260 
AUG. F. FOERSTE 
12. Kionoceras sp.; from Trenton of Middleville, New York. 
13. Kionoceras kentlandense Kindle and Breger. 
14. Leurorthoceras hanseni Gen. et Sp. nov. 
15. Leurorthoceras chidleyense Sp. nov. 
16. Actinoceras tenuifilum (Hall) ; types. 
17. Actinoceras sp. ; Boothia Felix-King William Land area. 
18. Actinoceras amundseni Sp. nov. 
19. Actinoceras sp.; HoltedahLs figured specimen. 
20. Actinoceras sp. ; Boothia Felix-King William Land area. 
21. Actinoceras tenuifilum centrale Var. nov.; New York. 
22. Actinoceras cf. tenuifilum centrale; Boothia Felix-King William Land 
area. 
23. Actinoceras tenuifilum ursinum Var. nov. 
24. Actinoceras parksi Sp. nov. 
25. Cyclendoceras annulatum (Hall). 
26. Cyclendoceras or Dawsonoceras. 
Ordovician age uncertain. 
27. Eurystomites (?) boreale Foord. 
Helderbergian 
28. Orthoceras sp. 
1. Cf. Euconia (?) quebecensis (Billings) 
Plate XXVII, fig. 1 
Pleurotomaria quebecensis Billings, Pal. Foss. 1, Geol. Surv. 
Canada, 1865, p. 190, fig. 174: 
Pleurotomaria (Euconia?) quebecensis Bassler, Bibliographic 
Index of Am. Ordovician and Silurian Fossils, 1915; gen. ref. 
Height of shell 17 mm.; apical angle 62 degrees. Volutions 
about 9, surrounding a deep conical umbilicus having an apical 
angle of about 30 degrees. Vertical sections of the volutions 
tend to have a trapezoidal outline. In these sections the outer 
surface of each volution is moderately convex. The inner sur- 
face, of each volution along the umbilicus, is very slightly convex 
along its upper half, but along its lower half it^ is very strongly 
convex curving strongly outward at its base. The line of con- 
tact between successive volutions curves slightly downward 
along most of its length but at its outer extremity there is a 
slight tendency toward reversal of curvature. The shell is 
very thin, but distinctly outlined in the matrix. The specimen 
consists chiefly of a vertical section through the center of the 
