ohosattrid^. 177 



humerus ; astragalus anchylosed to tibia ; five digits in pes, which 

 is plantigrade. A dermal armour, consisting of scutes and long 

 spines attached by their expanded bases. 



Equivalent to the Stegosauridw, Marsh ; in the characters of the 

 limb-bones and sacrum this family approximates to the Sauropoda> 

 which it connects with the Scelidosauridce. 



Genus OMOSAURUS, Owen 1 . 



The type genus. Skull unknown. Four sacral vertebras ; femur 

 with inner trochanter, and nearly double the length of tibia ; meta- 

 podials extremely short. 



The American Stegosaurus, Marsh 2 , differs by the absence of an 

 inner trochanter to the femur 3 . 



Omosaurus armatus, Owen 4 . 



The type species. Of large size, although much smaller than 

 Cetiosaurus oxoniensis. 

 Hob. Europe (England). 



The following specimens are the types, and belong to a single 

 individual ; they were obtained from the Kimeridge Clay ( Upper 

 Jurassic) of Swindon, Wiltshire ; and were presented by the 

 Swindon Brick and Tile Company, 1879. A note on their 

 exhumation, ivith figures of some of them, is given by W. Davies 

 in the ' Geol Mag.' dec. 2, vol. iii. pp. 193-197, pis. vii., viii. 



46013. The neural arch of a cervical vertebra. Figured by Owen 

 (Fig.) in his ' Mesozoic Reptilia,' pt. ii. pi. xi. (1876). 



46013 a. An imperfect dorsal vertebra. Figured, op. cit. pi. xii. 

 (Fig.) figs. 2, 3. 



46013 b. The centrum of a dorsal vertebra. Figured, op. cit. pi. xiii. 

 (Fig.) fig. 3. 



46013 C. Six imperfect dorsal vertebras. 



46013 d. An anterior caudal vertebra with its chevron. Figured, 

 (Fig.) op. cit. pi. xiv. figs. 1-4, and pi. xv. figs. 1-3. 



1 Mesozoic Eeptilia (Mon. Pal. Soc), pt. ii. p. 45 (1875). 



2 Amer. Journ. ser. 3, vol. xiv. p. 513 (1S77). See also vol. xix. pp. 253-259, 

 pis. vi.-xii. (1880) (the teeth figured in pi. vi. were subsequently referred to 

 Diplodocus) ; and vol. xxi. pp. 167-170, pis. vi.-viii. (1881). 



3 See Hulke, Quart. Journ. Gcol. Soc. vol. xliii. p. 702 (1SS7). 



4 Loe. cit. 



N 



