390 DESCRIPTION OF [RotatoriK. 



ovate, anterior acute, posterior obliquely truncated; eyes 

 distant from each other; the alimentary canal is often filled 

 with green matter. They increase rapidly in glass vessels. 

 Figures 457 to 459 represent three views of this animal- 

 cule. Found amongst conferva. Length of lorica 1 -288th. 

 Genus CLXXIV. COLURUS. The pincer-footed Rota- 

 toria have two frontal eyes-, a furcated foot, 'and a com- 

 pressed or cylindrical lorica. The lorica is open upon the 

 under side (scutellum) ; this is distinctly seen in four spe- 

 cies : a compound rotatory organ is present in all, over it 

 projects a retractile frontal hook (respiratory tube); an 

 (sesophagal head with two jaws, these in two species have 

 two or three teeth; oesophagus very short; two species have 

 a constricted stomach (gasterodela), the others have a sim- 

 ple alimentary canal (coelogastrica), with glands to all. 

 The red frontal eyes are delicate ; in C. uncinatus and bi- 

 cuspidatus they have escaped observation ; all have pecu- 

 liar vesicles at the back. They resemble Monura. 



676. COLURUS (?) uncinatus (Brachiomis unciaatus,M.) 

 The little-horned Colurus. Lorica ovate, compressed, pos- 

 terior and bi-pointed toes, very short ; at the middle of the 

 back is generally a circlet of vesicles, which at one time 

 Ehrenberg considered eyes, but now he regards them as 

 vesicles of oil, as they are seen in all the species, and abun- 

 dantly in the Cyclopides. Found both in fresh and sea 

 water. Length l-430th to l-288th. 



677. COLURUS (?) bicuspidatus. The large Colurus.- 

 Lorica ovate, compressed, the two points posteriorly strong, 

 toes short. Length 1 -288th. 



678. COLURUS cmidfttus. The long-fingered Colurus. 

 Lorica ovate, compressed, posterior points distinct; toes 



