7ol. XXIX, pp, 47-50 February 24, 1916 



PROCEEDINGS 



OF THE 



BIOLOGICAL SOCIETY OF WASHINGTON 



GENERAL NOTES. 



NOTE ON THE INDIGENOUS RODENT OF SANTO DOMINGO. 



Hitherto the only known specimen of the indigenous rodent of Santo 

 Domingo has been the type, sent to Paris by Ricord, and described as a 

 new genns and species, Plagiodontia ledium, Vjy F. Cuvier in 1836.* The 

 discovery of three left lower mandibles (one with dentition complete), 

 a tibia, and part of a pelvis among some miscellaneous bones taken by 

 ^V. ]M. Gabb from a kitchen midden in a cave on the shore of San Lorenzo 

 Bay, Santo Domingo, 1869-71, is therefore of much interest.! Two of the 

 mandibles represent adult individuals, while the third is not mature. 

 Some of the measurements of the two adults (Nos. 200,411 and 200,412 

 U. S. National Museum) are: length from projection behind articular 

 surface to posterior border of alveolus of incisor, 48, 50; depth through 

 articular process, 24.0, 24.6; diastema, 11, 1.3; toothrow (alveoh), 19.0, 

 20.2; first lower molar (alveolus), 4.4x4.4, 5.0x5.0. In both of the 

 adults the teeth were still growing from a basal pulp, so that the enamel 

 pattern undergoes no change at successive levels from crown to base. 

 The pattern is correctly represented by Cuvier (pi. 17, fig. 5) ; it is identi- 

 cal in character with that of Adelphomys from the Santa Cruz beds of 

 Patagonia as figured by Ameghino + and Scott. § The upper cheek teeth 

 as figured by Cuvier (pi. 17, fig. 4) are equally like those of a Santa Cruz 

 specimen regarded by Scott (pi. 65, fig. 13) as representing the maxillary 

 dentition of Scleromys Ameghino, a genus based on lower teeth diff'ering 

 widely from those of Adelphomys and Plagiodontia. The exact meaning 

 of the discrepancies can not now be explained. These conclusions, how- 

 ever, seem justified: that Plagiodontia is not closely related to Capromys, 

 and that the occurrence of these two genera and of Amblyrhiza in the 

 West Indies during relatively recent times indicates the probability of a 

 once-abundant Antillean representation of the Hystricine group. 



— Gerrit S. Miller, Jr. 



•Ann. Sci. Nat., Paris, ser. 2, vol. 6, p. 347. 



+ The cave and kitchen midden are described in Gabb's account of the topography 

 and geology of Santo Domingo. Trans. Amer. Philos. Soc, n.s., vol.15, pp. 14e-147. 

 1873. 



JMam. Fos. Argent., pi. 6, fig. 3 c. 



§Rep. Princeton Univ. Exped. Patagonia, vol. 5 (paleont. 2), pi. 66, fig. 21. 



11— PROC. Biol. Soc. Wash.. Vol. XXIX. 1916. (47) 



