290 PROCEEDINGS OF THE ACADEMY OF 



As they may be somewhat difficult to identify, the following tabular arrange- 

 ment will clearly point out their differences. 



Upper branch of the fork (formed by the tip of the mediastinal vein, with the 

 mediastinal crossvein), longer, somewhat arcuated ; the lower one short, 

 perpendicular. 



Two dark brown spots in the basal portion of the prsebrachial area, con- 

 nected together by the expansion of the first of them within the po- 

 brachial area ; tips of femora (?) hudsonica, 0. S. 



Brown spot at the basis of the prse- and pobrachial areae pale and not 

 distinct; a series of more or less numerous dots along the disc of the 

 former area. Tips of femora brown, a pale ring before them. 



golitaria, 0. S. 

 Branches of the fork of about equal length. 



Surface of the wings brownish, with some pale marks (besides the usual 



four large brown spots along the anterior margin) : tips' of femora 



brown, with a pale ring before them. californica, 0. S. 



Tips of femora yellow, but with a brown ring close before them; wings 



with brown clouds and spots ; an ocellated spot at the posterior end 



of the stigma. cinctipes, Say. 



Lower branch of the fork longer, oblique, the upper one being perpendicular ; 



wings marked like in L. cinctipes, but the brown spot at the posterior end 



of the stigma is not ocellated; tips of femora yellow, but with a brown 



ring close before them. immatura, 0. S. 



TRIMICRA nob. 



Proboscis and palpi short. Antennae of moderate length, 16-jointed ; joints of 

 the flagellum, especially the basal ones, subcylindrical, slightly incrassated at 

 the base, with moderate verticils ; three apical joints of the $ very abruptly smaller 

 than the preceding ones, subglobular. Feet long, hairy, moderately stout; without 

 spurs at the tip of the tibiae. Ungues very small, smooth, inserted under a pro- 

 jection of the last tarsal joint. Pulvilli small, but distinct. Wings somewhat 

 elongated, rather narrow; veins arranged more or less like Limnophila, or 

 Cladura, but no petiolate areolet ; petiole long, not arcuated at its origin, which 

 is removed towards the basis of the wing to a poiut situated some distance 

 before the middle of the wing ; mediastinal crossvein far removed from the tip of the 

 mediastinal vein, being more than twice nearer to the origin of the petiole than 

 to that tip. Genitals of the $ apparently like Limnophila (I neglected to make 

 a drawing of them from the living insect.) 



The position of this genus in the group of the Tipulce eriopterceformes is evi- 

 dent. It is easily distinguished by the three small-sized terminal joints of its <^ 

 antennae. Still, as this character may be less distinctly seen in dry specimens, 

 the position of its mediastinal veinlet, the absence of the petiolate areolet, the 

 form of the petiole, which is not, or is almost imperceptibly, arcuated at its 

 origin, and finally, the form of tbe male genital organs, will help to distinguish 

 it from Cladura. It is allied to Erioptera on account of the situation of the 

 mediastinal crossvein, but distinguished from it, besides the structure of the 

 antennae, by its glabrous wings only very slightly pubescent along the veins. 



T. anomala. Fusco-cinerea, anteDnis nigris, thorace vittis tribus fuscis, 

 femoribus apice infuscatis ; alis immaculatis, modice brunnescentibus ; long. 

 0-3 0-35. 



Brownish cinereous ; front with a brown line in the middle ; antennae and 

 palpi blackish-brown ; praescutum infuscated Id the middle, with three dark 

 brown lines, the intermediate one especially distinct ; the lateral ones extended 

 over the scutum ; scutellum paler ; metathorax and pleura? somewhat hoary ; hal- 

 teres pale, a little infuscated at the basis of the knob ; feet hairy, brownish yel- 

 low, tip of femora broadly, tip of tibiae slightly infuscated ; tarsi brown, paler 

 at base. Tergum brown, hairy, sides and forceps of the $ paler. Wings 



[Sept. 



