134 Bibliographical Notices. 



''^' Exmouth, July 18. 



Since the above was written I have taken two examples, one 

 this morning, of the smoothest variety of the ' convexum/ late the 

 'nitidum^ ; both are in the vase with the highly punctured one 

 captured 20th June last, now quite vigorous, in company with 

 the L. squamosum alluded to as taken 2nd July ; this capture 

 has given me the advantage of a live examination of the two 

 completely opposite conditions of the ^ conveccum/ whereas the 

 one above was only referable in comparison with an account of 

 a live ' nitidum ' taken last year. And I can again state that the 

 two varieties are identical. 



Lepton Clarkia (nova species). 



Annals Nat. Hist. New Series, vol. ix. pp. 191 & 293. 



The above references give every particular of the shell of this 

 new species, of which it is probable I may detect the animal ; but 

 the hinge is so completely identical with that of the L. convexum, 

 that it may be presumed its organs will not greatly differ from it. 



: . I am, Gentlemen, your most obedient servant, 



'^^'^'' William Clark. 



BIBLIOGRAPHICAL NOTICES. 



A History of Infusorial Animalcules, Living and Fossil. 

 By Andrew Pritchard, M.R.I. 8vo, pp. 704. Whittaker & Co. 



A NEW edition of the only English version of the laborious investi- 

 gations which have made Prof. Ehrenberg's name famous among 

 micro-naturalists (if we may for the nonce coin a word as good as 

 micro-mammalogists), must be looked upon as a praiseworthy and 

 creditable undertaking. 



So far as mere facts are concerned, so many have accumulated 

 during the fourteen years that have elapsed since the publication of 

 the great work, to which we have been indebted for the first im- 

 pulse to investigation, and for the first guidance in the confused 

 and difficult task, that the gathering them into one place, and making 

 them all accessible to the English reader, is a service of no small 

 merit. 



Again, however much Prof. Ehrenberg may condemn them as 

 heretical, it is indubitable that a large body of Fathers of greater or 

 less authority have added their writings to his Canon. Indeed, they 

 have not unfrequently ventured to impugn and protest against the 

 statements of the head of the church microscopical himself. 



Mr. Pritchard has with a laudable eclecticism gathered all these, 

 wheat and tares, poppy and clover, into one sheaf (a very consider- 

 able sheaf too) ; but thrashing and winnowing is evidently in his view 



