198 DIPTERA OF NORTH AMERICA. [PART IV. 



the outer appendages of the male forceps (Tab. IV, fig. 21, from 

 above, open) are horny, large, strong, serrated on the inside ; the 

 inner ones (b b of the figure) are not parallel to the outer pair, 

 and also different from the usual structure. The ovipositor of the 

 female is long and remarkably straight ; the feet rather stout, 

 hairy; the antennae comparatively short in both sexes, stout, 

 hairy ; their verticils but little apparent ; the wing-veins stout, 

 often infuscated; the venation like Tab. II, fig. 3. The new 

 species Limnophila munda, described below, shares most of the 

 above characters, and may also be considered as a Prionolabis. 



2. The subgenus Dactylolabis 0. S. (Proc. Acad. Nat. Sci. 

 Philad. 1859, p. 240). Type: Limnophila montana 0. S. The 

 forceps of the male (Tab. IV, fig. 26, from above, closed ; 26 a 

 from the side) has digitiform appendages of a soft texture, not 

 horny, and not overlapping each other in repose ; ovipositor of 

 the female with short, rather broad upper valves, abruptly taper- 

 ing towards the tip ; feet very long, slender ; wings usually 

 spotted ; both branches of the second vein and the third vein are 

 long, rather straight ; first submarginal cell very long ; great 

 cross-vein near the inner end of the discal cell (Tab. II, fig. 1) ; 

 head narrowed posteriorly ; collare broad ; antennae comparatively 

 short, verticils short, bristle-like. Since the adoption of this sub- 

 genus, Dr. Schiner has introduced it as a genus, including five or 

 six European species ; they are closely related to D. montana, 

 and have the same spots or clouds on the cross-veins and at the 

 origin of some of the veins, the intervals of the veins being with- 

 out spots. One of the European species, D. dilatata Loew, is 

 very large, and has the wings remarkably dilated anteriorly. The 

 North American LimncpJiila cubitalis, of which I have seen only 

 dried specimens, seems to have a forceps of a structure analogous 

 to that of Dactylolabis ; the ovipositor seems to be peculiar (com- 

 pare the description of the species below) ; the venation and the 

 structure of the antennae are not unlike those of Dactylolabis ; but 

 the feet are stouter, and the wings without any spots. If I had 

 followed Dr. Schiner's precedence in adopting Dactylolabis as a 

 genus, I would have been in doubt whether this species belongs 

 to it or not. Bhicnoptila Now. ( Verh. Zool. Bot. Ges. in Wien, 

 1861), specimens of which were kindly communicated to me by Dr. 

 Schiner, is a Dactylolabis with somewhat abortive wings. The 

 wings are shorter than the abdomen, rather narrow ; the venation 



