PARKER: XKW KXCI.AND SARCOPHAGIDAE. 35 
viewed from the side these plates generull\ show dark reflections that 
vary from grayish or l)rowiiish to deep hrowii. Among the species of 
the a.ssldiKi group (Sarcophagaj the color is the same whether tlie 
specimen is seen from the front or side, that is, there are no dark 
reflections. The transverse impression is usually less intensely 
colored than the plates just discussed. In Sarcophaga tuherosa liarpax 
(Pandelle), it has a reddish-brown color. At the basal ends of the 
arms of the frontal suture is a dark spot, that is reddish, brownish, or 
blackish. The facial plate is lighter than the purafrontals and genae 
and slightly if at all carinated; the vibrissal ridges or facialia often 
darker. In the asfddua group (Sarcophaga), for example, they are 
quite constantly grayish. The frontal vhta. varies from brown to 
blackish brown. The cheeks and back of the head are commonly 
grayish, sometimes with a bluish tinge; they are occasionally dusted 
with yellowish or golden pollen. Color distinctions, except for the 
genital segments, and certain areas where they are most constant, 
are not given in the specific descriptions, though, if important, they 
are referred to in the remarks which follow\ 
The eyes are bare and offer few characters. On the front, their 
upper orbits may be parallel or converge downward. In Bocffchcria 
latistcrna the lower inner margins may be concealed by prominent 
swellings of the lower portions of the parafrontals. The ratios of the 
width of the eyes to that of the front at its narrowest part, and of their 
height to that of the cheeks are fairly constant within species limits. 
A relatively broad front is characteristic of some genera, a narrow of 
others, while still others show a varying Avidth. In an undescribed 
species of Sarcophaga the cheek height is four sevenths that of the eye, 
but in other species of that genus is less. If specimens are undersized 
or distorted due allowance must be made. 
The frontal vitta offers several characters of minor importance, yet 
often quite typical. Its relative width to that of the front or the 
parafrontal plates has been used by some authors but does not seem 
to be of great importance. In typical specimens of Ravinia communis 
the sides converge backward in a curve, causing a characteristic 
swollen appearance at the base. One of the most constant characters 
of the vitta is the relation of its sides, whether parallel or convergent 
backward. I have seen females of exotic species in which the sides 
diverge backward, but this may have been abnormal. Small bristles 
sometimes occur toward the sides of the vitta just l)elow the anterior 
