NATURAL SCIENCES OF PHILADELPHIA. 359 



Oregon, Mr. A. Agassiz. This species has the size and form of our common 

 H. parenthesis, but the thorax of H. convergens. The elytra are 

 more elongate oval in form than in either, and more obtusely rounded at tip ; 

 the apical angle is also not at all acute, but on the contrary quite rounded. 



The spots of the elytra vary greatly ; the scutellar elongate spot is some- 

 times prolonged on the sutural margin for two-thirds the length ; the first and 

 second, or the second and third of the posterior spots are connected sometimes 

 as in varieties of H. parenthesis, and specimens will undoubtedly be 

 found in which all three are united to form an arcuated spot. It is also probable 

 that H. s i n u a t a M ids. (Coco. 1011) is an extreme form of this species, having 

 all the spots united into a sinuous vitta ; sometimes the spots are entirely 

 wanting. The pectoral and abdominal curved lines are obsolete, and it conse- 

 quently belongs in the same group with H. convergens. 



Description of a new Mexican Bat. 

 BY HARRISON ALLEN, M. D. 



In 1842, Prof. Gray described, in the Ann. and Mag. of Nat. Hist., a new 

 genus of bats, which he called Centurio, and gave the diagnosis of a new 

 species, C. senez. Both of these were afterwards introduced, with a plate and 

 extended description, in the Zoology of the Voyage of the Sulphur, p. 27. This 

 was the first notice given of a well marked group of Cheiroptera inhabiting the 

 tropical regions of America.* Since that time, Lichenstein and Peters - ]- have 

 published an account of a new species C. Jiavogularis coming from Cuba; 

 aud M. de Saussuref has added a third, under the name of C. mexicanus. 



A short time since, the author obtained from the collection of the Smith- 

 sonian Institution two bats, sent by Dr. Sartorius from Mirador, Mexico. One 

 of these was determined, from the descriptions furnished by M. de Saussure, to 

 be the C. mexicanus of that author. The other was an animal resembling the 

 members of the genus in question in many particulars, but differing so mark- 

 edly in others as to render a special description necessary. 



The head in its general expression and arrangement of the facial pleats 

 resembles that of the other species. The greater and lesser transverse frontal 

 ridges are present, the latter being less distinct than in the original plate of 

 Gray, and much less so than in' the figure of Lichenstein and Peters. The 

 mesial callosity between the nostrils, the nostrils themselves, the warts, setae 

 and oval crenations, are all similar in extent and relative proportions one to 

 the other, as in other Centuriones. The ear, however, presents some points of 

 difference. The " hatchet-shaped " internal lobe is of the same shape, but pos- 

 sesses longer and thicker hair. The auricle proper is similar, while the tragus 

 is much thicker on the inner than on the outer side, which thickness exceeds 

 that of C. mexicanus; and the external lobe is more acute, and has upon its 

 summit a minute, well-defined knob. 



But the great point of variance consists in the development of the corru- 

 gations beneath the chin. These in the known species are but leathery bands, 

 three in number, running from one side of the neck to the other, the lower 

 one being the largest and covered with hair. In our animal, in addition to the 

 three above noticed, there are two smaller ones, placed anterior to the rest. 

 On a comparison being instituted between these rugae, they were found to 

 differ greatly in the degree of their development. Thus, while the first pli- 



* Prof. Gray was in doubt as to the nativity of his species, from the fact that bats col- 

 lected both from Amboina and South America were contained in the same bottle. There 

 can be but little doubt, however, that his animal came from the latter country. 



t Abhandl. der Akad der Wissenshaften zu Berlin, 1854, p. 81, pi. 1. 



i Rev. et Mag. Zool., 1860, p. 378. 



1861.1 



