332 THE CANADIAN ENTOMOLOGIST. 



Thorax obpyriform or much narrowed posteriorly 52. 



48. Thorax quadrangular or nearly 49, 



Thorax about twice as long as wide, the sides more or less com- 

 pressed or sinuate medially. 



Head not wider than the thorax ; abdomen ovate, subsessile, the 

 second segment large, with two white spots. 

 (Africa.) Apteromutilla, Ashmead. 



50. Head somewhat large, but without a tooth on each side beneath, the 



hind angles rounded, not acute ; eyes oval or oblong ; antennal 



scape not specially long 51. 



Head large, with a tooth on each side beneath, the hind angles acute ; 

 eyes oval ; antennae rather widely separated, the scape long, the 

 third joint very long ; mandibles long, narrow, arcuate and 

 bidentate at apex. (North America.) Myrmilloides, Andre. 



51. Mandibles 3-dentate ; third antennal joint only about twice as long 



as the fourth, or as long as joints 4 and 5 united. (Europe, Africa, 



Asia.) Myrmilla, Wesmael, 



Mandibles acuminate at apex, with a tooth within before apex, never 

 tridentate ; third antennal joint more than twice longer than the 



fourth. (Europe, Africa.) Edrionotus, Radoszkowski. 



(Type Mutilla capitata, Lucas.) 



52. Head not wider than the thorax, strongly concave beneath, the 



margins rimmed ; second abdominal segment anteriorly depressed, 

 the depression limited by an oblong cushion. 



(Asia.) Platymutilla, Andre. 



(Type P. quinquefasciata, Andre.) 



A NEW JOINT- WORM PARASITE FROM RUSSIA. 



BY WILLIAM H. ASHMEAD, M.A., D.SC, WASHINGTON, D. C. 



Homoponis Vassiliefi^ sp. nov. — 9 — Length, 2 mm. Head and 

 thorax blui.sh, finely, closely punctured, the face and the pleura with a 

 greenish metallic lustre, the metapleura decidedly brassy; antenna? brown, 

 the scape yellow ; legs concolorous with the thorax, the hind coxae with a 

 metallic greenish fringe, the apices of all femora, all tibiae and tarsi, except 

 the last joint, yellow, the last joint dark fuscous ; wings hyaline, the 

 nervures brown, the stigmal vein two-thirds the length of the marginal, the 



