Bishop’s Slender Opossum

discussion

Discussion: Described as a subspecies of M. parvidens; treated as a species by Voss et al. (2001: 48).

Order Didelphimorphia

materials_examined

Type Locality: " 264 km N (by road) Xavantina (locality is at 12 ° 51 ' S, 51 ° 46 ' W), Serra do Roncador, Mato Grosso, Brazil. ".

Order Didelphimorphia

discussion

This appears to be the appropriate name for Bolivian specimens of the Marmosops parvidens group, of which we have examined eight examples from widely scattered localities in Beni, Cochabamba, La Paz, and Santa Cruz (fig. 10). These are all very small animals (table 7) with much shorter molar series (LM ³ 5.8 mm) than any other Bolivian congener. The skulls have rounded supraorbital margins that lack distinct beading, shallow postorbital constrictions are dorsally visible, there are no palatine fenestrae, and the upper canines have small posterior accessory cusps. Although one adult male (MSB 55843) has an almost­naked patch of skin and a streak of red­stained fur on the midline of the throat, two others (CBF 7531, LHE 1541) have no trace of a gular gland. All three adult males have well­developed, blade­like lateral carpal tubercles, and the scrotum is pale, with white fur and unpigmented skin. None of the females we examined had well­developed mammae, so it is not known whether or not this taxon has pectoral teats. 9 Because Anderson (1997) seldom cited museum catalog numbers, we consulted his card file of examined specimens (preserved in the AMNH Department of Mammalogy archives)

An Introduction to Marmosops (Marsupialia: Didelphidae), with the Description of a New Species from Bolivia and Notes on the Taxonomy and Distribution of Other Bolivian Forms