78 
PSYCHE 
[August 
as Loew’s description (“scutelluni totuni llavuin”) would indicate. When you try 
to make eastern species fit tlie de.scrii)tion of C. rentrironum, you have “troubles of 
your own.” d'he pentricostiin of the New Jersey list should therefore be C. drnvatum 
Walk. I have .seen no specimens of vnitriroxum from east of New Mexico and 
Colorado. It is certainly very close to the C. arcuatum Latr. of Europe. 
Chrysotoxum pubescens Loew, Wien. Ent. hlonatschr., IV, S4, I860. 
The types of this species are lioth from “111.” Specimens afjreeing in every 
respect with the types are frc(|uently taken throu<;hout the eastern United States 
from Maine to Virginia. The inverted V and Y which has been used in describing 
the markings on the fifth abdominal segment, is apt to lead to some confusion in 
separating the closely related species C . piibcsccns and C. latcrale-, the former calls 
for an inverted V, the latter an inverted Y. This distinction however is not as clear 
as it seems, as it varies in the two .sexes, being usually more V shaped in the c? and Y 
shaped in the 9. This variation has also been |>oiutcd out by Mr. C. 11. d'ylcr 
Townsend (Trans. Amer. Entom. Soc., XXI 1, 3.5, 189.5). The ty[»e (c?) of C. 
laieralr, from “Nebr.” is readily di.stinguishcd by having the third, fourth and fifth 
segments broadly, laterally margined with yellow. A s])ccimen (9) from the same 
state shows a very slight indication of the margin being interrupted. A similar 
specimen from New Jersey, 1 have also referred to C. laierah. In the twelve speci- 
mens before me there is an indication that InteraJc may po.ssibly prove to be only an 
extreme variation of puhesrcns. 
Chrysotoxum derivatum \\'alker. List III, 542, 1849. 
The type of this species is from “St. IMartins Eall, .-VIbany River, Hudson Bay.” 
We should therefore expect specimens from the same faunal area to be more typical 
than those from more southern localities. A specimen from Grand Lake, New- 
foundland, collected lyv Mr. klwen Bryant agrees more closely with the description 
than any other; between this s])eeimeu however and a .series from N. II., Mass., 
N. J., and Penna, it seems to be impossible to draw a line notwithstanding minor 
discrepancies. The Newfoundland sj)ecimen is about 9 mm. in length (Walker’s 
descri[)tion calls for 3J lines), the basal two-thirds of all the femora are blackish 
and the marldngs on the fifth segment can be tlescrilx'd as “three large yellow- .s|»ot.s.” 
-All of these characters are however extremely variable; the eight s()ecimens which 
I refer to this species vary from 9 to 1 1 mm. ; the specimen selected by Loew" from the 
English River, Can., as representing this species, has the basal half of the femora 
