Fig. 178.–Ancistrodon contortrix (Moccasin-Snake or Copper-head). × ¼.
A. contortrix s. Trigonocephalus cenchris (part), the "Moccasin-Snake" or "Copper-head," is one of the few poisonous snakes which possess a loreal shield, i.e. a shield intercalated between the pre-oculars and the nasals; below it lies the pit. The general colour is yellowish to pink or pale brown, with dark brown or red cross-bars or triangular marks. The under surface is yellowish or reddish, speckled with grey or brown, and with a lateral series of large blackish spots. Total length of full-grown specimens about one yard. The Moccasin-Snake ranges from Massachusetts and Kansas to Northern Florida and Texas. It prefers swampy localities or meadows with high grass, where it hunts for small Mammals and Birds.
Lachesis.–Without a rattle. The upper surface of the head is covered with very small shields or with scales. About forty species in South-Eastern Asia and in Central and South America.
L. (Bothrops s. Craspedocephalus) lanceolatus inhabits nearly the whole of South America, extending into Mexico and the Lower Antilles, e.g. Martinique, Guadaloupe, and Santa Lucia, where it is known as the "Fer-de-Lance," and is the curse of the sugar-plantations on account of its being so very common and so deadly poisonous. The Mongoose was introduced as a possible antagonist, but the little Indian Mammal wisely left the dangerous reptile alone, and has in some places established himself as another pest–as a destroyer of poultry. The Fer-de-Lance grows to a length of 6 feet, establishes itself everywhere–in swamps, plantations, forests, in the plains and in the hills–and is very prolific, producing, according to its size, dozens of young which are 10 inches long, very active and snappy.
Fig. 179.–Head of Lachesis lanceolatus after removal of the skin. × 1. D, Duct, bent upon itself, from the poison-gland into the tooth; Dig, digastric muscle or opener of the jaw; N, nostril; P.G, poison-gland; S.Gr, sensory groove or pit; S.Q, point of junction of the squamosal and quadrate; T.a, Temp.a, anterior, and T.p, posterior, temporal muscle.
L. (Trimeresurus) gramineus s. viridis, to mention one Asiatic species, grows to less than 3 feet in length, is bright green above, sometimes with faint blackish bars; green, yellow, or whitish below, and with a light streak along the outer row of scales. The end of the tail is usually bright red. This beautiful snake has a prehensile tail and is arboreal. Its range extends over the whole of India, to Hong-Kong and to Timor, and even into the Andaman and Nicobar Islands.
Sistrurus.–With a rattle. The upper surface of the head is covered with nine large shields. A few species in North America east of the Rocky Mountains, e.g. S. miliarius.
Crotalus.–With a rattle. The upper surface of the head is covered with small scales. Range from Southern Canada and British Columbia to Northern Argentina, but not in the West Indian Islands. About ten, mostly closely-allied species.