ANATOMY OF VERTEBRATES. 199 



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

 of certain species l of Teleosaur. In a Wealden Crocodile ( Gonio- 

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

 well marked, and from one of them Avas 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 bind 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 Telcosaurus, and this part is smooth and 

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

 toothed scutes, ascribed to the back of Goniopholis, and irregu- 

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

 gonal form, with a similarly pitted outer surface, but 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 Hylccosaurus and Scelidosaurus 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 Hylaosaurus 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 

 Xiphosurus. In Scelidosaurus the surface was defended by several 

 longitudinal series of massive unconnected bones : those in the 

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

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

 to seven subjacent vertebras : 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. 2 



1 cxlyi. p. 79. The volume of the Serial containing Natterer's memoir, though 

 bearing the date 1840, had not reached this country when I communicated the second 

 part of my ' Report on Fossil Reptiles ' to the British Association. 



2 cxcin. 



