Maryi . Classifica tion . 1 1 



XI. The species included by the modern Order CETE* 

 are either edentulousf or Monophyodont ; and all have the 

 external nostrils, spiracles, or blow-holes, situated on the top 

 of the head. They may be 



divided into Three Families, 

 1. The BalmnidcB, or true Whales, in which the teeth are 

 deficient, t and the two sides of the upper jaw, furnished with 

 thin transverse serrated laminae, termed baleen or whalebone. 

 2. The Physeteridce, or Sperm Whales, which have no baleen 

 plates in the palate, nor teeth in the upper jaw, except in a 

 very rudimentary condition. The superior portion of the 

 enormous head consists of cavities filled with an oil which 

 solidifies by exposure, called spermaceti. 3. The DelphinidcBj 

 which always have one or more teeth in the upper jaw. 



XII. The species included by the order SIEENIA have 



teeth of difterent kinds, are Diphyodont, and have nostrils 



situated at the upper fore part of the snout. In this order 



there are 



only Two Families. 



1. The Rhytinidcey now extinct, are said to have had no 



true teeth, but only a pair of bony plates, placed anteriorly, 



on the palate and lower jaw. 2. The Manatidce are always 



furnished with molar teeth. 



The three following Orders complete the "Unguiculata." 

 XIII. The Order IJNT-ENAMELLATA J (teeth devoid of 



In the Linnsean classification the term Cete was used of the same Group 

 of animals as that to which it is here applied. 



t In the adult. 



X The term In-Enamellata has heen here adopted in order to avoid that ex- 

 treme confusion which has arisen from employing, in different schemes of clas- 

 sification, one and the same term to denote quite distinct aggregations of families. 

 When Cuvier entitled his sixth order of Mammalia " Edentata" he did so having 

 regard to certain groups of animals which were possessed in common of this 

 negative character alone, viz. that they lacked teeth in the fore part of their 

 jaws. With him the Order Edentata connoted the E. Tardigrada {e.g. Bradypus) ; 



