6 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. 65. 



This tooth does not agree in structure with any yet described. It 

 most resembles the teeth described by Yoshiwara and Iwasaki^° as 

 lower second premolars. In those teeth, however, there are three 

 columns in the hinder transverse row. 



There are some reasons why the larger of the two teeth referred to 

 CornwaUius sookensis can not be regarded as identical with the 

 tooth 23 of the Oregon specimen. These are as follows : 



(1) The outer border of the Oregon tooth is straight; in the Vic- 

 toria tooth this border is strongly curved. (2) The transverse rows 

 of columns in the Oregon tooth appear to be arranged more obliquely 

 to the long axis of the tooth than in that from Victoria. (3) The 

 hinder end of the Victoria tooth is considerably broader than in the 

 one from Oregon. 



Until some lucky discovery shall decide the matter one way or 

 the other, the writer proposes to maintain the genus Cormvalh'vs 

 and to regard the larger of the two teeth (pis. 1, '2. tigs. 4, 5) as an 

 upper molar, and the smaller one (pi. 2, figs. 1-3) as a lower molar, 

 not the hindermost. The larger tooth is taken as the special type of 

 Cor-nvmUius sookensis. 



The cliffs in the vicinity of Sooke. Vancouver Island, ought to be 

 carefully and frequently searched for additional materials of this 

 sirenian. 



In their description of the skull of Desmostylus Yoshiwara and 

 Iwasaki attribute to Desmostylvs two pairs of lower tusks and one 

 pair of upper ones. The lower tusks projected some distance from 

 the jaw. The upper tusks were said not to have yet come into 

 full growth, only the left tooth being slightl}^ visible beneath the 

 ruptured surface of the maxilla. Their figure ^^ shows what was 

 seen of this tusk. 



In my description of Desmostylus from Oregon I referred to what 

 seemed to be an upper tusk. Although this was said ^' to show 

 only on the right side, there is on each side a projection at the 

 front of the specimen which represents the same structure. As 

 shown by my figures, a fragment of the snout about 30 mm. long had 

 been broken off in exhuming the skull and had later been cemented 

 in its place. Recently, wishing to come to a decision regarding this 

 supposed tusk, the writer removed the fragment and cleaned off 

 both surfaces of the break. The view presented Avas not satisfac- 

 tory. The circumference of the supposed tusk could not be traced 

 on the side next the mid-line. Next, the matrix was ground down 

 and polished to see whether any structure was hidden. What was 

 revealed is shown in figure 3 of plate 1. On each side there ap- 



'" PL 3, figs. 2 and 3. 



".Tourn. Coll. Sci., .Tapan. Imp. Univ., vol. 16, 1002, pi. 1, Vp I. 



'- Proc. U. S. Nat. Mus., vol. 44, p. 391. 



