PARIvER: NEW ENGLAND SARCOPHAGIDAE. 47 
inclined buckwanl than the latter so that they do not project ahove it, 
or else considerably longer. The outer presiiturui l)ristle is always 
present and well developed; the inner absent, (jr if present, of varying 
strength. The notopleurals prol>ably furnish generic characters. I 
have never noted other than four in most of our genera. Of these the 
first and third are always weak, the second and fourth strong, but in 
species of Wohlfartia fpossibly sometimes in Sarcophaga) only two are 
present, the first and third having disappeared. The humeral and 
posthumeral bristles are not important. The numbe'r of posterior 
(postsutural) dorsocentrals is important. In Boettcheria, so far as 
known, only three pairs are found, all of which are long. In species 
having four, all may be long, or only the posterior one or two. When 
five or six are present at least the anterior three or four pairs are 
always short and the foremost of these usually inconspicuous. Other 
variations may occur but do not need to be discussed here. If all 
postsuturals are long, the anterior are almost invariably considerably 
longer than the vestiture of the prescutum. Anterior acrostichals may 
be absent, present in whole or part, short or long, slender or stout. 
They are always present in Ravinia, absent in Bocticlwria hisriosa, 
long and slender in B. latisterna, of medium length and stout in B. 
fcrnaldi, while in Sarcophaga they vary even more widely. I sually 
only the prescutellar pair of posterior acrostichals is present, sometimes 
none. A pair just anterior to these may be very weakly developed, 
but ordinarily only one i)ristle of this pair is present. In some genera 
all may be present but only the prescutellar pair are at all conspicu- 
ous. Except the intra-alars the other bristles of the scutum seem to 
be constant in number and position. The former vary in number l)ut 
the variations within species are too great to permit their use. The 
only reliable factor found in the chaetotaxy of the scutellum is the 
presence or absence of apical bristles. For Ka\inia their absence is 
generic. 
The only bristles on the side of the thorax that present characters 
are those of the sternopleura. The sternopleurals vary in number 
but there are usually either three or two. ]\Iore sometimes occur, 
in certain instances probably an abnormality, in others not. There 
may be one or several rows of lower sternopleurals, the posterior always 
with the longest bristles; those of the other rows are less regularly 
arranged. Certain bristles occurring on the upper anterior part of 
the mesopleura have been defined as the subnotopleurals. While 
