FER-DE-LANCE,
LACHESIS LANCEOLATUS.
FROM THE WEST INDIES.

A deadly poisonous snake inhabiting nearly the whole of South America and the Lesser Antilles. This specimen exhibits the diabolical fang-mechanism characteristic of the Vipers and Pit-Vipers. The maxillary bones, bearing the long fangs, are movably attached to the fore part of the cranium, and can be rotated, when the snake is about to strike, so as to elevate the fangs until their points are directed well forward. At the instant of striking, the poison-glands are compressed by the violent contraction of the overlying muscles, and the venom is injected deep into the wounds through the canals of the fangs. When not "in action" the fangs are directed backward and covered with a fold of membrane. A bristle has been passed through one of the fangs of this specimen to show the course of the canal.

Donor, O. C. Marsh.

Osteological Collection 666.