Studies from the Johns Hopkins University Biological Laboratory, vol. iv., No. 7, October 1890, contains:—Notes on the anatomy of Sipunculus gouldi, Pourtales, by E. L. A. Andrews (plates xliv. to xlvii.). The very detailed anatomical account is prefaced by an interesting history of the habits of this little sipunculoid, which is very abundant at Wood's Holl, Mass. Comparisons are instituted between the author's accounts of this species and those by Andreæ on Sipunculus nudus and by Shipley on Phymosoma varians.—On the relationships of Arthropods, by H. T. Fernald (plates xlviii. to 1.). Though in working on the problem of the phylogeny of the Arthropods, much labour has been bestowed on the anatomy of the Crustacea, Arachnids, and on Limulus and Peripatus, next to nothing has been done among the Hexapods and Myriapods. Among the Thysanura, the section containing Campodea, lapyx, Lepisma, &c., is now well known; but for the anatomy and histology of the Collembola the author knew of only Sommer's article on Macrotoma plumbea, he therefore has devoted himself to a patient investigation of Anurida maritima, and from this stand point he considers the existing views of the relationships of Arthropods, which are passed in review and commented upon.