47 
Dimensions. Holotype, right valve — long axis, 37 mm.; short axis, 
25; semidiameter, 7; apical angle, 60 degrees. 
Locality. Zone of Aucella canadiana, west side of a small bay on 
southwest shore of the peninsula. 
Aucella spasskensoides 
Plate IX, figures 3, 4 
Resembles A. spasskensis Pavlow, but the diameter is notably greater 
and the right valve has a greater apical angle. Strong concentric costae, 
sharp as in .4. acutistriata, spaced 4 to 5 in a cm. of radius on the mature 
shell, though closer in the umbonal region. 
Dimensions. Holotype, right valve — long axis, 38 mm.; short axis, 
29; semidiameter, . . ; apical angle, 80 degrees; right valve — long axis, 36; 
short axis, 29 ; semidiameter, 7 ; apical angle, 90 degrees. Paratype, left 
valve — long axis, 55; short axis, 39; semidiameter, 16; apical angle, 67 
degrees. The largest specimen found, a left valve, had a long axis measuring 
60 mm. 
Locality. Zone of Aucella canadiana, west side of small bay on south- 
west shore of peninsula. 
Aucella cascadensis sp. nov. 
Plate X, figures 1, 2 
Having the same general aspect of the fischeriana stock which the 
last species shows. The costation is wider spaced; 3 coatse in a centimetre 
of radius on the mature shell. Also the costse are sharp like those of 
A. acutistriata. 
Dimensions. Holotype, left valve — long axis, 57 mm.; short axis, 43; 
semidiameter, 15; apical angle, 80 degrees. Paratype, right valve — long 
axis, 63; short axis, 54; semidiameter, 15; apical angle, 105 degrees. 
Locality. Zone of A. canadiana, west side of Harrison lake, 350 yards 
from shore and 1,200 yards north of Deer creek. 
Name. Cascade mountains. 
Aucella canadiana sp. nov. 
Plate X, figures 3, 4, 5 
This form has departed farther from the fischeriana ancestry than the 
preceding species. These costas are wide spaced: 1-5 to each centimetre 
of radius, and are sharp like those of A. acutistriata. 
Dimensions. Holotype, a left valve — long axis, 54 mm.; short axis, 
43; semidiameter, 22; apical angle, 75 degrees. Paratype, right valve — 
long axis, 60; short axis, 49; semidiameter, 12; apical angle, 93 degrees. 
Locality. Zone of Aucella canadiana, west side of Harrison lake 350 
yards from shore and 1,200 yards north of Deer creek. 
Name. A Canadian species, and peculiarly so, because it is strikingly 
different from any of the foreign forms. 
9325fr-4i 
