146 bulletin: museum of comparative zoology. 



behind the palatal margin. The molar alveoli are more or less square 

 in outline, and the re-entrant enamel-folds of the teeth are noticeably 

 more nearly at right angles to the axis of the tooth-row than in the 

 large Capromys inloridcs, remains of which are found associated in 

 the same caves. Another feature that comes out in comparison of the 

 jaws of this and the last-named species, is that in Geocapromys the 

 posterior face of the last lower molar is nearly straight across instead 

 of at a decided angle to the long axis of the tooth-row. This character 

 is useful to identify toothless jaws, since the shape of the alveoli is 

 thus quite different; frequently too, the presence of the additional 

 internal bony ridge in the alveolus of the premolar can be made out. 



While the Cuban Geocapromys is intermediate in certain palatal 

 characters between G. iiujrahami and G. broumi, I have been unable 

 to find any points of difference between fragments from the Cuban 

 caves and those from caves in Sierra de Casas, Isle of Pines, where Dr. 

 Barbour's party obtained a series. This is the more interesting, since 

 both species of Capromys from the latter island differ slightly from 

 their Cuban representatives. 



In a single skull in which the premaxillary is preserved, its ascending 

 process is less broadened proximally than in G. hrounii and G. ingra- 

 hami, and is thus more like that of G. thoracatus. 



The alveolar length of the maxillary tooth-row in a full grown speci- 

 men is 21 mm.; of the mandibular row 19 mm. 



Remarks. 



The preliminary exploration of the Cuban cavern-deposits, as carried 

 out by Dr. Barbour and his associates, as well as by Mr. H. E. Anthony 

 of New York, and Mr. William Palmer of W^ashington, has thus far 

 revealed nothing really comparable with the fossil or subfossil mam- 

 mals from the Porto Rican caves, with two exceptions. These are 

 the insectivore Nesophontes, of which a small representative is found 

 in Cuba, and a larger one in Porto Rico; and the small ground-sloth, 

 Acratocnus of Porto Rico, which is represented in Cuba by a closely 

 allied if not identical genus. For the rest, the three Cuban species of 

 Capromys find no strict counterparts elsewhere, though Geocapromys 

 is represented on Jamaica, Swan Island, and Plana Keys. The Porto 

 Rican Isolobodon is nearly allied to Capromys and to the Santo 

 Domingan Plagiodontia, but its origin is doubtful. In Porto Rico 

 Mr. J. L. Peters and I found its remains either in Indian shell-heaps or 



