﻿CRETACEOUS FORMATIONS. 



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portion of jaw (Tab. II, fig. 3), and of that figured in Tab. I, fig. 6, a , b, c, of 

 my former 'Supplement' (1857). The total length of the tooth (fig. 4) cannot 

 have been less than 4 inches. 



If the present fragment has belonged to an individual of the same species 

 as that on the upper jaw of which the Pteroclactylus Fittoni is founded, it shows 

 such species to have attained more than double the dimensions indicated by 

 the original specimens figured in Tab. I, figs. 3 and 4, of the ' Monograph' for 

 1857. Should the present fragment prove to belong to a distinct species, with the 

 sides of the jaw meeting above, at a less acute angle, and with the wall of the 

 outlet of the socket less prominent externally, such species may be indicated 

 as the Pteroclactylus Woodwardi, in honour of the founder of the Geological 

 Collection of the University of Cambridge. 



The mandible (Tab. I, figs. 6 — 10). 



The portion of the right ramus of a lower jaw, or mandible, figured in the 

 above-cited plate, may have belonged, by its size, to either of the gigantic 

 Pterodactyles above specified as Pt. simus and Pt. W oodwardi. Its texture and 

 configuration show it to have formed part of a Pterosaurian skeleton. It is 

 the part of the ramus which answers to the angular, sur-angular, and articular 

 elements in the Pterodactylus suevicus* but with only a part of the sutures 

 between the angular and sur-angular remaining on the inner side of the bone. 

 The angle is partially fractured, but seems to have been not much produced 

 beyond the articular concavity. 



The ramus, as it extends forward from the articular part, at first diminishes 

 slightly in breadth and depth, then increases in vertical, whilst continuing 

 to decrease in transverse, extent. 



The outer surface (fig. 7) presents, near the articular cavity, a shallow, 

 longitudinal depression, bounded below by a rather sharp border; a broader and 

 more shallow depression, the lower boundary of which is well defined, marks the 

 more advanced part of the ramus. These depressions indicate the insertions 

 of muscles. 



Both the upper (fig. 9) and lower (fig. 8) borders are obtusely rounded, 

 the latter being the thickest. Along the inner side of the fragment a longitudinal 

 channel (fig. 6, e) extends near the lower border, the upper boundary of the 

 channel being produced inwards, especially posteriorly (b) ; above this boundary 

 there is a deep, longitudinal depression (d) partly filled with matrix, and probably 

 communicating with the (pneumatic ?) cavity of this part of the jaw-bone. 



* Quenstedt, 'Ueber Pterodactylus sueviciis,' 4to, 1855, tab. i, figs. 2, 4, 5. 



