104 
Comparative Measurements of Perognathus Parvus Group 
Average, maximum and minimum (in millimetres) 
Species 
Perognathus laingi 
Perognathus lordi 
Perognathus parvus 
Males 
Females 
Males 
Females 
Males 
Females 
No. specimens 
Length (total) 
2 
175-5 
(191-0-158-0) 
1 
165-0 
24 
183-7 
(197-0-172-0) 
12 
171-7 
(181-0-162-0) 
5 
163-2 
(170-0-152-0) 
1 (immature) 
163-0 
Tail vertebrse 
90-3 
(102-0-69-0) 
88-0 
95-2 
(107-0-87-0) 
89-0 
(97-0-79-0) 
87-6 
(93-0-81-0) 
85-0 
Hind foot 
23-8 
(25-0-22-5) 
22-0 
24-9 
(25*5-23*0) 
22-7 
(24*0-21-5) 
22- 1 
(23-0-21-0) 
21*0 
No. skulls 
measured — 
Condylo-basal 
length of 
Hensel 
4 
IQ. 2 
(20-0-18-8) 
1 
19-5 
31 
18-9 
(20-5-18-1) 
9 
18-5 
(19-0-17-5) 
5 
17-8 
(18-8-16-8) 
1 
17-5 
Occipito-nasal 
length 
26-9 
(27-5-25-8) 
26-2 
27-1 
(28-5-25-1) 
25-1 
(27-0-24-5) 
24-8 
(25-5-23-8) 
25-5 
Mastoidal 
breadth 
13-6 
(14-5-12-51 
14-0 
13-9 
(15-0-13-0) 
13-4 
(14-0-11-0) 
13*2 
(13*0-13*0) 
12-8 
Interorbital 
breadth 
6-1 
(6- 5-6-0) 
6-5 
6-1 
(6 -5-6-0) 
(6 -0-5-0) 
5-8 
(6 -1-5 -5) 
6-0 
Length of 
interparietal 
3-8 
(40-3-5) 
3-5 
3-5 
(4 -0-3-0) 
3-3 
(3 -8-3-0) 
3-4 
(35-3-2) 
3-5 
Width of 
interparietal 
5-0 
(5*2-50) 
5-0 
4-9 
(5 ■ 2-4 ■ 1 ) 
4-7 
(5-0-4-2) 
5-1 
(5 -5-5-0) 
5-1 
Length of 
nasals 
9-4 
(10-0-9-0) 
10-2 
10-6 
(11-8-9-0) 
10-1 
(10-8-9-2) 
9-7 
(10-0-9-0) 
9-5 
Length of in- 
cisive fora- 
mina 
1-7 
(2-0-1 -5) 
2-0 
1-7 
(2-0-1-5) 
1-8 
(20-1-5) 
1-9 
(2-0-1 -5) 
2-0 
Ratio of inter- 
parietal 
width to con- 
dylobasal 
length 
26-4 
(27-6-25-0) 
26-3 
25*3 
(28*6-20*0) 
25-5 
(28-1-23-7) 
28-6 
(30-6-26*5) 
31-4 
Synaptomys borealis artemisiae new subspecies 
Similkameen Lemming Mouse 
Type. Male adult, skin and skull. No. 7952, National Museum of 
Canada; Stevenson creek, southwest of Princeton, British Columbia, on 
Hope-Princeton trail, east slope of Cascade range, about 2,400 feet altitude, 
latitude 49° 23' north, longitude 120° 35' west; October 4, 1927; collected 
