Art. 23 GENUS CYLINDEOMYIA MEIGEN ALDRICH 7 



2. Abdomen without red on sides, wliolly black ; front basitarsus shorter than 



the four following joints (eastern; argentea of Coquillett 1897, not of 



Townsend) nigra, new species. 



Abdomen broadly red on sides 3 



3. Female with distinct, symmetrical hooks on last genital segment, which are 



placed quite far apart ; male with the front basitarsus as long as the fol- 

 lowing four joints and concave on outer side, also with hind tibia villous 

 on inner side (widespread west and north ; European) __ intermedia Meigen. 

 Female with last genital segment compressed, pointed, without hooks ; fourth 

 abdominal segment with a pair of stout bristles near base above; male pre- 

 sumably without the characters just mentioned (Alberta). 



compressa, new species. 



4. Abdomen wholly shining, the incisures not white poUinose (Colorado). 



alticola, new species. 

 Abdomen with very evident white pruinosity 5 



5. Tibiae red ; veins around discal and first posterior cells with sharply blackish 



borders (California, Mexico) limbata, new species. 



Tibiae black; the dark color of the wings more diffused 6 



6. A conspicuous white poUinose spot on the sclerite just above the posterior 



thoracic spiracle (Cuba) bakeri, new species. 



No such spot, the sclerite shining black 7 



7. Abdomen without any red; large species (Porto Rico) atra Koeder. 



Abdomen broadly red on sides or apically 8 



8. Males J-- 9 



Females 14 



9. (MALES) — The posterior forceps short and great y swollen, soft and cush- 



ion-like, but suddenly contracted into a small apical beak 10 



The posterior forceps long and soft, basal half swollen, suddenly reduced at 

 middle, the apical portion reaching almost to tips of anterior forceps (east 



ern, widespread) argentea Townsend. 



Posterior forceps not as described 11 



10. The fifth sternite with a wide, shallow emargination in the middle (east- 



ern) euchenor Walker. 



The fifth sternite with two narrow prolongations close together, forming a 

 deep narrow notch at the middle line (Mexico City; Dominica). 



uniformis, new species. 



11. Both pairs of forceps yellow, shining, alike in consistency, the posterior 



ehitinized, both pairs small and somewhat concealed by the thin yellow 

 expanded margin of the last genital segment (widespread). 



nana Townsend. 



The posteiior pair of forceps much less ehitinized than the anterior pair, 



which are hard and shining 12 



12. Anterior forceps very broad apically, broader than at base, subtruncate 



(widespread) armata, new species. 



Anterior forceps tapering toward tip, not so wide apically 13 



13. Posterior forceps short and in profile rather thick, but not strikingly .swol- 



len, about half as long as anterior ones, which are grooved behind at the 

 bend ; back of head with some black hair on each side of the occipital 



region above (wulcspread) decora, new si>ecies. 



Posterior forceps more than two-thirds as long as anterior, which are not 

 grooved behind at the bend ; back of head with only pale hair inside the 

 orbital row (widespread; euchenor of Townsend 1916). 



vulgaris, new species. 



