TWO NEW NEMATODES, AND NOTES ON NEW FINDINGS 

 OF NEMATODES PARASITIC IN AMPHIBIA ' 



By A. C. Walton 



Knox College, Galesburg, III. 



Through the courtesy of Dr. M. C. Hall, chief of the zoological 

 division of the United States Bureau of Animal Industry, a number 

 of unnamed nematode parasites of amphibian hosts were recently 

 sent to the writer for examination. Two apparently new species 

 were found, and new host records for several other little-known species 

 were obtained. 



The genus Pharyngodon is represented up to this time by only one 

 species that has been reported from an amphibian host: P. hatra- 

 chiensis Walton, 1929, from a tadpole of Rana pipiens. Female 

 worms taken from adult specimens of Rana pipiens and of R. clamitans 

 afl'ord the basis for establishing a second species from amphibian 

 hosts. 



PHARYNGODON ARMATUS, new species 



Figure 1, a-c 



Specific diagnosis. — Pharyngodon: Male, unknown. Female, short 

 (3.5 mm long), of medium width (240/i), and tapering abruptly at the 

 posterior end to a naked spikelike tail. Anterior end shows distinct 

 annulations, which become indistinct caudad; inconspicuous lateral 

 flanges present. Mouth surrounded by three indistinct lips ; no buccal 

 cavity or vestibule present, but the pharynx seems to be protected by 

 chitinous plates for a short distance back from the mouth. Excretory 

 pore, like that of the other species from an amphibian host, is opposite, 

 instead of caudad to, the esophageal bulb. Vulva just in front of 

 midregion of body. Eggs a very slightly flattened ovoid with but 

 one distinct terminal plug; segmented (4- or 8-celled) at time of 

 oviposition. 



This form resembles P. batrachiensis , but in view of the presence 

 of the armored pharjmx, the relatively different measurements of 

 important structures, and the difference in the eggs, the variations 

 seem to be of specific importance. 



1 Contribution No. 42 from the Biological Laboratories of Knox College. 



No. 2947. — Proceedings U. S. National Museum, Vol. 82, Art. 6 



150257—33 1 



