Colour dull yellow or reddish-brown, with dark brown or brick-red cross-bars; these bars are sometimes interrupted on the vertebral line, and form alternating triangles; belly yellow or reddish, more or less spotted with grey or brown. 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. [Illustration: FIG. 69.--_Lachesis lanceolatus_ (_Fer-de-lance_ OF MARTINIQUE). (After Stejneger.)] Colour yellow or pinkish on the back, with a series of large rhomboidal brown or black spots enclosing smaller light spots; a black streak from the eye to the angle of the mouth. Total length, 1,995 millimetres; tail 170. _Habitat_: Central and Tropical South America. (2) _L. lanceolatus_ (known as the Fer-de-lance in Martinique, and Jararacussu in Brazil; fig. 69).--Snout obtuse, slightly turned up; upper head-scales small, imbricate, more or less strongly keeled, in 5-10 longitudinal series between the supraoculars, which are large; 7 or 8 supralabials. Scales in 23-33 rows, sharply keeled; 180-240 ventrals; 46-70 subcaudals, all or the greater part in two rows. Coloration very variable, grey, brown, yellow, olive, or reddish; uniform or with more or less distinct dark spots, or cross-bands, or with dark triangles on the sides enclosing pale rhombs; a dark streak from the eye to the angle of the mouth; belly yellowish, uniform, or spotted with brown. Total length, 1,600 millimetres; tail 190. _Habitat_: Tropical America; Mexico, Martinique, St. Lucia, Bequia Island near St. Vincent, Venezuela, Guianas, Rio de Janeiro.