Present knowledge does not, therefore, justify a more definite statement of the genealogy of Insects than this, that in common with Crustacea they had Annelid ancestors, and that _Lindia_, _Peripatus_, and _Campodea_ approximately represent three successive stages of the descent. When we reflect that Cockroaches themselves reach back to the immeasurably distant palæozoic epoch, we get some misty notion of the antiquity and duration of those still remoter ages during which Tracheates, and afterwards Insects, slowly established themselves as new and distinct groups of animals. CHAPTER XI. THE COCKROACH OF THE PAST. By S. H. SCUDDER, of the U.S. Geological Survey. _SPECIAL REFERENCES._ BERENDT, G. C. Mémoire pour servir à l’histoire des Blattes antédiluviennes (Ann. Soc. Entom., France, V.). Paris, 1836. 8vo. BRODIE, P. B. A History of the Fossil Insects in the Secondary Rocks of England. London, 1845. 8vo. GEINITZ, F. E. Die Blattinen aus der unteren Dyas von Weissig (Nova Acta. Acad. Leop.-Carol., XLI.). Halle, 1880. 4to. GERMAR, E. F., und BERENDT, G. C. Die im Bernstein befindlichen Hemipteren und Orthopteren der Vorwelt. Berlin, 1856. Fol. GOLDENBERG, F. Zur Kenntniss der Fossilen Insekten in der Steinkohlenformation (Neues Jahrb. Miner). Stuttgart, 1869. 8vo. ---- Fauna Saræpontana Fossilis. Heft 1–2, Saarbrücken, 1873, 1877. 4to. HEER, O. Ueber die fossilen Kakerlaken (Viertelj. Naturf. Ges., Zürich, IX.). Zürich, 1864. 8vo. KLIVER, M. Ueber einige Blattarien ... aus der Saarbrücker Steinkohlenformation (Palæontogr. XXIX.). Cassel, 1883. 4to. KUSTA, J. Ueber enige neue Böhmische Blattinen (Sitzungsb. böhm. Ges. Wissensch, 1883). Prag. 8vo. SCUDDER, S. H. Palæozoic Cockroaches (Mem. Bost. Soc. Nat. Hist., III.). Boston, 1879. 4to. ---- The Species of Mylacris (_Ibid_). Boston, 1884. 4to. ---- A Review of Mesozoic Cockroaches (_Ibid_). Boston, 1886. 4to. ---- Triassic Insects from the Rocky Mountains (Amer. Journ. Sc. Arts[3], XXVIII.). New Haven, 1884. 8vo. ---- Systematische Uebersicht der fossilen Myriopoden, Arachnoideen und Insekten (Zittel, Handb. Palæont. I. Abth., Bd. II.). München, 1885. 8vo. WESTWOOD, J. O. Contributions to Fossil Entomology (Quart. Journ. Geol. Soc., Lond., X.). London, 1854. 8vo.