NO. 15 MAMMALS FROM HISPANIOLA MILLER 3 



TADARIDA sp. 



Mandibles, 2. 



RATTUS RATTUS subsp. 



Mandible, i : auditory bulla, i ; femur, i ; tibia, I ; heads of tibiae, 3 ; 

 astragali, 2; calcaneum, i ; ulna. i. 



These few rat bones were the only remains of introduced European 

 rodents found in the deposit. Bones of the house mouse were entirely 

 absent. 



BROTOMYS VORATUS Miller 



Imperfect skull, i ; palate and rostrum, i ; right maxillae, 2 ; left 

 maxilla, i ; left nasal, i ; fragmentary palates, 5 ; loose cheekteeth, 27 ; 

 pieces of frontal, 2 ; pieces of braincase, 2 ; occipitals, i ; auditory 

 bullae, 2 ; mandibles, right. 5 ; left, 5 ; humeri, 2 ; ulnae, 4 ; radius, i ; 

 innominates. 12; sacra. 4; femora, 9; tibiae, 7; heads of tibia, 4; 

 astragalus, i ; calcaneum, i. 



The skull (pi. i, fig. 2), though imperfect, is the most nearly com- 

 plete specimen that has yet been found. It permits, for the first time, 

 a rather full comparison with the skull of Proechimys (pi. i, fig. i), 

 and it shows conclusively that, so far as cranial characters are con- 

 cerned, the differences between the two animals are of no more than 

 generic importance. Chief among the characters in which the island 

 genus differs from its mainland relative are the broader, deeper, less 

 downward bent rostrum, deeper zygoma (in a perfect specimen this 

 would be even more evident than it is in the slightly injured zygoma 

 of the Trujin skull), less developed supraorbital bead (not well shown 

 in the Trujin skull but obvious in other specimens), and less contrast 

 in size and form between the alveolar pit made by the inner root of 

 each cheektooth and the two pits made by the outer roots. Apparently 

 there is less space between the paroccipital process and the posterior 

 margin of the glenoid fossa, but this may be partly or wholly due to 

 incorrect reconstruction of this part of the skull. The auditory bulla 

 in the Trujin specimen is not exactly in place; it should lie about 1.5 

 mm. farther back. As compared with the mandible of Proechimys 

 semispinosus that of Brotomys voratus (see Smithsonian Misc. Coll., 

 Vol. 82, No. 5, pi. I, fig. 3, December 11, 1929) is more robust. In 

 particular the depth at the sigmoid flexure is noticeably greater in 

 proportion to the total length of the mandible. The coronoid process 

 is larger and the angular process is longer. 



In its dental characters Brotomys likewise differs no more from 

 Procchiiuvs than the latter differs from some of its living: South 



