288 
Psyche 
[October 
REMARKS ON THE PHYTOGENY AND INTERRELA- 
TIONSHIPS OF NEMATOCEROUS DIPTERA 
Massachusetts Agricultural College, Amherst, Mass. 
During the course of an anatomical study of the Nemato- 
cerous Diptera, undertaken at the suggestion of Dr. C. P. 
Alexander, a number of interesting and important points con- 
cerning the interrelationships of these most primitive represen- 
tatives of the order Diptera, were brought to light, and I would 
present herewith a brief resume of the principal features sug- 
gested by this study. The accompanying diagram of the lines of 
descent of the Nematocerous Diptera will serve to illustrate the 
interrelationships here indicated. 
Among the most primitive Diptera known, are the Tany- 
deridse and Bruchomyidse. Alexander, 1920, lists the Brucho- 
myidse as a subfamily (Bruchomyinse) of the Tipuloid family 
Tanyderidce, but it seems preferable to raise them to family 
rank, since they differ from the Tanyderidae in many important 
features. 
The immediate ancestors of the Bruchomyidse and Tany- 
dreidse evidently had a common origin — possibly in a Proto- 
By G. C. Crampton, Ph. D. 
Chironomoidea 
Simuiiidae 
Bibionoi 
Iton 
Mycetophiio 
Psychodidae 
Protodlptera 
Fig. 1. Lines of descent of the Nematocerous Diptera. 
