382 DESCRIPTION OF [Rotatoria. 



tube of the oesophagus is very short in all. The ali- 

 mentary canal is constricted, except in Salpina, which is 

 simple. The ovarium is globular in all, and a male sexual 

 vesicle is present in Salpina, in which species, probably, 

 a cerebral ganglion (no eye). L. ovalis is sometimes deve- 

 loped in myriads in stagnant water. 



652. LEPADELLA ovalis (Brachionus ovalis, M.) The 

 egg-shaped Lepadella. Lorica depressed, oval, attenuated 

 anteriorly, the ends truncated : it is not emarginate. The 

 alimentary canal of this animalcule is generally filled with 

 a yellowish substance, except when it feeds upon colour- 

 less Monads. Fig. 430 represents a back view ; Jig. 43 1 

 a side (right) view of a young specimen ; fig. 432 the 

 lorica;^. 433 the oesophagal head. Length l-240th. 



653. LEPADELLA emarginata (Brachionus spatella et 

 ovalis, M.) The emarginate Lepadella. Lorica depressed, 

 oval, broad anteriorly, extremities emarginate. Found 

 amongst conferva. Length, without foot, 1 -576th. 



654. LEPADELLA(?) salpina. The stock-fish Lepadella. 

 Lorica oblong, prismatic, obtusely triangular, back crested, 

 anterior denticulated. Found amongst conferva. Length 

 of lorica l-200th. 



Genus CLXVIII. MONOSTYLA. The spinous-footed 

 Rotatoria possess a single cervical eye, a simple styliform 

 foot, and a depressed lorica (testula) . Numerous rotatory 

 muscles are seen in two species, and also an oesophagal 

 head, having four muscles ; in one species the jaws are 

 single-toothed, in the other tw r o-toothed. They have a 

 very short oesophagus, and a constricted stomach (gaste- 

 rodela), with two glands. The ovarium is globular ; an 

 ovum, with the vesicle of the germ within it, is seen in two 



