INTRODUCTION. 
As this work will in all probability fall into the hands of those who have 
not seen the ornithological volume issued as a part of the Publications of the 
State Geological Survey of California, it is proper that the origin and connection 
of these two contributions to this branch of American natural history should 
be here explained. 
The Act authorizing a geological survey of the State of California, which 
became a law in 1860, required of the State Geologist, in addition to the 
topographical and geological work usually expected on such a survey, “ a full 
and complete description of the botanical and zoological productions of Cali- 
fornia.” In accordance with this requirement, the efforts of the head of the 
Survey were, from the time of the beginning of the work, directed toward the 
collection of such material as would be of value for use in the preparation of 
Reports in the various departments of the natural history of California and the 
adjacent regions of the Pacific coast. The establishment of a State museum 
of geology and natural history was also contemplated — although not provided 
for — in the Act authorizing the Survey, as supplementary to the preparation of 
such Reports on the various branches of science as should make possible the 
study of geology, botany, and zoology in the schools and colleges of California 
and the adjacent States and Territories. 
The Survey as thus organized went on without interruption until 1868, 
when appropriations were withheld for two years ; but the work was not brought 
to an absolute stoppage, all the materials having been left in the hands of the 
State Geologist, without any direction as to what was to be done with them, 
and also without any appropriation of money to pay either for the care and 
preservation of collections then on hand, or for the continuation of publications 
at that time actually in progress. 
Nevertheless the work did go on ; and among the volumes completed during 
the stoppage of the Survey was one on which considerable progress had been made 
at the time the appropriations were suspended. This volume belonged to the 
