46 MICROSCOPIC OBJECTS. 



for verification of some special organ or system, little 

 interest to the general observer. The forms, flutings 

 and sculpture of the loricated Infusoria are on the con- 

 trary always of deep interest. The chief localities from 

 which the fossil shells of Infusoria have been obtained 

 are given in the Catalogue. In these deposits it is usual 

 to meet with specimens of several genera together. 

 The relative numbers of each genus found in a deposit 

 afford much information as to its period ; while the state 

 of their preservation unfolds to us the conditions of dis- 

 turbance under which the strata were formed. 



It would be out of place here to enter into a detailed 

 account of these numerous and interesting creatures, 

 especially as the public are in possession of more than 

 one illustrated work on the subject of Infusoria. The 

 first work wholly devoted to the Natural History of Ani- 

 malcules was that by Mr. Andrew Pritchard, which 

 appeared in 1834. In 1838 Dr. Ehrenberg published 

 his large work on this subject, entitled ' Die Infusions - 

 thierchen,' price 18 pounds. In 1841 appeared the first 

 edition of Mr. Pritchard' s larger work entitled 'His- 

 tory of Infusoria, Living and Fossil,' with coloured plates, 

 price 30 shillings, or with uncoloured plates price 12 

 shillings. For those who do not wish to enter into the 

 minutise of this subject a separate publication of the First 

 Part, or * General History of Animalcules,' together with 

 all the engravings, may be purchased for five shiUings. 

 To these works and Dr. ManteU's ' Thoughts on Ani- 

 malcules,' the reader is referred. 



