354 Bibliographical Notices. 



unfi equent, and in these cases we hare no means of knowing how soon 

 Mr. Clark might recur to his original view. 



We have already mentioned the ruthless manner in which Mr. Clark 

 destroys those genera which he considers to repose on mere concho- 

 logical grounds, and it was to be expected that the species would 

 share the same fate ; but we were hardly prepared for the wholesale 

 destruction of names which have long figured in our lists, that we 

 here meet with. There can be no doubt that science is burdened 

 with an immense number of false species, arismg in some cases from 

 a zeal not sufficiently tempered with discretion, in others perhaps 

 from less worthy motives ; but we must confess, that when we see the 

 number of species admitted by Forbes and Hanley, which have been 

 suppressed by Mr. Clark, we cannot but suspect that his pruning has 

 been carried on with rather too unsparing a hand. 



Mr. Clark appears disposed to attach but little importance to the 

 characters derived from the lingual dentition of the Mollusca, which 

 have been regarded as of great value by Loven, Gray, Troschel, and 

 other zoologists. AVe fear that Mr. Clark is as much inclined to 

 undervalue these characters, as some other authors are to over-rate 

 them, for there can be no doubt that the disposition and form of the 

 teeth on the lingual ribbon may afford excellent generic and even 

 family characters, besides serving as important aids in the discrimi- 

 nation of nearl}' allied species. 



Notwithstanding the defects pointed out in the foregoing remarks, 

 we must regard Mr. Clark's book as one of the most important 

 original contributions to British Malacology that has been made for 

 some time. It contains a vast mass of valuable obsei-vations, inclu- 

 ding descriptions of the animals of more than 200 of our marine 

 Testaceous Mollusca, with many interesting notices of their habits, 

 and will, we have no doubt, contribute greatly to the advance of this 

 branch of natural history. 



The Ferns of Great Bi-ifain. Illustrated hy John E. Sowerby. 

 The Descrij)tio7is, Si/noni/ms, ^-c. iy C.Johnson. London, 1855. 



AVe have favourably noticed the first two Numbers of this book, 

 which is now before us in its completed form. The more recently 

 published parts appear to deserve the same meed of praise that we 

 awarded to their predecessors. Indeed we trust that the name of 

 Sowerby ■will long continue to be in itself a guarantee of the accuracy 

 and beautv of such botanical plates as may bear it. Almost the only 

 fault that we have to find with these drawings of ferns is that in 

 some few cases the top of a frond alone is represented, and thus a 

 satisfactory idea of the plant is not conveyed to the mind. It will 

 perhaps be said that it was impossible in the space afforded by an 

 octavo plate to give more complete representations of the larger 

 plants ; but when we see how Dr. Deakin has succeeded in doing so 

 in his ' Ferns of Britain,' that excuse cannot be admitted. It is a 

 singular, and, as it seems to us, unaccomitable fact, that writers upon 

 our ferns have by a sort of common consent neglected Dr. Deakin's 

 volume. The only probable cause is, that the large work of which it 

 originally formed a part has but slight value. 



