410 ANNUAL REPORT SMITHSOlSriAN INSTITUTION, 1917. 



of some of the species have a long, caudal appendage and are hence 

 called "rat-tailed maggots." One peculiar larva collected by Mr. 

 Hosier, the park warden, was referred to the genus Microdon by 

 Mr. C. T. Greene, who says that it differs from all allied larvae in 

 the collections of the Museum in the peculiar form of its spiracles. 



The wasplike Midas fly, Mydas clavatus (pi. 53, fig. 5), which has 

 a golden band across its abdomen, takes its generic name from the 

 Phrygian king Midas, concerning whom the legend relates that 

 everything he touched was transformed to gold. Like the robber 

 flies (Asilidae) it catches and devours other flying insects. Its larva 

 is also carnivorous, subsisting mainly on the grubs of beetles, 

 Archytas hystrlx (pi. 53, fig. 8) is a stout tachina fly, somewhat 

 resembling a bluebottle, but with a glossy brown body set with short 

 stiff hairs. It lays its eggs on living insects, principally on caterpil- 

 lars. Last of all may be mentioned the terrible little screw- worm fly, 

 Chrysomyia maceUaria (pi. 53, fig. 7), with a reddish brown face, a 

 Fteel blue thorax, and a short, broad, black abdomen, which lays its 

 eggs in wounds, or in the nostrils of living animals. It has even 

 been known to deposit its eggs in the nostrils of human beings sleep- 

 ing out of doors, but this is a rare occurrence. The eggs soon hatch, 

 and the larvae, called " screw worms," eat away the flesh of the inner 

 nose and pharynx, causing intense pain and sometimes death. This 

 little fly causes little trouble in the Southeastern States, but in the 

 Southwest it is a serious pest, infesting cattle, hogs, and other 

 domestic animals. Some times it lays its eggs in the navels of 

 new-born calves.^ 



FISHES. 



The Everglade fishes in the vicinity of Eoyal Palm State Park 

 have never been systematically collected. The highway from the 

 park to Cape Sable now under construction has a canal bordering 

 it, formed by the removal of material for the roadbed. The digging- 

 is accomplished by a dredge, the parts of which were brought from 

 Miami on trucks and assembled in the canal. This canal is already 

 well stocked with fishes which can be easily observed from the road. 

 The fish fauna should be studied before the canal reaches the ocean ; 

 for many marine fishes will undoubtedly make their way up the 

 canal and will destroy existing conditions, which may possibly lead 

 to the destruction of some of the existing species. Among them are 

 the alligator gar and mudfish, allied to the ancient ganoids; a bull- 

 head catfish; three or four minnows, or shiners (Cyprinidae) ; rare 

 Everglade killifishes, some of which bring forth their young alive; 

 sunfishes, or so-called breams ; and the widely distributed, big-mouth 

 bass, or "trout." 



1 See Farmers' Bull., p. 857, U. S. Dept. Agr., 1917. 



