Since the time when the entomological productions of Kansas were made known to science by Thomas Say, no expedition under the direction of government has so largely LE CONTE.-COLEOPETERA OF THE Near the Pacific coast, that is to say, as far east as the Sierra of California, another element of a more directly evident character, may be noted in connection with the same subject : it is the effect of the Arctic current which sweeps along the Californian coast, and equalizes the climate of the maritime portion of the State. On the crest of the Sierra this effect ceases, and the influence of the cold current is combated by the continental climate, which gives a region of extreme dryness during the whole year, with great ranges of temperature, in different portions of the day and year. This region, broken only by a few fertile mountain valleys in its eastern part, extends from the Californian sierra to the Rio Grande, when in the gentle descent to the Gulf of Mexico the climate again becomes more equable, assuming, however, the subtropical character belonging to its latitude.We accordingly find that in Texas a large proportion of the Coleoptera are identical with those found both at New York and New Orleans, the difference of latitude being accompanied with but moderate variation ; others are tropical species found in the adjoining portions of Mexico, and some again represent sparingly the group of Tene-brionidEe which play such an important part in the insect fauna of the regions farther west. Among genera not belonging to these categories must be noted Lutrochus, which here makes its first appearance in North America : the other species are found in South America, in Brazil.5. A small, but valuable set, collected at New Braunfels, Texas, and purchased from Mr. Lindheimer. 6. Large collections made by Dr. Thos. H. Webb in the region between the Rio Grande and Colorado River of California, chiefly in the valley of the Gila. 7. A considerable collection made by Mr. Schott in the region last acquired by purchase from Mexico, and now called Arizona. 8. A collection of considerable size made by Capt. Pope, while exploring Llano Estacado and the upper Rio Grande. , APR 18 1951 4feu §^ UNITED STATES AND MEXICAN BOUNDARY. 11 9. Large collections made by myself, in 1850-51, between San Diego, California, and Fort Yuma on the Colorado River. An excursion from the latter point to Tucson furnished but small results, as the season was unfavorable, and subsequent loss of transportation required my attention to be directed from science, to objects of more vital importance.Notwithstanding the copious materials here brought together, the region reported on must furnish still important results to future collectors. Every collection that has yet been made, has furnished a very large proportion of new species, and with few exceptions the same species have not occurred at different places or times. The minute ones, except in the region visited by myself, have received but little attention : an immense number yet remain.Exception has bee...
