> 
98 HYALINIA RADIATULA ELECTRINA, 
* It is, therefore, proposed to regard 
as strictly typical of the race, only those 
specimens possessing an amber-coloured 
shell and upon which the microscopic 
spiral striation is apparently absent or 
but faintly visible; to distinguish the 
albine form of electrinw as var. alba, 
a name applied by Dr. Gwyn Jeffreys in 
1872 in his Concordance of the Mollusea 
of Europe and Eastern North America ; 
and apply the term circwnstriata to 
the shells clearly exhibiting the deep 
and distinet revolving striw, a feature 
especially characteristic of the specimens 
inhabiting the States east of the Appala- 
Fic. M1.—Surface sculpture of the ultimate and chian range of mountains, and, according 
penultimate whorls of H. vadiatula electrina var, to the observations of Mr. G. H. Clapp, 
circumestriata, Wetumpka, Alabama, Mr, Clapp : S . 
30. (After micro-photo by Mr. J. W. Jackson). apparently culminating in Alabama, 
The saw of H. electrina Gould is described by 
Binney and Bland as of an arcuate form, with attennu- 
ated and slightly recurved ends, anterior surface 
centrally striate, concave margin smooth with a 
median rounded projection, on each side of which Fic. 12.—Mandible or jaw 
are two notches ‘ of A. electrina X 25 (after 
: ie Morse), 
The LINGUAL MEMBRANE is deseribed by Morse, and has a formula. of 
27 4.14.27 54=2,970. The median tooth is broad and long, with a long and 
slender mesocone, with small ectocones near its base; laterals three each, with a 
well-developed mesocone, and well-marked ectocone, the two admedian teeth at 
each side long and narrow, the third smaller; the marginal teeth are simply aculeate. 
Fic. 148. Fic, < 
3.—Halfa transverse row of the teeth of /7. edectrina X 600 (after Morse). 
{.—Median, admedian, and marginal teeth of //. e¢vauéa (Menke) Binney, highly magnified 
i 
Fic. 1 
Fig. 4 
(after Binney). 
This form is undoubtedly diffused over the whole of the North American 
Continent, being reported from Point Barrow in the extreme north of Alaska, 
quite into Florida in the extreme south, 
BRITISH NORTH AMERICA. . 
Alberta—Recorded as 1. radiatula by Dr. Dall from Red Deer and from Laggan 
at an altitude of 5,200 feet in the Rocky Mountains. 
British Columbia—Recorded as V. radiatuda by Dr. Dall from Departure Bay, 
Comox and Union Bay, and as V. hammonis from Field by Vanatta. 
Labrador—Recorded by A. S. Packard as H. electrina from Belles Amours. 
Mackenzie—Recorded as V. radiatuda from Fort Resolution on Great Slave 
Lake by Dr. Dall. 
Manitoba—Mr. R. M. Christy records it as H. viridula from Lake of the Woods 
and Turtle and Pembina Mountains; also from a dry pond hole on prairie near 
Brandon, and commonly at roots of grass by a sleugh at Carberry ; and Mr. Clapp 
reports it as V7. radiatula from Winnipeg. 
Ontario—//. electrina, St. Thomas, April 1886, T. D. A. Cockerell. As H. 
viridula it is recorded by F. R. Latehford from left bank of Rideau Canal, just 
below Bank street Bridge, near Ottawa; and Mr. Clapp reports it as V. radiatula 
from Bobeaygeon and Georgian Bay. 
Quebec—As Z. radiatulus it is recorded by A. W. Hanham from the bar of Bay 
of Barachois, Gaspé, in May 1892. 
Ungava—Recorded from Unga — as Z. radiatulus by Dr. Dall. 
