4io 



THE INFUSORIA 



branella round the body* 0-03-0-12. Diplodinium, Schuberg, differs 



Fio. 69. 



Cydoposthium bipalmatum, fron. 

 the coecum of the horse. M, 

 meganucleus; m, micronucleus ; 

 L, peculiar vacuolated band by 

 the side of which is situated a 

 row of contractile vacuoles. 

 (After Gunther.) 



cvi 



Fio. 71. 



Stichospira paradoxa, Sterki. 

 Length about '04 mm. Living in 

 a cavity of a leaf which is extended 

 forward by the addition of a tube (0 

 built by the animal itself, c, mouth ; 

 M, meganuclei ; c.v, contractile 

 vacuole. (After Sterki.) 



versely across the posterior 

 between these two groups a 



Fio. 70. 



Diagrammatic transverse section through the body 

 of a Hypotrichous Ciliate in the region of the peri- 

 stoine. o, membrane overhanging the mouth ; b, a 

 ventral cirrus ; c, a lateral cirrus. On the dorsal 

 side are rows of stiff, bristle-like cilia. (After Sterki.) 



from Entodinium in the presence of a 

 portion of the adoral membranella on the 

 left side of the body. The genera Cyclo- 

 posthium, Bundle (Fig. 69), and Didesmis, 

 Fior., from the coecum of the horse, should 

 be separated into a distinct family. 



APPENDIX. The genus Maryna, Gruber, 

 is probably related to the TINTINNOINA, and 

 should be included in the OLIGOTRICHA. 

 The individuals live in colonies which form 

 a system of dichotomously branched mucous 

 tubes. Freshwater. 



ORDER Hypotricha, Stein. 



The genera included in this order are 

 usually characterised by a well-marked com- 

 pression of the body in the dorso- ventral 

 axis. The dorsal surface has no movable 

 cilia, but is usually provided with a few 

 scattered, stiff, bristle-like processes of the 

 pellicle (Fig. 70). The ventral surface is 

 provided with a continuous covering of 

 short cilia, arranged in longitudinal rows, 

 in the more primitive forms (Urostyla, 

 Peritromiis) t or with more differentiated 

 rows or groups of cirri and membranellae 

 associated or not with small cilia. The 

 most important of the cirri are usually 

 arranged in three groups (cf. Fig. 1), one 

 just behind the anterior margin called the 

 frontal cirri, a row usually running trans- 

 ventral surface called the caudal cirri, and 

 number of abdominal cirri (3-10) arranged 



