Total length, 990 millimetres; tail 110.
Habitat: North America, from Massachusetts and Kansas to Northern Florida and Texas.
This snake is often more dreaded than a Rattle-Snake.
(b) Lachesis.
In Lachesis the caudal rattle is represented by a series of 10 or 12 rows of spiny scales, which are slightly hooked at the tips. The head is covered with small shields or smooth or keeled scales, with or without apical pits. The maxillary is much reduced; the transverse or pterygoid bone, on the contrary, is greatly developed.
The name is derived from one of the Parcæ, daughters of Night, who placed the thread on the spindle, and upon whom depended the fate of men.
In addition to the 19 Asiatic species, of which we have already given descriptions, the genus Lachesis includes 21 American species.
(1) L. mutus (Bushmaster, or Surucucu).—Two or three scales separating the internasals in front; 10 to 15 scales on a line between the supraoculars; 9 or 10 supralabials. Scales tubercularly keeled, feebly imbricate, in 35 or 37 rows; 200-230 ventrals; 32-50 subcaudals.
Fig. 69.—Lachesis lanceolatus (Fer-de-lance of Martinique). (After Stejneger.)