ALLEN: MAMMALS OF THE WEST INDIES. 197 



distance between the maxillopalatal suture and the end of the tooth 

 row, causing a marked interspace in the Grenada skulls; whereas 

 in mainland specimens the eighth molar but is very slightly in advance 

 of the palatal suture. The usual rule of the more rapid evolution 

 of the upper than of the lower jaw is also well illustrated by the fact 

 that in no case has the number of lower teeth been reduced beyond 

 seven, and in the type the eighth lower left tooth is still retained. In 

 the island animal, also, the teeth are noticeably smaller in absolute 

 size than those of the smallest of the Brazilian series. 



Measurements. — The external measurements of the three Grenada 

 specimens, taken in the flesh, and of an alcoholic specimen from Brazil, 

 are: — 



The skulls of the type, and of No. 3699 from Brazil (in parentheses) 

 measure respectively: — greatest length 85.5 (98); basal length, 71 

 (82); palatal length, 55.7 (65); zygomatic width, 35 (42); inter- 

 orbital width, 22 (23) ; length of premaxillaries, 9 (13) ; anterior tooth 

 to premaxillary, 9 (10); length from last molar to pterygoid, 19 (20); 

 length of upper left tooth row, 19 (24); length of lower jaw, 66.5 

 (80); length of lower tooth row, 20 (25). 



Of the three specimens of this armadillo obtained in Grenada, the 

 type is fully adult, and probably of nearly maximum size. The two 

 others are apparently full grown, but the sutures of the skull are not 

 so nearly closed. Their skulls are even smaller than those of the 

 type. A study of the nine-banded armadillos from Brazil in the 

 Museum collection shows that there is more or less variation in 

 size among fully grown animals, the smallest of which are very nearly 

 the size of the larger female from Grenada. The average size is, 

 however, much larger, and the cranial characters sufficiently striking. 

 It seems best, nevertheless, to regard the island animal as a subspe- 

 cies, both because of the probable intergradation, and because of the 

 expression of relationship thus made possible. 



An armadillo from Caparo, Trinidad, No. ^^42, American Museum 

 of Natural History, is clearly the same as the typical species of Brazil. 

 It measured: — total length, 802 mm.; tail, 360; ear, 38.5. Skull, 

 greatest length, 93; palatal length, 63; zygomatic breadth, 38.5; 



