Astasiaea.] THE INFUSORIA. 157 



Body extensible in a spindle-shaped manner, with the head 

 attenuated, blunted at the extremity, and two-lipped ; tail 

 short, and somewhat pointed; colour transparent and 

 whitish, rare. Length 1 -280th. 



128. EUGLENA deses (Enchelys deses, M.) The slothful 

 Euglena. Body extensible and cylinder shaped, abruptly 

 rounded at the head, and slightly bi-lipped. Tail very 

 short and pointed ; colour green ; motion a winding and 

 sluggish creeping, never swimming. Found amongst lemna. 

 Length 1 -240th to 1- 760th. 



129. EUGLENA wrn&s (Cercaria viridis, M.) The green 

 Euylena. Body extensible in a spindle-shaped manner, 

 with the head attenuated and short. Tail short, and cone- 

 shaped, not cleft ; colour green, excepting the two extre- 

 mities, which are colourless. The double-pointed tail, 

 supposed to have been seen by Leeuwenhoek, Ingenhousz 

 Miiller, Schrank, and Nitzsch, does not exist. The colour 

 of the eye is often pale red, when the creature is young, so 

 that it may be easily mistaken for the Astasia viridis or 

 Monas deses. When dried on glass, the eye seldom 

 retains its colour more than a week, but the proboscis may 

 be well examined, and preserved in this state. Length 

 1 -240th. 



130. EUGLENA spirogyra. The tortuous Euglena. 

 Body extensible and cylinder- shaped, very finely striated 

 and granulated. The head is a little truncated, and the 



hinder part attenuated into a short pointed tail ; colour 

 a brownish-green ; motion like E. deses. Found amongst 

 conferva and Bacillaria. Length l-240th to l-120th. 



131. EUGLENA pyrum. The pear-shaped Euglena. 

 Body obliquely fluted; when distended oval or pear-shaped. 



