ALLEN: FOSSIL MAMMALS FROM CUBA. 145 



the anterior end of the xiphisternum. The sternum of C. mclanurvs 

 is apparently similar, except that no trace of the small se^'enth sterne- 

 brum was found in the single skeleton examined. The sternum of 

 C. nana differs only in that the small seventh segment has fused with 

 the xiphisternum. The ends of the seventh and eighth pairs of ribs 

 are attached at this point. The manubrium is transversely lozenge- 

 shaped with a relatively long narrow stem, different from the short 

 stem of C. prchensilis and C. mdanurus. The xiphisternum also is 

 slender as in C. pUorides. 



In other details of the skeleton, C. nana resembles the three other 

 species of the genus. The clavicles are well developed, the tibia and 

 fibula are separate, and the femur has the straight outer border, rather 

 characteristic of many octodonts, without the prominent external 

 trochanteric ridge, seen for example in the house-rats (Epimys). 

 The species is probably altogether, the most generalized of the genus. 



Geocapromys columbianus (Chapman). 



Capromys columbianus Chapman, Butl. Amer. nuis. nat. hist., 1892, 4, p. 314, 



fig. 3, 4. 

 Synodontomys columbianus G. M. Allen, Bull. M. C. Z., 1917, 61, p. 5. 

 Geocapromys cubanus G. M. Allen, Bull. M. C. Z., 1917, 61, p. 9, pL, fig. 7-9. 



The wealth of excellent specimens received since my study of the 

 fragments described as Geocapromys cubanus, shows not only that the 

 latter represented young or smallish animals, but also that they are 

 undoubtedly the same species as Chapman's Capromys columhianus 

 described from Cuban cave-fossils. The approximation of the tooth- 

 rows appears to increase slightly with age, but though considerable, 

 does not amount to actual contact as had seemed to be indicated by 

 the figures of the type and by the specimen itself, which is slightly 

 broken at the front end of the palate. The Cuban Geocapromys 

 proves to have been an animal quite as large as the Jamaican G. 

 hrowni if not a trifle larger, hence considerably larger than G. thoraca- 

 tus and G: ingrahami. The palate offers several differential char- 

 acters. Its median bony ridge ends abruptly at the palatal margin 

 in G. brotvni; in G. thoracal us it continues as a short median projec- 

 tion at that point; but in both G. ingrahami and G. columhianus it 

 fades out before reaching the palatal margin. In the last species 

 also, the opening of the posterior nares is much the most narrowed 

 and the terminal wings of the palatals are correspondingly broadened 



