I 



I 



ANTHOMYIID.E. 29 



and a pair of longer ones on the liind margin. Tliesc })roccsses, and 

 the general surface of the bod}', are usually scabrous. Near the 

 upper base of the last segment is a small trilobcd process each side; 

 these are the posterior spiracles, and each has three short, straight 

 slits. Each ventral segment is transversely divided by a narrow 

 furrow or line which terminates each side in a slight tubercle. The 

 last segment has behind the usual transverse line another much, 

 curved, and with a double median forward extension. 



There is a munber of species of Uomalomyia, diiTering in the 

 proportions of the i)rocesses, and Walsh described three species from 

 the larval stage. There are many records of the passage of Ilomalo- 

 myia larvae, and we have others hi the office. Since they feed on 

 fruit and vegetables that are just beginning to decay one can readily 

 see that they are often swallowed by people. They also breed, at 

 least some species, in human feces, and as the flies occur in houses 

 they are, in a lesser way than the house fly, the possible conveyors 

 of disease. 



ANTHOMYIIDiE. 



(Plate yi, in part.) 



The larvae of AnthomyiidtiB are of the general shape of the larva of 

 the house fly, but hardly so slender in front; the head shows distinctly 

 a pair of papillae; there are two separate great hooks; the anterior 

 spiracles have not many lobes, often but 6 to 10 (13 are figured 

 for one species) ; segment 5 and others beyond have each a swollen 

 fusiform area on the ventral base, which is provided with roughened 

 ridges; the lateral fusiform areas are well developed. The caudal 

 end is truncate, but barel}" if at all sunken, and margmed with a 

 number of short, fleshy tubercles, about eight to fourteen in number, 

 according to the species, some rather larger than others, and often 

 with four of them in a transverse row; there are, usually at least, 

 two tubercles above the anal area; the stigmal plates are not far 

 apart, and each has three short slits arranged more radiately than 

 in the other groups; sometimes the button is absent. 



A few notes on some of the common species occurring on foods 

 and elsewhere will serve to show the range of form in the family. 



In Pegomi/a fusciceps Zett. (figs. Ill, 116) there are four simple, 

 conical tubercles in a transverse row below the stigmal plates; the 

 stigmal plates do not show a button; and the anterior spiracles have 

 about six lobes. 



In Pegomija cepetorum Meade (fig. 119) there are four simple 

 slender tubercles in a row and the stigmal plates are similar to 

 . those of P. fusciceps, but the anterior spiracles are larger and have 

 about ten lobes. 



