questioned or cited in the works of Price, he will arrive at the 

 following series: 14 hooks in 1 individual, 16 in 3, 17 in 1, 22 in 1, 

 23 in 4, 24 in 3, 30 in 2, 31inl, 32 in 6, 33 in 6, 34 in 4, 37 in 1, 

 38 in 2, and 40 in 2. This tabulation further strengthens our opinion that 

 Price dealt with more than one species, especially since our data in all 

 monogenetic trematodes show the insignificant numerical variability of the 

 given characteristic. This can be substantiated by the data on P. coronatus 

 which is discussed. We had at our disposal our 24 specimens of this species 

 frona Chrysemys sp, from U.S.A. (Michigan) collected in 1935 by D. Smith. 

 During the verification of the number of hooks of the sex armature we 

 obtained the follov/ing figures: with 28 hooks 1 individual, with 29- -2, 

 with 30--8, with 31 --4, with 32--2, with 33--6, and 35--1, which completely 

 corresponds to the usual degree of variability in the number of chitinous 

 elements of the copulatory organs among monogenetic trematodes. Until 

 the special varification and acquisition of new data> one must consider that 

 P. coronatus, just as the genus Polystomoides as a whole, are only known 

 from representatives of the superfamily Cryptodira. 



The genus Polystomoidella, containing only three species, is 

 encountered only on two closely related families --Chelydridae and Kino- 

 sternidae. The existing indications of the presence of P. oblongum (Wright) 

 in Chrysemys picta (Schn, ) (Testudinidae) are erroneous as Price correctly 

 pointed out (Price, 1939, page 86). 



Finally the genus Neopolystoma is indicated from Cryptodira, 

 Pleurodira, and Trionychidea, i.e., it is very widely distributed in all 

 turtles with the exception of Cheloniidae. The remaining species are 

 encountered on one species of host with the exception of P. orbiculare p. 282 



(Stunkard, 1916) for which is indicated a number of hosts from the family 

 Testudinidae ( Pseudemys spp. , Chrysemys spp. and others) and also 

 Trionyx (=Amyda) ferox. The data about the latest hosts are based on 

 finding of Polystoma aspidonectis MacCallum in the "nasal cavity, " lungs 

 and intestinal tract of Trionyx ferox from the New York Aquarium (Mac- 

 Callum, 1918b). Price made the last species synonymous with N. orbiculare. 

 To what extent this is correct we hesitate to say, but the finding of this 

 species on a distant host under artificial conditions forces us to consider 

 these conclusions with reserve. However, as a whole the correctness of 

 the data concerning the finding of Neopolystoma on the turtles of the super - 

 family Trionychoidea does not arouse any doubts, because N. palpebrae 

 Strelkov is authentically encountered on a single representative of a 

 superfamily in our fauna--Amyda sinensis (Wiegmann). The indication of 

 the finding of Neopolystoma on Pleurodira is based on N. chelodinae 

 (MacCallum) on Chelodina longicoUis (Shaw), it is true in aquarium conditions. 

 The entire genus apparently is actually widely distributed among all aquatic 

 turtles. 



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