386 



SOME NEW BOOKS. ■ 



Coal-Measure Molluscs. 



A Monograph on Carbonicola, Anthracomya, and Naiadites. Parts I., II., 

 and III. By Wheelton Hind, M.D. Pp. i8i, xxi. pis., circa 600 figg- 

 Palaeontographical Society, 1894-1895-1896. 



The present Monograph deals with the genera, better known by the 

 names of Anthracosia, Anthracomya, and Anthracoptera. While confined 

 to a description of British species, its author has explored various 

 continental museums, in order to determine the identity of species 

 recorded by European writers, and a critical bibliography of twenty- 

 four pages deals with the literature relating to the subject from the 

 year 1720. This bibliography illustrates how often unnecessary 

 labour has been undertaken by authors unacquainted with the 

 literature of their subject. It is on the whole a valuable contribution, 

 though some of the comments on previous authors will not meet with 

 general acceptance. 



The replacement of " Anthracosia "by " Carbonicola " is regrettable 

 on account of the wide-spread use of the former. It is questionable, 

 also, whether it can be supported on strict grounds of priority. King 

 put forward the term "■Anthracosia,'" in 1844, for "a group of 

 Unionidae characteristic of the Coal Measures," but neither described 

 nor figured specimens. It was a " preliminary notice " of the worst 

 sort, and was not recognised by McCoy when, in 1854, he proposed 

 the name of " Carbonicola " for the same group. McCoy failed, 

 however, to understand the genus he described, and his diagnosis 

 could only have been drawn up from specimens of other genera from 

 a younger formation. This was pointed out by King, who repudiated 

 the genus as in any way relating to the Coal- Measure Unios known to 

 him, which he then described in detail and correctly. Dr. Hind agrees 

 in the main with Professor King upon the question of McCoy's 

 faulty diagnosis. McCoy failed to publish figures of any species of 

 his genus, and under the circumstances it would seem better to have 

 taken King's later paper of 1856 as the starting point, and to have 

 retained Anthracosia, the diagnosis of which was clear and good. 



Before entering upon a description of the various species of 

 Carbonicola, the author defines what he regards as a species. He has 

 felt it necessary " to give specific rank to any forms which seemed to 

 be typical of a bed ; in other cases, when in the same beds a series 

 of varieties occurred, to include them under one species." This seems 

 a curiously retrograde step — ^specific character is made a resultant of 

 stratigraphical position, just as in the old days of cataclysms and 

 creations, and a check is thus placed on all endeavours to work out 

 the development of a genus and the mutual relations of its forms. 

 Moreover, this has not even the effect the author aims at, viz., " as an 

 aid to determine the horizons," for that which is defined by a horizon 

 cannot also define a horizon. The only excuse for this course would 

 be some proof that all the " varieties " included in the same bed 

 were derived from a common stock ; but the author neither defines 



