362 Ciliophora 



or the posterior end or near the equator. There are only a few rows of 

 somatic cilia. The Trichopelmidae resemble the Ctenostomina but lack 

 the adoral membranelles characteristic of these heterotrichs. 



The family includes the following genera from fresh water: Drepanomonas Fresenius 

 (102), Microthorax Engelmann (102, 165; Fig. 7. 17, C), Pseudomicrothorax Mermod 

 (102; Fig. 7. 17, D), and Trichopelma Levander (102; Fig. 7. 17, A). 



Family 14. Trichospiridae. This family contains the genus Trichospira 

 Roux (102; Fig. 7. 15, G, H). A band of densely set cilia, comparable to 

 that in Spirozona, extends posteriorly from the peristome but spirals to 

 the right instead of the left. The body does not taper to a point poste- 

 riorly and there are no caudal bristles. The only known species occurs in 

 fresh water. 



Fainily 13. Trimyemidae. The only known genus is Trimyema Lackey 

 (Sciadostoma Kahl). Except for a caudal bristle, somatic cilia are limited 

 to three or four spiral rows in the anterior half of the body (Fig. 7. 17, 

 E). The cytostome is subterminal. Species are known from fresh and salt 

 water. 



Suborder 3. Hymenostomina. 



Adoral cilia are fused into membranes, the number, size, and arrange- 

 ment of which vary in different genera. The peristomial area also shows 

 a certain amount of variation. In some genera there is a sort of oral pouch 

 containing the adoral membranes (Fig. 7. 19, B, D) and opening onto the 

 surface of the body. In others, the adoral ciliature arises in a groove which 

 may be fairly long (Fig. 7. 18, L) or may even extend throughout most of 

 the body (Fig. 7. 18, J). Although detailed information is not available 

 for a number of genera, modern investigations have demonstrated sev- 

 eral patterns of adoral organelles as well as differences in stomatogenesis 

 during fission. Eventually, the accumulation of such data should lead to 

 needed revisions in classification. 



Kahl (102) divided the suborder into five families: Cohnilembidae 

 (Lembidae), Frontoniidae, Ophryoglenidae, Philasteridae and Pleurone- 

 matidae. Of these, the Frontoniidae seem to be a particularly hetero- 

 geneous group which would be less so if Tetrahymena and certain related 

 genera were removed. Such an improvement has been effected by Mugard 

 (155) in transferring these ciliates to a 'Tamily Leucophrydae." Since 

 Corliss (42b) has concluded that none of Midler's species of Leucophra 

 ("Leucophrys" Ehrenberg) is congeneric with any species subsequently re- 

 ferred to "Leucophrys," and also that Leucophra should become a genus 

 dubium, the "Leucophrydae" shovild be replaced by the Tetrahymen- 

 idae- with Tetrahymena Furgason as the type genus. This procedure 



''The Family Tetrahymenidae has recently been erected by Corliss (1952. Proc. Soc. 

 Protozool. 3: 4). 



