ZEUGLODON CETOIDES. 61 



1. Teeth of two kinds ; molars and canine. The first are has- 

 tate, or of the general form of an arrow-head, or of a spear. This 

 form, however, appears under a modification, as will be seen by 

 reference to the figures. The second variety is that of the ordi- 

 nary canine tooth, or tusk. Molars, greatly compressed, margins 

 serrated or lobed, and edged, terminated by a middle central lobe 

 md rather rounded, and standing directly over the arch formed by 

 wo solid fangs. Cementum, (enamel) extending over the crowns 

 ind fangs, but thickest up the crown and but slightly wrinkled. 

 The transverse wrinkling upon the fangs (see fig.) appears only 

 vhen the first coat of cementum (enamel) has scaled off. Fangs 

 uperficially grooved, grooves varying in number on the two sides. 

 :he number of lobes, or crenatures vary : in the one figured, there 

 re four j yet in another tooth only three can be seen, and in the 

 Dwer tooth which stands by itself, there are three only ; but the 

 biddle lobe is serrated on the anterior edge as in the figure, and it 

 Itands obliquely to the arch upon which its base rests, or in other 

 rords, backwards. Fangs nearly parallel with each other. 



Canine tooth solid, compressed, tapering towards each extremi- 

 ky widest just within the alveolus, or socket. Cementum finely 

 mnkled longitudinally over the part external to the alveolus, but 

 xtends thinly over the fang, concealing the transverse wrinkles. 

 . shallow, wide groove on one side of the fang extends to the 

 ')wer end, on the opposite side ; it is traversed by three or four 

 arrow but shallow grooves with intervenino- ridoes 

 Measurements. 



Largest molar, 3|- inches Avide at its insertion into the alveolus, or 

 w; 2i inches high from the bifurcation to the termination 'of 

 .e middle lobe. Canine, 5 inches long and 1 h in its widest part 

 : Distance between the first and second canine, 2 inches ; between 

 e second and third canine, 2 1 inches. Breadth of the jaw at the 

 sertion of the second canines, at their inside insertions, 3 inches 

 eight of the jaw from the angle to the top of the coronoid pro- 

 Iss, 13 mches. The passage for the spinal marrow of one of the 

 'irvical vertebra has a transverse diameter of 4i inches, while the 

 irtical is only 2J. 



It is difficult in the present state of our knowledge to determine 

 'lether this animal, whose teeth have been particularly described 

 ■ould be considered a distinct genus, or species, from the one de' 



