Mr. 0. Thomas on a neio 3Jexican Bat. ^11 



coast at a place called Miri, North-eastern Sarawak, some 

 sixteen miles south of the mouth of the Baram River. 



No species appears to have ever been described at all 

 resembling this remarkable animal. Its nearest ally is 

 perhaps that figured by Peters * under the name of 

 >S'. chry sog aster \ but even this relationship is very doubtful, 

 the different distribution of the colours and the conspicuous 

 difference in the colour of the crown widely separating the 

 two forms. 



LX. — Description of a new Mexican Bat. 

 By Oldfield Thomas. 



The British Museum has received from Dr. A. C. BuUer 

 two bats belonging to the group called Rhogeessa by Dr. H. 

 Allen, but clearly differing from Rh. parvula, the only species 

 of the group recognized by Dr. Dobson, by whom also the 

 group itself was placed simply as a subgenus of Vesperugo. 

 This reference I am not disposed to endorse, and think that 

 it should rather be looked upon as related to Nycticejus^ with 

 which it agrees in the number of its incisors and premolars, 

 and from which it differs mainly by the cylindrical form of 

 its outer lower incisors. Pending, however, a renewed 

 revision of the whole group I propose to use the term Rho- 

 geessa in a generic sense. The new species, which appears to 

 be of a somewhat annectant nature, I propose to dedicate to 

 Dr. Harrison Allen, the chief authority on North-American 

 bats and the founder of the group to which I refer it. 



Rhogeessa Alleni, sj). n. 



Decidedly larger than Rh. parvula ; muzzle obliquely 

 truncate as in that species. Ears large, laid forward they 

 reach about 1 or 2 millim. beyond the nostrils ; their inner 

 margin very convex forwards below, straight or even sliglitly 

 concave above; tip narrowly rounded off; outer margin con- 

 cave below the tip, then straiglit, becoming slightly convex 

 below, outer basal lobe but little marked. Tragus long, its 

 broadest ))oint opposite to base of its inner edge ; inner edge 

 straight or slightly concave^ tip rounded, outer margin slightly 

 convex, the edge indistinctly crenulate, somewhat as in 

 Antrozous pallidas -^ ; a marked lobule at the base of the 

 outer margin, above and below which there is a concavity. 

 Thumb very short and thick, no longer than in Rh. parvula, 



* MB. Ak. Berl. 1870, pi. iv. a. 



t There is also a slight crenulatioii in Rhogeessa parvula. 



