412 Ciliophora 



California coast, these ciliates have been reported from European waters. 

 Species of Spirochona occur on fresh-water gammarids but the other 

 genera all seem to be marine. 



The body is usually more or less vase-shaped, and is attached to the 

 host by either a basal disc or a fairly short stalk. The peristome lies at 

 the upper end of the body and is usually surrounded by a thin-walled 

 funnel, near the base of which several rows of cilia extend to the cyto- 

 stome. The body is generally constricted at the base of the funnel. The 

 funnel in Kentrochona is a simple structure with a continuous wall (Fig. 

 7. 49, F). More often, the wall is incomplete and one end is rolled up to 

 form a secondary spiral funnel (Fig. 7. 49, A, H). Stylochona is unusual 

 in that a wide funnel of the Kentrochona-type surrounds an inner and 

 apparently separate funnel (Fig. 7. 49, B). The general surface of the body 

 is usually not ciliated. The contractile vacuole opens into the pharynx 

 (vestibule), as in the Peritrichida. 



Budding and conjugation (with oral ends in contact) have been re- 

 ported. In Trichochona lecythoides there is a lateral pouch ("marsu- 

 pium") into which the developing bud extends. As the bud grows, it 

 protrudes from the marsupium and finally becomes separated from the 

 parent (154). The bud in Cliilodochotia quennerstedti (82) is set free as 

 a migratory larva with a ciliated ventral surface, an apparently undif- 

 ferentiated cytostome, and a scopula-like organelle which will produce 

 the stalk of the adult (Fig. 7. 49, J). Similar migratory stages have been 

 reported for species of Heliochona and Spirochona (82). 



The relationships of the Chonotrichida remain somewhat uncertain 

 and further work is needed on the morphology and life-cycles. However, 

 the present scanty information is believed by some workers to indicate 

 that this group is more closely related to the Holotrichida than to any 

 other ciliates (62). Three families have been recognized by Mohr (154). 



Family 1. Chilodochonidae. This family includes Chilodochona Wal- 

 lengren (82, 106; Fig. 7. 49, I, J) in which there is no very marked con- 

 striction ("neck") at the base of the funnel .A well-developed stalk is 

 characteristic. The "funnel" is rudimentary and the peristome is better 

 described as a groove bordered by two lips. This type of organization 

 would require a rather simple metamorphosis of the migratory stage. 



Family 2. Stylochonidae. Funnels are well developed but are not spi- 

 rally twisted. A stalk may or may not be present. 



Four genera have been assigned to the family: Heliochona Plate (106; Fig. 7. 49, E), 

 Kentrochona Rompel (106; Fig. 7. 49, F), Stylochona Kent (106; Fig. 7. 49, B), and 

 Trichochona Mohr (154; Fig. 7. 49, G). 



Fam,ily 3. Spirochonidae. The funnel is folded into spirals and there is 

 no stalk. The single genus, Spirochona Stein (106, 202, 207; Fig. 7. 49, A, 

 C, D, H), includes species from fresh-water gammarids. 



