OP THE TONGUES OP^ THE MAMMALIA. l5l 



Suborder PINNIPEDIA. 



A. Apex entke. Posterior part of tongue elevated. Fungiform 



papilljB aggregated round edges of dorsum Trichechtis. 



B. Apex cleft. Postprior part of dorsum not elevated. Fungi- 



form papillae not aggregated round edges of dorsum. 



a. Halves of apex rounded and blunt. No vallate papillae nor 



lateral organs. Large pedunculated conical papillae on base 

 oftongue Otaria. 



b. Halves of apex sharper. Vallate papillae or lateral organs or 



neither present. No large pedunculated papillae on base, 

 i. No fungiform papillae. No vallate papillae. No lateral 



organs Salichcerus. 



ii. Fungiform papillae, vallate papillae, and lateral organs well 



marked PJioca. 



iii. Fungiform papillae present. Vallate papillae or lateral 



organs present Ci/stophora. 



It is, therefore, evident that Phoca has a fuller complement of 

 gustatory organs than all other Pinnipedia described above. 



Comparisons with the Cetacea. 



It IS now believed that the Cetacea have affinities with the 

 Arctoidea and Pinnipedia, so it is necessary to compare the 

 tongues. A full description of the Cetacean tongue is contained 

 in the previous paper of this series (29). 



The tongue is long, narrow and thin in the Arctoidea, but 

 wider and thicker in the Pinnipedia and Cetacea. The ajjex is 

 entire in most Arctoidea and all Cetacea, but is deeply cleft in all 

 Pinnipedia except Trichechtis. The lateral borders have papillae 

 in the Arctoidea ; they are lobulated in the Pinnipedia and 

 Odontoceti, but entire in the Mystacoceti. Vallate joapillce are 

 present in all Arctoidea, many Pinnipedia, but no Cetacea. 

 Conical papillce are present in all Arctoidea and most Pinnipedia, 

 but they are scanty or absent in the Cetacea. Lateral organs 

 are variable in the Arctoidea and Pinnipedia, but they are 

 absent in all Cetacea. The onfices of glands are innumerable 

 in the Cetacea, fewer \\\ the Pinnipedia, and scanty in the 

 Arctoidea. The frenuni is well marked and the lytta is present 

 in the Arctoidea, but the former is slight and the latter is 

 absent in the Pinnipedia and Cetacea. The lingual fat is well 

 developed in the Mystacoceti, in smaller quantity in the Odonto- 

 ceti and Pinnipedia, and very scanty in the Arctoidea. The 

 lingual muscles are well developed in the Arctoidea and Pinni- 

 pedia, but thej'' are poor in the Cetacea. 



It is, therefore, evident that the tongues of the Arctoidea 

 differ markedly from those of the Cetacea, but the conditions 

 ai-e intermediate in complexity in the Pinnipedia. The condi- 

 tions in the Cetacea are a mixture of degeneration and hyper- 

 trophy. The mechanical and gustatory organs have almost dis- 

 appeared, but the glands have increased. And the pharyngeal 

 glands are very numerous as well. The secretion of these glands 



