42 CONNECTICUT GEOL. AND NAT. HIST. SURVEY. [BuU. 



24. Peristome covering the whole right side, with a large 



membrane Lcmbadion* 



Peristomial furrow parallel to the right side ; a very 



large projecting membrane in a depression on the 



posterior half of peristome Pleiironema* 



Like the above but smaller, with a shorter peristome 



and one or more long posterior bristles. . .Cyclidium* 

 Like Pleuronema but inclosed in a lorica. .Calyptotricha 



25. With a single row or large cilia Mcsodiniiim* 



With two, many-rowed crowns of free cilia .... Didi.nium 

 With a broad, ring-like band of cilia Urocentrtim* 



26. Pharynx not basket-like or tube-like 27 



Pharynx basket-like or tube-like 28 



2y. With a long neck; body oval ending in a short tail. . 



Lionottis'^ 

 With the anterior end hook-like and showing an evi- 

 dent peristome and pharynx; brownish Loxodes* 



28. Pharynx smooth ; small 29 



Pharynx basket-like 30 



29. Only the anterior end and the right border ciliated. . 



Ervilia 

 With a middle, swollen, ciliated zone Trochilia 



30. Body flat 31 



Body not flat 33 



31. Mouth in the anterior half 32 



Mouth in the posterior half Opisthodon 



32. Without a movable tail ChUodon^ 



With a movable tail Aigyria 



Body crenate in cross section ; without a movable tail 



Nezv genus* 



33. Body purse-shaped Phascolodon 



Body ovate ; six rows of cilia New genus* 



Description of Genera. 

 Coleps Ehrbg. 



Barrel-shaped, but not always symmetrical ; rigid, pro- 

 vided with an armor composed of single plates. The 

 plates, arranged in zones around the body, are almost rec- 

 tangular, sculptured upon their surface, on the one side 



