16 



ORDER CHIROPTERA.— GENUS DYSOPES. 



TRIBE I. DIPHALANGIA ANISTIOPHORA. 



Syn. Anistiophobi, (in part.) — Spix, Sim. et Vespert. Bras. 



Noctilionina Less. Mam Gray, in Mag. Zool. and Bot. II. 498. 



CHARACTERS OF THE TRIBE. 



The Index with two ossified phalanges. 

 The Nose simple, without a leafy appendage. 



GENUS VI. DYSOPES.'— BULL-DOG BATS. 



Syn. Molossus. — Geoff. Ann. Mus. VI. 150. — Desm. Mam. p. 11& 



Dysopes.— Illig. Prodr. p. 122 Temm Mon. Mam. I. 205. 



Dinops. — Savi, in Nuov. Giorn. di Letter. No. 21, p. 230. 

 Nvctinomus. — Geoff. Descr. d'Egypte, II. 28. — Desm. Mam. p. 116. 



— Horsf. Jav. 

 Cheiromeles. — Horsf. Jav. 



Thvropteka? — Spix, Sim. et Vespert. Bras. p. 61. 

 Vespertilio, (in part.) — Linn. Gmel. I. 49. 



GENERIC CHARACTERS. 



The Head thick. The Muzzle broad and flat. 



The Ears very large, mostly approximated, recumbent over the eyes, 

 and arising from the commissure of the lips. The Upper Lip large and 

 wrinkled. 



The Auricular Operculum round, thick, placed in front. The 

 Tongue smooth. 



The Dental Formula varying according to the age ; as under — 



First Age, 

 Very young, 

 Young, 

 Adult, 

 Old, 



ij2^^^F+3)M_. 

 l3-j-C+(2F+3)M" 



i|_|.C-L.(F+3)M _ 



-I*. 

 = 19 : 



12 



=32 



I3+C+(2F+3)M ]« 



i |.|_C+(F+3)M __]2_ 



|2+Cf-(,2F-1-3)M — 16^ 



=30 



28 



1 + C+(F+3)M = H! 

 |l + C+(2F+3)M 14 £K> 



=24 



*| l + C+(F-f3)M _12_ 

 C+(2F-f3)M — r2" 

 The Toes covered with bristlts. The Thumbs of the hinder feet free, 

 and sometimes opposable. 



The Alar Membranes narrow. The Tail long, partly engaged in 

 the Interfemoral Membrane. 



Inhabit the tropical parts of the entire globe, and the warmest portions 

 of the temperate zones. 



The Bull-Dog Bats have the muzzle simple, their ears broad and 

 short, arising from the angle of the lips, and uniting together upon 

 the muzzle, the auricular operculum short, and not surrounded by 

 the auricle. The tail occupies the entire length of the interfemoral 

 membrane, and often extends beyond it. [In the adult state only 

 two incisive teeth appear in each jaw ; according to M. Temminck, 

 in their extreme youth, their incisors are as many as six in the 

 lower, and four in the upper jaw ; these are gradually reduced with 

 age to two in the upper jaw only.] 1 



The following admirable description of the characters of this genus is 

 supplied by M. Geoffroy. The Bats belonging to the genus Dysopes 

 tuay be easily recognised by their fierce-looking physiognomy, and the 

 peculiarity of their whole figure : their large head and broad muzzle has 

 led to their being compared to the Bull-Dog, and to their being desig. 

 nated by his name. The head is remarkably full across the ears, which 

 approximate and are festooned over the eyes, so that they are calcu- 

 lated quite as much to protect these organs, as to favour the power of 

 hearing: they arise very near the commissure of the lips, and after pass- 

 ing behind the auditory foramen, sweep upwards and forwards to unite 

 upon the brow. Most of the Chiroptera have the tragus placed in the 

 auditory cavity, where it forms a kind of second external ear, and then 

 receives the name of auricular operculum ; but in the Dysopes there is a 



difference, because this second ear is situated in front and exteriorly; it 

 is, moreover, round and thick. Lastly, the species of this genus are re- 

 cognised by their tail, which is long, and generally more or less engaged 

 in the interfemoral membrane. The tongue is smooth, and the muzzle 

 unfurnished with hairs; the nose is destitute of membranes and cavities; 

 the nostrils are but slightly prominent, open in front, and margined with 

 a small hood. 



