194 ANNAL8 NEW YORE ACADEMY OF SCIENCES 



INTEODUCTION 



The material that forms the basis of this paper came to the American 

 Museum of Natural History through Dr. Franz Boas, who conducted 

 archaeological investigations in Porto Eico in 1915 as part of the natural 

 history survey of the island, undertaken by the New York Academy of 

 Sciences with the cooperation of the Insular government. From a cave, 

 the Cueva de la Ceiba, between Utuado and Arecibo, a number of human 

 bones were taken and more or less intermingled with them were remains 

 of several species of mammals. From the upper layers of the cave floor, 

 largely a heavy deposit of ashes, came a number of bones of a new rodent 

 genus described recently by Dr. J. A. Allen as Isolohodon portoricensis.^ 

 This part of the deposit Dr. Boas regards as artificial.^ From deeper in 

 the cave floor came the material under present discussion, and this for- 

 mation appears to be of stalactite origin, dark red in color and of a depth 

 of from 18 to 24 inches. 



Before more extended search for additional material is made, it has 

 seemed best to make a preliminary report on this material, leaving the 

 finer details of the question of affinities to be discussed in a later paper. 

 The present paper is part of the author's plan to report on the mammals 

 of Porto Eico as his assignment in the natural history survey mentioned 

 above. 



The author wishes to acknowledge indebtedness to Mr. Gerrit Miller, 

 Curator of Mammals in the United States National Museum, for the 

 privilege of comparing the rodent material with the collections of fossil 

 rodents now at Washington; and to Dr. J. A. Allen, Curator of Mam- 

 malogy and Ornithology, and to Dr. W. D. Matthew, Curator of Verte- 

 brate Paleontology, both in the American Museum, thanks are due for 

 valued advice and suggestions. 



A list of the material is as follows : 



Eostrum with one tooth, fragments of mandibular rami, part of a 

 humerus, end of a radius, three vertebrae, one femur and part of the 

 other, two tibiae, portions of two fibulae and a calcaneum, all seemingly of 

 one individual, an unknown grormd sloth. 



Two fragmentary rami of different sizes, of an unknoAvn insectivore? 

 or bat ? 



A fragmentary mandibular ramus, too incomplete for present determi- 

 nation, of a large hystricomorph rodent. 



«J. A. Allen: Annals N. T. Acad. Scl., Vol. XXVII, pp. 17-22. 25 January, 1916. 

 ' J, A. AlleNj I. c, p. 18. 



