ON A LABYRINTHODONT AMPHIBIAN. 209 



propose to name Batrachiderpeton Uneatum. One of the speci- 

 mens is in a good state of preservation, and is almost entire. 



The anterior portion of it, however, is crushed and otherwise 

 injured ; but the characters of the hinder part are well displayed, 

 and so are those of the median coronal bones, the surface-struc- 

 ture of the whole being beautifully preserved. The other speci- 

 men has lost a considerable portion of the right side, and is 

 much crushed and distorted, but nevertheless exhibits, in excel- 

 lent order, some of the more important characters. 



The first-mentioned and the more perfect of the two specimens 

 is flat and shield-like, having the contour in front pointed and 

 broadly wedge-shaped, the sides of this part being broken ; the 

 occipital region is exceedingly wide, and considerably arched 

 inwards at the posterior margin. It is evident, however, that 

 when perfect, the front was broad and rounded, the muzzle 

 being quite short, and that the sides were arched outwards. 

 The skull is remarkable for its great width in proportion to its 

 length, and for the wing-like character of the lateral expansions 

 of the occipital region, which are very largely developed, and 

 project considerably backwards, the lateral posterior angles being 

 produced into long processes or cornua : consequently, from this 

 peculiar formation, the inward arching of the occipital margin 

 arises. From the outer angles of the occipital bones there are 

 two other or inner horns, which are much less than the outer 

 pair. When entire, the skull must have had the form of a broad 

 inverted shield, with the apex in front rounded, and the basal or 

 posterior margin concave. It measures two inches and three- 

 tenths in length from the muzzle (the extremity of which is pre- 

 sent) to a line extending from tip to tip of the external horns, 

 but only an inch and seven-eighths to the extremity of the inner 

 or occipital cornua. One side of the skull, behind, is quite per- 

 fect ; so, by doubling the width of this from the median line, the 

 breadth of the entire skull can be correctly determined: measured 

 thus, it is two inches and five-eighths across the widest part ; it 

 is two inches and a quarter in width without making such al- 

 lowance. 



The central coronal bones are narrow in proportion to the 



o 



