58 TRANSACTIONS OF THE ROYAL CANADIAN INSTITUTE. [VOL. XI 
appears to have a smaller apical angle and the height of a given whorl 
to its width is 28 to 38, whereas the relation in our species is 28 to about 
50. 
Locality—Limestone rapids, Severn river, District of Patricia, Ontario. 
Horizon—Silurian. 
No. 345 S. Royal Ontario Museum of Palaeontology. 
Cf. COELIDIUM MACROSPIRA, Hall sp. 
MURCHISONIA MACROSPIRA, Hall. Pal., New York, Vol. II, p. 346, pl. 83, fig. 5, 1852. 
COELIDIUM MACROSPIRA, Clarke and Ruedemann. New York State Museum, Memoir 5, 
p. 65, pl. 7, figs. 2-8; pl. 10, fig. 13, 1903. 
COELOCAULUS MACROSPIRA, Whiteaves. Geol. Sur. Can., Palaeoz. Foss., Vol. III, pt. IV, 
Pp. 333, 1906. (See this work for further synonomy.) 
One fragmentary cast which is so near to this species that it may be 
provisionally referred to it. 
Locality—Limestone rapids, Severn river, District of Patricia, Ontario. 
Horizon—Silurian. 
No. 365 S. Royal Ontario Museum of Palaeontology. - 
Cf. COELIDIUM BIVITTATA, Hall sp. 
MURCHISONIA BIVITTATA, Hail. Pal., N. York, Vol. II, p. 345, pl. 83, figs. 1a and 1b, 
1852. 
COELOCAULUS BIVITTATUS, Wiktootes Geol. Sur. Can., Palaeoz. Foss., Vol. III, pt. IV, 
P. 334, 1916. (See this work for further synonomy.) 
One fragmentary cast of the interior closely resembling this species 
in the shape and proportions of the whorls and in the nature of the spire. 
The characteristic structure of the species is doubtfully indicated in 
the interior; but lacking better material, our specimen may reasonably 
be referred to C. bivittata. Following Clarke and Ruedemann I have 
ascribed the species to Coelidium rather than to Coelocaulus. 
Locality—Limestone rapids, Severn river, District of Patricia, Ontario. 
Horizon—Silurian. 
No. 366 S. Royal Ontario Museum of Palaeontology. 
COELIDIUM, sp. indet. 
Plate I, Figure 6. 
CLATHROSPIRA sp., Parks. Bur. Mines of Ont., 22nd Rep., pt. I, p. 194, 1913. 
This species is represented by one broken cast of the interior showing 
the body whorl in a fairly complete manner and portions of the suc- 
ceeding two whorls. The figure is largely restored and is therefore 
open to objections, particularly with regard to the whorls represented 
by dots. 
The body whorl has a width of 45 mm. and it is relatively large 
compared with the whorls of the spire. A slightly elevated band can be 
