548 DUSCEIPTION OF \JPolygastrica. 



may be that nutriment is derived from the substances caught by the 

 fibres, by means of absorbing powers resident in the bulbous ex- 

 tremities of the hotter. 



The beings of the form now described resemble the Acineta 

 mydacma (Ehr.) In this Acineta, Ehrenberg designated the outer 

 sher,th, a lorica ; the diverging fibres, the tentacles ; the contained 

 globules, stomachs ; the micleus, a testes ; and the fine granules, 

 ova ; whilst he also supposed the existence of a mouth at the an- 

 terior extremity. 



In different examples the length of the pedicle varies much. In 

 some cases, the enclosing case was nearly fUled by the granular body ; 

 in such, the diverging fibres were few and smaU, the contained 

 granules and globules large, whilst the nucleus was indistinct or in- 

 visible (P. 22, f. 11.) These forms are an early condition of the 

 Acineta, which is destined to undergo progressive changes, chiefly 

 observable in the growing diminution in volume of the granular 

 aidmal mass, which proceeds until diverging fibres, nucleus, and 

 contractile vesicle, are no longer to be traced in the mere speck re- 

 maining (P. 22, figs. 13, 14, 15.) 



As in Eputylis, so in Vaginicola, the Acineta-body developes a 

 discoid, ciliated embryo, but there is no contraction of the outer case 

 (sheath) as happens in the former. 



Vaginicola crystallina ( Vorticella stentorea et Trichoda ingenita, M.) 

 — Lorica crystalline, straight, pitcher-shaped, slightly contracted near 

 the open end ; ova green. Found upon Lemna, &c. Length of lorica 

 l-210th (P. 22, f. 19, 24.) 



V. tincta. — Lorica brownish-yellow, urceolate, and nearly cylin- 

 drical ; body hyaline. Found upon Zygnema decimum. Size of 

 lorica 1 -280th. 



V. decumhens. — Lorica brownish-yellow, oval and compressed, as 

 shown in the engraving, group 2.56. The lorica is decumbent, the 

 body hyaline. Lives with the preceding. Length of lorica 1 -280th. 



V. vaginata. — Under the name Vorticella raginata, Miiller has 

 described a Vaginicola found in the Baltic, having a deHcate pedicle 

 as long as the body, and insei'ted at the upper end of a sheath six 

 times longer than itself, into the orifice of which the body cuu with 

 diiliculty enter. 



