306 Annals Entomological Society of America [Vol. VIII, 
those differences which arise between taxonomists because of 
their personal relations, 1t is often impossible to decide which 
is the correct attitude regarding certain disputed points. 
It has been my task lately to identify certain species of 
Stratiomyide contained in the collection of the Illinois State 
Laboratory of Natural History, and in doing this I have been 
confronted with a situation such as I have briefly outlined 
above. It is not my intention to deal with species other than 
those included in that group of the subfamily Pachygasterinze 
which has the scutellum without distinct thorns, although 
mention is made of certain analogous cases in other genera. 
In addition to the taxonomic details given herein, I have 
summarized such biological data as I have been able to obtain. 
The genus Pachygaster Meigen has been subdivide by 
Austen (Neopachygaster), Coquillett (Zabrachia), and Kertesz 
(Eupachygaster), or at least species considered by other authors 
as belonging to Pachygaster sens. lat., have been removed to 
- other genera by the authors just mentioned. Austen erected 
the genus Neopachygaster* to receive Pachygaster meromelaena 
Perris, considered by Verrallt as synonymous with P. orbitalis. 
Austen distinguished this genus from Pachygaster by the 
separated eyes in the male and the fact that the posterior 
orbits are not produced in the form of a prominent ridge in 
either sex. It is, to my mind, a weakly defined genus, and it 
has been rejected by Verrall in the work already referred to. 
Whether it is expedient to retain it 1s a point upon which there 
is ground for diversity of opinion. Coquillett erected the 
genus Zabrachiat for the reception of a species which he 
described under the name polita. This genus he distinguished 
from Pachygaster and its allies by the simple third vein. Though 
uncertain as to whether the species is or is not synonymous 
with Pachygaster minutissimus Zetterstedt, I am inclined to the 
opinion that they are identical; but in the absence of European 
examples of the latter I refrain from expressing a decided 
opinion. It is, however, pertinent to point out that Kertesz 
has placed minutissimus in Zabrachia in a recent paper on the 
genera, and that English writers have suggested that the species 
*Ent. Monthly Mag., Vol. 37, 1901, p. 245. 
tBull. 47 N. Y. State Mus., 1901, p. 585. 
