746 BULLETIN UNITED STATES GEOLOGICAL SURVEY. 



the tlioras. The antenuse show fourteen joints, without counting the 

 basal joint, and perhaps one or two more next the base, where the an- 

 tennae are parted ; the joints are submoniliforQi, slightly broader than 

 long, subequal ; the last joint subconical, twice as long as broad. The 

 wings show a principal vein, which strikes the costa about the middle, 

 and apparently another, striking the costa half-way between this and 

 the tip, a feature which does not accord with the structure of the 

 Cecidomyidw geaershllj ', but the wing at this point is very obscure, so 

 that the appearance may be accidental. The legs are apparently about 

 as long as the body, and rather slender. Length of body 1.4"^™ ; of au- 

 tenpfe 0.6°""" ; wings 1"^". 



Lithomyza (m0u?, iJ-iy^w), uov. gen. 



Ocelli present. Antennse nine-jointed, scarcely longer than the 

 thorax, the first joint cylindrical, the remainder submoniliform, ovate, 

 about twice as long as broad, minutely and sparsely pubescent. Wings 

 resembling those of Atiarete in neuration, but differing considerably 

 in shape, being broadest beyond the middle and tapering toward the 

 base. The first longitudinal vein extends beyond the middle of the 

 wing; the auxiliary vein runs close beside the first longitudinal vein, 

 but only half as far, terminating independently; the second longitudi- 

 nal vein extends to the tip of the wing, curving downward in the distal 

 part of its course; the third longitudinal vein forks as in Anarefe, but 

 the independent or fourth longitudinal vein beneath it in Anarete is 

 absent from Lithomyza. The tibise are destitute of spurs, but furnished 

 with a posterior row of slight recumbent spines. 



LWiomyza condita. — Eepresented by a single specimen in an unusually 

 perfect condition, although somewhat indistinct. The joints of the 

 antennae are difflcult to determine, but with little doubt are nine in 

 number ; although short, they are not so abbreviated as in Anarete, the 

 joints being twice as long as broad ; toward the tip, they grow smaller. 

 The legs are long and bristly. The fork of the third longitudinal vein 

 is at the centre of the wing, and nearer the base than the extremity of 

 the first longitudinal vein. There is a faint indication of a transverse 

 vein between the first and second longitudinal veins, about midway 

 between the fork of the third longitudinal vein and its separation from 

 the second. There is also a faint and very doubtful indication of an 

 oblique cross-vein just beyond the transverse vein mentioned, running 

 from the first longitudinal vein to the costa. Length of body 2.7''''" ; 

 of antennns 0.75™°^ ; of wings 2™™ ; fore legs 0.7(!)°i'"; middle legs 2™'"; 

 hind legs 3.4'^™ ; hind tibise O.SS''^™ ; hind tarsi 1.28'^™. Chagrin Valley. 



Family Tipultd^. 



Dicranomyia stlgmosa. — The neuration and the presence of a stigma 

 in a fine, nearly perfect specimen of this species indicate a form closely 



