ANATOMY OF VERTEBEATES. J 99 



not carinate ; and such Is the case likewise with the dorsal scutes 

 of certain species' of Telcosaur. In a Wealden Crocodile (Gonio- 

 pholis), the angles of the oblong quadrilateral dorsal scutes are 

 well marked, and from one of them was continued a peg-like 

 process, which fitted a depression on the under surface of the con- 

 tiguous angle of the next scute, thus serving to hind together the 

 scutes in the way in which the enamelled scales were united in 

 many extinct ganoid fishes, fig. 125. The outer surface was 

 impressed by numerous deep, round, or oblong pits ; but a larger 

 proportion of the fore part of this surface was overlapped by the 

 antecedent scute than in Teleosaurus, and this part is smooth and 

 thinner than the rest of the scute. Associated with the quadrate 

 toothed scutes, ascribed to the l^ack of Goniojiholis, and irregu- 

 larly scattered in the matrix, I have observed others of a hexa- 

 gonal form, with a similarly pitted outer surface, l)ut without the 

 peg, and with thick sutural margins. They indicate a similar 

 alternate arrangement and interlocking of the ventral scutes, as 

 in Teleosaurus. 



The dermal armour of Ilijlceosaurus and Seelidosaurus appears to 

 have consisted of series of detached scutes of an elliptical or circular 

 form, without sutural or smoothly overlapping margins : of great 

 thickness, with the outer surface, in most, pyramidal, or rising to 

 a longitudinal ridged summit. In Hylcensaurus certain scutes 

 situated above the dorsal spines were of a very long and narrow 

 triangular form with the base oblique ; and seem to have 

 formed a defensive fringe of strong spines along the back, as in 

 Xiphnsurus. In Seelidosaurus the surface was defended by several 

 longitudinal series of massive unconnected bones : those in the 

 middle of the dorsal surface being in jiairs upon the nape, and 

 single along the tail, where three are coextensive with from five 

 to seven subjacent vertebraj : a corresponding medial series of 

 rather smaller and less vertically developed scutes defended the 

 under surface of the tail ; and there were one or more lateral 

 series of a more depressed and fuller ovate form, in that region.^ 



' cxivi. p. 79. The volume of the Serial containing Nattercr's memoir, though 

 bearing the date 1840, had not readied this coimtry when I communicated the second 

 part of my ' Eeport on Fossil Eeptiles ' to the British Association. 



^ CXCIII. 



