PAHKKH: NKW KNCILAND SAHCOiMIAdlDAE. 23 
to the lateral processes. It is easy to see in a j^eiieral way, a rou^h 
resemhlaiiee l)etween the i)eiies of Ravinia and Sareopha^a as repre- 
sented hy the two types taken, and the regions of the penis of Raviniu 
can be homologized with definite phites of that of iS. carnaria. Other 
species, perliaps, show this even l)etter than the one considered. 
Within the cavity of the penis can he sei'n two small, chitinous, 
rod-like structures extending up the sides. They first bend inward, 
and near the center, slightly forward, apparently terminating in a 
sensory surface. These are the stilettes (Stilette, Bottcher). Beneath 
them can be seen a membrane forming the base of the cavity. 
When not in use the genital segments are 'rolled' forward into the 
cavity of the fifth segment. The anterior ventral portion of the 
eighth partially telescopes within the seventh, the forceps bends 
forward and upward, and the penis slips into the pocket beneath the 
fifth ventral plate. The opening between the base of the forceps and 
the edge of the notuni of the second genital segment is closed by the 
accessory plate. The posterior dorsal surface of the seventh segment 
is now exposed, also the dorsal and posterior surfaces of the eighth. 
In this genus the forceps is usually exposed, or at least only the tips 
are hidden, Ijut in other genera it is usually partially, sometimes com- 
pletely hidden. 
Ch.\etotaxy. 
The chaetotaxy is of considerable importance in the classification of 
this group. Consequently, as no one species ofl'ers all the characters 
concerned, it has seemed best to make a complete list of these irre- 
spective of the species taken as a type. It has also seemed advisable 
both in the description of the external anatomy and in the .systematic 
descriptions to discuss the bristles of the legs and genital segments in 
connection with the other characters of the parts concerned rather 
than under a separate heading. 
Head. 
Vibrissae: a pair of very stout bristles, one borne on the lower 
extremity of each vibrissal ridge. They are convergent, usually 
crossing near the tips (PI. 1, figs. 3, 6, v.). 
Froniah: a row of bristles on each side of the frontal vitta. They 
originate dorsally about on a line with or slightly below the anterior 
ocellus and extend to or below the base of the vitta (PI. 1, figs. 3, 6; 
PI. 2, fig. 15, hfr.). 
