1264 BULLETIN 92, UNITED STATES NATIONAL MUSEUM. 



Tetradella quadrilirata — Continued. 



Dep. Geol. Nat. Res., Indiana, 1908, p. 1048, pi. 53, figs. 4, 4a.— Grabau and 

 Shimer, N. A. Index Fossils, 2, 1910, p. 353, fig. 1658f, g.— Bassler, Zittel- 

 Eastman Textb. Pal., 1913, p. 738, fig. 1425J. 



Richmond: Waynesville, Clarksville, etc., Ohio; Indiana; Kentucky; etc. 



Black River: Kentucky; Tennessee; Minnesota; etc. 



Plesiotypes.— -Cat. Nos. 41582, 41583, U.S.N.M. 



Tetradella quadrilirata var. simplex. See Tetradella simplex. 



Tetradella simplex (Ulrich). 



Tetradella quadrilirata var. simplex Ulrich, Geol. Surv. Canada, Cont. Micro-Pal., 

 pt. 2, 1889, p. 55, pi. 9, fig. 13.— Whiteaves, Geol. Surv. Canada, Pal. Foss., 3, 

 pt. 2, 1895, p. 127.— Cumings, 32d Ann. Rep. Dep. Geol. Nat. Res., Indiana, 

 1908, p. 1049, pi. 53, figs. 5, 5a. 



Tetradella simplex Ulrich and Bassler, Proc. U. S. Nat. Mus., 35, 1908, p. 307. 



Richmond: Stony Mountain, Manitoba; Anticosti; Ohio; Indiana; etc. 



Plesiotype— Cat. No. 41584, U.S.N.M. 



Tetradella subquadrans Ulrich. 



Tetradella subquadrans Ulrich, Jour. Cincinnati Soc. Nat. Hist., 13, 1890, p. 115, 

 figs. 2a-c— Ulrich and Bassler, Proc. U. S. Nat. Mus., 35, 1908, pi. 39, 

 figs. 1-3. 

 Trenton: Trenton Falls, New York. 

 Holotype.— Cat. No. 41384, U.S.N.M. 



TETRADIUM Dana. Genotype: T. fibratum Safford. 



Tetradium Dana, Wilkes' U. S. Expl. Exped. 1838-42, 7, 1846, p. 701.— Safford, 

 Amer. Jour. Sci. Arts, 2d ser., 22, 1856, pp. 236-237.— Hitchcock, Geol. 

 Vermont, 1, 1861, p. 289.— Safford, Geol. Tennessee, 1869, p. 533.— Nicholson, 

 Geol. Surv. Ohio, Pal., 2, 1875, p. 221; Rep. Prov. Ontario, pt. 2, 1875, p. 

 27. — Nicholson and Etheridge, Ann. Mag. Nat. Hist., 4th ser., 20, 1877, 

 pp. 161, 165; Mon. Sil. Foss. Girvan Dist., 1878, p. 29.— Nicholson, Tab. 

 Corals Pal. Period, 1879, pp. 23, 231.— Zittel, Handb. Pal., 1, 1880, p. 619 — 

 Roemer, Leth. geog., pt. 1, Leth. Pal., 1883, p. 481.— Miller, N. A. Geol. Pal., 

 1889, p. 206.— Lambe, Cont. Can. Pal., Geol. Surv. Canada, 4, pt. 1, 1899, 

 p. 92. — James, Jour. Cincinnati Soc. Nat. Hist., 15, pt. 4, 1893, p. 153. — 

 Sardeson, Neues Jahrb. Min., Geol. Pal., Beilage-Band, 10, 1896, p. 345 — 

 Ruedemann, Amer. Geol., 22, 1898, p. 16-25.— Lindstrom, Ofvers. K. Vet.- 

 Akad. Forhandl., 56, No. 2, 1899, p. 44; Kongl. Sven. Vet.-Akad. Handl., 

 32, No. 1, 1899, p. 29.— Grabau and Shimer, N. A. Index Fossils, 1, 1906, 

 p. 99.— Cumings, 32d Ann. Rep. Dep. Geol. Nat. Res., Indiana, 1908, 

 p. 700. 



Tetradium apertum Safford. 



Tetradium apertum Safford, Amer. Jour. Sci. Arts, 2d ser., 22, 1856, p. 238. — 



Lindstrom, Ofvers. K. Vet.-Akad. Forhandl., 56, No. 2, 1899, p. 44. 

 Tetradium fibratum var. apertum Safford, Geol. Tennessee, 1869, p. 535. 

 Middle Ordovician: Central Tennessee. 



Observation. — Several distinct species, including T. cellulosum, are included 

 in Safford's description, and until the subject has been revised, T. apertum 

 can not be considered valid. 



Tetradium approximatum Ulrich. 



Tetradium approximatum Ulrich, Amer. Geol., 1, 1888, p. 183. 

 Tetradium minus Nicholson (not Safford), Rep. Pal. Province Ontario, pt. 2, 

 1875, p. 28; Geol. Surv. Ohio, Pal., 2, 1875, p. 222.— Nicholson and Etheridge, 



