170 OPHIDIA. 
Trunk with about thirteen broad black cross-bands, twice as broad as the interspaces 
of the whitish ground-colour, more or less confluent or alternating on the hinder part 
of the trunk. Upper part of the head mottled with brown, separated by a pure white 
collar from the first black cross-band. A brown streak from the eye to the angle of 
the mouth. Lower parts white. 
4. Leptodira annulata. 
Coluber annulatus, Linn. Mus. Ad. Fred. p. 34, t. 8. fig. 2; Syst. Nat. i. p. 386. 
Leptodeira annulata, part., Giinth. Cat. Col. Sn. p. 166; Cope, Bull. U.S. Nat. Mus. no. 32, p. 67 
(1887) (Sibon annulatum, part.). 
Dipsas septentrionalis, Kennicott, U.S. Mex. Bound. Surv., Rept. p. 16, t. 8. fig. L. 
Hab. Norta America, Texas.—NortHern Mexico, Matamoros (Kennicott). 
Scales in twenty-one rows. Anterior frontals nearly square, half the size of poste- 
rior; vertical as long as the snout, and shorter than the occipitals; loreal about as 
high as long. One preocular, reaching the vertical; two postoculars. Eight upper 
labials, the third, fourth, and fifth entering the orbit. Temporals 1+2-+3, the fore- 
most in contact with the postoculars. Ventrals 194. 
Whitish, with about twenty-four subrhombic transverse black spots on the back, 
broader than the intervening spaces of the ground-colour. A whitish unspotted collar. 
Upper part of the head with brown spots. 
5. Leptodira affinis, sp. n. 
Hab. Centra America (Mus. Brit.) ; exact locality unknown. 
Scales in twenty-one rows. Anterior frontals about one-third of posterior; vertical 
rather shorter than occipital and in contact with the upper preeocular; loreal longer 
than deep. Preoculars two, the lower small; two postoculars. Eight upper labials, 
of which the fourth and fifth enter the orbit. Temporals 1+2+3. Posterior chin- 
shields longer than anterior. Ventrals 189. 
Ground-colour reddish-olive. A series of transverse or irregular, rounded, brown spots 
edged with darker runs along the back; they descend some distance down the sides, 
and are about thirty-seven in number on the trunk. Another series of smaller and 
very numerous spots runs along the lower part of the side. The first dorsal spot is 
large and subquadrangular, truncated in front, leaving a collar not divided by a brown 
median line. Upperside of the head mottled with brown; a brown temporal band. 
Lower parts yellowish, 
A single female specimen is 21 inches long; the tail, which is somewhat mutilated, 
would have measured about 24 inches. 
