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A NEW TREMATODE FROM THE MUD-EEL — ZELIFF 225 



ootype, Laurer's canal, seminal receptacle, oviduct, and vitelline 

 receptacle have not been observed or are not clearly defined. In 

 C. sirenis the esophagus is shorter, and the caeca do not terminate 

 regularly in the intertesticular zone as in T. parvus Braun, 1901. 

 There is considerable variation between this species and T. medius, 

 T. corti, T. lohosuSy and T. diminutus described by Stunkard (1916). 

 Although the measurements approach the last-named species, the 

 caeca of C. sirenis do not extend so far posterior, the esophagus is 

 shorter, the cutus sac extends to the ovary, and the vitellaria are 

 grouped. The size of the body and various organs, including the 

 shorter caeca of C. sirenis, separates it from T. insculpti, T. pallidus, 

 T. guttati, and T. chelopi described by MacCallum (1918), The 

 caeca do not extend so far caudad of the posterior testis, the length is 

 much less, and the ova are smaller in the collapsed and noncollapsed 

 condition than is given by Chandler (1923) for T. stunkardi from 

 A. means. The species is much smaller than C. neduri described by 

 Perkins (1928) and also it differs in having a prepharynx, smaller 

 pharynx, shorter esophagus, less caudad caeca, and ova, ovary, testes, 

 and other organs of noticeable differences of dimensions. In contrast 

 with T. stenonura, a species that apparently belongs in Cercorchis, 

 recorded from Clemmys marmorata by Ingles (1930), the smaller size, 

 shorter caeca, and location of the genital pore are points of difference. 

 When compared with C. texanus, C. hairdi, and C. singularis, the 

 more minute size and the more cephalad caeca of C. sirensis are very 

 noticeable points that distinguish it from the descriptions given by 

 Ilarwood (1932) and Bennett (1935) of these species. Compared 

 with C. kinosterni, recently described by Byrd (1936), the esophagus 

 of C. sirenis is much shorter, the caeca extend less posterior, and the 

 vitellaria are more anterior. In this last comparison the differences 

 in measurements of some of the organs and the bodies are not large. 

 Other differences of the measurements of organs are probably more 

 or less important for all species concerned. The drawing (pi. 11, 

 fig. 6) was made with the camera lucida. 



Keys to the species of Telorchis are given b)^ Goldberger (1911) and 

 Dollfus (1929). Perkins (1929) gives a key to Cercorchis, which in- 

 cludes transfers from the srenus Telorchis. 



