62 PROCEEDINGS: BOSTON SOCIETY NATURAL HISTORY. 
prolonged forward laterally as two short arms; median process about 
as broad as penis, bluntly bilobed at end, extending farther forw^ard 
than laterals, and practically completely chitinized; lateral processes 
entirely chitinized, blackish, and nearly filling space between median 
process and the short arms of posterior plate. 
Redescribed from more than fifty specimens. 
Range. — New England: Conn.: Stonington. 
United States: N. J., Md., Va., W. Va., Ga., D. C, Fla., Tex., Nev., 
Calif. 
Foreign: Porto Rico, Bermuda, St. Vincent. 
This species has a wide distribution over the southern United States 
and is probably common in the \Yest Indies. Its occurrence in 
Mexico is not unlikely, though I cannot identify it with any of Van 
der Wulp's descriptions. 
It is not always easy to separate this species from R. latisetosa, due 
to the fact that the lateral vertical bristles in the latter are sometimes 
only weakly developed. Other differences, however, are more or less 
marked; the front is generally less broad, the intermediate row of 
bristles on the anterior face of the posterior femur is lacking or vesti- 
gial, while the forceps prongs are separated from near their base and 
are slightly convergent at their tips. In latisetosa the prongs are paral- 
lel, not convergent. The penes, while similar, easily differentiate the 
species; the lateral processes in quadrisetosa are large, in latisetosa 
small. The end of the penis in quadrisetosa is sometimes covered with 
membrane concealing the processes and is apt to be deceptive. 
This species was described by Coquillett from two males and four 
female specimens, and placed by him in the genus Helicobia. It is 
unquestionably a Ravinia and Helicobia, as a genus, is of very doubt- 
ful validity. I was unable to find Coquillett's types at the National 
Museum, but from other material identified by him, which agreed 
with my own previous identification from his description, I was able 
to be reasonably certain of the species, the more so as the specimens 
from which the above description is taken were all southern. The 
following species, with which it is apt .to be confused, has not been 
reported from the south. 
In the American Museum of Natural History at New York are four 
CO types of Williston's chaetopygialis (St. Vincent). Three of these are 
specimens of quadrisetosa and only the labeled specimen is chaetopygialis 
and agrees with the description. 
