8 INTRODUCTION. 



Series B. — Firmisternia. 



Coracoids firmly united by a simple epicoracoid 

 cartilage ; prsecoracoids resting with their distal 

 extremity upon the coracoids, or connected with the 

 latter by the epicoracoid cartilage. 



Family 5. — Ranid^;. 



Vertebras proccelous ; no ribs; diapophyses of 

 sacral vertebra cylindrical ; upper jaw toothed. 



8. Bana, L.. 1766. 



13. esculenta, L., 1766. 



14. arvalis, Nilss., 1842. 



15. earner ani s Blgr., 1886. 



16. temporaria, L., 1766. 



17. grxca, Blgr., 1891. 



18. iberica, Blgr., 1879. 



19. latastii, Blgr., 1879. 



20. agilis, Thorn., 1855. 



We are thus now acquainted with twenty well- 

 established species, as against twelve and eighteen 

 enumerated in the two preceding general works on 

 the Batrachians of Europe, viz. Schreiber's ' Herpe- 

 tologia Europasa,' 1875, and be Bedriaga's ' Frosch- 

 lurche Europas,' 1889. 



Most of the additions made during the last twenty 

 years fall to the genus Rana, and are in fact dismem- 

 berments of the Linnean species R. temporaria. That 

 the forms here admitted as species are fully entitled 

 to that rank, no one acquainted with their histories 

 will contest for a moment. Nor, among recent acces- 

 sions to our knowledge, is the distinction of the two 

 species of Bombinator or the two of Alytes likely to 

 meet with any opposition. Bat the rank to be 

 assigned to the principal forms of Hyla arborea and 

 JRana esculenta, regarded by me as only varieties, 

 perhaps remains an open question in these days of 

 extreme multiplication of species. 



