100 
2.5 mm. long, with the surface minutely rugose. They are laid in masses 
(as illustrated in Plate IX, Figure 37, single masses containing as many 
as 500 eggs) on rushes and the like over water or wet ground. The 
larva is larger than that of the species just described, and at the con- 
nection of each segment is a broad blackish band which widens on the 
sides to form a broken lateral longitudinal blackish line. Otherwise it 
resembles T. sulcifrons. It is well illustrated by Figure 28. The pupa 
is similar to that of sulcifrons but is slightly larger (Pl. VIII, Fig. 32). 
According to Walsh and other authors this species is semiaquatic 
and feeds on water-snails, and probably also on various soft-bodied 
insects and earthworms. 
Mr. Hart obtained a hymenopterous parasite (Phanurus taba- 
nivorus Ashm.) from the eggs of T. atratus (Pl. IX, Fig. 37, and 
Pl. X, Fig. 39) and the same parasite has been reared from this host in 
Ohio and Louisiana by Prof. J. S. Hine (38). Another parasite, ob- 
tained by Mr. F. C. Bishopp from tabanid eggs collected in Texas, has 
been recently described by A. A. Girault as Phanurus emersoni (31). 
These two species of Phanurus are the only parasites known to attack 
the tabanids in any stage. 
CoLEOPTERA (CARABIDAE) 
Carabid larvae are always to be found in abundance in fields which 
are being plowed, and occasionally they have been seen in unusual abun- 
dance in those heavily infested with white-grubs. While the evidence 
Fic. 29a. Harpalus pennsylvanicus Dej., larva, much enlarged. 
in their favor in these cases is largely circumstantial, it is very probable 
that they are often predaceous on grubs, and much more beneficial than 
at present supposed. 
While following the plow at Victoria, Texas, February 18, 1916, 
Mr. J. D. Mitchell found carabid larvae abundant in a grub-infested field ; 
in fact they were nearly twice as numerous as the grubs, and the adults 
which we reared from the larvae sent to us, proved to be our common 
Harpalus pennsylvanicus Dej. (Schwarz det.). In our underground 
breeding-cages larvae and adults of H. pennsylvanicus (PI. VII, Fig. 
28) and Amara sp. have been found abundant, with evidence of their 
predaceous activities, and in the cages it appeared that the adult beetles 
as well as the larvae (Fig. 29a) attack the grubs. In the field this 
