764 
PROCEEDINGS OF THE NATIONAL MUSEUM. 
vol,. XXIV. 
body, 203 (193-210); tail, 238 (222-240); hindfoot, 41.8 (41-44); hind- 
foot without claws, 40 (39-42). For detailed measurements see table 
below. 
Cranial measurements of type: Greatest length, 45 (47.6)^ mm.; 
basal length, 40 (41); basilar length, 37 (37.6); palatal length, 21.4 (22); 
least width of palate between anterior molars, 5 (5); diastema, 13 (13); 
length of incisive foramen, 8.8 (8); combined breadth of incisive foram- 
ina, 3 (4); length of nasals, 18 (18); combined breadth of nasals, 4.& 
(5.4); zygomatic breadth, 19.8 (22); interorbital breadth, 6 (7); mas- 
toid breadth, 18 (18); breadth of braincase above roots of zygomata, 
16 (16.4); depth of braincase at anterior border of basioccipital, 11.4 
(12); fronto-palatal depth at posterior extremity of nasals, 11 (11.4); 
least depth of rostrum immediately behind incisors, SA) (9); mandible, 
26 (27.6); maxillary toothrow (alveoli), 7.4 (8); width of front upper 
molar, 2.2 (2.6); mandibular toothrow (alveoli), 7.4 (7.8). 
Specimens examined. — Seven, all from the type locality. 
Remarks. — These rats were trapped, together with the specimens of 
Mus stoicus.^ in the dense jungle with which Henry Lawrence Island is 
covered. The. types of both species were taken on the south side of 
the island on the shore of Kwantung Straits. Other specimens were 
secured at a point about 2 miles farther north. The names which I 
have used for the two species were suggested by Dr. Abbott's note 
that the smaller animal squeals piteously when caught, while the 
larger is silent. 
Table of measurements of Mus stoicus, 3Ius laciturnus, and Mus flehilis. 
Name. 
Number. 
Sex. 
Total 
length. 
Head and 
body. 
Tail. 
Hind 
foot. 
Hind foot 
without 
claws. 
2111834 
111835 
111836 
111838 
111839 
111842 
111845 
111846 
111847 
111848 
111849 
111850 
111851 
111853 
111856 
111818 
111820 
111822 
2111828 
111831 
111832 
111833 
111837 
111840 
2111841 
111843 
111852 
111854 
Male 
do.... 
do.... 
Mm. 
442 
415 
Mm. 
249 
240 
246 
223 
233 
222 
260 
252 
242 
240 
220 
237 
218 
200 
222 
242 
200 
230 
266 
216 
237 
224 
210 
195 
210 
207 
193 
202 
Mm. 
193 
175 
""\m 
192 
188 
205 
198 
200 
212 
"'"'263' 
197 
"""266' 
190 
197 
200 
228 
213 
209 
190 
237 
222 
242 
253 
235 
240 
Mm. 
47 
47.6 
49 
46 
48.6 
48 
49 
47.6 
46.4 
48 
45.6 
48 
48.6 
41.4 
48 
48 
45 
44 
53 
48 
47.6 
44 
44 
42 
41.4 
31.4 
41 
41.6 
Mm. 
45 
Do 
Do 
45 
47 
Do 
Do 
Do 
Do 
Do.. 
Do 
Do 
Do 
do.... 
do.... 
do.... 
do.... 
do.... 
do.... 
Female . . . 
Male 
403 
425 
410 
465 
4.n0 
442 
452 
44 
46 
45 
47 
45 
44 
46 
43 
Do 
Do 
Do 
......do.... 
do.... 
440 
415 
45.6 
46 
39.6 
Do 
Male 
do.... 
do.... 
Female . . . 
Male 
Female . . . 
do.... 
do.... 
Male 
do.... 
Female... 
do.... 
do.... 
Male 
422 
432 
397 
330 
494 
429 
446 
414 
447 
417 
4.52 
400 
428 
442 
45.6 
46 
Do 
Do 
44 
43 
Do 
50 
Do 
46 
Do . 
45.6 
Do 
42 
42 
Do 
41 
Do 
39 
Do . 
39.6 
Do 
39 
Do 
40 
1 Measurements in parenthesis are those of the type of Mui< pannosus. 2Xype. 
