288 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 90 



Melrose Highlands, Mass., while it was under the direction of 

 C. W. Collins. 



The characters employed by Curran, particularly those pertaining 

 to the genitalia and sternites, appear to be the most satisfactory ones 

 for the separation of the species. In order that they may be given 

 careful study the specimen must be relaxed and the genitalia exposed. 

 Unless this is done considerable doubt remains as to the formation of 

 the anal forceps and the lobes of the fifth sternite. In panaetius and 

 apicata the lobes are smooth distally, their inner edges ridgeless 

 except at base, where they unite in an abrupt, upwardly rounded 

 flange. While there is no basal flange in any of the other species, 

 except possibly foridemis, some of them have the distal portion of 

 each lobe furnished with a more or less conspicuous ridge along its 

 inner edge. It is not clearly understood how much importance 

 should be attached to this structure. Obviously it is subject to 

 considerable variation within the species, as shown in the case of 

 cana and acosta. However, in nearly all the specimens of variata 

 that have been seen the ridges are well developed and provide a good 

 character for identification. The form of the anal forceps is best 

 determined by the aid of a crosshatched eye-piece micrometer, which 

 will forestall any imaginary concept. An additional character is 

 found in the lengthened villosity of the inner surface of the hind 

 tibiae, and while applicable only in the case of panaetius, florldensis, 

 and apicata (fig. 17, g), it is of constant occurrence and readily 

 recognized. 



The females are identified with clifiiculty. With a few exceptions 

 the species, even in the males, appear more or less similar, and fre- 

 quently their identity is doubtful. Since several of them occur simul- 

 taneously in the same region, association of sexes has but little value. 



Little is known regarding the biology of the species. Townsend 

 (1911, p. 141) tentatively placed Tachinomyia in his meigeniine 

 series, species that glue a flattened macrotype ^gg to the body of 

 the host. Several of the species have been occasionally bred from 

 lepidopterous larvae, but records of rearing are rare in comparison to 

 the field abundance of the flies, wdiich are among the earliest vernal 

 tachinids. Aldrich regarded T. panaetms^ sensu lato^ as one of the 

 commonest North American species. In New England there is a 

 single generation, the species passing the winter as puparia. 



The generic characters of Tachinomyia are as follows : Eyes bare, 

 although frequently thinly pilose in freshly emerged specimens; 

 facial ridges bristly on at least the lowest third, usually about two- 

 thirds way, but in no instance meeting the lowest f rontals ^ ; ocellar 



"^ Allophorocera montana Smith (191T, p. 140), which Aldrich (1927, p. 21) believed 

 to be a Tachinomyia, can be excluded from the genus by this character as well as others. 



