4 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 74 



KET TO DESCRIBED SPECIES OF COOPEKIA 



1. Species placed in, but not definitely recognizable as belonging to, the genus 



Cooperia 2. 



Species definitely recognizable as belonging to the genus Cooperia 3. 



2. Gubernaculum present ; spicules 120^1 to ISO/x long, terminating in two processes 



of different shape and size; male 2.9 to 3.5 mm. long; female 4.3 to 4.9 mm. 



long Cooperia elegans. 



Gubernaculum absent ; spicules 134/x to 156m long, terminating in three processes 

 of different shape and size; male 4.5 to 6 mm. long; female 4.3 to 4.9 mm. 

 long Cooperia falsa. 



3. Gubernaculum present ; spicules 115fi long, with a recurved hook located at a 



distance of 45/x from tip ; male 2.8 mm. long ; female unknown. 



Cooperia alata. 



Gubernaculum absent ; spicules more than 115^ long and withou*: a recurved 



hook in posterior third 4. 



4. Ventro-ventral ray thicker than latero-ventral ray ; spicules 170 to 180/i long, 



each with median process 120jU, long, and each spicule terminating in two 

 slender processes ; male 7 to 9 mm. long ; female 7 to 11 mm. long. 



Cooperia macieli. 



Ventro-ventral ray more slender than latero-ventral ray ; spicules not ending 



in two processes 5. 



5. Spicules over 300/a long, with 7 toothlike structures in the posterior portion ; 



female vulva covered by a linguiform flap ; male 7.2 mm. long ; female 11 



mm. long Cooperia nodulosa. 



Spicules not over 300^ long and without toothl.ke structures 6. 



6. Spicules less than 200m in length 7. 



Spicules more than 200m in length 8. 



7. Branches of dorsal ray curved to form a lyre-shaped structure ; spicules 135 



to 185m long ; vulva with transverse slit ; male 4.6 to 7.3 mm. long ; female 



5.4 to 7.8 mm. long Cooperia curticei. 



Branches of dorsal ray nearly straight, almost parallel ; spicules 120 to 150m 



long; vulva crescentic in shape, elongated longitudinally Cooperia punctata. 



8. Spicules 224 to 240m long ; vulva covered by a large linguiform process ; male 



7.2 to 7.8 mm. long; female 8 to 9.5 mm. long Cooperia bisonis. 



Spicules 240 to 300m long ; vulva not covered by a linguiform process 9. 



9. Main branches of dorsal ray widely divergent, forming U-shaped arch with 



cleft tips ; spicules 240 to 300m long ; terminal portion of female with annu- 

 lar striations ; combined lengths of muscular ovcjectors about 700m ; male 



5.5 to 9 mm. long; female 6 to S mm. long Cooperia oncophora. 



Main branches of dorsal ray close together and parallel, with uncleft tips; 



spicules 240 to 300m long, with corrugated edge in middle third ; terminal 

 portion of female sharply pointed and not marked with annular striations; 

 combined lengths of muscular portions of ovejectors about 300m ; male 7 mm. 

 long; female 7.5 to 9 mm. long Cooperia pectinata. 



BIBLIOGRAPHY 

 Ckam, Eloisb B. 



1925. — Cooperia hisonis, a new nematode from the buffalo. Joum, Agric. 

 Research Dept. Agric, Wash., vol. 30, pp. 571-573, figs. 1-7. 

 FiEBiGER, Joseph. 



1923. — Die tierischen Parasiten des Haus-und Nutztiere, sowie des Menschen 

 ed. 2, xvi-f439 pp., 353 figs., 1 pi., 8 figs., Wien und Leipzig. 



