Astasiaea.] THE infusoria. 159 



shaped Euglena. — Body slender, spindle-shaped, and 

 straightened in the form of a bodkin ; head attenuated, 

 and a little truncated ; tail very pointed ; body green in 

 the middle, and colourless at the extremities. This is one 

 of the most beautiful animalcules I have seen under the 

 microscope ; its graceful form when swimming, its bright 

 red eye, the curious forms it assumes when stationary, 

 and its remarkable appearance when undergoing self- 

 division, all combine to render it worthy of observa- 

 tion. Group 78 shews the normal form of this creature ; 

 the figure to the right, the same bent and contracted ; 

 and the lower, another undergoing longitudinal self-divi- 

 sion. Found both in fresh and brackish water. Length 

 1 -570th to 1 -210th. 



136. Euglena rostrata. The beaked Euglena. — Body 

 elongated and conical, with the hinder part gradually 

 attenuated into the tail, which is very short. Head 

 slightly bent, like a beak ; colour green. Found amongst 

 oscillatoria and Bacillaria. Length about l-500th. 



Genus XXXV. Chlorogonium. The Astasiaea with 

 a double jwoboscis. — This genus comprises those members 

 of the family Astasiaea which are provided with an eye, 

 tail, and double thread-like proboscis ; their motion in 

 swimming is free, the creature not being attached by 

 means of a pedicle or foot-stalk. The only known species 

 is of a very beautiful green colour, and has numerous 

 transparent vesicles within it, which are apparently sub- 

 servient to the purpose of nutrition, although this fact has 

 not been determined by the application of coloured food. 

 A faint, clear, glandular body, most probably belonging to 

 the male generative system, is perceptible in the centre of 



