14 PROCEEDINGS OF THE NATIONAL MUSEUM VOL, 125 
very near B. angustatus Champ. O. H.” (presumably by Otto Heide- 
mann). 
In my key (1962, p. 260) for American Mezira species both series 
run to M. granulata Say. Comparison of both series with a paratype 
of M. angustata (Champion) reveals that they are not related. Com- 
parison with various specimens of M. granulata Say shows that 
they are closely related. The general shape of these two series and 
M. granulata is the same; biometric measurements show the same 
pattern though the specimens from Puerto Rico and Haiti are slightly 
larger. The main differences are: postocular tubercles are shorter, 
not reaching to outer border of eye in specimens from Puerto Rico 
and Haiti, reaching it in M. granulata; lateral notch of pronotum 
in specimens from Puerto Rico and Haiti is angular, but in M. granu- 
lata sinuate, rounded, though J have seen specimens of M. granulata 
also with angular lateral notch; paratergites in the female are slightly 
shorter in specimens from Puerto Rico and Haiti reaching to one- 
fourth segment IX, while in M. granulata they reach to the middle 
of segment IX; the last but not the least difference is in pilosity: 
M. granulata has setigerous granulation with straight hairs, whereas 
specimens from both Puerto Rico and Haiti have distinct curled 
hairs. Mezira granulata shows a certain variability in the length of 
setae; specimens from Texas and Mississippi have setae distinctly 
longer than specimens from Georgia, or Virginia, but the setae always 
are straight, never curled. 
The differences between specimens from Puerto Rico and Haiti 
are even smaller. Besides color, which in Mezira usually has no 
specific value, the main difference is the median ridge on the hypo- 
pygium: in the specimens from Puerto Rico it reaches three-fourths 
the hypopygial length, whereas in the specimens from Haiti it reaches 
to, or almost to, the hind border of the hypopygium. 
The best solution is to consider the specimens from Puerto Rico 
as a new species, herein named Mezira placida, new species, and the 
specimens from Haiti as its geographical subspecies, M. p. haitiensis, 
new subspecies. The following key will separate the two new taxa 
from each other and from M. granulata: 
1. Postocular spines produced as far as outer borders of eyes; lateral borders 
of pronotum mostly roundly sinuate; setigerous granulations with straight 
setae; paratergites in the female reaching to the middle of segment IX. 
Mezira granulata Say, United States 
Postocular tubercles not reaching to outer borders of eyes; lateral borders 
of pronotum with an angular notch; setigerous granulations with curled 
hairs; paratergites in the female reaching to one-fourth segment IX. 
Mezira placida, new species, West Indies 
2. Median ridge extending three-fourths length of hypopygium; color dark 
ferruginous ............ . M. placida placida, Puerto Rico 
