198 MAESXJPIALIA. 



Plagiaulax medius, Owen \ 



This form is considerably smaller than the preceding, from which 

 it apparently differs by the contour of the corouoid process of the 

 mandible. 



Hob. England. 



47728. The left ramus of the mandible, showing the incisor and 

 (Fig.) premolars ; from the Middle Purbeck of Durdlestone Bay, 



Swanage, Dorsetshire. This specimen, which is the type, 

 is described and figured by Owen in the ' British Mesozoic 

 Mammalia' (Mon. Pal. Soc), p. 85, fig. 7, and p. 90, 

 fig. 12 ; it is also figured by Palconer in the ' Quart. Journ. 

 Geol. Soc' vol. xiii. p. 280, fig. 14, under the name of 

 P. becJclesi. BecHes Collection. Purchased, 1876. 



Plagiaulax falconeri, Owen ^. 



Approximately equal in size to P. becMesi, but distinguished by 

 the smaller depth of the mandibular ramus, the more slender incisor, 

 and the larger pm. 2. 



Hab. England. 



47730. The imperfect right ramus of the mandible, showing the 



(Fig.) premolars and incisor; from the Middle Purbeck near 



Swanage, Dorsetshire. This specimen is the type, and is 



figured by Owen in the ' British Mesozoic Mammalia ' 



(Mon. Pal. Soc), pi. iv. fig. 6. 



Becldes Collection. Purchased, 1876. 



Plagiaulax minor, Palconer ^ 



Syn. Plioprion minor ^ Cope *, 



This is the smallest species, and is distinguished by the presence 

 of four lower premolars, on which account it has been made the 

 type of a distinct genus by Cope. 



Hab. England. 



47729. The imperfect right ramus of the mandible, showing the 

 (Fig.) complete dentition ; from the Middle Purbeck near Swan- 

 age, Dorsetshire. This specimen is the type, and is figured 

 by Falconer in the ' Quart. Journ. Geol. Soc' vol. xiii. 

 p. 28, fig. 15, and by Owen in the ' British Mesozoic 

 Mammalia ' (Mon. Pal. Soc), pi. iv. fig. 9. 



Beckles Collection. Purchased, 1876. 



^ 'British Mesozoic Mammalia' (Mon. Pal. Soc), p. 85 (1871). 



* Op. cif. p. 8^. 



8 Quart. Journ. Geol. Soc. vol. xiii. p. 264 (1857). 



* Amer. Nat. vol. xviii. p. G91 (1884). 



