_Habitat_: Arizona, New Mexico, and Texas to Southern Brazil, and Northern Argentina. (2) _C. scutulatus_ (Texas Rattle-Snake; fig. 74).--13-16 supralabials; scales in 25 or 27 rows; dorsals striated and strongly keeled; 167-170 ventrals; 18-20 subcaudals. Colour yellowish or greyish-brown, with a series of large dark brown light-edged rhomboidal spots; an oblique dark streak below the eye; belly uniform yellowish-white. Total length, 760 millimetres; tail 65. _Habitat_: Arizona, New Mexico, Texas, North Mexico. (3) _C. confluentus_ (Pacific or Mottled Rattle-Snake; fig. 75).--Upper head-scales small, striated; 13-18 supralabials; body scales in 25-29 rows, striated and strongly keeled; 168-197 ventrals; 17-34 subcaudals. Colour yellowish, greyish, or pale brown, with a dorsal series of large brown or red spots, usually rhomboidal or transversely elliptic in shape; a light streak or triangular marking across the supraocular shields; belly yellowish, uniform or spotted with brown. Total length, 1,520 millimetres; tail 140. _Habitat_: Western North America, from British Columbia to South California, eastwards to Assiniboia, Dakota, Nebraska, Kansas, and Western and Southern Texas; Northern Mexico. * * * * * According to Holbrook, this reptile feeds upon young rabbits, squirrels, rats and other small mammals. It lays its eggs in August, and the young are hatched at once, and are capable of seeking their own food. In captivity as well as under natural conditions the Mottled Rattle-Snake is an excessively irritable species. “The noise of the wind,” says Brehm, “or even the distant view of a man or animal, are sufficient to irritate it. It then coils itself up in a spiral, and places its head and tail in the centre of the disc thus formed, in a state of absolute immobility. After a short interval the creature raises its head to a height of about 8 to 12 inches above the ground, curves its neck in the shape of an S, and elevates its tail into a vertical position and shakes it vigorously, whereupon the strident noise caused by the rattle is heard. So rapid are the movements communicated by the _Crotalus_ to its tail that they can scarcely be distinguished. So long as the _Crotalus_ believes itself menaced it remains in the position that we have just described, and continues to sound its rattle. If one withdraws from the irritated snake, the sound gradually lessens and ceases, to begin again more vigorously when the reptile is once more approached.” The bite of these snakes is exceedingly dangerous. Pigs wage an inveterate war against them and devour them. At the Pasteur Institute at Lille, I have kept several of these reptiles in captivity for eighteen months and longer. They invariably refused their food, and I always had to resort to artificial feeding. They are easily capable of withstanding a prolonged fast.