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GossE, P. H. On the Structure, Functions and Homologies of the ^Manducatory 



Organs in the Class Rotifera. Phil. Trans. Roy. Soc. London, 1S55. 

 Idem. The Crown Animalcule (Stephanoceros Eichhornii). Popular Science 



Review, 1, 1862. 

 Idem. Contribution to the History of the Rotifera, 2. The Floscules, Ibid., 



1862. . 



Grenacher, H. Einige Beobachtungen uber Raderthiere. Zeit. wiss. Zool., 



19, 1869. 

 Hood, J. Floscularia hoodi. Intern. Journ. Micr., (3), 5, 1895. 

 Hudson and GossE. The Rotifera; or, Wheel-Animalcules. London, 1886-1889. 

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Inland Lakes of Michigan. Bull. Mich. Fish Comm., No. 3, 1S94. 

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 Idem. Rotatoria of the United States. Bull. U. S. Fish Comm., 1900. 

 Leidy, J. Dictyophora vorax. Proc. Acad. Nat. Sci. Philadelphia, 1857. 

 Idem. Rotifera without Rotatory Organs. Ibid., 1882. 

 Idem. Dictyophora as Apsilus vorax. Ibid., 1884. 

 Leydig, F. Ueber den Bau und die systematische Stellung der Raderthiere. 



Zeit. wiss. Zool., 6, 1854. 

 Lord, J. E. A New Rotifer (Stephanoceros longispinatus?). The Naturalists' 



World, 2, 1885. 

 LtTND, C. W. Danmarks Rotifera. Kobenhavn, 1899. 



]\Iecznikow, E. Apsilus lentiformis, ein Raderthier. Zeit. wiss. Zool, 16, 1866. 

 Montgomery, T. H. On Floscularia Conklin nov. spec, etc. Biolog. Bull., 1903. 

 MoxoN, W. Notes on Some Points in the Anatomy of Rotatoria. Trans. Lin- 



nean Soc. London, 24, 1864. 

 MtJLLER, O. F. Naturforscher. Halle, 1776. 

 Oken, L. v. Lehrbuch der Naturgeschichte. 1815. 

 Peirce, C. N. Remarks on Stepahnoceros Eichhornii. Proc. Acad. Nat. Sci. 



Philadelphia, 1875. 

 Perty. Zur Kenntniss der kleinsten Lebensformen. Bern, 1852. 

 Pritchard, a. a History of Infusoria, London, 1861. 



RosSETER, T. B. Tube of Stephanoceros Eichhornii. Science Gossip, 1881. 

 Idem. Observations on the Life-History of Stephanoceros Eichhornii. Journ. 



Roy. Micr. Soc, 4, 1884. 

 Stokes, A. C. Notes on the Genus Apsilus and other American Rotifera. Journ. 



Roy. Micr. Soc, 1896. 

 Vallentin, R. Some Remarks on the Anatomy of Stephanoceros Eichhornii. 



Ann. Mag. Nat. Hist., (6), 5, 1890. 

 Weber, E. F. Notes sur quelques Rotateurs des environs de Geneve. Arch. 



Biol, 8, 1888. 

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arten nebst Bemerkungen i'lber dieselben. Bull, math.-phys. Acad. St. Pet- 

 ersburg, 3, 1845. 

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Male of Stephanoceros eichhornii. Journ. Quekett Micr. Club, 5, 1893. 



Explanation of Plates XVIII, XIX, XX, XXI. 



The figures, with very few exceptions, are freehand drawings, each con- 

 structed from a considerable number of sketches or various details of structure. 

 The degree of magnification is not uniform. These figures were made with the 

 pen and were not reduced in size, which will account for occasional irregularities 

 m the lines. The following is the significance of the abbreviations employed: 



A Sens.O., antero-lateral sense organ. ; Cer., cerebral ganglion. 



B.C., body cavity. ; Cir., cirrhus (penis). 

 eel c C.2., contractor coronse primus CI., cloaca. 

 ' and secundus. Cl.Ap., cloacal aperture. 



