Besmdieie.] infusorial animalcitles. 293 



probably ova, and the three vesicles in 0. filiformis, stomach cells 

 and fecundating glands. In 0. unidendata, the glandular body is 

 very distinct from the digestive sacs. (See OdonteUa in next section.) 

 Odontella desmidium. — Space between the processes of each pair 

 distinct, (see f. 108.) Size l-1150th. to l-570th. (See page 242.) 

 0. (?) filiformis. — The two slender processes connecting each pair 

 leave a square space between them. (f. 107. See page 243.) 



0. unidentata. — Oval binary coi-puscles, often ii-rcgular ; they are 

 connected by a single process in the middle. (See page 243.) 



Genus Gymxoztga (Ehr.) — Generic characters assigned to it by 

 Ehrenberg, unknown. 



G. moniliformis. — Corpuscles ovate, concatenate, forming a filament, 

 furnished with a median sulcus like that of GallioneJla, with a soft, 

 not siliceous integument ; and, after the manner of the Conjugate, 

 two corpuscles coalescing and producing another individual by their 

 zygosis, or conjugation. Diameter 1-1 150th. Common in the marshes 

 of Berlin. (\T.de DidymopriumBorreri.) 



Genus Poltsolenia (Ehr.) — Generic characters unknown. 

 P. c/os^criK»«.— Corpuscles very largo, obtusely fusiform, straight 

 or slightly lunate; thick, green, and smooth; at a later period 

 hyaline cirrhose on every side. Length l-60th. to l-48th. Berlin. 



Has the habit of Closterium acerostim, whose structure it entii'ely 

 resembles, except that, at certain periods, very many (to the number 

 of fifty) cirrhi shoot out from as many apertures, not before visible, and 

 seem to withdraw, in their exit, the internal green mass. 



This account appears like a misconception of some phenomenon, 

 such as the germination of a spore, or the growth of mycelium on a 

 Closterium, according to Mr. Ralfs it is = Penium digitus. 



Genus ZYsoxANTHruM (Ehr.) — Generic description wanting. 

 Ehrenberg has most probably instituted Zggoxanthium as a sub-genus 

 oi ^antliidium . 



Z. echinus "^ Xanthidium echinus, 1839. — Corpuscles (segments, 

 Ralfs) globose, single and in pairs, aculeate, aculei thick, short, 

 forked at the apex, or trifid ; and provided on the sides with two 

 median tubules, having a stellate orifice : contents (ovaria Ehr.) 

 green. Diameter of a single corpuscle 1 -480th. Internal granules 



