280 The American Geologist. November, 1897 
Palceophyllnm. ruyosuviBUVmgs (1858) Rep. Proj^ress Geo). Sur. Can- 
ada for 1857, p. 168. Trenton limestone. 
Petraia aperta Billings (1862) Palaeozoic Fose., vol. 1, p. 102, f. 89, 
Black River formation. 
Petrciid angulafd Billings (1862) Pala30zoic Foss., vol. 1, p. 103, f. 90. 
Hudson River group. 
Petraia caiiadensis Billings (1863) Geol. Canada, p. 208, f. 205. 
Zaplrrcntifi canadensis Billings (1862) Palaeozoic Foss., vol. 1, p. 105, 
f. 93. Hudson River group. 
Petraia cornicida Billings (1863) Geol. Canada, p. 156. f. 118. 
Zaphrentis afflnis Billings (1865) Canadian Nat. and Geol., vol. 2, p. 
430. Hudson River group. 
Zayhrentis bellistriata Billings (1865) Canadian Nat. and Geol., vol. 
2. p. 430. Hudson River group. 
Streptelasma cornieidum Nicholson (1875) Pal. Ontario, p. 12. 26. 
Sfreptelasina cornieidum Nicholson (1875) Pal. Ohio, vol. 2. p. 218. 
Cincinnati group. 
Pata'.ophijUani divaricans Nicholson (1875) Pal. Ohio, vol. 2. p. 220, 
pi. 20, f. 10, 10a, 10b. Cincinnati group. 
Sf^rcptelasma cornieidum Rominger (1876) Fossil Corals Michigan, 
p. 142, pi. 51, f. 1, 2. Hudson River group. 
Streptelasma cornieidum Hall (1882) 11th Rep. Geol. Sur. Indiana, p. 
376, pi. 51, f . 2-4. Cincinnati group. 
Streptelasma cornicuban Nicholson (1889) Manuel Pal., vol. 1, p. 247, 
f. 127B: p. 278, 279, f. 156 AB; p. 280, f. 157: p. 297, f. 178. Cincinnati 
group. 
Streptelasma cornicnlum Keyes (1894) Missouri Geol. Sur. Rep. vol. 
4, p. 117, pi. 13, f. 9. Trenton. ' 
Streptelasma corniculum Zittel (1892) Grundzuege d. Palteontol. f. 
HI, p. 71, (after Nicholson). 
Zaplirentis canadensis Zittel-Eastman (1897) Textbook of Palaeontol- 
ogy, f. Ill, p. 75, (same figures as last). 
Streptelasma profundum Winchell and Schuchert (1893) Final Rep. 
Geol. Nat. Hist. Sur. Minnesota, vol. 3, p. 88, pi. G, f. 17-19. Black 
River and Birdseye. 
Streptelas'ma parasiticum Ulrich (1893) Final Rep. Geol. Nat. Hist. 
Sur. Minnesota, vol. 3, p. 89, f. 6. Trenton shales. 
Streptelasma cornicnlum Winchell and Schuchert (1893) Final Rep. 
Geol. Nat. Hist. Sur. Minnesota, vol. 3, p. 92, f. 7. Galena shales (Tren- 
ton). 
Streptelesma breve Ulrich (1893) Final Rep. Geol. Nat. Hist. Sur. 
Minnesota, vol. 3, p. 92, f. 7. Galena shales. 
Streptelasma rusticum Winchell and Schuchert (1893) Final Rep. 
Geol. Nat. Hist. Sur. Minnesota, p. 93, pi. G. f. 22, 23. Hudson River 
group. 
Streptelasma rohustum Whiteaves (1896) Canadian Record Sci., vol. 
6, p. ,301; (1897) Palseozoic Foss. vol. 3, p. 153, pi. 18, f. 1. 