To these indications M. Temminck adds the following : In all the 



species of this genus the posterior members are very short, the fibula is 

 perfect, often as large as the tibia, and the wide separation of these bones 

 supplies large space for the strong muscles of the feet. They have all 

 bristles on their toes, and the outer or inner one is usually freer than the 

 others, and sometimes opposable. The thumb is short, strong, and 

 bulky; the upper lip is ample, and wrinkled ; the snout more prominent 

 than the lips. Their most striking characteristic, however, is the appa- 

 rent insufficiency of their wings, seemingly quite disproportioned to the 

 size of their bodies, which are big and heavy. To such an extent is this 

 narrowness of their wings, that in some species we should be led to con- 

 clude they could not serve them in a long continued flight, and must be 

 useful only as a parachute. Forced to subsist in subterranean and deep 

 caverns, it would appear that it was chiefly by scaling the walls of build- 

 ings and the trunks of trees, or by crawling by means of their prehensile 

 organs, that they provided for their wants. Insects and larva; are pro- 

 bably the food of these creatures ; whose manners and appetites are, 

 however, as yet but little known. 



All Naturalists agree that this group of animals is very distinctly and ac- 

 curately defined and circumscribed, and yet it was for a long time separated 

 into two, or more. This circumstance was owing to the reputed differ- 

 ences in the number of their incisive teeth, arising from changes produced 

 by age, and which it is now ascertained occur alike in them all. The 

 Molossus was said to be characterized by two incisors above and two be- 

 low, and the other section, the Nyctinomus, by two above and four be- 

 low ; the latter being, moreover, supposed to belong exclusively to the 

 old world, whilst the former alone were found in the new. All this, 

 however, was the result of hasty inference. It would appear that the 

 maximum number of the incisors is not less than six above and four be- 

 low. To these succeed the canines, which on their mesial side are 

 supplied with prominent heels. These appear as the animal advances 

 in age, and before them the incisors, one by one, drop out till there is 

 only one pair left above, and sometimes none below. In the words of Tem- 

 minck, a part of the canines takes the place of the incisors which fall 

 out, and the heels of the lower canines discharge, along with the upper 

 incisors, the functions of mastication. 



The Genus Dinops of M. Savi is formed of one of these Bull- 

 Dog Bats (Dysopes Cestonii) which [being examined in its first 

 age] was found to have six incisors in the lower jaw. 



Again, M. Geoffroy has formed those with four incisors only in 

 the lower jaw, into the Genus Nyctinomus. [These are the young.] 



At first, the Bull-Dog Bats were found only in America; at 

 present they have been discovered in both Continents, [and more 

 recently in New Holland.] Many of them have the thumbs of 

 the hinder feet more separated than the fingers, and distinctly 

 moveable, a character which has led Dr Horsfield to form a new 

 Genus Cheiromeles, with a single species in which this character 

 is very distinctly marked. 



It is probably to this genus that we should refer the Thyrop- 

 tera of M. Spix, which have been but imperfectly described by 

 him. They appear to have many of the characters of the Bull-Dog 

 Bats, and their thumb has a concave dilatation, peculiar to them, 

 and enabling them to cling with greater security. 



1 Dysopes, from qvguttsu, to frighten with excessive ugliness. 



2 The precise words of the Baron Cuvier are, " One seldom finds more than two incisors in each jaw ; but, according to M. Temminck, many have at first six incisors 

 below, of which they successively lose four," — a remark not strictly accurate, as an examination of the dental formula; noted above will serve to explain. 



