2004 
TABLE 11 
VOSS ET AL.: BOLIVIAN MARMOSOPS 
31 
Measurements (mm) and Weights (g) of Selected Specimens of Marmosops ocellatus* 

AMNH AMNH MSB MSB 
260027 261267 58512 58513 
Sex female female female female 
HBL 104 111 117 {137]}4 
LT 146 146 160 {133]4 
HF 16 17 15 [12]4 
Ear 25 25 23 22 
CBL 30.3 30.6 31.8 31.3 
NB 3.6 3.4 3.9 3.7 
LIB 5.7 5.5 5.5 5.8 
ZB 16.5 16.5 16.8 17.0 
PL 17.0 17.4 18.3 17.8 
PB 10.0 10.6 10.3 10.4 
MTR 12.7 12.9 13.2 13.2 
LM 6.4 6.7 6.8 6.8 
M1-M3 5.6 5.9 5.9 5.9 
WM4 2.4 2.6 2.6 2.5 
Weight 30 24 28 28 

BMNH AMNH AMNH AMNH 
26.1.5.25b 260026 261266 263549¢ 
male male male male 
140 117 132 126 
186 161 170 166 
20 18 19 19 
25 25 21 24 
36.8 32.5 34.5 34.0 
4.2 4.0 4.2 3.2 
6.3 5.9 6.0 5.9 
19.8 17.5 18.2 17.9 
20.7 18.5 19.2 19.4 
11.0 10.7 10.9 10.9 
14.7 13.6 14.1 14.2 
6.8 7.0 6.8 6.8 
5.8 6.0 5.9 5.8 
2.6 2.7 2.6 2.6 
— 39 38 36 


aAll specimens are from the Bolivian department of Santa Cruz; see text for other locality information. 
bHolotype. 
¢Misidentified by Anderson (1997: 163) as Thylamys macrurus. 
dThe collector’s recorded values for these dimensions are unusually large (HBL) or small (LT, HF) and may have resulted from 
mismeasurements. 
taxa (about 5.7%; table 6) is not as large as 
the differences observed among other species 
recognized by us, the phenotypic distinctive- 
ness of M. ocellatus and its apparently dis- 
crete geographic distribution suggest that it 
represents a unique evolutionary lineage that 
should be known by its own name. 
Most of the material that we refer to Mar- 
mosops ocellatus was identified by Anderson 
(1997) as M. dorothea, but two specimens 
(MSB 67020, 87094) were identified as Gra- 
cilinanus agilis buenavistae, and another 
(AMNH 263549) was identified as Thylamys 
macrurus. 
BOLIVIAN SPECIMENS EXAMINED: Santa Cruz, 6 
km by road W Ascencié6én (AMNH 261265), As- 
erradero Pontons (CBF 6163), Ayacucho (USNM 
390571, 390572), Buenavista (BMNH 26.1.5.25 
[holotype], 28.2.9.87, 28.2.9.90), 4.5 km N and 
1.5 km E Cerro Ambor6é (MSB 55844), El Refu- 
gio (LHE 1569, 1573, 1577, 1596), 3.5 km W 
Estacién El Pailon (AMNH 260026—260028; 
MSB 55070), Hacienda el Pelicano (AMNH 
275462), 7 km E and 3 km N Ingeniero Mora 
(AMNH 247652), Lago Caiman (USNM 581979), 
2 km SW Las Cruces (AMNH 263549; MSB 
63274), Mangabalito (MJS 005), 3 km SE Mon- 
tero (MSB 87094), Palmar (USNM 390569), San 
Miguel Rincén (AMNH 260029), 10 km N San 
Ramon (AMNH 261266, 261267), 15 km S Santa 
Cruz (MSB 58510-58514, 59886, 67020), 27 km 
SE Santa Cruz (59884, 59885), Santa Rosita 
(USNM 390022), Tita (MSB 55071). 
Unidentified Marmosops 
Among the Bolivian specimens we ex- 
amined are three that we are unable to con- 
fidently identify with any of the taxa recog- 
nized in this report. Two (AMNH 275461, 
MSB 67021) were collected 7 km SE Ari- 
ruma at an elevation of 1750 m on the lower 
Andean slopes of western Santa Cruz de- 
partment. Unlike Marmosops ocellatus, 
which occurs in the adjacent lowlands of 
Santa Cruz, these specimens have darker dor- 
sal fur, paler (self-white) underparts, and lack 
distinct postorbital constrictions. They differ 
from M. impavidus by their grayer dorsal fur, 
by lacking lateral zones of gray-based ventral 
fur, and by lacking distinct postorbital con- 
strictions. They differ from all of the forms 
herein referred to M. noctivagus by lacking 
interorbital beads. They differ from M. bish- 
opi by having grayer dorsal pelage, well-de- 
