68 TRANSACTIONS OF THE ROYAL CANADIAN INSTITUTE. [VOL. XI 
One cast of the interior probably referable to this species. It most 
closely resembles figure 5 of Whiteaves’ plate. 
Locality—Limestone rapids, Severn river, District of Patricia, Ontario. 
Horizon—Silurian. 
No. 358 S. Royal Ontario Museum of Palaeontology. 
Cf. DIAPHOROSTOMA PERFORATUM, Whztteaves. 
DIAPHOROSTOMA PERFORATUM, Whiteaves. Geol. Sur. Can., Ann. Rep., Vol. XIV, pt. F, 
Pp. 52, 1904. 
DIAPHOROSTOMA PERFORATUM, Whiteaves. Geol. Sur. Can., Palaeoz. Foss., Vol. III, 
pt. IV, p. 261, pl. 29, figs. 7 and 7a, 1906. 
One crushed and broken specimen with part of the shell preserved; 
it is referred to this species with much doubt. 
Locality—Above Limestone rapids, Severn river, District of Patricia. 
Horizon—Silurian. 
No. 359 S. Royal Ontario Museum of Palaeontology. 
Also two internal casts resembling this species but with a whorl 
rather drawn out on the inferior lateral margin. The whorl is con- 
sequently less symmetrical as to its superior and inferior lateral out- 
line than in the other example referred to this species. 
No. 383 S. Royal Ontario Museum of Palaeontology. Locality as above. 
LIOSPIRA STEVENSONI, SP. nov. 
Plate IV, Figures 10 and 11. 
LIosPIRA sp. tndet, Parks. Bur. Mines of Ont., 22nd Rep., pt. 1, p. 194, 1913. 
This species is represented by two casts of the interior. The spire 
is greatly depressed with an apical angle of about 125°. The body 
whorl is relatively large and the whorls of the spire small. The maximum 
diameter of the largest shell does not exceed 15 mm. The whorls pre- 
sent a sharp keel at about the mid height; above, the outline is at first 
concave and then convex to the suture, which is but slightly marked; 
below, the outline is very slightly concave and then rounded. Surface 
markings, umbilicus and aperture unknown. 
These little casts are very different from any other species in the 
collection, and appear to belong to Liospira; the specific name -is for 
Professor Geo. S. Stevenson of the University of Toronto, whose death 
occurred on the day this account was written. 
Locality—Limestone rapids, Severn river, District of Patricia, Ontario. 
Horizon—Silurian. 
No. 401 S. Royal Ontario Museum of Palaeontology. 
