98 



YORKSHIRE TYPE AMMONITES. 



Yorkshire Type Ammonites, edited by S. S. Buckman, part I., pp. i-xii, 

 i.-ii., 12 plates, and Descriptions Nos. i-8._ London : Wesley & Sons. 3/6. 



One of the greatest difficulties a geologist has to encounter is the identifi- 

 cation and proper naming of his specimens. In the case of Liassic Am- 

 monites, which have long been keenly sought by collectors, this difficulty 

 is a very serious matter, and, as was shewn by Mr. C. Thompson in these 

 pages recently, even the generally accepted names to the common forms 

 are often wrong. This state of things is partly due to the fact that the 

 first descriptions of the species given by Simpson, were published without 

 illustrations ; partly owing to a confusion of somewhat similar forms, and 

 partly because one writer has copied the errors of another. Mr. Buckman, 

 however, has gone to the fountain head. Simpson's types are still pre- 

 served in the Whitby Museum. These have been examined, and compared 



Ammonites polyopbyllus, Simpson, 1843. 

 Lias, Whitby. 



with the original descriptions, and photographs have been taken by Mr. 

 J. W. Tutcher. In each case the original description is reprinted, and 

 additional details and remarks are supplied by the editor. There, together 

 with the very fine reproductions from photographs (with sketches of the 

 suture lines, etc.), give all that anj'one can desire. On the completion of 

 Mr. Buckman's monograph, the identification of Liassic ammonites will 

 be, for the first time, a comparatively easy matter. The species figured in 

 part I. are Ammonites reticularis, ripleyi, aureus, mulgravius, exaratus, 

 resiipinatiis, dennyi, polophylliis, alternatus, subconcaviis and boulbiensis. 

 One of the smaller illustrations we are permitted to reproduce herewith. 

 In view of the number and excellence of the plates, the price is very- 

 reasonable. 



Naturalist, 



