580 HOWARD 



the dung were almost inconceivable. Every morning for several 

 days the breeding cages were apparently full of swarming masses 

 of these flies. The species was at first identified as Lucilia ccBsar 

 L., and, as such, was mentioned on page 249 of Professor 

 Riley's annual report as Entomologist in the Annual Report of 

 the U. S. Department of Agriculture for 1890, and was figured 

 on Plate vii of the same report. Eggs and larva are illus- 

 trated herewith, and the adult is shown at Plate xxxi, fig. 3. 

 In the course of the present work the adult fly has been cap- 

 tured upon human excrement at Snickers Gap, Virginia, but it 

 has not been reared from this substance. 



Py?-ellia ochricornis Wied. 

 Flies of the true genus Pyi-ellia^ as the names of two of the 

 species {cadaverina L. and cadaveruni Kirby) indicate, are 

 found upon dead animals, although P. serena is said by Por- 

 chinski to be coprophagous. The species here mentioned is not 

 known to occur in the United States. It was originally de- 

 scribed from Brazil, and has also been reported from Cuba and 

 Porto Rico, and was captured on human excrement at Culebra 

 Island, Porto Rico, by Mr. Busck in February, 1899. 



Family ANTHOMYIID^. 



This family comprises an assemblage of forms somewhat 

 similar to the house fly but structurally distinct. They are 

 difficult to separate. The larval habits are variable. Many of 

 them attack vegetables, both healthy and diseased, as well as 

 decaying vegetables, some are parasitic within living insects 

 and others are found in excrement. Several forms are respon- 

 sible for authentic cases of internal myiasis and have been taken 

 into the alimentary canal with spoiled vegetables, retaining their 

 vitality and in some cases issuing alive with the freces. 



Homaloniyia brevis Rondani. 

 This is one of the small, shining, black flies, found more or 

 less often in houses and which, by non-entomologists, are fre- 

 quently considered to be immature house flies. Three species 

 of the genus Homaloniyia have been reared or captured in the 



