WILLIAM P. HALL (Department of Biology, University of Puerto Rico, Rio 
Piedras) and his student Alberto Espinoza N have been devoting much attention 
to karyotypes and karyotype variation in Jamaican anoles, 
Their study is still incomplete but some conclusions are already possible, 
and the questions that should guide further collecting can be formulated. 
1. Anolis reconditus has a 2n=30 karyotype not obviously different from 
the standard pattern shown by lineatopus, valencienni and garmani. 
2. Anolis lineatopus, reconditus and valencienni show no indications of 
intraspecific chromosomal variability. 
3. Some complications are evident in A. opalinus, Gorman suspected 
possible X-Y heteromorphism: Hall and Espinoza are not certain whether this 
is the condition or a pericentric inversion of pair 7. In addition, one of 
three individuals from hear Hector's River, St. Thomas Parish had two 
intermediate-sized chromosomes in addition to pairs 6 and 7, resulting in a 
2n of 32. One of two individuals from 2.5 mi E of Yallahs, St. Thomas Parish 
had an additional microchromosome (2n=31). Obviously, A. opalinus needs to 
be sampled further. 
4. Anolis garmani also shows accessory chromosomes in some populations 
(e.g. near Golden Spring, St. Andrews Parish and at Southfield, St. Elizabeth 
Parish). 
5. Gorman has long suspected polymorphism in A. grahami. Hall and 
Espinoza are already able to demonstrate a pattern of considerable complexity. 
Chromosome numbers range from 2n=30 to at least 2n=36, Two independent 
phenomena are involved: (1) occasional accessory chromosomes, (2) fissioning 
of at least three pairs of macrochromosomes. (Although insufficiently 
documented at the moment, there may also be considerable non-Robertsonian 
variation in the macrochromosomes.) 
The fissioning has a zoogeographic aspect that gives it special interest. 
Populations along the south coast appear to carry only one fission (possibly 
excepting Southfield, where accessory chromosomes may be complicating the 
picture). At some localities the single fission appears to be fixed (e.g. 
the UWI campus at Mona), while at others it appears to be present as a morph 
in addition to the standard Jamaican 2n=30 karyotype (Belvedere, Port Morant). 
Populations in Portland Parish in the northeast appear to be usually fixed 
for two fissions (presumably including the south coast fission) and poly- 
morphic for a third. Populations with intermediate frequencies of fissions 
are found at Hope Bay, along the Wag River (Coakley), on the crest of the 
pass at Stony Hill separating the Blue Mountains of eastern Jamaica from the 
main body of the island and in the Hector's River valley draining the eastern 
end of the John Crow Mountains. 
