OF WASHINGTON. 91 



by the following characters : Antennae 3-jointed, the third 

 joint always simple and with a dorsal arista ; proboscis present 

 (except in some bot-flies), usually short and fleshy, but some 

 times long, horny and adapted for piercing ; only one sub- 

 marginal and always three posterior cells present, discal cell 

 usually present but sometimes absent ; pulvilli present, the 

 empodia never developed pulvilliform. They have a true 

 coarctate puparium, from which they emerge through a curved 

 seam or lid in the anterior end (not through a slit in the 

 back). 



By far the most important works on our Calyptrate Muscida? 

 are two very recent ones : That of Mr. van der Wulp in the 

 Biologia Centrali-Americana (Diptera, vol. II), begun in 1888 

 and still being published ; and that of Messrs. Brauer and von 

 Bergenstamm on the Muscaria schizometopa, published in 

 1889 in Vienna. The latter attempts a revolution in the 

 classification of these flies, and though there are some good 

 points in it there is much that ought not to be accepted. I 

 have followed it in some minor particulars, but I do not adopt, 

 even in the main, the views of these authors, who have 

 brought forth a system that is in many respects more unnat 

 ural than the old one. Yet the plates of this work (n plates ; 

 310 figures, mostly of heads alone) are well drawn, and may 

 be found useful. 



Mr. van der Wulp's work is particularly valuable as collect 

 ing all the tropical North American forms so far known, 

 and presenting the full results not only of the rich collections 

 made under the direction of the Biologia publishers, but also 

 of the collection of Prof. Bellardi in Turin. The work gives 

 excellent synopses of all the genera and species, and includes 

 many forms not before known as inhabiting this country. 



Though the Acalyptrata have been studied in this country 

 (by Loew), the Calyptrate have received no systematic atten 

 tion from American students. Not that they are an unat 

 tractive group, for many of them are our most interesting and 

 showy flies, and always invite the attention alike of the col 

 lector and the student. But incomplete, wrongly referred 

 and scattered descriptions in works difficult to obtain, detail 

 ing insufficient or misinterpreted characters and involving a 

 complex and intricate synonymy, have unfortunately deterred 

 many workers from devoting their attention to this section of 

 the MusddcE. This paper, it is hoped, will, with others to 

 follow it, serve the important object of bringing together all 

 the North American genera described and recognized up to 

 the present time, and at the same time enable their separation 

 with a fair degree of certainty. Many new forms will have to 



