674 DESCEIPTIOK OF [Rotatoria. 



Family.— BRACHIONAEA. 



The concluding family of the Eotatoria, BracMonaea, is dis- 

 tiugiiislicd by its members having two rotatory organs, and a lorica. 



The lorica is a testuJa, and not a scutellum. The rotatory 

 apparatus is often apparently composed of five parts, three central 

 and two lateral. The latter alone constitute the rotatory organs, the 

 others are only ciliated frontal portions, which during the vibration 

 of the rotatory organs, remain stiffly extended as feelers. Seme 

 (perhaps all) have two setae at the rotatory apparatus, as in Synchaeta. 

 The genera Noteus and Braclnonus have a forked foot, Anuraea is 

 destitute of foot, and Pterodina has a suctorial disc at the end of the 

 foot, but no toes. All the genera have jaws, with teeth attached to 

 an oesophageal head, having four muscles. In Pterodina the jaws 

 are partly two-toothed and the teeth in a line {zygogomphia locho- 

 gomjjhhi), in the other genera they are many-toothed f2}(>Jygomphia.J 

 In JVoteus and Pterodina, the alimentary canal is constricted, forming 

 stomachs (gasterodela) ; in the rest it is partly simple {coelogadrica), 

 partly with stomachs. Biliary glands have been observed in all the 

 genera, as also an ovarium, male glands, and contractile vesicle. 

 Many species of Anuraea, Brachionm, and Noteus, carry their eggs 

 attached to them, after ex]3ulsion. In all the genera, except Pterodina, 

 internal tremulous gill-like organs, attached to the glands, have been 

 observed ; respiratory tubes exist in some species of the genera 

 Anuraea, Brachionus, and Noteus. A nervous system is indicated by 

 the presence of red visual points in all, except Koteus, which, 

 however, possesses a cerebral ganglion, 



Feme of the Brachionaea may become so numerous, as to render 

 the water milky and tiu'bid. 



The genera are disposed as follow : — 



Eyes absent, -with a furcate foot Noteus. 



f f no foot Anuraea. 



one (cerTical) eye < 

 Eyes present < L foot furcate Brachionus. 



two fruital eyes, fool .-tyliform rteroclina. 



