314 ORDERS OF MAMMALIA. 



" Sarmatian " deposits, all of which a]ipear to be more or less 

 closely related to the living Finner Whales {Balmnoptera). 

 The living genus Balmna appears for the first time in the 

 Pliocene of Europe ; and it is probable that the ear-bones or 

 " cetotolites," which occur in the Eed Crag (Pliocene), are, in 

 some instances at any rate, referable to members of the 

 BalmnidcB. 



Fam. 2. Catoclontidcc. — -Tlie family of the Cafodontidce, or 

 Physcteridm, comprises the Sperm Whales or Cachalots, with 

 which we commence the series of the Tootlied Whales {Odon- 

 toccti). They are characterised by the fact that the palate is 

 destitute of baleen-plates, and the lower jaw possesses a series 

 (about fifty-four) of pointed conical teeth, separated by inter- 

 A'als, and sunk in a common alveolar groove, which is only 

 imperfectly divided by septa. The upper jaw is also in 

 reality furnished with teeth — but, with a single partial ex- 

 ception, these do not cut the gum. 



Eemains of Cachalots [Physeter) occur in tlie Pliocene and 

 Post - Tertiary deposits, and their existence has even been 

 indicated in the Miocene Tertiary. They are, however, of no 

 special importance. 



Fam. 3. DclpMnidm. — This family includes the Dolphins, 

 Porpoises, and Narwhal, and is characterised by usually jdos- 

 sessing teeth in both jaws ; the teeth being numerous, and 

 conical in shape. The nostrils, as in the last family, are 

 united, but they are placed further back, upon the top of the 

 head. The single blow- hole or nostril is transverse, and 

 mostly crescentic or lunate in shape. The head is by no 

 means so disproportionately large as in the former families, 

 usually forming about one-seventh of tlie entire length of 

 the body. 



The genus Delphinus, comprising the common Dolphins, 

 appears to date from the Miocene Tertiary, and is well repre- 

 sented in deposits of Pliocene age. In Miocene strata also 

 occur the Delphinoid remains which have been referred to 

 the genera Priscodelphinus, Stereodelphis, and Champsodelphis. 



Fam. 4. Rhynchoceti. — This family is allied to that of 

 the Cachalots or Sperm Whales, and includes the so-called 

 " Ziphioid Whales." They are distinguished by the posses- 



