1858.] HUXLEY STAGONOLEPIS. 449 



" The verticillate cuirass of these ancient Crocodiles is thus 

 securely braced round the trunk by this interlocking of the inferior 

 extremities of each ring of scutes, whilst the imbricated arrange- 

 ment would allow of a certain sliding motion of the rings upon each 

 other, sufficient for the expansion of the chest in breathing." 



No evidence is produced in favour of the existence of a structure 

 so aberrant from that of the other Teleosaurians, and it seems to me 

 that, in leaving an interspace between the dorsal and ventral shields, 

 nature has provided for the wants of the economy in a far more 

 efficient manner than that here imagined. 



Ventral Scutes. — The characters of the ventral armour of the 

 Teleosauria are beautifully displayed in the two specimens from the 

 Tesson Collection, of Teleosaurus temporalis and of T. Cadomensis, to 

 which I have referred. The ventral shield is, in the latter case, 

 incomplete ; but the scutes are imbedded undisturbed in the rock. 

 In the Teleosaurus temporalis, on the other hand, the shield is nearly 

 complete, but all the parts have been artificially fitted together upon 

 a plaster-slab; by whose hand I know not. The comparison of the 

 two specimens, however, leads me to believe that the operation has 

 been very carefully and conscientiously effected. 



In Teleosaurus temporalis the scutes are so arranged that the 

 middle hue is occupied by the suture between the two innermost 

 rows, and that there are three longitudinal rows on each side. 

 Anteriorly, the innermost scutes are nearly square, while posteriorly 

 they become pentagonal, or even hexagonal. The scutes of the two 

 outer rows on each side are also nearly square anteriorly, but more 

 or less completely hexagonal in the posterior part of the shield ; and, 

 from the manner in which the scutes are fitted together, the result 

 is, that, while the anterior transverse rows are nearly or quite 

 straight, the posterior ones form an angle, open forwards on each 

 side of the middle line, so that each of the hinder rows assumes 

 somewhat the form of a "W. 



There are altogether twenty transverse rows of scutes. Those of 

 the last row do not exist in the specimen, but, from the outliaes on 

 the plaster, were evidently thought by its restorer to be smaller 

 than those which preceded them, and to be so arranged as to give a 

 rounded posterior margin to the ventral shield. Anteriorly, also, 

 the scutes are partially wanting ; but the transverse rows appear at 

 first to have had not more than half their greatest width, and the 

 anterior five rows seem to have contained only two scutes on each 

 side of the median line. The shield does not attain its full width 

 before the tenth series. 



The lateral edges of the scutes are united by serrated sutural edges. 

 The anterior edge of each exhibits a bevelled articular facet, occupying 

 nearly a third of the whole external surface, and overlapped by a 

 corresponding extent of the posterior margin of the preceding 

 scute. Both surfaces of these scutes are smooth and flat, and the 

 pitted sculpture radiates from a point which nearly corresponds with 

 the centre of each scute, in a fine specimen of a fragment of the 

 ventral shield of Teleosaurus Cadomensis (32,591 B.M.). The ex- 



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