LIST OF PLATES. 
Fig.' 
6. 
b. 
Molar teeth of the upper jaw. 
Fig. 
12. 
a. 
Ramus of lower jaw of Mus Bra- 
— 
7. 
a. 
Skull of Mus nasutus. 
ziliensis. 
— 
7. 
1. 
Molar teeth of upper jaw. 
— 
13. 
a. 
Molar teeth of upper jaw of Mus 
— 
7. 
c. 
ditto of lower jaw. 
micropus. 
— 
8. 
a. 
Skull of Mus Galapagoensis. 
— 
13. 
b. 
ditto of lower jaw. 
— 
8. 
b. 
Molar teeth of upper jaw. 
— 
14. 
a. 
Ramus of lower jaw of Mus Gala- 
— 
8. 
c. 
ditto of lower jaw. 
pagoensis. 
XXXIV. 
Skulls and molar teeth of various species 
— 
15. 
a. 
Molar teeth of upper jaw of Mus 
of 
Rodents, &c. 
griseo-flavus. 
Fig. 
1. 
a. 
Skull of Mus longicaudatus — natu- 
— 
15. 
b. 
ditto of lower. 
ral size. 
— 
16. 
a. 
Molar teeth of upper jaw of Mus 
— 
1. 
b. 
Molar teeth of upper jaw of ditto. 
xanthopygus . 
— 
1. 
c. 
ditto of lower jaw. 
— 
16. 
b. 
ditto of lower jaw. 
— 
1. 
d. 
Ramus of lower jaw — natural size. 
— 
17- 
a. 
Molar teeth of upper jaw of Mus 
— 
2. 
a. 
Skull of Mus elegans — natural size. 
Darwinii. 
— 
2. 
b. 
Molar teeth of upper jaw. 
— 
17. 
b. 
ditto of lower. 
— 
2. 
c. 
ditto of lower jaw. 
— 
18. 
a. 
Molar teeth of upper jaw of Mus 
— 
3. 
a. 
Skull of Mus bimaculatus — nat. size 
Gouldii. 
— 
3. 
b. 
Molar teeth of upper jaw. 
— 
18. 
b. 
ditto of lower. 
— 
3. 
c. 
ditto of lower jaw. 

19. 
a. 
Molar teeth of upper jaw of Mus 
— 
3. 
d. 
Ramus of lower jaw — natural size. 
insularis. 
— 
4. 
a. 
Skull of Mus gracilipes. 
— 
19. 
b. 
ditto of lower jaw. 
— 
4. 
b. 
Molar teeth of upper jaw. 
— 
19. 
c. 
Portion of ramus of lower jaw. 
— 
4. 
c. 
ditto of lower jaw. 
— 
20. 
a. 
.Skull of Reithrodon chinchilloides 
— 
4. 
d. 
View of the under side of the tarsus 
— natural size. 
— 
5. 
a. 
First and second molar teeth of 
— 
20. 
b. 
ditto, viewed from beneath. 
upper jaw of Mus Jlavescens. 
— 
20. 
c. 
ditto, side view. 
— 
5. 
b. 
Two posterior molar teeth of the 
— 
20. 
d. 
Ramus of lower jaw — natural size. 
lower jaw of ditto. 
— 
20. 
e. 
Molar teeth of upper jaw. 
— 
6. 
a. 
Molar teeth of the upper jaw of 
— 
20. 
/• 
ditto of lower. 
Mus Magellanicus . 
— 
21. 
a. 
Skull of Reithrodon cuniculoides , 
— 
6. 
b. 
ditto of lower jaw. 
viewed from beneath. 
— 
7. 
a. 
Skull of Mus arenicola. 
— 
21. 
b. 
ditto, side view of fore part. 
— 
7. 
b. 
Molar teeth of upper jaw. 
— 
21. 
c. 
Ramus of lower pair. 
-r- 
7. 
c. 
ditto of lower jaw. 
_ 
22. 
a. 
Hinder part of ramus of lower jaw 
— 
7. 
d. 
Ramus of lower jaw. 
of Abrocoma Bennettii. 
— 
8. 
a. 
Molar teeth of upper jaw of Mus 
— 
23. 
a. 
Skull of Abrocoma Cuvieri , viewed 
brachiotis. 
from beneath. 
— 
8. 
b. 
Two posterior molars of lower jaw. 
— 
23. 
b. 
Lower jaw of ditto, viewed from 
— 
9. 
a. 
Molar teeth of upper jaw of Mus 
beneath. 
obscurus. 
— 
23. 
c. 
Ramus of lower jaw, inner side. 
— 
9. 
b. 
ditto of lower jaw. 
— 
24. 
a. 
Ramus of lower jaw of Octodon 
— 
10. 
a. 
Ramus of lower jaw of Mus nasutus. 
Cumingii , inner side. 
— 
11. 
a. 
Molar teeth of lower jaw of Mus 
— 
25. 
a. 
Skull of Didelphis crassicaudata. 
tumidus. 
— 
25. 
b. 
ditto, viewed from beneath. 
