4 i 8 THE INFUSORIA 



long flagellate cilia. O'l 2. Rectum of Termes. Joenia, Grassi. Similar 

 to Lophomonas, but more elongated, and with a number of short non- 

 mobile cilia at the posterior end. Rectum of Callotermes. Pyrsonympha, 

 Leidy. (Fig. 84.) With a long anterior flagellum of attachment. O'l. 

 Rectum of Termes. Dinennymplw,, Leidy. More elongated than Pyrso- 

 nympha, and spirally twisted. O'l. Rectum of Termes. 



CLASS ACINETARIA, LANKESTER 



The majority of the animals included in this class are per- 

 manently or temporarily sedentary in habit. It seems probable, 

 however, that some of the species of the genus Sphaerophrya may 

 be permanently free. 



The characteristic feature of the class is the possession of the 

 organs known as Suckers, Tentacles, and Arms. The morphology 

 of these organs is discussed in another place (p. 370). 



In Rhynceta (Fig. 1 3) there is only one sucker, and in Hypocoma, 

 which may be only a persistent larval form, the single ventral 

 sucker is supplemented by a patch of cilia on the same aspect of 

 the body. In Sphaerophrya the body is furnished with a few 

 suckers evenly distributed, and in the pedunculate Acineta there are 

 numerous suckers scattered on the surface that is free. In some 

 species of Ephelota the suckers and tentacles are evenly distributed 

 on the free surface, whilst in ToJcophrya, Podophrya, and Solenophrya 

 the suckers are restricted to three or four bunches at the angles of 

 the disc. In Dendrocometes these bunches of suckers are represented 

 by 4-6 arm-like processes of the body-wall, and very probably the 

 1-4 arms of the remarkable genus Ophryodendron have a similar 

 significance. 



The attachment of the individual to the host or to some foreign 

 weed or other substance may be effected by a broad flattened base 

 as in Dendrocometes, Dendrosoma, Solenophrya, or by a stiff cuticular 

 peduncle with a protoplasmic core as in Acineta and Podophrya. 



There is, as a general rule, no mouth, the food being held by 

 one or more of the suckers and the dissolved products passing 

 down the suckers into the general protoplasm of the body. 



The body-wall is covered with a thin pellicle which is in many 

 forms finely loricate. Some species have the power of withdrawing 

 themselves from this pellicle, which is left behind as a shell, together 

 with a certain amount of cytoplasm. They then develop a temporary 

 covering of cilia and swim away to a more suitable locality. The 

 cilia disappear when the individual again becomes fixed. This has 

 been observed in Dendrocometes, but it probably occurs in other 

 genera as well (Podophrya and Metacineta). 



The peduncle of the Acinetaria appears to be formed as a 



