366 TIPULID^E. 



species is one of Osten Sacken's own, and he would surely have 

 mentioned the fact in his monograph, yet he does not do so, 

 although referring to this particular species on another point. 

 Needhain also illustrates the wing of another somewhat abnormal 

 species, D. cinerea, Doane. Neither subcostal nor marginal cross- 

 vein is present ; the 2nd vein is comparatively short, turning 

 upward at its tip ; the discal cell is open, coalescing with the 

 3rd posterior cell, which is pointed proximally, the upper branch 

 of the 4th longitudinal vein being forked. 



A still more abnormal venation is shown by D. ivhartoni, 

 Needham, which this author refers doubtfully to Dicranomyia. 

 The marginal cross-vein divides the marginal cell ; the subcostal 

 cross-vein is absent ; the discal cell is open, coalescing with the 

 2nd posterior cell, of which latter (posterior) cells there are only 

 three, through neither branch of the 4th longitudinal vein being 

 forked ; the posterior cross-vein is anterior to the base of the 

 2nd posterior cell ; the 7th vein very short, and the whole wing 

 more elongate than in any species I have seen. 



Affinities of the yenus Dicranomyia. Very close to both Limnobia 

 and Geranomyia. The latter genus is, of course, quite easily 

 distinguished at once from both the others by its elongated pro- 

 boscis, which is immediately conspicuous. Apart from this feature, 

 however, the three genera have much in common, the present 

 genus being especially akin to Limnobia. 



In the venation the most conspicuous difference is the position 

 of the tip of the auxiliary vein, which in Dicranomyia ends in 

 the costa nearly opposite the origin of the 2nd longitudinal vein, 

 just beyond it or, iu a few cases, a little before it. In a few 

 exceptional cases it is continued some distance beyond the origin 

 of the 2nd vein ; Osten Sacken mentions this regarding four 

 North American species. In Limnobia the auxiliary vein nearly 

 always ends considerably beyond the origin of the 2nd longitudinal 

 vein, generally about half-way between that point and the tip of 

 the 1st vein.* 



The differences in the male genitalia consist rather of modi- 

 fications of the same plan of structure than of fundamental 

 differences of form. The claspers in Dicranomyia are large and 

 fleshy, whilst in Limnobia the second joint develops into a strong 

 horny hook-shaped process. 



The relative position of the subcostal cross-vein and the tip of 

 the auxiliary vein is somewhat different in the majority of species 

 of both genera, for though the cross-vein is in both sometimes 

 placed at the tip of the auxiliary vein, in Dicranomyia it is 

 invariably situated between the 1st vein and the auxiliary vein, 

 joining them together ; in Limnobia it is very often placed between 

 the auxiliary vein and the costa, uniting those two veins, in which 



* Osten Sacken mentions only one exception known to him in 1869, the 

 European D. macrostigma, Schuin. I have found it so in one Oriental species, 

 which I am referring to Limnobia, i. e., L. f estiva. 



