CESTODARIA 453 



to belong to the genus Caryophyllaeus, the differences 

 from • C . m u t a b i 1 i s ' ( = C . 1 a t i c e p s) only being specific 

 and not generic, and in view of the indefiniteness of such terms 

 as ' subcylindrical ' when applied to a pleomorphic structure 

 like the head, of ' depressum ' when applied to the body which 

 may be flat anteriorly and oval in section posteriorly even in 

 the same animal, and of ' single ' and ' separate ' when these 

 refer to genital apertures which show all degrees of opening 

 into a common atrium in different species which undoubtedly 

 are to be included in one genus, it is impossible not to agree 

 with Wagener and Monticelli. Further, as is demonstrated 

 in the present communication, the muscular cylindrical type 

 of head, which was the most characteristic feature of Diesing's 

 genus Monobothrium, is to be found associated, indis- 

 criminately, with two very different types of body, w^hence it 

 is evident that the character of the head cannot serve in this 

 group as a feature of generic value. The name Monobothrium 

 thus also lapses. 



Having thus concluded that eight of the ten Carj^ophyllaeid 

 specie*; described previously to this communication belong to 

 the genus Caryophyllaeus, and provisionally alloAving 

 Archigetes to stand as a separate genus on the sole ground 

 that it possesses a ' caudal ' appendage in the sexual condition, 

 it is necessary to redefine the genus Caryophyllaeus and 

 to show reason for creating a new third genus, Wenyonia. 



The genus Caryophyllaeus was apparentl}^ founded by 

 0. F. Muller in 1787 (18), but since I have not been able to 

 consult this work I will give the definition of this genus supplied 

 by Gmelin (7) in 1790, which is probably fully as comprehensive 

 as that of Muller, both being based on specimens of C . 1 a t i - 

 c e p s . Gmelin's definition of the genus is : ' Corpus teres : 

 ore fimbriato. . . . Habitat in piscium, aquas dulces inhabitan- 

 tium, potissimum cyprinorum, carpionis, tincae, jesis, bramae 

 intestinis, rarior, margaritaceus, ad pollicem longus, reliquis 

 intestinalibus vitae tenacior, fine posteriori rotundato, anteriori 

 latiori.' This definition clearly applies to C. laticeps, 

 but it is too special to include other species subsequently 



NO. 267 H h 



