Introductory Remarks.

The first contribution to the herpetology of the islands of the Pacific Coast of North America of which I have knowledge was, curiously enough, a description of the lizard of Socorro, an island perhaps the least accessible of them all. This description was published by Professor Cope in 1871. Six years later Dr. Streets recorded a few notes on the fauna of Cerros, San Martin, and Los Coronados. Since that time there have appeared at intervals contributions from Yarrow, Belding, Cope, Garman, Townsend, Stejneger, and Van Denburgh, resulting in the gradual accumulation of a considerable fund of knowledge. The papers in which this information is contained are so widely scattered through journals and the publications of various societies and museums as to be but little available. It has, therefore, been thought expedient to review the whole subject while reporting upon the material which in the last few years has been accumulating in the collection of the Academy.

In this paper there are mentioned or described twenty-nine species and subspecies, representing the fauna of eighteen islands. Of these four are amphibians, nineteen are lizards, and six are snakes.

The following forms are here described as new:—

The island distribution of the various species and subspecies is indicated in the following table:

Distribution of Island Reptiles and Amphibians.

Table Key:

  1. Farallon
  2. San Miguel
  3. Santa Rosa
  4. Santa Cruz
  5. Ana Capa
  6. San Nicolas
  7. Santa Barbara
  8. Santa Catalina
  9. San Clemente
  10. Los Coronados
  11. San Martin
  12. San Benito
  13. Cerros
  14. Natividad
  15. Magdalena
  16. Santa Margarita
  17. Socorro
  18. Clarion
  19. Mainland
NameABCDEFGHI
Autodax lugubris farallonensisX
Batrachoseps attenuatusX
Batrachoseps pacificusXX
Hyla regillaX
Dipsosaurus dorsalis
Callisaurus ventralis
Crotaphytus wislizenii
Uta stansburianaXXXX
Uta martinensis
Uta stellata
Uta nigricauda
Uta auriculata
Uta clarionensis
Sceloporus zosteromus
Sceloporus beckiX
Sceloporus biseriatus beckiXX
Phrynosoma cerroense
Gerrhonotus scincicaudaXXX
Gerrhonotus scincicauda ignavus
Xantusia riversianaXXXX
Verticaria hyperythra beldingi
Cnemidophorus rubidus
Cnemidophorus multiscutatus
Cnemidophorus labialis
Bascanion anthonyi
Bascanion laterale fuliginosum
Pituophis catenifer
Crotalus exsul
Crotalus oregonusX
Crotalus mitchellii
NameJKLMNOPQRS
Autodax lugubris farallonensis
Batrachoseps attenuatusX
Batrachoseps pacificus?
Hyla regillaXX
Dipsosaurus dorsalisXX
Callisaurus ventralisXX
Crotaphytus wislizeniiXX
Uta stansburianaXXX
Uta martinensisX
Uta stellataX
Uta nigricaudaXX
Uta auriculataX
Uta clarionensisX
Sceloporus zosteromusXXXX
Sceloporus becki
Sceloporus biseriatus becki
Phrynosoma cerroenseX
Gerrhonotus scincicaudaX
Gerrhonotus scincicauda ignavus?XX
Xantusia riversiana
Verticaria hyperythra beldingiXXX
Cnemidophorus rubidusXXX
Cnemidophorus multiscutatusX
Cnemidophorus labialisX
Bascanion anthonyiX
Bascanion laterale fuliginosumX
Pituophis cateniferXX
Crotalus exsulX
Crotalus oregonusXX
Crotalus mitchelliiXX

Little can be stated about the faunal relationships of the various islands beyond the fact that all except, probably, the Farallons are clearly Sonoran. Of the island reptiles, only fourteen are not known to live on the mainland. These are

Although the evidence is thus too meager to enable one to speak positively, it would seem that the probable faunal relationship is about as follows:

Transition Zone.

Pacific Fauna:

Farallon Islands.

Upper Austral Zone.

Californian Fauna:

San Miguel, Santa Rosa, Santa Cruz, Ana Capa.

San Diegan Fauna:

San Nicolas, Santa Barbara, Santa Catalina, San Clemente.
Los Coronados, San Martin.
Perhaps San Benito, Cerros, Natividad.

Lower Austral Zone.

Perhaps San Benito, Cerros, Natividad.
Magdalena, Santa Margarita.
Socorro, Clarion.