Bibliographical Notices. 289 



freshwater shells which have been erroneously, as he believes, in- 

 troduced into the British list, with his reasons for their exclusion ; 

 an outline of the geographical distribution of the native species, both 

 with reference to other parts of the world and to the topographical 

 divisions of our own country, accompanied by a tabular view ; no- 

 tices of the localities which different species select ; an enumeration 

 of the fossil species belonging to land and freshwater genera that 

 have been hitherto discovered in Great Britain ; an historical review 

 of the additions made to this department of our Fauna by each suc- 

 cessive writer from Merret downwards ; and a list of the British and 

 of the principal foreign works treating on the subject. 



An " Artificial 7\ibleofthe Genera" constructed for the use of the 

 mere conchologist who confines his observations to the shell, is fol- 

 lowed by some observations on the principal points to be attended 

 to in the description of shells, founded on their relation to the ani- 

 mal, with reference to which alone they can be properly studied ; 

 and we then arrive at the more strictly Systematic pait of the work, 

 the only part in which any portion of Dr. Turton's ' Manual' has 

 been retained. But even here all that has been derived from the 

 original work consists of the mere characters and descriptions of the 

 shells, with a few occasional observations, all of which have under- 

 gone revision ; while the outline of the distribution of Mollusca, the 

 characters of the classes, orders, families, and genera ; the descrip- 

 tions of the animals ; the physiological and other notices accompany- 

 ing these descriptions, &c. &c., which constitute the chief value of 

 the work, have been added by Mr. Gray. 



The number of species described amounts to 128, arranged under 

 38 genera; and all of these with one exception (Vertigo angustior, 

 which, as the author states, could not be procured) are figured iu 

 the plates, supplementary tables containing the more recently disco- 

 vered species having been added to those previously contained in 

 Dr. Turton's work. The original plates have also, it is stated, been 

 revised, compared with the specimens, and corrected where neces- 

 sary ; and enlarged details of some of the smaller species have been 

 added. Woodcut illustrations representing the animals of the dif- 

 ferent families and of most of the genera, together with a few of the 

 shells, have also been introduced in the form of vignettes ; and the 

 work is got up in a handsome and creditable style. 



It would be superfluous to recommend such a work and so edited 

 to those for whose use it is intended, and to whom it can only be 

 necessary to indicate its existence and its contents. 



Ann. Nat. Hist. Vol.5. No. 31. June\%i.O. x 



