ig6 CLASSIFICATION OF THE INFUSORIA. 



year 1841, is mostly notable for the distinction given to the Flagellate 

 section of the Infusoria, many members of which, bearing new generic titles, 

 were now for the first time figured and described with considerable accu- 

 racy. These Flagellata, while included in Order III. of his classificatory 

 system given at page 202, were not, however, invested with any specially 

 distinctive title. 



C. T. Von Siebold's scheme, reproduced at page 203, bearing the date 

 of 1845, and already referred to at length at page 20, is chiefly remarkable 

 for its subdivision of the Infusoria into the two primary groups of the 

 Astomata and Stomatoda ; the former including the Opalinidae and all 

 the Flagelliferous types, and the latter all the ordinary Ciliata. 



The next system demanding notice is that of Maximilian Perty, em- 

 bodied in his work ' Zur Kenntniss kleinster Lebensformen,' published in 

 the year 1852. In this treatise marked progress is made upon the classifi- 

 catory schemes previously noticed. The entire series of infusorial forms 

 are included in one primary sub-kingdom designated the Archezoa — in 

 all essential respects synonymous with the Protozoa of Von Siebold — and 

 its representatives separated into the primary sections of the Filigera or 

 Phytozoida and Ciliata, which practically correspond with the Flagellate 

 and Ciliate subdivisions as recognized at the present day. Twenty-six 

 family and one hundred generic groups are comprehended in Perty's classifi- 

 catory table (see pages 203 and 204), the number of species incorporated 

 falling short, however, of that made known by Ehrenberg. 



Claparede and Lachmann's extensive work, ' Etudes sur les Infu- 

 soires,' published as a complete treatise in 1868, but which had previously 

 appeared as separate contributions to the ' Memoirs of the Institute of 

 Geneva' during the years 1858 to i860, next demands attention. In 

 this for the first time we find the Infusoria definitely restricted to the 

 limits within which they are circumscribed in this volume, the leading sub- 

 divisions of the entire series included closely corresponding also, as shown 

 at page 205, with those here accepted as affording the most convenient 

 and natural arrangement. By promoting, in point of fact, the three orders 

 of the Infusoria distinguished by these authorities by the titles of the 

 Flagellata, Suctoria, and Ciliata, to the rank of classes, retaining meanwhile 

 their fourth group of the Cilio-Flagellata as a subordinate order only of 

 the class Flagellata, the main basis of arrangement of the extensive series 

 of forms noticed in this treatise is at once arrived at. It is to be re- 

 gretted that Messrs. Claparede and Lachmann did not bestow upon the 

 ordinary Flagellate division the same attention which they gave to the 

 three remaining groups. But two or three forms only referable to this 

 important section are described, the order as recognized by them not being 

 even so much as tabulated. The most important improvements upon the 

 earlier classificatory schemes accomplished by Messrs. Claparede and Lach- 

 mann, consist of the introduction of the two groups of the Suctoria and 

 Cilio-Flagellata, the former being compounded chiefly of forms previously 



