294 Records of the Indian Museum. [Voiv. VT, 



Doleschall's figure to be correctly drawn, a point of discrepancy, 

 which, nevertheless, as a similar variation occurs in Gonomyia, may 

 not be regarded as of generic distinction. In albitarsis, the con- 

 tact of the upper basal corner of the discal cell with the 2nd 

 longitudinal vein is punctiform, so that there is neither ^rd longi- 

 tudinal vein nor anterior cross-vein. This is the only species in 

 which I have noted this extraordinary feature. In manca and 

 pallida, as in all other species, what I am compelled to regard as 

 the 3rd longitudinal vein is always short, but always of quite a 

 reasonable length, merging in the 4th vein at the upper basal 

 corner of the discal cell, and at about the same spot in the 4th 

 vein, when the discal cell is absent. 



Regarding the correct terminology it might have been assumed 

 in studying the wing of, let us sa^^, trentepohlii, that the 3rd 

 longitudinal vein was continued to the wing-border, forking soon 

 after quitting the 2nd vein ; that the anterior cross- vein was 

 present, and tliat the 4th longitudinal vein was simple ; but on 

 comparing this wing with Mongonia, sensii stricto, it becomes 

 obvious that such a suggested anterior cross-vein is in both types 

 of wing the normal base of the discal cell, the closed or open nature 

 of this cell not affecting the question. Adopting this view, the 

 3rd longitudinal vein is restricted to a comparatively short length, 

 the anterior cross- vein is then seen to be absent, and in the case of 

 albitarsis, as before noted herein, the discal cell is formed at the 

 ver}' juncture of contact with the 2nd vein, thus, in this species, 

 obliterating the 3rd vein altogether as well as the anterior cross- 

 vein.' 



1 It seems advisable here to make reference to the genus Paratropesa, Sch. , 

 a genus which Osten Sacken considered not to be allied to the Gonomyia and 

 Mongoma group, in spite of its apparent affinity by virtue of a somewhat similar 

 venation. Subsequently, in his "Studies on Tipulidae " he confirmed this lack 

 of real affinity, yet, although I have not seen any specimen of it, a study of the 

 wing, as figured by Schiner, convinces me of its real kinship, and this view is 

 supported by the position it holds in Prof. Kertesz's recent catalogue of Diptera. 



The genus is quite likely to be found within the geographical region embraced 

 by this volume and therefore a few notes on the terminology bearing important 

 references to Gonomyia and Mongoma may not be out of place. The 2nd lon- 

 gitudinal vein starts before the middle of the wing in a very wide sweep, fork- 

 ing widely close to the wing-tip; the upright marginal cross-vein placed at about 

 the middle of the praefurca joining the ist vein some distance before its tip. 



Posterior to the 2nd vein there is only a cross-vein, in a direct line with the 

 marginal cross- vein connecting the 2nd vein with the discal cell. The rest of 

 the veins are more or less normal, though rather widely separated. 



The point, however, to which attention is called, is the short upright cross- 

 vein joining the 2ud vein and the discal cell. In Mongoma there is a short 

 very oblique vein at this point which I term the s^d longitudinal vein, losing itself 

 in the 4th vein, the anterior cross-vein being absent. In Paratropesa, this up- 

 right .short cross- vein seems to assert itself self-evidently as the anterior cross- vein 

 and not as the beginning of the third vein. Ttiis being so, it is to be understood 

 that I recognize in Mongoma a short oblique 3rd vein merging in the 4th vein, 

 the anterior cross- vein being absent ; and in Paratropesa an upright anterior cros.s- 

 vein joining the 2nd vein to the discal cell, the 3rd vein being absent. It is 

 so seldom that either the 3rd vein or the anterior cross- vein is absent that it i.*: 

 difficult to decide which should be considered of the more anatomical value ; 

 personally I think at first sight the latter. 



