THE WHEEL ANIMALCULES (ROTATORIA) 595 



44 (43) Lorica broader Cathypna Gosse. 



Several species. 



Representative species (Fig. 892). . . . Cathypna luna Ehrenberg. 



45 (42) The two plates not connected by membrane. . Euchlanis Ehrenberg. 

 Large, conspicuous, clear species; lorica not sculptured or otherwise marked. Many species. 



Representative species (Fig. 893) . . Enchlanis macrura Ehrenberg. 



46 (41) One toe Monostyla Ehrenberg. 



Many species. 



Representative species (Fig. 894) . . Monostyla lunaris Ehrenberg. 



47 (32) Lorica undivided, of a single piece 48 



48 (51) Lorica somewhat pipe-shaped, often unsymmetrical. 



Family RATTULIDAE . . 49 



Lorica closed all around, cylindrical, fusiform, ovate, or conical, with an opening at each end 

 for head and foot; often unsymmetrical and with oblique ridges or furrows. Toes bristle- 

 like; sometimes equal, then short; sometimes very unequal, so that but one is noticeable, this 

 then very long. 



49 (50) Toes equal, or, if unequal, the shorter one more than one-third the 



length of the longer Diurella Bory. 



Many species. 



Representative species (Fig. 895) Diurella sulcata Jennings. 



(Fig. 862, page 562) D. tigris Miiller. 



50 (49) Toes unequal. The smaller less than one-third length of longer. 



Rattulus Lamarck. 



Many species. 



Representative species (Fig. 896). . . . Rattulus cylindricus Imhof. 



(Fig. 897) R. latus Jennings. 



(Fig. 898) R. longiseta Schrank. 



51 (48) Lorica not pipe-shaped. Symmetrical 52 



52 (59) Foot and toes not exceptionally long. No spines. 



Family COLURIDAE . . 53 



Lorica of a single piece, either covering both dorsal and ventral surfaces, or only the dorsal. 



53 (58) Head surmounted by a chitinous shield 54 



