The very extensive collection of galls from the U. S. presented to the Museum in 1870 by Baron von Osten Sacken, contains all his types. There are 138 different galls of Cynipidæ, gall flies 56 species, guest flies 23 species, parasites 66 species, and from Dr. Reinhard 38 types of European Cynipidæ. Further galls of other insects 121 species (Diptera 70, Hemiptera 30, etc.); the types of B. D. Walsh, galls of Salix, 13 species. To these were later added by the Baron his types of Colorado galls, 12 species, and those of California, 15 species. The permanent aim to enlarge this excellent collection has met with success. The prominent additions from Europe are 88 species from Mr. Brischke, in Danzig, Prussia, and 96 types of oak galls from Prof. G. Mayr, in Vienna, Austria, and 18 types of mite galls from Dr. Thomas. The additions of N. Am. galls are very numerous; prominent among them are large additions from California, Washington Terr., and Mexico.