52 
Family, pectinidab 
Genus, Entolium Meek 
Entolium hertleini sp. nov. 
Plate XIV, figure 1 
Shell, very flat. Ears, small. Upper margins of the ears make a 
shallow re-entrant. External surface appears smooth, but the X 10 power 
of magnification shows it to be marked by even, continuous, concentric 
striae. These have a characteristic curve which is shown in the plate 
by a black line. Lateral margin of disk, also ears, are marked by faint, 
microscopic radial striae as well. The species is very similar to the wide 
variety of Entolium leachii McLearn, but is separable by its smaller ears, 
concentric curve. 
Dimensions, Holotype — length, 27 mm.; height, 27; semidiameter, 2; 
base of anterior ear, 5*5; base of posterior ear, 7 ; upper margins of ears, 
total 6*5; re-entrant angle, 165 degrees; apical angle, 115 degrees. Para- 
type — length, 57; height, 56; apical angle, 125 degrees. Both types are 
right valves. 
Locality, Above zone of Cadoceras brooksi, at an altitude of 2,100 feet 
on a small brook which enters Deer creek from the north at 1,700 feet. 
Name. After Mr. Leo G. Hertlein. 
Entolium vulmnicmn sp. nov. 
Plate XIV, figure 2 
Shell, very flat, large. Ears, small, with a notable re-entrant above. 
Next below the dorsal margin of the shell, and bounded below by a radial 
line, there is an area where the shell is thickened. These are plainly 
visible in the figure. Exterior, smooth or nearly so. Some specimens 
have an appearance of faint, concentric striae. 
Dimensions. Holotype, a left valve — length, 68 mm.; height, 62; 
semidiameter, 4; base of anterior ear, 12; base of posterior ear, 17; upper 
margins of ears, total, 17; re-entrant angle, 140 degrees; apical angle, 128 
degrees. 
Locality. Associated with Cylindroteuthis ihemis, on the west shore 
of Harrison lake, 1,820 yards north of Harrison River point. 
Name. In allusion to habitat. The species was an inhabitant of the 
powerfully volcanic British Columbia of Bajocian times. 
Entolium aucellarum sp. nov. 
Plate XIV, figure 3 
Shell, flat, smootfi. The ears are larger than those of E. hertleini 
and E. vulcanicum, and are of a different shape from those of either, or of 
E. leachii McLearn. As is usual with this genus the apical angle increases 
with age. 
Dimensions. Holotype, a right valve — length, 27 mm.; height, 29; 
midiameter, 2; base of anterior ear, 7; base of posterior ear, 8; upper 
