82 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 5 1 



Van der Wulp's figure (in the Biol. C. A. Dipt., n, pi. 13, fig. 12) of 

 Mexican specimens gives somewhat the same impression. Two 

 specimens from Mexico (one Tehuantepec, Sumichrast) show this 

 character markedly, the third antennal joint not being truncate at 

 tip as in the figures given by Brauer and von Bergenstamm and by 

 Williston. It therefore seems evident that not only is tvillistoni a. 

 good species, but the genus Ocyptcrosipho may be retained, 0. wil- 

 listoni being the West Indian and Central American form, while 

 O. cclops is the more northern form occurring in our Southern 

 States. It is to be noted that St. Vincent belongs to the South 

 American fauna, while Santo Domingo belongs to the Central 

 American, which includes parts of Mexico and the Southern United 

 States. 



ICHNEUMONOPS, gen. nov. 



Bearing much superficial resemblance to Ocyptcra, but differing 

 radically in the structure of the basal portion of the abdomen, and 

 in head characters as well. Elongate and narrowed in form. Head, 

 thorax, and abdomen of almost equal width, but the head distinctly 

 wider than the thorax, the abdomen constricted basally into a pedicel 

 formed principally by the base of second segment, which shows 

 more constriction than any other part. 



No vibrissas that can be differentiated from the bristles of peristo- 

 malia. Second antennal joint rather elongate, about three times as 

 long as first; third joint elongate, narrowed, about two and one-half 

 times as long as second. Arista not distinctly jointed. Front at 

 vertex narrower than eye width, but about equal to latter at base of 

 antennae. One row of weak frontal bristles extending only to base 

 of antennae. One pair of weak ocellar bristles, slightly proclinate. 

 One pair of vertical bristles longer than frontal bristles, directed well 

 backward. No orbital bristles (male). Cheeks about two-fifths of 

 eye height. Face receding, facial profile straight, epistoma promi- 

 nent. Facialia bare, not divergent below, ptilinal area about as 

 wide as eye width, parafacials about half as wide above, but nar- 

 rower below. Facial plate elongate, not narrowed below, produced 

 on lower edge. Antennae inserted above eye middle, rather above 

 three-fourths of head height. Eyes bare, descending about three- 

 fourths way to lower margin of head, which is long. Seen from in 

 front, the space between lower angles of eyes is more than twice that 

 between upper angles, the frontofacial area evenly widening from 

 middle of front to cheeks. Proboscis below geniculation hardly as 

 long as antennae, labella well developed. Palpi extremely small and 

 short, atrophied. Occiput convex, swollen on lower three-fourths. 



