60 CYKTIDAE OF NORTH AMERICA 



female, with five obvious segments; short pubescence fairly abun- 

 dant. Genitalia concealed beneath the rather small fifth segment. 



Legs rather short and stout, but simple and without any trace 

 of spurs or processes; tarsi with first and fifth joints longer than 

 the others. Pulvilli and claws well separated from fifth tarsal 

 joint; claws long and thin; pulvilli in male almost equally long 

 and thin, but shorter and more pad-like in female. 



Wings short in male, but larger and longer in female; vena- 

 tion very imperfect; in 0. costatus the two large basal cells and 

 the closed anal cell can be traced, but the small cross-vein is 

 absent; the wing-tip is clear of all venation for a considerable 

 space; second longitudinal vein absolutely absent; third vein 

 sloping downwards, incomplete, and not forked; fourth vein in- 

 dicated by three incomplete veins running toward the margin 

 long after the wing tip. Squamae (thoracal) enormous, de- 

 pressed, and clothed all over upper surface with not at all dense 

 wooly pubescence; alar pair rather small but thick, clothed only 

 with minute down. Halteres on comparatively short stems, 

 hidden beneath squamae. 



Verrall considers that there are six species in the Palaearctic 

 region, although Kertesz gives thirteen in his Catalog. There 

 are thirteen species from North and Central America: one from 

 South Africa, one from Southern Asia, and about six from Aus- 

 tralia and New Zealand. 



Erichson gave a fairly good characterization of Ogcodes in his 

 Monograph of 1840. He preferred Ogcodes to Henops, claiming 

 that the former name was older and that Meigen had not clearly 

 defined Henops. Dr. Benno Wandolleck, in 1909. published a 

 paper on the "Mouth opening of Ogcodes," and gave a detailed 

 account of its structure. He found that dried material was use- 

 less in this study, as did Erichson in 1846. 



The following artificial table may help to separate the species 

 of this difficult genus. I have not included engonatus and humer- 

 alis in this table, as I have not seen either of the species, and the 

 descriptions offer no striking characters that would establish 

 them. Both arc near costatus Loew, and the types would have to 

 be examined ])eforc drawing any conclusions as to their status. 



