ART. 17 PARASITES OF AMPHIBIA AND KEPTILIA HAEWOOD 59 



it is readily distinguished in both sexes by the structure of the caudal 

 regions. 



PHYSALOPTERA PHRYNOSOMA Ortlepp, 1922 



This parasite has been taken from the stomach of Phrynosoma 

 cornutum both at Houston and at Anderson, Tex. Judged by these 

 and other records, it is a frequent and widespread parasite of 

 Phrynosoma sp. 



Genus THUBUNAEA Seurat, 1914 



This small genus is closely related to Physalopfera. Hitherto it 

 has been known by only three species, one from Africa and the other 

 two from South America. The following account adds a new 

 species, and extends the known geographic range of the genus to 

 Xorth America. 



THUBUNAEA LEIOLOPISMAE, new species 



Plate 5, Figure 8 



Specific diagnosis. — Thiibunaea: A white worm with a very finely 

 striated cuticula. The lips exhibit the usual three teeth, and around 

 the base of the lips there is a slight thickening of the cuticula that is 

 reminiscent of the cephalic collarette of the closely related genus 

 Physaloptera. The nerve ring lies near the cephalic margin of the 

 last fifth of the muscular esophagus, and the cephalic papillae lie at 

 about the same level. The excretory pore lies near the union of the 

 two parts of the esophagus. 



Male: Length 8.7 to 9.9 mm, width 0.21 to 0.3 mm. The vestibule 

 is about 42/M long, the muscular esophagus 0.21 to 0.27 mm long, and 

 the glandular esophagus 1.55 to 1.75 mm long. The nerve ring and 

 excretor}'^ pore are 0.21 and 0.25 to 0.265 mm, respectively, from the 

 anterior end. The male tail is 0,145 to 0.22 mm long. The caudal 

 alae are well developed, and as usual for the genus the inner side 

 of the alae is strongly tuberculated. This makes the papillae very 

 difficult to distinguish, and I am far from certain that the three pairs 

 of stalked papillae and the five pairs of sessile papillae that are 

 figured are the only ones present. Those papillae that are figured, 

 however, could be seen fairly clearly. The spicules are unusually 

 well cutinized for this genus. The right spicule is longer than the 

 left, but the ratio varies in different individuals. The measurements 

 are 84/i to 93)Li for the right spicule and 50/^ to 72/* for the left spicule. 



Female: Length 13.4 to 14.8 mm, width 0.31 to 0.34 mm. The 

 vestibule is 0.2 to 0.24 mm long, the muscular esophagus 0.31 to 0.34 

 mm long, and the glandular esophagus 2.36 to 2.45 mm long. The 

 nerve ring and excretory pore are 0.285 and 0.31 mm to 0.34 mm. 



