182 Psyche [October 
Prosopis modesta Say 
1837. Hyleus modestus Say, 2 (not o’), Bost. Jour, Nat. His. 1:392. 
1859. Hyleus modestus Lec. ed. Say’s Writ. 2:771. 
1869. Prosopis affinis Cr. 2 o, Pr. Bost. Soc. Nat. Hist. 12:270. 
1882. Prosopis affinis Prov. 9 o, Faun. ent. Can. Hym. p. 727. 
1901. Prosopis modesta Lov. 2 o’, Ent. News, 12:5. 
Say’s description of P. modesta is so brief and indefinite that the 
correct determination of the species has long been regarded as 
problematical. Unfortunately the types are no longer in existence. 
But the name has been so widely used that to reject the species 
as indeterminable is open to serious objection, since it will long 
linger on in lists and synonomies and continue to prove a source 
of error. The elimination of P. affinis Sm., greatly simplifies the 
problem, as-it was with this species that P. modesta was most 
frequently confused. 
In 1825, Say left Philadelphia, his native city, and joined Wil- 
liam Maclure’s community at New Harmony, in Indiana, where 
he remained until his death in 1834. His description of “‘Hyleus 
modestus’’? was published in 1837, so that it is probable that his 
specimens were collected in Indiana; and that, as he described 
only one species, they were common forms. Some years ago Mr. 
R. J. Weith collected for me at Elkhart, Indiana, a large number 
of bees, among which were three species of Prosopis: two of these 
were P. pygmea, and P. zizi@, and the third the most common 
form, I believe was the P. modesta of Say. Of the four or five 
other species of Prosopis occurring in this state there is little 
probability that any one of them can be Say’s species, so that 
there would seem to be no objection to the acceptance of this 
identification of P. modesta. 
Say’s description of the female of P. modesta is as follows:—* . Black, opake; 
abdomen polished; hypostoma on each side with a triangular spot; collar with an 
abbreviated, transverse, yellowish line on each side; pleura with a yellowish spot 
under the humerus; wings hyaline, with blackish nervures; feet with whitish knees. 
Length over one fifth of an inch.” 
It will be noticed that there is no mention of a spot on the edge 
of the wing base, or on the tegule, so that the description cannot 
apply to P. zizie. To suppose that Say omitted to mention these 
marks would be a gratuitous assumption, the burden of proving 
which would rest upon the person suggesting it. I give below 
