102 



PROTOZOA 



some of them indifferent to their base ; others are only found on 

 Algae, or again only epizoic on special Metazoan hosts, or even 

 on special parts of these. Thus Rhyncheta is only found on the 

 couplers of the thoracic limbs of Cyclops, and Choanophrya on 

 the ventral surface of its head and the adjoining appendages. 



'tr 



Fig. 62, — Ohoanophrya infundibulifera. A, adult ; B-D, tentacles in action in various 

 stages ; E, tentacle at rest ; F, young, just settled down, a, a, a, Tentacles in various 

 stages of activity ; c, central cavity ; c.v, contractile vacuole ; em, ciliated embryo 

 showing contractile vacuole and nucleus ; /, spiral ridge ; m, muscular wall of 

 funnel ; n, nucleus ; tr, opening of funnel. (A-D, F, modified after Zenker ; E, 

 original. ) 



We owe our knowledge of this group to the classical works 

 of Ehrenberg, Claparede and Lachmann, Stein, E. Hertwig, and 

 Biitschli. Plate has shed much light on Bendrocometes, and 

 Hickson has studied its conjugation. Ischikawa-^ has utilised 

 modern histological methods for the cytological study of Uphelota 

 hiitschliana. Een^ Sand has written a useful, but unequal, and 

 not always trustworthy monograph of the Order,^ containing an 

 elaborate bibliography. 



^ In Journ. Coll. Sc. Japan, x. 1896. 



^ ^hide monographique sur le growpe des TentacuUfires, Ann. Soc. Beige Micr. 

 xxiv.-xxvi. 1901. 



