19481 Bequaert — Genus Pachodynerus 109 
(Ashmead, 1900). I liave seen the types of Odynerus 
sancti-vincenti at the British Museum and at the U. S. 
National Museum, as well as two additional females col- 
lected in St. Vincent by J. Ogilvie. Structurally these 
wasps agree with P. guadulpensis from the other Lesser 
Antilles, but they are more abundantly marked with yel- 
low. The apical band of the first tergite extends along 
the sides and often projects somewhat inward along the 
edge of the slope. Usually also there is a free discal yel- 
low spot on each side of tergite two. In some of the types 
these spots are very small or barely indicated. I have 
not seen them in any guadulpensis from any of the other 
Antilles. So far as known at present var. sancti-vincenti 
is peculiar to St. Vincent. 
4 a. Pachodynerus tibialis (de Saussure, 1853), typical 
form. So far as known, this form is restricted to His- 
paniola and the neighboring Mona Island. It is black, 
with fairly numerous yellow markings on head, thorax and 
legs ; but clypeus, mesopleura and propodeum are mostly 
black; tergites 1 and 2 and sternite 2 have a broad yellow 
margin, but there are no yellow discal spots. 
45. Pachodynerus tibialis var. (or subsp.) barbouri, 
new. 
Female . — Black, with the following parts yellow: en- 
tire clypeus ; narrow margin of lower inner orbits ; streak 
along upper outer orbits ; small interantennal spot ; basal 
spot on mandible ; scape beneath ; much of dorsal area of 
pronotum; most of mesopleura, tegulae and propodeum 
(broad center of concavity black) ; postscutellum ; broad 
apical margins of tergites 1 and 2 and sternite 2 ; that of 
tergite 1 abruptly widened and extending somewhat 
mesad along the edge of the slope ; that of sternite 2 ex- 
tensively widened on the sides ; a spot on each side of ter- 
gite 2 narrowly divided from the yellow margin; most of 
coxae; apical portion of fore and mid femora; apical spot 
on hind femora; tibiae except for a narrow inner black 
streak. Structurally like the typical form, except that 
the lamellar superior ridge of the propodeum is not 
straight but wavy, forming a broad upward curve midway 
between the lateral angle and the postscutellum. If this 
