8 THOMAS SAY FOUNDATION 



are sufficiently distinguished by tlie metallic abdomen, 

 although there are other differences. 



Among the species included in the present paper, 

 all have been assigned to Sarcophaga except a few 

 aberrant forms with arista short-plumose, or with vi- 

 brissse high u\) and approximated, or with a few other 

 analogous characters. See table of genera for these. 

 Characters of one sex are not used for ultimate sep- 

 aration of genera, though they are often of much 

 j)ractical value. 



The genus Sarcophaga is undoubtedly a large 

 and rather homogeneous group, a natural large genus, 

 as much so as Tabanus, Rhamphomyia, Culex, Bem- 

 bidium, Formica, etc. Even granting the separation 

 of some of its components in accordance with the views 

 of recent writers, there remains a mass of several hun- 

 dred species, scattered all over the world. 



After much consideration, I have decided not to 

 attempt the separation of the genera Bliesoxipha, Ra- 

 vinia, and Bottcheria, but to regard them as sub- 

 genera or merely groups having some common char- 

 acters. 



Blffisoxipha (Loew, Wiener Ent. Monatsch., v, 

 384, 1861) was established on a single female speci- 

 men (European) described as grylloctona n. sp. in 

 the same place. The only character differing from 

 Sarcophaga as announced at the time was the pres- 

 ence of a long larvipositor curved downward and for- 

 ward. The group of species possessing more or less 

 of this character is very complex and closely related 

 in Europe as well as in North America; it has not 

 yet been well worked out in Europe. Species num- 

 bered from about 52 to 66, of the present paper, and 

 a few others, are more or less of this type in the fe- 

 male ; but the amount of development of the sternites 

 is often slight, usually so. Figures 61b and 61c show 

 the extreme form, from which a series might be made 

 of species showing less and less development of larvi- 

 positor, down to an ordinary Sarcophaga. Further- 

 more, the species are so similar in the middle part of 



