NO. 2113. EXTINCT SIRENIAN DESM0STYLU8 HESPERUS— HAY. 395 



department of the University of Oregon, the tooth which has been 

 already mentioned as having been found at Yaquina Bay by Pro- 

 essor Condon. Two views of this tooth are here presented (pi. 58, 

 figs. 3, 4). The tooth is considerably worn and all but the base of 

 the root is missing. The crown consists of eight columns, three in a 

 transverse row at one end, a single column at the other end, and 

 between these two rows of two columns each. I interpret this tooth 

 as the second upper molar of the right side. It has quite exactly 

 the size and the arrangement of the columns seen in the uncut second 

 molar of the skull here described, except that the oblique line joining 

 the centers of the columns of each row is directed differently. Ex- 

 cepting in size, the tooth resembles closely the upper first molar of 

 the Japanese specimen. The front end of the tooth is concave from 

 side to side and the polished surfaces on the free faces of the columns 

 show that another tooth of considerable size abutted against it. 

 But there is likewise a surface of wear near the base of the single 

 column which is supposed to be at the rear of the tooth. If, there- 

 fore, I am right in identifying this tooth as the upper second molar, 

 it must be concluded that a third molar was coming up at the rear 

 of it. 



The length of the tooth here described, taken at the middle of the 

 width, is 51 mm.; the greatest width, 33 mm.; the height of the col- 

 umns, 27 mm. The largest columns have a diameter of 16 mm. 

 Those of the anterior row are pretty strongly curved, with the con- 

 cavity toward the contiguous columns. In the vaUey between the 

 various columns is seen a small quantity of cement. It is not unlikely 

 that this supporting material was more abundant during life. 



In his paper published in 1911, already referred to, Merriam figured 

 a tooth which had been found near Coalingua, Fresno County. This 

 tooth is nearly identical in form with the one just described, but it 

 is slightly larger. The length is 56 mm. ; the width, 40 mm. A con- 

 siderable part of the root is retained. There is a single fang in front 

 and a larger one (possibly subdivided) at the rear. The grinding 

 surface is worn concave from front to rear and from side to side. 

 Judging from the teeth of the Proboscidea, we might be led to regard 

 this tooth as one of the lower jaw. 



It seems to me that there are, between the Japanese specimen and 

 that from Oregon, differences of specific importance. The most 

 striking of these is found in the sizes of the two animals. The 

 Japanese skull was about twice as long as the American. Here fol- 

 lows a table which shows certain common dimensions and their 

 ratios, those of the Japanese specimen being taken as 100. The 

 dimensions of the latter specimen have been taken mostly from 

 Yoshiwara and Iwasaki's statements, but partly from their 

 illustrations. 



