On a neio Short-Unhd Opossum from Brazil. 441 



skulls of true loftusi, raiiginj^ from Karj'atein {Carrvthers) 

 to Moliammorali {Loftus)^ before me, and three of the Muscat 

 f(irm, I find that there are certain cranial differences between 

 tlie two and would suggest that tlie latter sliould be distin- 

 guished as 



Jacalus loftusi vocator, subsp, n. 



External characters quite as in loftusi, but, the specimens 

 being or having been inspirit, the exact tone o£ colour cannot 

 be observed. 



Skull of about the same size as in lof/usi. Anteorbital 

 foramina smaller, of more equal breadth above and below, 

 not exj)anded above as in loftusi ; greatest breadth across 

 the two foramina in four specimens of loftusi 15"8j 16*2, 15*2, 

 and lo'4, in three specimens of vocator 14'2, 14"0, and 14*0. 

 Front edge of zygomatic plate outside the foramina more 

 vertical, nearly at right angles (88°, 89°) to the line of the 

 tooth-row, wiiile in lojtusi it slants back considerably (75°, 

 76°). Interparietal smaller, averaging about 4*5 X 5"4 as 

 compared with 5'5x 7*0 mm. Other characters apparently 

 quite as usual. 



Dimensions of type, measured on the spirit-specimen : — 



Head and body 95 mm.; tail 164; iiind foot 57 ; ear 21. 



Skull : greatest median length 29'7 ; greatest diagonal 

 length to back of bullae 32 ; greatest breadth across face 22'4 ; 

 interorbital breadth 12 ; biineatal breadth 23'2 ; anteorbital 

 foramen, height 5'4, breadth across the two foramina 14"2 ; 

 upper molar series 4'8. 



Hah. Coast region near Muscat ; type from Sohar, others 

 from Seeb, 



Type. Adult male in spirit. B.M. no. 0. 5. 22. 3. 

 Presented by Dr. A. S. G. Jayakar. 



Although the two co-types of loftusi (of which 55. 1. 6. 82 

 may now be formally selected as a lectotype) have the 

 zygomatic plate broken away, enough remains to show tliat 

 the anteorbital foramina are of quite the same shape as in 

 our series from Karyatein. 



XLIV. — A new Short-tailed Opossum from Brazil. 

 By Oldfield Thomas. 



(Publislied by permission of the Trustees of the British Museum.) 



Monodelphis theresa, sp. n. 

 Most nearly allied to M. ilieringi. 



Size about as in iheringi; fur similarly short and close, 

 hairs of back about 4 mm. in length. Coloration on the 



