Oxytrichina?^ infusobial animalcules. 597 



tical, attenuated at both ends ; and having a hand of nnchii at the 

 middle of the belly. Ehrenbcrg has seen transverse and longi- 

 tudinal division, and the growth of gemmae. Found in infusions. 

 Size 1-H4th ; ova granules 1 -24000th. 



Stylonychta silunis {Trichoda siliirus, Kerona silurus, Hymen- 

 topus lava, ^'C, M.) — Body small, white, of the form of a mussel ; 

 cilia and uncini rather long. Found in fresh water. Size 1 -280th. 



S. appendiculata. — Body elliptical, white, small, and flat ; cilia 

 and styles long ; the setae disposed obliquely in fascicles. Found 

 in fresh water. Size 1 -280th. 



S. histrio. (^Paramecium histrio, Kerona histrio, M.) — Body el- 

 liptical, white, middle slightly turgid, finished anteriorly with a 

 cluster of uncini ; no setae. Dr. Ehrenberg states the absence of 

 the three posterior setae in this and the following species is 

 remarkable, inasmuch as the others possess them. Found amongst 

 Conferva. Size 1 -280th. 



S. lanceolata. — Body pale greenish, lanceolate in shape, ex- 

 tremities equally obtuse, under side flat ; it has uncini in a cluster 

 near the mouth, but no styles. Ehrenberg saw in one specimen a 

 simple contractile vesicle on the left side, below the mouth, and 

 near it a large oval gland. Green Monads and Bacillaria may be 

 seen in this voracious animal, surrounded with colourless stomach 

 juice. Fig. 343 represents an under view, and fig. 344 the side 

 view of another. Found amongst Conferva. Size l-144th to 

 l-120th. 



The only genus to be appended to this family is the one called 

 by Dujardin — 



Halteria. — Body nearly globular or turbinate, surrounded by 

 long, very fine retractile cilia, which adhere to the glass, and then 

 conti-acting suddenly, enable the animal to change its place briskly, 

 as if by leaping ; a row of very strong oblique ciliae occupies the 

 circumference. 



The type of this genus is Halteria grandinella, (f. 31, a, b, c, 

 P. 21,) called by Ehrenberg Trichodina, and placed by him in the 

 family Vorticellina, along with species totally different, and which 

 Dujardin terms Urceolaria. 



