228 proceedings of the academy of [may, 



Bibliography. 



Crawley, Howard. 1903. List of the Polycystid Gregarines of the United 



States. Proc. Acad. Nat. Sci. of Phila., January, 1903, pp. 41-58, pis. 1-3. 

 Crawley, Howard. 1903a. The Polycystid Gregarines of the United Sates. 



(Second Contribution.) Proc. Acad. Nat. Sci. of Phila., October, 1903, pp. 



632-644, pi. 30. 

 DiESSiNG, C. M. 1859. Revision der Rhvngodeen. Sitz. Wien Akad., Bd. 37, 



pp. 719-782. 

 L.\BBE, A. 1899. Das Tierreich; 5 Lief., Sj^orozoa. Berlin, R. Friedlander und 



Sohn, 1899. 

 Leidy, Joseph. 1853. On the Organization of the genus Gregarina of Diifour. 



Trans. Amer. Phil. Society, Vol. 10, N. S., pp. 233-241, pis. 11, 12. 

 Leidy, Joseph. 1856. Proc. Acad. Nat. Sci. of Phila., Vol. 8, p. 47 (verbal 



communication). 

 ScHEWiAKOFF, V. 1894. Ueber die Ursache der fortschreitenden Bewegung der 



Gregarinen. Zeitschr. /. iviss. zooL, Bd. 58, pp. 340-354, Taf. 20, 21. 



Explanation of Plate XVIII. 



Fig. 1. — Gregarina achetoe-abbreviatoe (p. 220). Camera outline of sporont. 



Fig. 2. — Stephanophora pachyderma (p. 226). Cephalont. 



Fig. 3. — Stephanophora pachyderma (p. 226). Sporont. 



Fig. 4. — Geniorhynchus oeschnoe (p. 227). Cephalont. 



Pig. 5. — Stenophora erratica (p. 221). Young sporont. 



Figs. 6, 7. — Gregarina melanopli (p. 223). Young solitary sporonts. 



Figs. 8, 9. — Gregarina melanopli (p. 223). Camera outlines of two pairs. 



Figs. 10, 11. — Gregarina kingi (p. 223). Paired individuals. 



Fig. 12. — Gregarina kingi (p. 221). Discharged c^'st. Only the basal oortion of 



the sporoduct is shown. 

 Fig. 13. — Gregarina locustoe-carolina (p. 225). Cephalont 



