448 PKOCEEDINGS OF THE GEOLOGICAL SOCIETY. [DgC. 15^ 



first accurate description of the dermal skeleton of the Teleosaurians, 

 and who had the opportunity of examining all the specimens de- 

 scribed by Cuvier, writes thus, without referring to Cuvier's state- 

 ment : — 



" In the Teleosaurians it is the ventral plastron which is the more 

 complete. It is protected by numerous contiguous series of six 

 strong thick scales, which are flat and imbricated at their posterior 

 edges. Upon the back there are indeed other larger scales, but they 

 are only two in number in each row ; bent scales exist only on the 

 upper part of the tail *." 



Dorsal Scutes. — As the Tesson Collection has recently been pur- 

 chased for the British Museum, some of the specimens on which 

 Geoffrey made his observations are probably to be seen there. At 

 any rate, the beautifidly preserved remains of Teleosaurus temporalis 

 and T. Cadomensis, in that collection, fuUy bear out his statements. 

 In these Crocodilia (and I may add in T. BoUensis in the same col- 

 lection), the dorsal scutes are arranged in only two longitudinal 

 series, or, in other words, there are only two scutes in the successive 

 transverse rows, which occupy the middle of the dorsal region. In 

 T. Cadomensis, it is clear that each pair of scutes corresponds with 

 a vertebra ; and the posterior two-thirds of the broad terminal face 

 of the short and thick spinous process is so shaped that the interior 

 faces of its appropriate pair of scutes seem to have rested upon and 

 have been closely connected with it. The internal edge of every 

 scute is thick, and interlocks with . its fellow by strong serrations. 

 The suture thus formed lies in the middle line. The anterior edge 

 presents a broad articular facet, overlapped by the posterior edge of 

 the preceding scute ; the posterior edge thins out to overlap its suc- 

 cessor. The outer edge also thins out, and neither its upper nor its 

 under surfaces present the least trace of overlapping, or being over- 

 lapped by, or articulating with, other scutes. 



Dr. A. Wagner f, who has given a very good account of the dermal 

 armour of Teleosaurus Cadomensis, finds only two longitudinal rows 

 of dorsal scutes, either in this species or in Mystriosaurus Muensteri, 

 Bronn and Kaup J figure only two longitudinal series of dorsal scutes, 

 in their Pelagosaurus typus ; and I can nowhere find the least evi- 

 dence that the dorsal scutes were connected by anything more than 

 the general integument with the lateral or ventral scutes. 



Prof. Owen § admits the existence of a double row of large or 

 peculiarly formed medio-dorsal scutes in Teleosaurus CJiapmanni ; 

 but he evidently conceives, from the following passage, that the 

 lateral scutes were directly articulated with the dorsal ones, so that 

 the body was surrounded by continuous circles of bony plates : — 



"^ Memoires de TAcad^mie, vol. xii. p. 24. 



t Abhandlimgen, iiber die Gavial-artigen Reptilien der Lias-Formation, 1842. 



\ Die fossilen Ueberreste Gavial-artigen Saurier aus der Lias-Formation in 

 der k. palaontologischen Sammlungzu Miinclien. Abhandlimgen der Mathem.- 

 Physikalisclien Classe der Koniglichen Bayerischen Akademie der Wissenschaften, 

 Bd. V. 1850. 



§ Eeport on British Fossil Reptiles, Re]3. British Assoc. 1841. 



