﻿370 PROCEEDINGS OF THE NATIONAL MUSEUM vol. loo 



(52-59), dry, from notch, 52 (49-57); condylobasal length, 61.6 

 (59.9-63.5); zygomatic breadth, 33.4 (32.7-34.5); length of nasals, 

 27.1 (25.5-28.1); greatest combined width of nasals across premaxil- 

 lary sutures, 13.9 (13.7-14.2); least length of palatal bridge, 6.2 

 (5.7-7.0); greatest distance between outer sides of maxillary plates of 

 tooth row, 21.5 (20.5-22.5); alveolar length of upper molar row, 13.9 

 (13.2-14.4). Of an adult male from Piraputangas and a female from 

 Urucum, respectively: Total length, 370, 365; hind foot, 80, 79; ear, 

 dry from notch, 58, 54; condylobasal length, 64.9, 60.3; zygomatic 

 breadth, 34.0, 33.3; length of nasals, 28.8, 24.1; greatest combined 

 width of nasals across premaxillary sutures, 15.2, 14.1; least length of 

 palatal bridge, 5.5, 5.5; distance between outer sides of maxillary 

 plates of tooth rows, 22.0, 21.9; alveolar length of upper molar row, 

 14.6, 13.7. Of a male and female from Santa Ana de Chapada 

 (chapadae), respectively: Condylobasal length, 63.5, 66.1; zygomatic 

 breadth, 33.3, 34.7; length of nasals, 30.4, 30.1; greatest combined 

 width of nasals across premaxillary sutures, 16.1, 15.2; least length 

 of palatal bridge, 6.1, 7.0; distance between outer sides of maxillary 

 plates of tooth rows, 21.5, 21.5; alveolar length of upper molar row, 

 14.5, 14.6. 



Remarks. — Available topotypes, part of the original series collected 

 by Foster, represent the gray phase while the type and two available 

 topotypes of chapadae are buffy-phase individuals of the same geo- 

 graphic race. Other specimens from the Paraguayan and Brazilian 

 Chaco show the racial unity of tapitis in the area drained by the Rio 

 Paraguay. One of three specimens from Urucum de Corumbd, Mato 

 Grosso, Brazil, agrees with typical chapadae, another with typical 

 paraguensis, the third is intermediate. A skin from Asunci6n, Para- 

 guay, is practically indistinguishable from topotypes of chapadae. 

 Bolivian tapitis here referred to paraguensis generally agree with 

 huffy phase individuals already mentioned but indicate gradation into 

 the more warmly colored inca. 



The skull of a male topotype of chapadae (U.S.N.M. No. 113432) 

 with posterior wing of supraorbital process short and nearly entirely 

 coalesced with frontal led Nelson to believe that S. aquaticus and 

 S. palustris were closely related to S. brasiliensis. Nelson evidently 

 overlooked the female topotype of the series with aU but tip of posterior 

 wing of supraorbital process widely separated from frontal. 



Specimens examined. — Twenty-five. Paraguay: Sapucay, 8 (the 

 type, B. M.; 7, U.S.N.M.); Asunci6n, 1 (C.N.H.M.); Colonia Nueva 

 Italia, Villeta, 1 (C.N.H.M.); Orloff, Chaco, 2 (C.N.H.M.); Puerto 

 Casado, Chaco, 1 (C.N.H.M.). Brazil: Santa Ana de Chapada, 3 

 (type of chapadae, B. M.; 2, U.S.N.M.); Urucum de Corumba, Matto 

 Grosso, 4 (C.N.H.M.); Piraputangas, Matto Grosso, 1 (C.N.H.M.). 



