LIST OF DIPTERA. 841 



grayish, with pale tawny borders. Length of the body 4 lines ; of 



the wings 8 lines. 



a. North America. From Mr. Children's collection. 



Dexia Pristis, n. s., mas. Niyra, capite albo micante, thorace cine- 

 reo vittis quatuor nigris, pectore cano, abdomine maculis canis 

 bivittato, antennis pedibusque nigris, Mis basi palpis tibiisque 

 ferrugineis, alis sublimpidis. 



Body black, clothed with black hairs and bristles : head co- 

 vered with white lustre, clothed beneath with white hairs ; a dark 

 ferruginous stripe fringed with bristles, widening from the eyelets to 

 the feelers ; epistoma not prominent ; sides of the face fringed with 

 bristles at the base: eyes dark red, hairy: sucker yellow, clothed 

 with yellow hairs ; palpi tawny, beset with black bristles : feelers 

 ferruginous, nearly as long as the face ; third joint black, ferrugi- 

 nous at the base, full thrice the length of the second joint, slightly 

 increasing in depth from the base to the tip, which is rounded ; 

 bristle tapering, very slender, more than twice the length of the 

 third joint, downy for half the length from the base : chest tinged 

 with gray, fluorned with four slender black stripes; breast hoary, 

 partly clothed with pale yellow hairs : abdomen long-obconical, 

 much longer and a little narrower than the chest, adorned with 

 hoary reflections, which form a large spot on each side of every seg- 

 ment ; underside bluish gray : legs black, clothed with black hairs 

 and bristles ; thighs tinged with bluish gray ; shanks dark ferrugi- 

 nous ; foot-cushions yellow ; claws hairy : wings nearly colourless ; 

 wing-ribs tawny ; veins black, tawny at the base ; tip cross-vein 

 forming a right angle with the fourth longitudinal vein, slightly 

 curved inward near the base, straight from thence to the tip, joining 

 the border at some distance above the tip of the wing ; lower cross- 

 vein with two curves, the lower inward, shorter and more distinct 

 than the other, which is outward ; scales whitish, with pale yellow 

 borders. Length of the body 4^ lines ; of the wings 9 lines. 



a. Massachusetts. From Prof. Sheppard's collection. 



Dexia Ogoa, n. s., fem. Fulva, pectore albo, abdomine basi jlavo 

 apice piceo vittato, pedibusfulvis, alis sublimpidis vix fulvescen- 

 tibus. 



Body pale tawny, clothed with black hairs and long black 

 bristles : head wanting : scutcheon armed with two long black 

 spines : breast white : abdomen elliptical, much longer than the 

 chest, pale yellow towards the base ; a short pitchy stripe at the tip, 

 which, like the sides, is armed with a few long black spines : legs 



