ART. 17 PARASITES OF AMPHIBIA AND EEPTILIA HAPiWOOD 57 



of cervical alae. Since the size variations are not mentioned by 

 either Walton or Steiner, it seems advisable to give those that I have 

 found in my material. 



Male: Length, 6 to 10.75 mm; width, 0.35 to 0.65 mm. The esopha- 

 gus is 0.35 to 0.5 mm long. The cuticular expansions at the anterior 

 end are 75/i to 120/x long; and the head is 38/i to 55/x wide. The nerve 

 ring and excretory pore are 0.14 to 0.19 mm and 0.3 to 0.375 mm, 

 respectively, from the anterior end. The spicules are 0.16 to 0.25 mm 

 long and 25/x to 34|U, wide. 



Female: Length, 9.5 to 13.55 mm; breadth, 0.55 to 0.85 mm. Tha 

 esophagus is 0.3 to 0.6 mm long. The cuticular expansions at the 

 anterior end are 85/x to 125/x long ; and the '' head " is 40/i to 55/i 

 wide. The nerve ring and excretory pore are 0.16 to 0.225 mm and 

 0.3 to 0.374 mm, respectively, from the anterior end. The vulva is 

 6 to 9.5 mm from the anterior end and divides the body as 1.8 to 

 2.6 : 1. The female tail is 0.26 to 0.32 mm long. The eggs are 42/^ 

 to 50^ wide by 75/a to 88/x long. 



From the foregoing measurements it will be seen that my largest 

 female is smaller than the average recorded by Walton, but as 

 environment makes large differences in the size of nematodes I do 

 not consider this significant. 



I have taken these worms from Bufo ten^estris, B. valliceps^ Rana 

 palustris, R. sphenocephala^ Leiolopmna laterale^ Emneces fasclatus, 

 Terrapene Carolina tiiungui^ and T. ornata at Houston, Tex. ; from 

 Hyla cinerea, Rana sphenocephala, Scelopm^s undulatits, and Lei- 

 olopisma laterale from Huntsville, Tex., and from Rana sylvatica at 

 Crown Point, N. Y. 



Family SPIRURIDAE Orley, 1885 



Subfamily Physalopterinae Stossich, 1898 



Genus PHYSALOPTERA Rudolphi, 1819 



Of this large and widely distributed genus there has been until 

 very recently only one well-described species, Physaloptera pkryno- 

 sonia, from North American cold-blooded hosts. Walton (1927) has 

 added several other species to this list. 



PHYSALOPTERA SQUAMATAE, new species 



Plate 5, Figube 7 



Specific diagnosis. — Physaloptera^ group " didelphis." A slender, 

 white nematode with very finely striated cuticula, reflexed over the 

 lips. The lips are dome-shaped, and each bears a large outer tooth 

 and three small, inconspicuous inner teeth. The nerve ring lies near 



