Size: 857 mm SVL, TL 1.4 m. The only Trinidad and Tobago Leptophis species to have a subacuminate snout in profile, the rostral barely visible from above, and the primary temporal in contact with three or four upper labials. Tobago specimens of L. coeruleodorsus have two upper labials contacting the primary temporal with the last upper labial excluded from primary temporal contact. In L. haileyi, the last upper labial makes narrow contact with the primary temporal. Leptophis haileyi has longitudinal dorsolateral stripes on the anterior body scale rows 2–4; nine upper labials, 2–3–4 at the loreal-prefrontal shield, 5–6 in the orbit; 5/4 lower labials at the first pair of chin shields. Similar species: L. coeruleodorsus on Tobago has eight upper labials with 2–3 contacting the loreal-prefrontal shield, 4+5 in the orbit, and two upper labials contacting the primary temporal. This species can also be distinguished from L. coeruleodorsus by its domed snout (prefrontal –internasal area), its relatively high ventral count (173), and proportionally shorter tail. The male holotype has a tail:SVL ratio (0.64) and a subcaudal count (166) that fall within the range of L. coeruleodorsus females. Distribution: Roxborough River drainage of Tobago.