176 PROCEEDIXGS OF THE NATIONAL MUSEUM. vol. 48. 



Genus ORTHELLIA Desvoidy. 



ORTHELLIA CORNICINA Fabricius. 



Present on the range. 



Family SARCOPHAGIDAE. 

 Genus MICROCHAETINA v. d. Wulp. 



MICROCHAETINA CINEREA v. d. Wulp. 



A pair taken on the mesa August 10. 



Family DEXIIDAE. 

 Genus RHYNCHIODEXIA Bigot. 



RHYNCHIODEXIA FLAVOTESSELLATA s new species. 



Plate 6, fig. 1. 



Yellowish, opaque, wings hyaline, legs reddish, length 10-12 mm. 

 Head at yibrissae as long as at base of antennae, inferior occiput 

 swollen. Front in male one-fifth as wide as eye, in female distinctly 

 wider than eye. Vitta dark brown, linear in male, less than one- 

 half as wide as sides of front in female. Front in male olive gray. 

 In female upper portion brown with whitish pollen, an olive gray 

 quadrate patch enveloping base of antennae and extending nearly 

 to anterior margin of eye. Face and cheeks in each sex brownish, 

 thinly ochraceous pollinose, lower half of face on sides bearing a few 

 scattered hairs. 



Antennae in both sexes very short. In male less than one-half, 

 in female slightly more than one-half length of facial plate. First 

 and second joints yellow; third yellow at base, apical half black. 

 Arista long plumose, at least twice length of third antennal joint. 

 Facial depression narrower than sides of face, vibrissal angles ap- 

 proximated, vibrissas cruciate, situated fully the length of second 

 antennal joint above oral margin. Kidges bristly on less than lowest 

 fourth. Margin of face below vibrissas bearing a row of closely set 

 slender macrochaetae. Cheeks slightly broader than one-half eye 

 height, brownish with yellowish pollen. Proboscis brown, about 

 one and one-fourth times height of head, lower half distinctly chiti- 

 nized. Labella small, horny. Palpi yellow, slender, attached to 

 proboscis at about one-third its length measured from base. Eyes 

 bare. Thorax yellowish brown, ochraceous pollinose. Five longi- 

 tudinal vittas visible, brown, the median and outer ones wide, the 

 intermediate pair more grayish and narrow. Post-sutural bristles 

 in these specimens three, sterno-pleural bristles three. Scutellum 

 brown, ochraceous pollinose, bearing two pairs of long marginals 

 and some smaller bristles. Also a pair of cruciate apical bristles. 

 Abdomen elongate ovate, yellowish brown, pseudo-maculate with 



