The earlier references, beginning 1699, mostly from Taschenberg. 10. BAKER (1905), _The Classification of the American Siphonaptera_. Proc. U.S. National Museum, Vol. XXIX., p. 121. Gives an index of hosts and their fleas. Additional bibliography. 11. ROTHSCHILD (1898), _Contributions to the knowledge of the Siphonaptera_. Novitates Zoologicæ, Vol. 5, p. 533; (1900) FURTHER CONTRIBUTIONS, _etc._, Vol. 7, p. 539; (1903) Vol. 10, p. 317; (1904) Vol. 11, p. 602; (1905) Vol. 12, pp. 153 and 479; (1907) Vol. 14, p. 329; (1909), Vol. 16, pp. 53, 57, 61, and 332; (1906) _Notes on Bat-fleas_, Vol. 13, p. 186. These papers contain, for the most part, descriptions of new species in the writer’s collection. Many fine plates illustrating morphology and structure of the external skeleton. B. The following references are to papers on the systematic position of the _Siphonaptera_ and their relationship to other insects. 1. KRAEPELIN (1884), _Ueber die systematische Stellung der Puliciden_. Hamburg, 1884. 2. PACKARD (1894), _The Systematic Position of the Siphonaptera_. Proc. Boston Nat. Hist. Society, Vol. XXVI., p. 312. 3. DAHL (1897), _Puliciphora, eine neue flohänliche Fliegengattung_. Zoologischer Anzeiger, Vol. XX., p. 409. 4. WANDALLECK (1898), _Ist die Phylogenese der Aphaniptera entdeckt?_ Zoologischer Anzeiger, Vol. XXI., p. 180. A humorous reply to Dahl. 5. DAHL (1899), _Die Stellung der Puliciden im System_. Archiv für Naturgeschichte, Vol. 65, I. p. 71. Plates. 6. HEYMONS (1899), Die systematische Stellung der Puliciden. Zoologischer Anzeiger, VOL. XXII., pp. 223 and 301. Three figures. A destructive criticism of the views advanced by Dahl. 7. SEMENOV (1904), _Zur Frage der systematischen Stellung der Flöhe_. Revue Russe d’Entomologie, Vol. IV., p. 277. In Russian. C. The following references are chiefly to works on plague and fleas. 1. ADVISORY COMMITTEE (1905-1909), _Reports on Plague Investigations in India_. Journal of Hygiene, Vols. V., VI., VII., VIII. and X. These volumes contain the five “Extra Plague Numbers.” Many references to observations and experiments on rats and fleas. 2. HANKIN (1905), _Plague Epidemiology_. Journal of Hygiene, Vol. V., p. 48. 3. OGATA (1897), _Ueber die Pestepidemie in Formosa_. Centralbl. für Bacteriol., Vol. XXI., p. 769. 4. SIMOND (1898), _La Propagation de la Peste_. Annales de l’Institut Pasteur. Vol. XII., p. 625. 5. HANKIN (1898), _La Propagation de la Peste_. Annales de l’Institut Pasteur, Vol. XII., p. 705. 6. VERJBITSKI (1908), _The part played by insects in the epidemiology of the plague_. Journal of Hygiene, Vol. VIII., p. 162. Experiments made 1902-3 at Cronstadt and S. Petersburg with fleas. This important research was written in Russian and not translated or published till 1908. 7. DOANE (1910), _Insects and Disease_. Constable and Co.