610 DESCEIPTION OF [^Rotatoria. 



and a doubtful genus, .named Planariola. These genera in having 

 a symmetrical figure, are distinguished by him from all other 

 Infusoria. 



One species of Chaetonotus described by Dujardin is probably new, 

 although it may be, as he remarks, but the C. maximus of Ehrenberg. 



The following are its characters : 



Chaetonotus squmnatus. — Body elongate, narrowed on its an- 

 terior third, but expanded in its posterior half. Length l-130th to 

 l-135th. Covered with short hairs; dilated in a scale-like form 

 toward the base, and regularly imbricated. Found in sea water 

 brought from Toulouse, long kept. 



Genus Sacculus (Gosse). — One eye, frontal; body destitute of 

 hair, and without a foot ; rotatory organ a simple wreath ; alimen- 

 tary canal very large ; jaws set far forward, apparently consisting of 

 two delicate unequal mallei and a slender incus; very evanescent ; 

 eggs attached behind, after deposition. 



This genus comes nearest to Glenophora, but, unlike the latter, 

 has but one eye. 



S. viridis. — Body pear-shaped ; flattened ventrally, the anterior 

 end the narrower ; head conical pointed, surrounded by a wreath of 

 long cilia; digestive canal occupying nearly the whole body, and 

 always filled with a substance of a rich green hue in masses. 

 Length l-150th. This curious animal (found in considerable num- 

 ber in a little pool on Hampstead Heath) must be placed in this 

 family, according to Ehrenberg's system, but the mode of carrying 

 its eggs indicates an aflSnity with the Brachionoea. 



Genus Glenophora. — The eye Animalcule is characterised (as 

 its name imports) by the presence of two eyes, placed anteriorly; 

 it has a frontal circular rotatory organ, and a truncated bifid tail, 

 or false foot. The alimentary canal is short, thick, and conical ; it 

 sometimes contains green matter. The two protruding forceps- 

 like bodies, in the middle of the rotatory organ, may, says Dr. 

 Ehrenberg, be considered teeth ; pancreatic glands are indicated by 

 knot-like turbid bodies. The eyes are sharply circumscribed, 

 and situated at the frontal region ; a respiratory tube unknown. 

 Dujardin believes this genus based on young animals, and as such 

 unsatisfactory. 



