NO. 1355. FRESH- WA TER BR YOZOA—DA VENPOR T. 221 



1887. Kkaepelin, K. Die Deutycheii SuHS\va.«ser Bryozf)en. Kine Moiiographie. 



1. Anatomisch-Systematischer Teil. Abhandl. aus deni (Tebiete der Naturwi.s- 

 sensch. Naturw. Verein, Hamburg, X, 168 pp. 



1901. Landacke, F. a. Sponges and Bryozoans of Sandusky Bay. The Ohio 



Naturalist, I, pp. 96, 97, April. 

 1851. Leidv, J. On Some American Fresh-water Polyzoa. Proc. Acad. Nat. Sci. 



Philadelphia, V, 1851, p. 261. 

 1851 ((. Cristatella magnifica, new species. Proc. Acad. Nat. Sci. Phila., 



V, p. 265. 



1851 h. Plumatella diffusa. Proc. Acad. Nat. Sci. Phila., V, 1851, p. 261. 



1854. On Urnatella gracilis and A New Species of Plumatella. Proc. Acad. 



Nat. Sci. Phila., VII, pp. 191-192. 



1858 On Cristatella Idaj. Proc. Acad. Nat. Sci. Phila. , 1858, p. 189. 



1879. On Cristatella Idee. Proc. Acad. Nat. Sci. Phila., 1879, pp. 203-204. 



1883. Urnatella gracilis. Jour. Acad. Nat. Sci. Phila., IX, pp. 5-16. 



1884. Potts, E. On a Supposed New Species of Cristatella. Proc. Acad. Nat. Sci. 

 Phila., 1884, pp. 193-199. 



1884 a. On Paludicella erecta. Proc. Acad. Nat. Sci. Phila., 1884, pp. 437-439. 



1896. Ward, H. B. A Biological examination of Lake Michigan in the Traverse 

 Bay Region. Bull. Michigan Fish Commission, No. 6, 100 pp. 



EXPLANATION OF PLATE VI. 



Fig. 1. Urnatella gracilU from Illinois River at Urbana. x 20. 



2. Poltsiella erecta from Kraepelin's figure of a Pennsylvania specimen, x 35. 



3. Paludicella ehrenhergii from Illinois River, x 8. 



4. Fredericella regina from East Harbor, Sandusky, x 10. 



5. Plumatella pr'incepti, var. emarginata, Squaw Bay, Put in Bay, Ohio; lily pads. 



X 6. 



6. Plumatella pulyiHurpha, var. repens, Lake Erie, x 8. 



7. Plumatella j)unctata, var. prostrata, Lake Erie, x 8. 



8. Pectinotella Diagnifica, on jilant stem. Squaw Bay, Put in Bay, Ohio, x §. 



9. Cristatella mucedo. Illinois River, x 10, 



