Prof. Ehrenherg's Researches on the Iiifusoi-ia, 91 



It is remarkable that, of these 57 species, there are only 7 

 which belong to genera not found in Europe, and that each of 

 these species forms the type of a distinct genus, in none of which 

 more than one has yet been found, viz. 



Another singular fact exhibited by this table is, that on no 

 one point of observation has more than two species of one genus 

 been discovered. Only the genera Trichoda and Cyclidium 

 present four species ; all the others less, and by far the greater 

 number only one. 



The following species are those characterized by the greatest 

 geographical extension. 



Anguillula fluviatilis, Stations III. & VII. 



Monas termo, III. VI. & VII. 



glaucoma, III. & X. 



Paramaecium.Chrysalis, i. IV. IX. & X. 



We shall now present a similar analysis of M. Ehrenberg's 

 Russian observations. Notwithstanding the rapidity of his jour- 

 ney, he succeeded in establishing differences among the infusoria 

 of no less than 21 different points of this vast empire, in the 

 Northern Urals, the Siberian Steppe, the shores of the Caspian, 

 and the Altai range, even to the Chinese Dzungarei : 



I. Salt Lake of Kurotschkinsk near Astrachan ; tvater examined in 

 Astrachan. 46° N. Lat. 66° E. Long. ?— 1 Form. 

 Monas erubescens, n. sp. . . . . i '" 



11. Buchtarma, in the Altai Mountains, on the Irtysch. 

 101° E. Long — 6 Forms. 



Bacillaria elongata, n. sp. 

 E. Diglena capitata, n. sp. ? 

 E. Monas mica, Muller, 

 E. Navicula fulva, 

 E. gracilis, n. sp. 



- .•• ■ fusiformis, n. sp. 

 I ventricosa, n. sp. 



49° N. Lat. 



37 

 T55 



