THE ALF.YRODIDS, OR MEALY-WINGED FLIES, OF CALI-FORNIA, WITH REFERENCES TO OTHER AMERICAN SPECIES. B}^ Florence E. Be:mis, Of Stanford University, California. INTRODrCTIOX. This paper includes tlie descriptions, iisuall}' with account of egg and larval stage, of nineteen new species of North American Aleyro-didiB, or meah-winged flies, all found in California; a catalogue with references, food-plants, and distriV)ution of all the other American species so far described, and an analytical ke}^ of all the American species now known. This ke}' is practically that of Quaintancc (1900), expanded and modified to include the author's nineteen new species. The addition of these new forms brings the total number of species of American Aleyrodes, so far known, to sixt3^-six. In beginning the study of the Californian Aleyrodid}^, it was found that but four species in this little known family of insects had been recorded from this State. The accounts of these species consist solel}' of the technical specific descriptions, and are mostly included in the papers of jVIaskell " and Quaintance.* Quaintance's Monograph enables one to become acquainted readily with our knowledge of American Aleyrodid{\3 up to 1900. The insects themselves have been found to be very i)l(Mitiful, the author having collected them from 30 native plants (see p. -174) and from various cultivated plants in gardens and conservatories. The\' are so plentiful in some cases as to vie with their near relatives, the Coccids, in economic importance; the author has found the leaves of the native live oak {Quercus agrlfoUa), the madrofio {Arhiifiis //len-ziesli), and the sow thistle {Sonchns oleraceus)^ curled, a))normally small, and incrusted on the under side with the immature stages; a cultivated fern kept in the laboratory and left to its own resources «Maskell, Trans. New Zeal. Inst., 1895, p. 415. '>Quaintance, Contributions toward a Monograph of the American Alenrodidse (U. S. Agri. Dept., Division of Entomology. Technical Ser., No. 8, 1900). Proceedings U. S. National Museum, Vol. XXVII— No. 1362. 4 ) 1