292 Records of the Indian Museum. [Woh. VI 



Notes on MONGOMA, PARAMONGOMA and 

 MONGOMIOIDES. 



Including the three new ones herein introduced, seven species 

 have been recorded from the East, all of which, except albitarsis, 

 Dol., occur in India. This latter, described from Java, and appar- 

 ently not recognized since its discovery, may very likely be found 

 in South India, Ceylon or in some parts of the Malay Peninsula. 



The genus is highly interesting as presenting one of the most 

 conspicuous variations from the normal type of venation in this 

 family. Previous to describing the genus Prof. Westvvood wrote 

 to Osten Sacken for his opinion, and the latter' s reply is indicative 

 of its abnormality in his words: '' The systematic position of this 

 species (M. jragillima) is very puzzling . . . ." He pointed out that 

 the apparent resemblance between its venation and that of Para- 

 iropesa, Sch.,' was only superficial and that it was certainly a new 

 genus. 



Westwood's figure of the original species, fragiUima, from 

 Central Africa, is excellent, and distinctly portrays the distinctive 

 features of the genus: the long auxiliary vein ending only just 

 before the tip of the rst longitudinal; the wide forking of the 

 2nd vein which, with the marginal vein, gives a first impression 

 of the marginal cell being divided by two cross-veins into three 

 portions ; the merging of the ^rd longitudinal vein in the .\th * 

 at the upper basal corner of the discal cell, thereb}^ causing the 

 absence of the anterior cross-vein ; the abrupt curve downwards of 

 the end of the 5th vein, closing, in most cases (speaking sensu lata), 

 the anal cell ; the shortening of the two basal cells and the very 

 short 7th vein, all characteristic features of this singular genus.^ 



Even Osten Sacken, than whom I consider no better authority 

 in Tipulidae has existed, recognized the difficulty in allotting to the 

 veins their correct names (Berl. Ent. Zeits., xxvi, 90), and in des- 

 cribing his first new species in the genus, tenera, from the Philippine 

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



1 For description of Paratropesa see Verb, zool.-bot. Ges. Wien, xvi, 932 

 (1866). 



2 This view is in accord with Williston's opinion (Tr. Ent. Soc, 1896, 

 p. 292) but I only recently saw this author's paper, long after I had studied the 

 question personally. It is satisfactory to find my resultant view coincides with 

 that of so good an authority as Prof. Williston. 



'i Of course, if the short vein joining the 2nd vein with the discal cell (or the 

 corresponding part of the 4th vein when the discal cell is absent) be considered 

 the anterior cross-vein instead of the 3rd longitudinal vein, it follows that there 

 would be only one submarginal cell in any of the three genera concerned, and 

 the cell exterior to the anterior cross-vein will become the ist posterior cell. 

 This would give Mongoma five posterior cells, and Mongomioidcs and Paramongoma 

 four posterior cells each. In support of this suggestion it may be urged that the 

 3rd vein is not known elsewhere to terminate in the interior of the wing. Person- 

 ally I know of no case where it does so, but it must be remembered that excessive 

 abnormalities are not rare in Tipulidae. It may also be urged in analogy that in 

 Sciat-a, a very extensive and dominant genus in Mycetophilidae, the anterior cross- 

 vein invariably takes a longitudinal position. 



To my thinking, however, the vein has every appearance of the 3rd longi- 

 tudinal 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 submarginal cell 

 than of that of the ist posterior cell. 



lu connection with this point, conf. footnote ', p. 294. 



