616 DESCBIPTION or [Rotatoria. 



upon water plants. Size of single animalcule l-36th; of the 

 spheres l-6th. (P. 23, Fig. 1.) 



Megalotrocha velata (Gosse). — Animals separate ; disc partially 

 enveloped in a cleft granular integument; eggs not attached to 

 the parent after deposition. Length l-55th. 



Family.— FLOSCULARI A. 



Rotatoria enveloped in a case, and provided with a single rotatory 

 organ, flexuose at the margin, and lobed or divided, with from two 

 to six clefts; when the latter number, it appears compound. The 

 cilia of this organ in some genera are quiescent, and only vibratile 

 occasionally. The alimentary canal has toothed jaws, and generally 

 a stomach ; the genus Lacinularia only has csecal appendages to 

 the latter, but in all of them oval or semi-spherical pancreatic 

 glands are seen. The reproductive organs are, a short ovarium, in 

 which only a few ova are developed at a time, and in Lacinularia, 

 Melicerta, and perhaps in Floscularia and Stephanoceros, male 

 glands. In Lacinularia four transverse circular vessels, and a 

 strong vascular network at the base of the rotatory organ, are seen ; 

 internal tremulous gill-like organs in Lacinularia and Stephanoceros 

 only ; eyes are distinct in all, except Tubicola?'ia. In Lacinularia, 

 Limnias, and Melicerta, brain and masses of nervous matter are 

 seen. Touching their muscular structure, two pairs of muscles 

 seemingly contract the body posteriorly ; the rotatory organs of 

 Lacinularia and Melicerta have special ones. The evolution of 

 young in the ovum takes place as in Hydatina. 



The faTiily is disposed in genera, thus : 



Eyes absent Tubicolaria. 



One eye present (when young) Stephanoceros. 



Two eyes 



present 



(when 



young.) 



{envelope of the single animal- -i j • 

 cules distinct or separated j-^'nimas. 

 envelope of the single animal- i t ■ i • 

 ciies conglomerated. jLacmulana. 



rotatoiy organ four-parted when full-grown Melicerta. 



rotatory organ five to six -parted when full-grown Floscularia. 



Dujardin has a family Flosculariens, which, however, differs much 



