Coccidæ--California Coccidæ exchanged for specimens from all parts of the world. E. O. Essig, Secretary State Commission of Horticulture, Sacramento, Cal.
Wanted--Cephalopods (in alcohol); Chitons (in alcohol or dry); shells of West American Mollusca; zoological literature. Offered: West American and other molluscan shells; zoological pamphlets, mainly on the Mollusca. S. S. Berry, 502 Cajon St., Redlands, California.
California Syrphidæ, Aphididæ to exchange for non-California Syrphidæ. W. M. Davidson, Walnut Creek, Cal.
Wanted--For exchange, papers on marine and fresh-water Protozoa. Albert L. Barrows, Department of Zoology, University of California, Berkeley, Cal.
Wanted--Information on any mite-papers for sale or exchange that have an economic bearing. H. V. M. Hall, Room 8, Court House, San Diego, Cal.
Wanted--Specimens and separates relating to the pseudoscorpions, in exchange for local species. M. Moles, Claremont, Cal.
Wanted--Literature and determined specimens of Collembola, in exchange for local forms and literature. G. Bacon, Claremont, Cal.
Wanted--Determined specimens of Thysanura in exchange for local species. R. Gardner, Claremont, Cal.
Wanted--Separates relating to the nervous system and sense organs of the invertebrates in exchange for reprints by a number of authors on this and other topics relating to the anatomy of invertebrate animals. W. A. Hilton, Claremont, Cal.
Tabanidæ from all parts of North America to exchange for Tabanidæ from the Western United States and Mexico and Central America. Jas. G. Hine, Ohio State University, Columbus, Ohio.
Sarcophagidæ from all parts of the world bought or exchanged, according to arrangement. North American material determined. R. R. Parker, Ent. Lab., Mass. Agri. College, Amherst, Mass.
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Journal of Entomology and Zoology--_Advertising Section_
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=Mineralogy=: Prepared collections; Blowpipe and Laboratory material; Museum specimens, etc.
=Geology=: Fossils and Rocks in collections, and Museum specimens; Casts, Models, Charts, etc.
=Biology=: Systematic collections; Laboratory material for dissection; Museum specimens; Models, Charts, Microscope slides, etc.