MONGOMA. 479 



is known, recognised the difficulty in allotting to the veins their 

 correct names (Berl. Ent. Zeits. xxvi, p= 90), and in describing 

 his first new species in the genus, M. tenera, from the Philippine 

 Islands, he says in a footnote (referring to the words "the presence 

 of the two cross-veins inside the marginal cell " used in the text) : 

 " I call them cross-veins merely for shortness' sake, because one 

 of them may also be considered as a branch of the 2nd vein." 

 He spoke of the genus as representing " a form of venation which 

 is of very rare occurrence among Diptera, and we must suspend 

 our judgment on this point * until we have an opportunity of 

 seeing the insect from Java described by Doleschall." 



At this time he was accepting three species as congeneric, 

 fragiUima, Westw., albitarsis, Dol. (which latter it is evident from 

 the above quotation he had never seen), and his new species tenera. 

 In pointing out the difference of Doleschall's species in having 

 only three posterior cells instead of four, as in fragiUima and 

 tenera, it is obvious that he was guided by Doleschall's figure- 

 alone. The Dutch author's remark " two marginal cells " does not 

 help in the question of terminology. 



Table of Species. 



Middle tibiae with conspicuously thickened 

 tips through the presence of short snow- 

 white pubescence pennipes, Os. Sac., p. 479. 



Middle tibise without such adornment. 



Legs mainly yellowish ; femora whitish 



at tips . ". tenera, Os. Sac., p. 480. 



Legs mainly blackish ; femora pale at 



base pallidiventris, sp. n., 481. 



343. Mongoma pennipes, Os. Sac. (PI. IX, fig. 14; PI. XI, 



fig. 13.) 



Monyoma pennipes, Osten Sacken, Berl. Ent. Zeits. xxxi, p. 204 

 (1887). 



<$ $ . Body bright brownish yellow or yellowish, very much like 

 Mongomioides trentepoklii,but't\\e proboscis, palpi, and antenna are 

 yellowish, the latter more or less darker. Thorax: in some speci- 

 mens three shining rather brownish thoracic stripes are distinctly 

 visible, the side ones much abbreviated in front, but continued 

 beyond the suture ; in other specimens the whole thoracic dorsum 

 is 'almost unicolorous. Abdomen with a little pale pubescence, 



in TIPULID,E. It may also be urged in analogy that in Sciara, a very extensive 

 and dominant genus of MYCKTOPIIILID.H, the anterior cross-vein invariably 

 takes a longitudinal position. To my thinking, however, the vein has every 

 appearance of the 3rd longitudinal vein by its manner of origin, its superior 

 length to the usual anterior cross-vein, and the cell concerned has much more 

 the appearance of a subinarginal cell than of that of the 1st posterior cell. 

 * /. ., the correct identification of the veins. 



