I 



Dr. B. Baikie on the Skull of a species 0/ Mecistops. 311 



Po, that island being a common point of call for vessels on their way 

 home. 



In August 1854, while at the town of Ojogo on the river Binue, 

 my assistant procured from a native the skull of a Mecistops ; and as 

 this was the only occasion on which I met with its remains, and as I 

 never saw one in the river, I conclude that it is there a comparatively 

 scarce species. I have since described the animal to Dr. Barth, who 

 informs me that during his lengthened wanderings he never remem- 

 bers to have met with it. Crocodiles again were everywhere to be 

 seen, and in many places most abundant. 



The skull seems from its appearance to be that of an adult animal. 

 Its extreme length is 22J inches, the greatest breadth being 9 j inches, 

 or nearly in the proportion of 2^ to 1 . From this it may be inferred 

 to be most probal)ly M. cataphractus, that being the proportion of 

 the length to the breadth in that species, while in M. Bennettii (if 

 distinct) it is said to be as 3 to 1 . It has seventeen alveolar sockets 

 on each side of the upper jaw, and fifteen in the lower, in which par- 

 ticulars it agrees with the characters originally given by Cuvier in 

 the * Ossemens Fossiles,' *' la longueur de sa tete etant comprise deux 

 fois et demie dans sa largeur." * * * '*0n lui compte dix-sept 

 dents de chaque cote' a la machoire superieure et quinze a I'inferieure,** 

 4 ed. tom. ix. p. 116. In each are intermaxillary sockets; but for 

 various reasons I am inclined to believe that this is the case only in 

 the adult, and that in the young animal there are five intermaxillary 

 teeth on each side. The ninth remaining upper tooth is the most 

 prominent, and it is distant from the extremity of the snout 

 7^ inches. 



In all essentials the skull of the Mecistops shows it to be properly 

 a member of the family Crocodilidce rather than the Gavialidce. 

 The teeth are irregular, the sides of the jaws are not parallel, there is 

 a distinct swelling opposite the ninth remaining upper molar, and 

 the lower canines are received in notches in the upper jaw. 



The skull is considerably depressed, much produced anteriorly, 

 and the extremity of the snout somewhat enlarged. Upper surface 

 smooth. Forehead nearly flat, pitted, sides not raised, converging 

 anteriorly. Cranial fossae nearly circular, resembling those of the 

 Gavial. Orbits rather more convergent than in the Crocodiles, and 

 the nasal aperture more circular. Nasal bones more prolonged than 

 in GavialiSy yet not reaching, as in the Crocodili, the nasal opening, 

 but distant from it an inch and a half. Anterior spine of middle- 

 frontal very long, slender, tapering, and pointed. Lacrymal bones 

 lengthened and narrow. Notch for lower canines about an inch 

 beyond posterior edge of nasal foramen, and about half an inch from 

 the anterior extremity of the nasal bones. Anterior palatine foramen 

 small. Palatine bones tapering and pointed anteriorly. 



Extreme length of lower jaw 24| inches, suture 5f inches in length, 

 extending to opposite the seventh tooth on each side. Narrowest 

 portion of lower jaw between fifth and sixth teeth, where it does not 

 exceed an inch and three- eighths. Tenth and eleventh teeth nearly 

 equal, the latter being rather the larger, but by no means exceeding 



