BIBLIOGRAPHIC LIST OF GENERA AND SPECIES. 929 



Pachydictya crassa Hall. 



Stictopora crassa Hall, Pal. New York, 2, 1852, p. 45, pi. 18, figs. 4a-c. 

 Ptilodictya crassa Nicholson and Hinde, Canadian Jour., n. s., 14, 1874, p. 142; 



Pal. Prov. Ontario, 1875, p. 45. 

 Pachydictya crassa Ulrich, Geol. Minnesota, 3, 1893, p. 147. — Nickles and Bassler, 



Bull. U. S. Geol. Surv., 173, 1900, p. 338.— Bassler, ibid., 292, 1906, p. 57, pi. 



18, figs. 11, 12; pi. 21, figs. 14-16.— Grabau and Shimer, N. A. Index Fossils, 



1, 1907, p. 160. 

 Ptilodictya rustica Billings, Cat. Sil. Foss. Anticosti, 1866, p. 36. 

 Pachydictya rustica Ulrich, Geol. Minnesota, 3, 1893, p. 146 (gen. ref.). 

 Ptilodictya arguta Billings, Cat. Sil. Foss. Anticosti, 1866, p. 36. 

 Pachydictya arguta Ulrich, Geol Minnesota, 3, 1893, p. 146 (gen. ref.). 

 Stictopora scitula Hall and Simpson, Pal. New York, 6, 1887, pi. 61, figs. 24, 25. 

 Pachydictya scitula Ulrich, Geol. Minnesota, 3, 1893, p. 147 (gen. ref.). 

 Ptilodictya farctus Foerste, Proc. Boston Soc. Nat. Hist., 24, 1889, p. 328, pi. 6, 



fig. 31. 

 Pachydictya farctus Foerste, Geol. Surv. Ohio, 7, 1895, p. 599, pi. 31, fig. 31. 

 Ptilodictya alcyone Billings, Cat. Sil. Foss. Anticosti, 1866, p. 36. 

 Pachydictya alcyone Ulrich, Geol. Minnesota, 3, 1893, p. 146 (gen. ref.). 

 Ptilodictya tenera Billings, Cat. Sil. Foss. Anticosti, 1866, p. 33. 

 Ptilodictya rudis Foerste, Proc. Boston Soc. Nat. Hist., 24, 1889, p. 329, pi. 6, 



fig. 33. 

 Pachydictya (Rhinidictya) rudis Foerste, Geol. Surv. Ohio, 7, 1895, p. 599, pi. 



31, figs. 32, 33. 

 Early and Middle Silurian: An abundant and widespread species in New York, 



Canada, Ohio, Kentucky, Tennessee, etc. 

 Plesiotype.— Cat. No. 35754, U.S.N.M. 



Pachydictya elegans Ulrich. 



Pachydictya elegans Ulrich, Geol. Minnesota, 3, 1893, p. 154, pi. 8, figs. 18, 19; 



pi. 9, figs. 8, 9— Bassler, Bull. U. S. Nat. Mus., 77, 1911, pp. 138, 139, figs. 



61, 62. 

 Trenton (Prosser): St. Paul, etc., Minnesota; Decorah, Iowa. 

 Middle Ordovician (Wesenberg): Wesenberg, Esthonia, Russia. 

 Cotypes and plesioty pes. —Cat. Nos. 43583, 57234, U.S.N.M. 



Pachydictya emaciata Foerste. 



Pachydictya emaciata Foerste, Bull. Sci. Lab. Denison Univ., 2, 1887, p. 62; 



ibid, 3, 1888, pi. 35, fig. 8; Geol. Surv. Ohio, 7, 1895, p. 599, pi. 28, fig. 8. 

 Upper Medinan (Brassfield): Dayton, Ohio. 



Pachydictya rmarckscens Foerste. See Ptilodictya expansa emareescens. 



Pachydictya everetti Ulrich. 



Pachydictya everetti Ulrich, Geol. Surv. Illinois, 8, 1890, p. 523, pi. 33, figs. 1-lf. 

 Black River (Platteville): Dixon, Illinois. 

 Holotype.— Cat. No. 43429, U.S.N.M. 



Pachydictya? famellca (Foerste). 



Ptilodictya famelicus Foerste, Proc. Boston Soc. Nat. Hist., 24, 1889, p. 329, pi. 



6, fig. 32. 

 Upper Medinan (Brassfield): Eaton and Belfast, Ohio. 



Pachydictya farctus Foerste. See Pachydictya crassa. 



