of the Cold Blooded Vertebrata, procured by Prof. James Orton during his
Exploration of Peru in 1876-77.
E. D. Cope
before the American Philosophical Society May 4, 1877.)
ORTONII, Cope, sp. Nov.
species is intermediate in character between the Boa constrictor and
the Boa imperator. It
has the stout proportions of both species, while the squamation of the
head is like that of the former, and that of the body resembles that of
the latter. There are no
large scuta on the loreal or orbital regions, and the scales of the head
generally are characterized by their small size.
The characters of the species are best brought out in a comparative
table, which I give :
89-95 rows of scales on the body.
ring not in contact with labials, gastrosteges 234-40;
II. 55-69 rows of scales.
Orbital series separated from labials by a row of scales;
No large loral plate; form stout; g. 252, u. 53;
orbital ring composed of 19 scales; 64 rows on the
Orbital ring reaching labials.
No large loral plate; stout; u. 56; 57-62 rows on
plate as large as the orbit; proportions as in the last
large loral plate; form elongate; g. 272; u. 69
the typical specimen I associate one from Greytown, Nicaragua, which
agrees with it in the generally smaller size of the scales of the head and
body than is found in the B. imperator, the usual Mexican species.
It has 69 rows of scales; 21 labials and 17 scales in the orbital
ring; gastrosteges 242.
from Chilete, near Pacasmayo, 3000 feet above the sea. This species is dedicated to Professor James Orton, whose
explorations of the western regions of South America have yielded such
We would like to thank Jim Pomaville (translated by William Joy) for kindly providing this material.
constrictor ortonii Cope
1878.---Boa ortonii, Cope; Proc. Amer. Phil. Soc., 17, p. 35,
Chilete near Pacasmayo.
1878.---Boa ortonii, Cope; Proc. Amer. Phil. Soc., 17, p. 35, Chilete near Pacasmayo.
The head presents three dark brown stripes, one medial with faint lateral projections beginning behind the rostral, running between the eyes where it widens, joining the first band on the body; the remaining two are wide, beginning near each nostril, encompassing the first supralabials until touching the preoculars, continuing behind the eyes going down through the corner of the mouth until reaching near the neck, (fig. 18-c). In the juvenile specimen a narrow dark brown bar is seen beneath the eye.
Rostral slightly wider than it is tall, barely visible from above. Nasals separated by tiny scales. Head with tiny scales slightly larger than the snout, one of the preoculars a little larger than the rest. Orbital scales number from 16 to 18 and 14 small scales cross the forehead from eye to eye. There is no loreal scale; instead there are 9 to 10 tiny scales between the nostril and the eye. The orbitals are separated from the supralabials by a row of scales on both sides of the head. Labial pits are not present.