66 - A NEW GENUS OF BOIDA OF CUBA. 
larly pentagonal, much larger than broad; the supra-orbitals are irregularly hexagonal, 
convex above, not projecting over the eyes; the post-frontals are irregular in shape, a 
little larger than broad, and have three small plates between them; the nasal plates are 
quadrilateral, larger than broad, in contact anteriorly with the vertical, posteriorly with 
the pre-frontals; the nostrils are small, latero-superior, each situated in the nasal plate, 
nearer its anterior than posterior margin; there-is but one ant.-ocular plate, but 
there are three post-oculars; the former is in contact above and posteriorly with the 
supra-orbitar, and above with the posterior frontal; the three posterior oculars are 
of nearly equal size, the superior perhaps a little the largest; the eye rests on the fourth 
and fifth superior labial plates; the posterior margin of the occipital plate is about a line 
in advance of the posterior extremity of the gape of the mouth; there are ten superior 
labials; of these the third and the seventh appear to be the largest; the eye is of moderate 
size, circular; there are fourteen sublabials exclusive of the mental; the posterior part of 
the head is covered with scales; the teeth in the upper Jaw, constituting the external row, 
are well developed, sharp-pointed, recurved, their points directed backward, the anterior 
longer than the posterior; the inner rows of teeth are smaller; the teeth in the lower 
jaw are also well developed, the anterior ones longer than the posterior; the neck is small, 
the body more or less cylindrical; the tail short and rounded, tapering gradually to its 
extremity; the scales are carinated, with the exception of the four inferior rows, which 
are perfectly smooth; the scales are broad, and more or less quadrangular; 26 rows may 
be counted at about the middle of the body; the middle row of scales along the back and 
tail is larger than the others (1 line and 4 in breadth) and distinctly hexagonal, present- 
ing two carine in the middle of each scale; the adjacent rows are about a line in breadth, 
and a line and a half in length; the most inferior row is somewhat larger than either of 
the lateral rows. The ventral scales are remarkable for their extreme narrowness, being 
only about 44 lines in breadth. 204 ventral scuta; 40 subcaudal. The latter single; 
the preeanal scale is also single; the lateral and posterior borders of the anus present a 
semicircular row of small scales; no spurs evident; colour rufous throughout, without 
spots. 
Dimensions. Length of head 8: lines; greatest breadth 52; length of body 16 inches 7 
lines (Fr.;) of tail 23 inches; greatest circumference 2 inches 4 lines. 
Habitat. Cuba. Specimen in Acad. N. 8. presented by Dr. Gavin Watson. 
Gen. Remarks. The Boide form the second tribe of the Aproterodonts of Duméril and 
Bibron, in their arrangement constituting the second sub-family of Pythonians, which be- 
long to the second section of the Ophidians, the Azemiophides, or non-venomous circuiform 
Serpents. The family of Pythonians are divided into two sub-families, viz., the Holodonts 
