138 DBSCEIPTION OF \^Polygastrica. 



nodina and the Euglenia, contain Infusoria possessing two -filaments, 

 by one of whicli they progress, by the other adhere for support to 

 any solid body, and produce a sudden movement backwards by its 

 contraction. To prevent confounding specimens of these several 

 families the same distinctions which mark the Monadina generally, 

 must be found in order to constitute the Heteromita members of that^ 

 family ; such as the absence of integument, the gelatinous appear- 

 ance of the entire mass admitting of agglutination to other objects, 

 and the drawing out of its substance into filamentous processes, 

 together with the existence of certain corpuscles, which can only 

 have penetrated the interior as a consequence of the formation of 

 vacuolse at the sm-face. 



Heteromita ovata. — Body ovate, narrower anteriorly, containing 

 vacuolae, granules and navicula). Length l-1050th to l-1150th. 

 (P. 21. f. 5.) 



This is probably the Bodo grandis of Ehrenberg. His other Soda's 

 are not Heteromita, but imperfectly observed Cercomonads or Amphi- 

 monads. 



H. gramdmn. — Body globular, surface granular. Length l-2600tli. 

 Pound in rather putrid sea water. 



H. angusta. — Body narrow, lanceolate, slightly bent, tapering at 

 each end, with a flagelliform and another filament from the same 

 point anteriorly, erect at the base, but floating freely the rest of its 

 length. Length 1-1 050th 



This is a doubtful species. It is of the shape of a lanceolate leaf, 

 with a mid-rib or longitudinal fold. 



Genus Teichomonas, (D.) — Body ovoid or globular, capable of being 

 drawn out when adherent, and in this way presenting sometimes a 

 caudal prolongation, the anterior flagelliform filament is accompanied 

 with a group of vibratile cilia. 



T. vaginalis. — Body gelatinous, nodular, unequal, hollowed by 

 vacuola), often adhering to other bodies; movement oscillating. 

 Length 1 -2600th. 



T. Limacis. — Body ovoid, smooth pointed at each end and termi- 

 nating in front by a flagellifonn filament, from the base of which a row 

 of vibratile cUia is directed backwards. Progressive movement active, 

 the animalcule at the same time turning on its axis. Length 

 1-1 730th. Found in the intestine oi Limax agrestis. 



