152 DESCRIPTION OF [Polygastrica. 



Euglena longicauda and amblyophis we have the first indi- 

 cations of the presence of nervous matter that is to be 

 found in the polygastric Infusoria : it appears in the form of 

 a white glandular knot, situated below the eye. 



The following table is descriptive of the genera of this 

 family : — 



Eye wanting Astasia. 



, ( with one j ^^^ ^^"^'°S - Amblyophis. 



free J Pi-ol>oscis ^ ^^^ present ... Euglena. 



!With one 1 

 eye I V with two proboscides Chlorogonium. 

 V attached by a pedicle Colacium. 

 With two eyes Distigma. 



Genus XXXII. Astasia. The members of this genus 

 are characterized by their being free (not attached by a 

 pedicle), and being furnished with a long or short tail, but 

 no eyes; Astasia pusilla is the only species in which diges- 

 tive cells have been clearly seen. Ova are perceptible in 

 Astasia haematodes, and probably exist in the three other 

 species; a locomotive organ in the form of a thread-like 

 proboscis exists in A. pusilla. 



The immense numbers in which these Infusoria are deve- 

 loped in a few days, and the blood red-colour they assume, 

 have not unfrequently been the cause of considerable alarm 

 and anxiety to persons residing in the vicinity of the 

 waters wherein they are found. 



120. Astasia haematodes. The blood-like Astasia. — 

 Body fusiform, or spindle-shaped, when extended ; tail very 

 short, body green at first, afterwards of a blood-red colour. 

 Gronp 68 represents one creature extended, and another 

 contracted. (Hampstead). Length l-380th. 



