56 



characters given in the table. As stated under P. flavicornis I can 

 only consider the polished abdomen of P. nitida as accidental. 

 The type of P. nitida has the base of the abdomen opaque. 



This species has been bred by the writer from mushrooms 

 {Agaricus campestris) , Newton, Massachusetts, September 17-26, 

 and by Mr. C. A. Frost, Framingham, Massachusetts, October 2. 



Platypezoides, gen. nov. 



This genus has in part the characteristics of CalUmyia: short 

 third antennal joint and the same-shaped hind metatarsi. The 

 wing venation, however, is nearer that of Platypeza. The fourth 

 vein branches near the posterior cross-vein, all the veins reaching 

 the posterior margin; the second and third posterior cells are about 

 equal. The eyes are divided by a transverse groove on a line 

 with the base of the antennae. Type, the following species. 



. Platypezoides diversa, sp. nov. 



Plate 5, fig. 6-8. 



cf , 9 . — Face and antennae black, proboscis dark brown, the cheeks and 

 occiput with numerous prominent hairs, the facets of the lower portion of the 

 eyes minute. Thorax and scutellum black, the latter with four marginal bris- 

 tles. Abdomen black, venter brownish. Legs brown, the hind femora and 

 tibiae somewhat enlarged and the hind metatarsi much enlarged, about twice 

 as wide as long and as long as all the other joints of the tarsi together. In the 

 female, the hind femora, tibiae and metatarsi are not enlarged. Halteres 

 black, caljrpters with whitish hairs. Wings brownish, with a darker oblong 

 clouding at the end of the first vein; the costal cell is about one-third longer 

 than the first basal cell; anal cell acute and as long as the first basal cell. 



Length 3.5 mm. 



Holotype, Mt. Washington, New Hampshire (Mrs. A. T. Slos- 

 son); allotype and three paratypes. Center Harbor, New Hamp- 

 shire, September 11, 1914 (one 2.5 mm. long) and Bar Harbor 

 C'Witch Hole Pond^'), Maine, September 11, 1922 (C. W. John- 

 son); in the collection of the Boston Society of Natural History. 

 One paratype, Niagara Falls, New York, September 9, 1910 

 (M. C. Van Duzee) in the author's collection. 



Table of the Species of Agathomyia. 

 Males. 



1. Thorax and abdomen largely yellow 2. 



Thorax and abdomen largely black 3. 



2. The last two segments of the abdomen and halteres black . . perplexa Johnson. 

 The last two segments of the abdomen, pleura and metanotum black, 



halteres yellow dubia Johnson. 



3. Abdomen broadly banded with yellow 4. 



Abdomen not banded with yellow 7. 



4. Scutellum yellow 5. 



Scutellum black 6. 



5. Thorax opaque black (2 mm.) pulchella Johnson. 



Thorax opaque black, with a large square of yellow in front of the scutellum 



brooksi, sp. nov. 



Thorax shiny black, subcostal cell yellowish monticola, sp. nov. 



