18 TRANSACTIONS OF THE ROYAL CANADIAN INSTITUTE. [VOL. XI 
The total height is about 60 mm., while the width of the body whorl 
is only 18 mm. The whorls are evenly rounded and the sutures rather 
deeply impressed. The aperture is not well shown, but it appears to 
be narrow and moderately elongate. There are probably twelve whorls 
in all. A second broken portion showing two whorls probably belongs 
to this species and indicates a somewhat greater size, as the larger whorl 
is about 20 mm. in diameter. The sutures, however, are not as deep and 
the whorls are flatter: it may possibly represent another species. 
H. acuminata is of the type of H. gracilis, and except for its much 
greater size approaches close to some of the varieties of that species: 
it also resembles H. salteri, Ulrich. 
Ami has listed two species of Hormotoma from Beechey island as 
H. arctica and H. affinis, but as they are from a horizon probably much 
higher, it is not likely that the present species is identical with either.! 
Locality—Lower rapids, Shamattawa river, Manitoba. 
Horizon—Ordovician. 
No. 363 S. Royal Ontario Museum of Palaeontology. 
The collection contains also a fragment of a body whorl of a Hormo- 
toma indicating a much larger shell than the above. Ordovician, Shamat- 
tawa river. 
No. 384 S. Royal Ontario Museum of Palaeontology. 
HOLOPEA MEDIA, Sp. nov. 
Plate IV, Figure 4. 
This species is founded on one broken cast of the interior; as it is 
distinctly different from any other of the specimens from this horizon, 
I venture to ascribe a specific name. The general shape of the whorls 
and the nature of the spire are fairly well shown, but there is no infor- 
mation available as to the surface markings, the aperture, or the umbili- 
cus: the generic position must therefore be left in doubt, but the character 
of the whorls suggests Holopea. 
The maximum width of the specimen is 40 mm. and its height to 
the top of the third whorl about 31 mm. The whorls are fairly evenly 
rounded on the outer side, but there is a slight degree of flattening on 
the upper lateral aspect which is more pronounced towards the aper- 
ture. The whorls expand rapidly, the body whorl being relatively very 
large and those of the spire being impressed to about a third of their 
height in the whorl below.. The cast shows no evidence of surface 
markings of any kind. This form is remarkably like Holopea guelphensis, 
Billings, from the Guelph of Ontario, but it cannot be identical at the 
present horizon. 
1“The Cruise of the Neptune’’, Appendix IV, pp. 329 and 330, 1906. 
