IN the November 1933 issue of Grand Canyon Nature Notes¹ mention was made of the collecting of two specimens of rattlesnakes from areas in which the reptile is little known, the north and south rims of the Grand Canyon. These specimens have since been sent to Mr. L. M. Klauber of the San Diego Museum who has kindly examined and passed judgment on them.

---

1. Grand Canyon Nature Notes, Vol, 8, Number 8, Nov. 1933.

---

Concerning the rattlesnake collected near Havasupai Point on October 9, Mr. Klauber makes the following statement - "the smaller specimen from the South Rim seems to me to be rather closer to C. c. confluentus (Prairie Rattlesnake) than to C. c. abyssus, (Grand Canyon Rattler) and this corroborates findings based on previous specimens, for heretofore the specimens of confluentus found at such points further south as Anita and Valle."

The skin collected from the vicinity of Swamp Point on the North Rim is, according to Mr. Klauber, "undoubtedly abyssus as in color and lack of spots, it is quite typical of an adult of that sub-species. It also agrees in coloration with specimens that I have seen from Shinumo Creek and Burro Spring - - ."

The importance of the specimens under discussion will be realized if reference is made to the accompanying map showing known ranges of the species of rattlesnakes found in this region. Also brought out by this map is the need for material for study from certain intermediate and critical areas which as yet have furnished no specimens of rattlesnakes.