160 PROCEEDENGS OF THE NATIONAL MUSEUM vol. vr. 



Conops {Sphenmconops') velutinus Krober 



Conops velutinus Krober, Arch. Naturg., vol. 81, Abt. A, Heft. 5, p. 146, 1915. 



The type (in USNM) has been examined. This species is very 

 closely related to brunneosericeus. 

 Range: Ai'gentina (Mendoza). 



Conops (Sphenoconops) nobilis Williston 



Conops sericeus Walker, Insect a Saundersiana, Diptera, vol. 4, p. 256, 18521 



(preoccupied) . 

 Conops argentifacies Williston, Kansas Univ. Quart., vol. 1, p. 43, 1892 (in key). 

 Conops nobilis Williston, Kansas Univ. Quart., vol. 1, p. 45, 1892. 

 Conops palliditarsis Krober, Konowia, vol. 6, p. 139, 1927. 



The type of sericeus, a female, is in the British Museum. Oldroyd 

 has supplied information indicating that it belongs here; however 

 the name is preoccupied by Conops sericeus Olivier. Williston used] 

 the name argentifacies in his key, but described the species underi 

 nobilis. 



Range: Mexico, Costa Rica, Brazil, and Bolivia. 



Material examined: Brazil: Chapada, Mato Grosso, Jan., 11 

 female (AMNH, cotype, labeled argentifacies). Bolivia: Reyes, 

 October, W. M. Mann, 1 male (USNM). Mexico: North Yucatan, 

 Gaumer (Krober det.: magnusi; species No. 4 of Williston in Biologia 

 Centrali-Americana) , 1 female (BM). AhuacatUn, Nayarit, July 

 18-22, 1951, P. D. Kurd, 1 female (UCB). 



Mallochoconops, new genus 



Similar to Conops and Physoconops, but differing from aU of the othert 

 members of the subfamily in having very wide cheeks, half the size; 

 of the eye-height. Ocellar swelling absent. Abdominal segments; 

 2 and 3 elongated. Proboscis short, about equal to the head height. 



Type: Microconops atratulus Malloch. 



This genus differs from Microconops Krober in having a more slender i 

 abdomen, shorter proboscis, and no ocellar swelling in addition to thei 

 wider cheeks. The ocellar swelling in Microconops is very distinct. 

 The differences in the length of the abdominal segments 2 and 3 in 

 Microconops fasciatus Krober mentioned by Malloch are due to the 

 difference in sex. 



There is a superficial resemblance to the new subgenus Gyroconops, . 

 agreeing with it in the short proboscis, the interruption of the wing! 

 pattern (very faint in atratulus) in the middle of the first posteriori 

 cell, the long third antennal segment, and the dark coloration. How- 

 ever, besides the wider cheeks, the head is not as long, and the vertex 

 does not extend anteriorly more than usual. 



