OF NORTH AMERICA. 533 



PLATE LVII. 



Figure 1. Manitou, near Charlotte, Lake Ontario. The pool back of the 

 breakwater is caused by the water being thrown over the breakwater by the 

 waves. Habitat for Galba catascopium (SAY). Photograph by F. C. Baker. 



Figure 2. Small pond near Manitou, Lake Ontario. Habitat for Galba 

 palustris (MULLER) and (rarely) Lymn&a stagnalis appressa SAY. Photo- 

 graph by F. C. Baker. 



PLATE LVIII. 



Figure 1. North end Irondequoit Bay, near Sea Breeze, Lake Ontario, N. Y. 

 Habitat for Pseudosuccinea columella (SAY). Photograph by F. C. Baker. 



Figure 2. Genesee River, Rochester, N. Y., north of city, showing marked 

 contamination of river by sewage. Former habitat for Galba catascopium (SAY). 

 Photograph by F. C. Baker. 



ERRATA. 



Page 36, footnote 4, for Wasserathruna, read Wasserathmung. 



Page 101, line 3, for Cockrell, read Cockerell. 



Page 102, line 20, for those, read that; line 37, for vrtical, read vertical 



Page 103, line 4, take out "a" before "very." 



Page 113, line 8, should be placed above Harris, G. D. 



Page 120, line 4, for, after shell, read ; 



Page 137, line 21, for (Say), read Say. 



Page 151, line 6, for (Walker), read Walker. 



Page 152, line 1, for (Hemphill), read Hemphill. 



Page 153, line 2, from bottom, for (fiaker), read Baker. 



Page 154, line 27, for ^J ,read J_V 



Page 156, line 21, for (Walker), read Walker. 



Page 206, line 8, for f , read f 



Page 207, line 17, for Rhoods, read Rhoads. 



Page 221, line 3, for Nov, Sp., read Nov. Var. 



Page 238, line 12, for construction, read constriction. 



Page 240, line 3, from bottom, for Molluska, read Mollusks 



Page 246, place two last lines above last paragraph. 



Page 310, line 6, for Murray, read Maury. 



Page 322, insert line 3 on p. 323, above line 26. 



Page 373, line 24, for placate, read plicate. 



Page 376, line 17, for Dexter, read Drexler. 



Page 395, line 17, for Baker, read (Baker). 



Page 396, line 18, for "by," read "in." 



Page 424, line 7, for Kirtland, read Kirkland. 



Page 438, line 6, from bottom, for - s ^ > fead f_\ . 



Page 447, line 11, 12, for variety, read species. 



Page 499, line 26, for Samson, read Sampson. 



