ORDER CROCODILIA. 1 1 89 



enamel generally fluted at the base of the crown, but without ser- 

 rations on the carina?. The pectoral limbs are extremely small. 

 This genus ranges from the Oxford Clay to the Portland Oolite. 

 In the Oxford Clay and Kelloway rock, both of the Continent 

 and England, we meet with M. superciliosus and M. moreli, which 

 are readily distinguished by the sculpturing of the frontals and 

 the form and relations of the prefrontals. Beautiful examples 

 of this genus occur in the Oxford Clay near Peterborough, which 

 exhibit the absence of dermal scutes ; a skull from this locality, 

 to which the name Steneosaurus dasycephalus has been applied, 

 may be referred to M. superciliosus. The Portlandian form was de- 

 scribed as Steneosaurus gracilis. It is probable that Gnathosaurus 

 and Rhacheosaurus are synonyms. The most specialised genus is 

 Geosaurus (Cricosaurus or Dacosaurus), in which the skull is com- 

 paratively short, and is devoid of frontal sculpture, and also of the 

 premaxillary expansion; while the teeth (fig. 1088) are compressed, 

 smooth, and carinated, with distinct serrations on the carinas. The 

 type species, which occurs in the Lower Kimeridgian of Bavaria, 



Fig. 1088. — Crown of tooth of Geosaurus maximus ; from the Kimeridge Clay of Ely. 

 (After Wood-Mason.) 



and is of comparatively small size, was long thought to belong 

 to the Mosasauridce. A much larger form, occurring in the 

 Kimeridge, and perhaps the Oxford, Clay of England and the 

 corresponding beds of the Continent, has been described under 

 the name of Dacosaurus, but can be only specifically distinguished 

 from the type. A tooth is shown in the accompanying woodcut. 

 It is not improbable that vertebrae from the Lower Greensand of 

 Germany, described under the name of Enaliosuchus, indicate a 

 closely allied form. 



As members of this family, of which the serial position is uncer- 

 tain, may be mentioned small forms respectively from the Kimerid- 

 gian of Bavaria and France, to which the names s£olodon and 

 Crocodiltzmus have been applied, both of which have a dermal 

 armour ; the ventral shield consisting of a number of small and 

 closely-joined scutes. In the type of JEolodon these scutes are only 

 slightly pitted, and the teeth alternate in size. 



Family Goniopholidid/e. — The members of this family resemble 



