446 MURIDA—AGRESTIS 








Tail (with- | Hind foot Ear . : 
ee out terminal! (without (greatest Welght in 
; hairs). claws). length). sr = 
SPECIMENS FROM REIGATE, SURREY (continued). 
SexuaLLy Mature Femaves :— 
1. 14th June 1909 ; 3 small foetuses a 82 30 16 
2. 23rd June 1909; 6 small foetuses : 98 35 16 
8. 12th July 1909. : 85 30 16 
4, 16th July 1909; 6 small foetuses 5 84 25 14 
5. 20th July 1909; 7 small foetuses ; 96 34 16 
6, 24th July 1909 : 5 small foetuses ‘ 94 33 15°5 
7. 2nd Oct. 1909; 5 small fcetuses . & 112 41 175 
8. 11th Oct. 1909; 4 small foetuses 5 94 82 16 ee ni 
9. Ist June 1911; 5 small foetuses . F 104 41 165 115 33 
10. 8rd June 1911; 3 small foetuses . C 94 86 | 16 10 20 
11. 29th Aug. 1911; 5 small fetuses 5 100 36 | 16 115 29 
12. 24th Sept. 1911 ; 2 small foetuses . 84 58 16 12 17 
13, 29th Oct. 1911 : 94 32 16 11 19 
14, 19th May 1912; 5 large foetuses, head 
and body of which av. eraged 34 97 38 16 il 35 
16, 13th June 1912; 6 small foetuses 5 97 25 16 11 22 
16. 20th Sept.1912 . : 5 5 96 82 16 11 20 
17. 28th Sept. 1912; 3 small fetuses : 88 29 17 il 23 
18. 10th Oct. 1913 . . . . 92 34 17 11 25 
19. 18th Oct. 1913 . 5 ° A 90 34 17 10 18 
20. 21st Oct. 1913 c 5 : - 98 40 17 12 27 
Average 5 E 5 93°5 34°5 16°3 11 24 




Notes on tables of dimensions :—The young make occasional excursions 
from the nursery as soon as they can see, but frequently retain it as 
their headquarters until they attain sexual maturity, which is not 
usually until the head and body reaches a length of go to 95. 
Specimens with the head and body exceeding 110 are rare, but 
probably represent the size regularly reached by really old animals. 
Occasionally, even larger specimens are captured ; ¢.¢.,a male with head 
and body 123 (Coward, Cheshire). A female nursing young, but not 
fully grown, sent by the late Lord Lilford from Oundle, Northampton- 
shire, reached 117 (for further details see my paper in Proc. Zool. Soc., 
London, 19th May 1896, 599). The status of these “giants” requires 
investigation. Evidently “voles” continue to grow for a long and some- 
what indefinite period (cf above, under Hvotomys, p. 411). 
Skull :—Condylo-basal length, 24-4 to 26; breadth: zygomatic, 14 
to 15-2; inter-orbital,, 3-0 to 3-4; occipital, 11 to 12-2; depth, median 
occipital, 6 to 6-8; length: of nasals, 6-6 to 7-4; of diastema, 6-8 to 7-8 
of mandible, 15-2 to 16-2; of maxillary tooth-row, 5-8 to 6-4; of 
mandibular tooth-row, 5-8 to 6-4. 
Grass Mice’ are gregarious and sociable animals, restricted 
under normal circumstances to a diet of green stuff, preferably 
For an excellent account of the habits of Grass Mice, see Victor Fatio’s Les 
Cantpagnoles du Leman. 
