PARIiER: NEW ENGLAND SARCOPHAGIDAE. 41 
few jiiul scattering. The posterior is usually the best developed, 
but in one American species of Sarcophaga both are equal. Tiie 
middle and to a less extent the anterior tibiae sometimes sliow a 
similar, but weaker hairiness. On the whole, these characters nuist be 
used with discretion, as they often vary greatly according to the size 
of the specimens. The color of the tibiae as a whole, or individually, 
may differ from that of the femur, those of Ravinia being almost con- 
stantly brownish or piceous. The presence or absence of the submeso- 
tibial bristles presents the only character that seems to be of any 
actiuil value in the arrangement of bristles. Ravinia communis is the 
only species of that genus in which it has been noted. The relative 
length of the fourth and fifth segments of the tarsus is perhaps of no 
value as a specific character; in all species of Boettcheria the ratio is 
less than one half, usually about one third. In most species the 
posterior tarsi are equal in length to the tibiae but in others may be 
shorter or longer. The reflecting bands on the ventral surface of the 
tarsi are not of practical use for specific determination though some- 
times the characters (color, segmental arrangement) are reasonably 
constant. The color of the legs as a whole is sometimes dark, some- 
times browTiish or fulvous. The latter color is probably not common 
though it appears in several American species. In Sarcophaga assidua 
Walker the legs are part dark, part light; in S.fulvipes ]Macquart they 
are fulvous but in the subspecies blackish (not a variation). I have 
seen specimens of Boettcheria laiistcrna with the femora and tibiae 
partly fulvous, but without question this was merely an individual 
variation. 
Abdomen. — The outline* of the abdomen may be somewhat conical 
or oval; that of the female often differs from that of the male. The 
dorsal surfaces of the nota are clothed with short reclining bristles, 
the ventral usually with hairs, rarely bristles. The ground color of the 
abdomen is the same as that of the thorax, but is variously and irregu- 
larly marked with spots or longitudinal bands or both, which may 
change color with each change of light or remain constant. The 
fourth notum, in part or in its entirety, may be dull orange in color, 
and in certain species yellowish or golden pollinose; sometimes these 
characters are combined. They are somewhat varial)le at best. 
The ventral plates, which usually overlap the nota, offer the most 
important features found on the abdomen. In Boettcheria, the sides 
of the plates as a whole, diverge backward ; in Ra^■inia they are essen- 
