50 



the forehead, — also in breadth at the ninth tooth to agree with C. 

 marginatus, while the converging shape of the forehead differs from 

 both. 



I shall add some few other general characters derived from these 

 skulls : — Cranial fosses somewhat oblong and ear-shaped, converging 

 anteriorly, and almost touching by their inner and anterior margins, 

 the outer side being nearly straight. Orbits with a slight notch an- 

 teriorly. Nasal foramen broadly pyriform, and almost quadrilateral. 

 Foramina for the two anterior teeth converted in old specimens into 

 deep notches. Articulating extremities of lower jaw much curved 

 inwards. 



I have compared these skulls with twelve others of Indian and 

 American species, from all of which they are cprite distinct. 



The ninth upper tooth of Crocodiles is said to be enlarged like a 

 canine, but this is not strictly correct. I have examined the denti- 

 tion in eighteen skulls of various species ; in the lower jaw there are 

 always nineteen teeth, but in the upper jaw the number in the adult 

 is seventeen on either side, while in the young it is eighteen. This 

 is owing to the second incisor being deciduous, and in old skulls the 

 socket is completely obliterated by the enlargement of foramen for 

 the two anterior teeth. Thus in old animals there are only four 

 teeth in each intermaxillary bone, while in younger individuals there 

 are always five. So, more strictly, it is the tenth and not the ninth 

 upper tooth which is enlarged. 



The characters which I have above enumerated seem to me di- 

 stinctive, and possibly on further investigation, when the entire animal 

 is examined, and its external characteristics determined, it may prove 

 a new species. The Crocodiles which I saw on the mud banks, or 

 swimming about in the river, appeared of a dark green colour. 

 Adanson mentions two apparently from the upper parts of the Niger, 

 which he distinguished — "Crocodile vert du Niger" and " Crocodile 

 noir du Niger." Whether either of these resembles my specimens 

 I have no means of ascertaining ; but Cuvier speaks of African Cro- 

 codiles "qui out la tete un peu plus allongee a proportion de sa 

 largueur," though he adds, " et un peu plus plate, ou plutot moins 

 inegale, a sa surface." If this prove to be separate I would suggest 

 for it the specific designation C. Binuensis, from the name of the 

 river whence I obtained the specimens. 



3. Descriptions of Four undescribed species of Bats. 

 By Robert F. Tomes. 



1. SCOTOPHILUS PACHYOMUS, 11. S. 



Muzzle rather obtuse ; ears ovoid ; tragus short, of nearly uni- 

 form breadth, and round at the end. JJ'ing-membranes ex- 

 tending to the base of the toes. Fur bicoloured. Size rather 

 larger than S. noctula. 



This species appertains to the same division of the genus as £. 



