Papers to which Reference is Made. 
313 
the head with that of the body follows the extension of the an¬ 
terior edge of the valves and runs nearly perpendicular to the 
long axis of the animal. In Pleuroxus, Chydorus and allied 
genera, this line runs far back toward the posterior end of the 
valves. Monospilus belongs very plainly to the first group of 
genera. 
LIST OF PAPERS TO WHICH REFERENCE IS MADE. 
Birge, ’78. Notes on Cladocera: E. A. Birge, Madison, 1878. 
Trans. Wis. Acad., vol. IV. 
Birge, ’91. List of Crustacea Cladocera from Madison, Wis. : 
E. A. Birge, Madison, 1891. Trans. Wis. Acad., vol. 
VIII. 
Daday, ’88. Crustacea Cladocera Faunae Hungaricee: E. Daday 
de Dees, Budapest, 1888. 
Eylmann, ’86. Beitrag zur Systematik der Europaeischen 
Daphniden: E. Eylmann, Freiburg i. B., 1886. Ber. 
Naturforsch. G-esellsch. zu Freiburg, B. II. 
Forbes, ’90. On some Lake Superior Entomostraca: S. A. 
Forbes, Washington, 1890. Rept. Fish Com., 1888. 
Forbes, ’93. A preliminary Report on the Aquatic Invertebrate 
Fauna of the Yellowstone National Park, Wyoming, and of 
the Flathead Region of Montana: S. A. Forbes, Washing¬ 
ton, 1893. Bull.U. S. Fish Com., 1891. 
Gruber and Weismann, ’78. Ueber neue oder unvollkommen 
gekannte Daphniden: A. Gruber and A. Weismann, 
Freiburg, 1878. Ber. Naturforsch. Gesellsch. zu 
Freiburg. 
de Guerne et Richard, ’91b. Entomostraces recueillis par 
M. Ch. Rabofc en Russie et en Siberie: J. de Guerne et 
J. Richard, Paris, 1891. Bull. Soc. Zool. France, 1891. 
