332 
PANAMA DERMAPTERA 
Sarcinatrix anomalia Heim 
1903. Opisihocosmia (Sarcinatrix) anomalia Rehn, Proc. Acad. Nat. Sci. Phila., 
1903, p. 308. [Tiirrrialba and San Carlos, Costa Rica.] 
Trinidad River, Pan., V, 2, 1911, (Bnsck), 1 cf • 
Alhajuelo, Pan., IV, 19, 1911, (Bnsck), 1 9 . 
It is hard to understand Burr’s removal of the present genus 
and species to the Ancistrogastrinae. Careful comparison with 
americanus, genotype of Dinex, shows without question the close 
relationship of these genera. That Dinex is a characteristic 
Opisthocosmiine genus is agreed by all. The entire structure of 
Sarcinatrix shows close agreement with Dinex, excepting the 
faintly suggested tegminal keel and the very remarkable char- 
acter of the male forceps and penultimate ventral abdominal 
segment. This tegminal condition and the production of the 
penultimate ventral male abdominal segment are given by Burr 
as showing Ancistrogastrine affinity. The development of a 
tegminal keel is found in other genera of the Opisthocosmiinae, 
so this condition can not be used for assignment to one of the two 
subfamilies under consideration. The specialization of the 
penultimate ventral male abdominal segment is anomalous, no 
approach to such development being found in any known species 
of the Dermaptera. That it would seem to be a high specializa- 
tion of the not thickened projections of this segment character- 
istic of some, not all, of the species of the Ancistrogastrinae, as 
argued by Burr, would appear to be true for Burr’s figure, but 
this figure is either incorrectly drawn, or is taken from an example 
of a different species, the projections of the segment in anomalia 
being not large rounded lobes, but large, heavy, recurved, spini- 
form processes, which curve outward and upward, flanking the 
bases of the cerci, as described by Rehn. 
The Ancistrogastrinae and Opisthocosmiinae, though at pres- 
ent poorly characterized, clearly represent valid divisions. 
The head and pronotum in Dinex americanus and Sarcinatrix 
anomalia are very similar; the head has the meso-caudal depres- 
sion, and transverse, arcuate sulcus between the caudal margins 
of the eyes, more decided in anomalia] the strikingly colored and 
annulate antennae are similar in these species; the pronotum is 
Proc. U. S. Nat. Mus., xxxviii, p. 431, fig. 5. (1911). 
