BaciUaria.] the infusoria. 191 



united, which are connected with the next pair by two 

 processes, a small space being left between them (see 

 engraving fig. 108), and hence they differ from the genus 

 Desmidium. The internal coloured granular matter is 

 probably ova ; and the three vesicles in O. filiformis, 

 stomach cells and fecundating glands. In O. unidentata, the 

 glandular body is very distinct from the digestive sacs. 



187. Odontella desmidium is shewn magnified at 

 fig. 108 ; the space between the processes of each pair is 

 distinct. Found amongst conferva. Size 1-1 150th to 

 1-5 70th. 



188. Odontella? filifo7'mis (Tessararthra filiformis). 

 The filiform Odontella. — Figure 107 exhibits a chain-like 

 group magnified ; the two slender processes connecting 

 each pair leave a square space between them. Size of 

 single member l-2010th. 



189. Odontella? unidentata. The one-toothed Odon- 

 tella has oval binary corpuscles, often irregular ; they are 

 connected by a single tooth or process in the middle. 

 Size of member l-1440th. 



Genus LIT. Micrasterias. The little star Animal- 

 cules are characterized by their members being free, by 

 their having a simple compressed lorica, composed of one 

 piece, and grouping themselves together in definite num- 

 bers, in the form of a flattened star. The latter generic 

 character arises from incomplete self-division when they 

 are young, like Gonium. Projecting organs of locomo- 

 tion have not been observed, though slow change of place 

 has been noticed. Numerous vesicles, analogous to poly- 

 gastric digestive cells, are seen in several species ; ova-like 

 green granules are abundant; and Ehrenberg states he 



