Webster - p. 2 
However, although there is substantial geographic variation in protein 
phenotypes, there is no evidence for genetic discontinuities like those 
observed in Haiti. All populations should probably be considered Species C. 
In the western Valle de Neiba A. brevirostris is nearly identical to Cul 
de Sac Species C, but between that area and Barahona two proteins (XGPD 
and IDH-2) change to variants formerly thought to be characteristic of 
Species B. Populations of the Barahona type occur down the eastern side 
of the Barahona Peninsula, but on the arid plain stretching from Oviedo 
to Pedernales there is a partial (IDH-2, but not*XGPD) return to Cul de 
Sac conditions. A sample from Belle-Anse, Haiti, is also Species C. It 
seems that A. brevirostris from the San Juan Valley is also Species C of 
the type around Barahona, 
With the finding that some populations of Species C in the Dominican 
Republic are more similar to Species B than are Haitian populations, the 
number of proteins diagnostic for Species C has slipped to 3 (transferrin, 
PtE, and esterase, with the last in need of confirmation). Species A 
remains very distinct. 
Hybrids between A. distichus ravitergum and A. brevirostris were found 
at three localities in the Dominican Republic. The two species differ in 
average male size and in body color (brown versus grey, plus a shoulder spot 
in brevirostris) and in the usual presence of a preoccipital in distichus, 
but tend to have similar dewlaps. Hybrids are intermediate in color, 
larger than brevirostris, similar to d. ravitergum in dewlap (the species 
differ in detail) but tend toward brevirostris in the usual absence of a 
preoccipital, The number of hybrids indicates that hybridization is 
frequent at the zones of contact, but whether females of one or both 
species err in choice of mates is unknown. Of 19 hybrid males examined, 
all had active testes. However, the prophase of the first meiotic division 
shows there is considerably asynapsis with chiasma formation between un- 
homologues. The first division is not reductional. Male hybrids are 
certainly sterile. 
Hybridization has been confirmed by an electrophoretic study. The 
species do not share alleles at six of the loci so far examined. Hybrid 
individuals are heterozygous for all six. 
Animals electrophoretically recognized as hybrids were collected at 
Balneario la Zurzas (Banos de la Surza) (5 km WNW Duverge) and 0.5 km E of 
Cachon. The linear distance between these localities is 45 km, Some of 
the females from Balneario la Zurzas, although quite similar to A. d. 
ravitergum, were suspected hybrids. Unexpectedly, however, two males 
classed as A. d. ravitergum were also hybrids. 
Morphologically, hybrids 0.5 km E of Cachon are intermediate to the 
two parental species. The characteristic markings of A. brevirostris are 
present but subdued, with light browns predominating in the body coloration. 
