[Illustration: FIG. 6.--Remnant of the (original) prairie animal habitat in central Illinois. Loxa, Illinois. These areas are becoming extinct rapidly. Photo. by T. L. Hankinson.] KING, L. A. L., and RUSSELL, E. S. 1909. A Method for the Study of the Animal Ecology of the Shore. Proc. Roy. Phys. Soc. of Edinburgh, Vol. XVII, pp. 225-253. An associational study of shore animals. ORTMANN, A. E. 1896. Grundzüge der marinen Tiergeographie. pp. 96. Jena. Contains much of ecological value. ENDERLEIN, G. 1908. Biologisch-faunistische Moor- und Dünen-Studien. Ein Beitrag zur Kenntnis-biosynöcischer Regionen in Westprussen. 30 Ber. des Westpreussischen Bot.-Zoöl. Vereins Danzig, pp. 54-238. Adopts Dahl’s (1903) classification of habitats. HÖPPNER, H. 1901. Die Bienenfauna der Dünen und Weserabhänge zwischen Uesen und Baden. Beitr. nordwest-deutsch. Volks- und Landesk. her. vom Naturwissen. Ver. zu Bremen, Bd. XV, pp. 231-255. PIERCE, W. D. 1904. Some Hypermetamorphic Beetles and Their Hymenopterous Hosts. Univ. of Nebraska Studies, Vol. IV, No. 2, pp. 153-190. This gives a description of the bee community of _Epinomia triangulifera_ Vachal, a list of insects in it and valuable data on their parasitic interrelations. VESTAL, A. G. 1913. An Associational Study of Illinois Sand Prairies. Bull. Ill. State Lab. Nat. His., Vol. X, pp. STENROOS, K. E. 1898. Das Thierleben im Nurmijärvi-See. Eine Faunistisch-Biologische Studie. Acta Soc. Pro Fauna et Flora Fennica, Vol. XVII, pp. 1-259. A descriptive associational study of a lake fauna, correlating the fauna and the vegetation. FORBES, S. A., and RICHARDSON, R. E. 1909. The Fishes of Illinois. Ill. State Nat. Hist. Surv., Vol. III. pp. 357. Contains numerous observations on the habitats and associations of fish; a subject hitherto greatly neglected. WESENBERG-LUND, C. 1908. Plankton Investigations of the Danish Lakes. Danish Freshwater Biol. Lab., Op. 5, Part I, pp. 389. Part II, Copenhagen. The only fresh-water plankton study known to the writer, which takes up the plankton from a distinctly modern ecological standpoint. An excellent summary of the problems of the fresh-water lake plankton. Abundant references to the literature. ALLEE, W. C. 1912. Seasonal Succession in Old Forest Ponds. Trans. Ill. Acad. Sci., 1911, Vol. IV, pp. 126-131. To determine the complete composition of an animal association observations must cover all seasons of the year. This paper and the following ones will indicate the general character of the seasonal changes. WOOD, J. G. and T. 1886. The Field Naturalist’s Handbook. pp. 167. Fourth Edition. London. This is a British work. It gives by months the seasonal succession of moths, butterflies, birds, flowering of plants, notes on habitat, etc. FRITSCH, C.