1). That at Pontsford Hill the Longmynd Rocks in contact with 

 the Rhyolite are altered. 



(2). That at Narnell's Rock there is an unconformity separating 

 Cambrian from " Monian " rocks. 



(3). That at Charlton Hill the conglomerates and grits are super- 

 ficial, and are not a part of the Uriconian series. 



Paper-contests in geology are rather unsatisfactory work, and I 

 therefore propose to attempt a settlement of these disputed points, 

 and any others that may be agreed upon, in the following manner. 

 A competent geologist, to be selected by Mr. Blake and myself, to 

 visit the ground in our company, and to publish his conclusions. 

 The disputant who is convinced of his error to publish his re- 

 cantation. The disputant against whom the referee decides in the 



