EEV. A. E. EATON ON RECENT EPHEIMEEID.E OR aiATELIES. 247 



S . Wing-membrane transparent, tinged universally with a light brownish yellow 

 approaching tlie lightest shades of raw-umber. Eore tarsus lighter than the tibia, and 

 with narrow brownish joinings. Notum in one specimen as dark as in the d ; in 

 another specimen it is of a much lighter brown-ochre. Length of body, c? 9-12, 2 

 (shrunken) 9 ; wing, c? 11-14, ? 15 ; setae, s im. 28-36, 2 im. 22 mm. 

 ITab. Mt. Hood, Oregon, and (Edwards) California (M'^Lach. Mus.). 



CINYGMA, geu. nov. 



Illustrations. — Achilt (details), PI. LXV. 4, 5. 



Adult. — Very closely related to Iron, the proportions of the tarsal joints of the inter- 

 mediate legs being similar ; but in the hind tarsus, joints 1-4 diminish successively in 

 length, and there are differences in the proportions of the joints of the fore tarsus. 

 First joint of the 6 fore tarsus shorter than the second, and this a very little shorter 

 than the third joint ; first joint of the ? fore tarsus shorter than the second, but as long 

 as the third joint ; ungues each unlike the other. Penis-lobes similar to those of Rhi- 

 throgena. Fore leg of d t% as long as the body; tarsus about 1| the length of the 

 tibia, which is barely longer than the femur ; the tarsal joints in the order of their 

 shortening rank 3, 2, 4, 1, 5, and the first is about f as long as the second joint. Pore 

 leg of ? about -^ as long as the body ; tarsus about f the length of the tibia, and this 

 about as long as the femur ; the tarsal joints in the order of their shortening rank 2, 1 

 equal to 3 and to 5, 4, and the first f as long as the second. Hind tarsus oi 6 \ the length 

 of the tibia, and this about f that of the femur ; its joints in the order of their 

 shortening rank 5, 1, 2, 3, 4, the proximal three joints differing (if at all) successively in 

 length by only small gradations. Ungues in every tarsus, each unlike the other. Hind 

 wings of the usual form ; the axiliar region narrow. In the dried 2 abdomen the 

 relative lengths of the dorsal segments 2-10 may be formulated thus : — 5, 6, 8, 10, 10, 

 10, 9, 7, 5 ; ventral lobe of the ninth segment refuse. Porceps-basis either produced 

 into short lobes (as in Epeorus) for the support of the limbs, or else saliently toothed 

 near the insertions of the liml)s on each side of its posterior border ; penis-lobes similar 

 to those of BhUhrogena. Outer caudal setae of d thrice, of 5 about twice, the length 

 of the body. Median ocellus of 2 somewhat isolated, and (though prominent) lower 

 than the anterior border of the upper surface of the L ead ; occipital margin almost even 

 nith the posterior orbits of the oculi. Pronotum of 2 emarginate in the middle behind ; 

 :he refiexed lateral lobes angular. 



SuUmago. Wings uniformly greyish or yellowish ; their neuration opaque, but not 

 )ordered. 



Type. C. integrum, sp. nov. 



Distribution. North America. 



Etymology. Kivvjfxa, from the hovering habits of the flies. 



33* 



