All were irritable from the first, promptly broke through the membranous sacs in which they were enclosed and struck violently at any passing object. All were marked and colored much like the adults except that the delicate pink along the venter of the latter was not in evidence; and the tails, which in the adults are salmon or terra cotta red (including the basal segment of the rattle) were brilliantly sulphur yellow for at least their distal half.... The newborn snakes measured about eight inches in length. Distribution—This subspecies is found in much the same type of country as the banded rock rattlesnake, being partial to rock slides high in the mountains. The two counties in the state in which it is known, El Paso and Culberson, are both in extreme western Texas. In disposition it is said to be quite timid; however, at times, it becomes irritable without much provocation. [Illustration: Distribution map] BLACKTAILED RATTLESNAKE _Crotalus molossus molossus_ [Illustration: BLACKTAILED RATTLESNAKE] Description—There are about 32 dark rhomboid markings along the back. These light edged blotches are centered with one or two irregular light areas, while the outer edges form bars which extend down each side to the belly. Body color varies from gray to olive green, while the blotches are dark brown or black. The tail is uniformly black, as its name implies. Size—The blacktailed rattlesnake is one of our largest poisonous snakes. Texas specimens average three and a half feet but may grow somewhat longer. One, nearly 50 inches long, was collected at Persimmon Gap in Brewster County. Young—About five young comprise the average brood. Distribution—Records are available from the following counties: Bandera, Bexar, Brewster, Burnet, Comal, Culberson, Edwards, El Paso, Hudspeth, Jeff Davis, Kendall, Kerr, Kimble, Medina, Pecos, Presidio, Real, San Saba, Terrell, Travis, Upton, and Val Verde. Hilly areas with steep canyons are the preferred habitat of this snake. In the Big Bend region of Texas, where apparently it is the most common rattlesnake, specimens have been taken from as high as 7,400 feet elevation. It shows an inclination to coil in bushes or on tree limbs near the ground, although by far the majority of specimens encountered are found on rocky ledges. Its disposition has been reported by some to be very irritable, while others claim it is quiet and docile. [Illustration: Distribution map] MOJAVE RATTLESNAKE _Crotalus scutulatus scutulatus_ [Illustration: MOJAVE RATTLESNAKE]