- AMERICAN MUSEUM NOVITATES 

Figs 1, 
gazetteer entries in appendix 1. 
Museum specimens of Marmosops are fre- 
quently misidentified due to the absence of 
any comprehensive current reference for 
identifications. Although progress has been 
made in sorting out the taxonomy of Mar- 
mosops in southeastern Brazil (Mustrangi 
and Patton, 1997), western Amazonia (Patton 
et al., 2000), and the Guiana region (Voss et 
al., 2001), no revisionary literature has ad- 
dressed the species-level systematics of the 
genus in other parts of its enormous geo- 
graphic range, especially along the Andes. 
Even a superficial familiarity with the large 
collections that have accumulated since 
Tate’s (1933) revision suggests the urgent 
need for testing traditionally accepted species 
concepts with newly available material. 
Herein we formally rediagnose Marmo- 
NO. 3466 
Marmosops 
@ Type locality 
Type localities of nominal species referred to the genus Marmosops. Numbers are keyed to 
sops to facilitate its recognition as a distinct 
clade and to provide a foundation for sub- 
sequent revisionary work. We next describe 
a new species from Bolivia and summarize 
what little is known about its ecogeographic 
distribution on the eastern slopes of the An- 
des. Lastly, we review the taxonomy and dis- 
tribution of other Bolivian congeners in order 
to assess the regional diversity of the genus 
based on museum specimens examined in the 
course of this study. 
MATERIALS AND METHODS 
Specimens cited in our tables and text are 
preserved in the following collections (listed 
in order of their standard institutional abbre- 
viations): AMNH, American Museum of 
