﻿LEPID0SIRENID^3. 2 09 



Dental plates robust, attaining a length of about 0'02, irregularly 

 triangular ; inner border obtusely angulated at a pointnear its middle. 

 Denticles four in the mandibular dental plates, five in the palatine, 

 the ridges rounded, separated by deep notches at the outer border, 

 terminating abruptly and extending more than halfway to the inner 

 angulation. 



Form. Sf Loc. Upper Jurassic : Colorado. 



Not represented in tho Collection. 



Ceratodus capensis, A. S. Woodward. 



1889. Ceratodus capensis, A. S. Woodward, Ann. Mag. Nat. Hist. [G] 

 vol. iv. p. 243, pi. xiv. fig. 4. 



Type. Dental plate ; British Museum. 



Dental plates thin, attaining a length of not less than 0*023, 

 triangular in shape ; angulation of inner margin acute and placed 

 near the posterior extremity. Denticles five or six, the ridges being 

 acute, well separated by deep and wide notches and valleys, extend- 

 ing within a short space of the inner angulation, gradually sloping 

 to a point at the outer border, and very faintly marked with coarse 

 crenulations. 



Form. Sf Loc. Upper Karoo Formation (Stormberg Beds) : Orange 

 Free State, South Africa. 



P. 4807. Type specimen, wanting one or perhaps two anterior denti- 

 cles ; Smithfield. By exchange, 1884. 



Ceratodus phillipsi, Agassiz. 



1838. Ceratodus philippsii, L. Agassiz, Poiss. Foss. vol. iii. p. 135, 



pL xix. fig. 17. 

 1877. Ceratodus phillipsi, A. Crane, Geol. Mag. [2] vol. iv. p. 211. 

 1890. Ceratodus phillipsi, A. S. Woodward, Proc. Geol. Assoc, vol. xi. 



p. 292, pi. iii. fig. 5. 



Type. Dental plate; unknown. 



Dental plates thin, attaining a length of about 0*02, almost trian- 

 gular in shape ; angulation of inner margin acute and placed near 

 the posterior extremity. Denticles four or five (? or six), the ridges 

 being sharply rounded, well separated by deep notches and valleys, 

 extending nearly to the inner angulation and terminating abruptly 

 at the outer border. 



Form. <$f Loc. Bathonian : Oxfordshire (Stonesfield Slate) and 

 Northamptonshire (Great Oolite). 



