1 1 86 CLASS REPTILIA. 



portion, but may be single ; while in the transverse rows of this 

 buckler the scutes always imbricate anteriorly, but in the posterior 

 part usually articulate by suture ; each scute being invariably com- 

 posed of a single piece of bone. 



It may be incidentally mentioned here that while in the anterior 

 region of the ventral buckler of all Crocodiles the component scutes 

 of each transverse row articulate together by suture with those on 

 either side, yet, as will be gathered from the foregoing characters, 

 in the posterior portion of the same buckler in the present series 

 the articulation of the different transverse rows with one another 

 may be either by suture, or by imbricating like the tiles on a roof. 



The present series ranges in time from the Lias to the Lower 

 and Middle Cretaceous, and is especially characteristic of the 

 European strata. 



Family Teleosaurim:. — The members of this family are readily 

 distinguished from the more specialised forms by the circumstance 

 that the supratemporal fossae are always much superior in size to 

 the orbits, and that the latter are completely separated by a bony 

 bar from the infratemporal fossse ; both these features being well 

 shown in the accompanying figure of the cranium of Steneosaurus. 

 In front of the orbit there is always a well-marked vacuity (not 



Fig. 1085. — Upper view of the cranium of Steneosaurus Fleberti ; from the Oxford Clay of 

 France. Much reduced. The bones on the right side of the rostrum are imperfect, and there 

 should have been a line connecting the apex of the frontals with the suture dividing the maxillae. 

 The large vacuities behind the orbits are the supratemporal fossse, below which are the infra- 

 temporal fossae. 



shown in the figure) ; the dorsal scutes, when present, are rounded, 

 and arranged in two longitudinal rows ; while the ventral buckler is 

 divided, and the component scutes of the posterior transverse rows 

 are united by suture. The axis vertebra carries two facets for its 

 rib, as in Dinosaurs. The members of this family were of marine 

 habits, and range throughout the Lias and Jurassic system of 

 Europe. They may be divided into two subfamilies. 



In the subfamily Teleosaurince the skull is generally produced into 

 a long slender rostrum, like that of the existing Gharial ; the nasals 



