296 BULLETIN 140, UNITED STATES NATIONAL MUSEUM 



KEY TO SPECIES OF PHYSALOPTERA 



1. True Physaloptera, i. e., species agreeing with the generic diagnosis 2. 



Species inquirenclae, placed in this genus but not agreeing entirely with the 



generic diagnosis 16. 



2. Normally in reptiles; found as pseudoparasite in Ciconia alba. 



Physaloptera abbreviata, p. 307. 

 Normally in birds 3. 



3. Teeth of lips undescribed 4. 



Teeth of lips described 0. 



4. Description very incomplete; from Lanius minor. 



Physaloptera bilabiata, p. 307. 

 From other hosts than above 5. 



5. Male 18, female 30 mm. long; cuticle enlarged posterior to the lips; eggs 



81jt long by 26/* wide ; located in head of Micropogon, species. 



Physaloptera fusiformis, p. 303. 

 Male 26, female 26 mm. long ; cuticle reflected over lips ; eggs not described ; 

 in proventriculus of Falco, species; (probably a synonym of P. alata). 



Physaloptera megalostoma, p. 300. 



6. Two teeth on each lip, an outer and an inner (tripartite) 7. 



One tooth or more than 2 teeth on each lip 15. 



7. Relative sizes of teeth not described ; distinctive character consists in the 



one species (P. truncata) of the outer tooth being widened or "knobbed" 

 at the top, in the other species (P. crassa) of the presence of only 1 pair 



of central caudal papillae 8. 



Relative sizes of teeth described ; outer tooth not as above ; pedunculated 

 papillae number 11 to 13 9. 



8. Male 14 mm., female 23 mm. long ; 5 pairs of lateral pedunculated caudal 



papillae; 1 pair of ventral papillae Physaloptera crassa, p. 302. 



Male 25, female 33 mm. long ; 4 pairs of lateral pedunculated caudal papil- 

 lae, 13 ventral papillae Physaloptera truncata, p. 306. 



9. Outer tooth large, inner tripartite tooth small 10. 



Inner tripartite tooth large, outer tooth small 14. 



10. Caudal alae with 4 pairs of lateral pedunculated papillae. 



Physaloptera acuticauda, p. 297. 

 Caudal alae with 5 pairs of lateral pedunculated papillae 11. 



11. More than 11 ventral caudal papillae (14 as figured) ; tail of female short 



(from 1/40 to 1/70 of total body length) Physaloptera crosi, p. 302. 



Eleven ventral caudal papillae; tail of female elongate (1/30 to 1/21 of total 

 body length) 12. 



12. Male 7 mm. long; cervical papillae situated 100/j. posterior to the end of 



muscular esophagus Physaloptera alata chevreuxi, p. 301. 



Male 17 mm. or longer ; cervical papillae at level of terminal region of 

 muscular esophagus 13. 



13. Male 22 to 28.5 mm., female 33 mm., long ; cloacal aperture of male 1.2 mm. 



from posterior extremity; vulva of female anterior to end of esophagus, 

 at about the anterior eighth of total body length. 



Physaloptera alata nouveli, p. 301. 

 Male 17 to 20 mm., female 19 to 27 mm. long; cloacal aperture of male 650/* 

 from posterior extremity ; vulva of female posterior to end of esophagus, 

 at tbe anterior fifth of body length (according to Seurat) or more pos- 

 terior (according to Schneider) Physaloptera alata, p. 298. 



