lO SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 68 



of centrum, ii.o (12.5) ; depth of lateral canal, 12.6 (-). Sixth 

 cervical: greatest breadth, 69.6 (72.4) ; greatest median depth, 54.2 

 (66.7) ; breadth of spinal canal, 33.0 (29.6) ; median depth of spinal 

 canal, 17.6 (17.8) ; breadth of centrum, 34.7 (36.2) ; depth of cen- 

 trum, 31.5 (40.0) ; thickness of centrum, 12.4 (14.2) ; depth of lateral 

 canal. 13.7 (-). Seventh cervical : greatest breadth. 109.5 (109.8) ; 

 greatest median depth, 63.2 (106.7) ! breadth of spinal canal, 33.6 

 (29.5) ; median depth of spinal canal, 20.2 (20.2) ; breadth of 

 centrum, 32.6 (41.2) ; depth of centrum, 31.8 (37.6) ; thickness of 

 centrum, 15.5 (16.2) ; breadth of lateral canal, 27.3 (-) ; depth of 

 lateral canal, 12.0 (-). 



Remarks. — The general form of Lipotes vexillifer is sufficiently 

 well indicated by the photograph and tracing in plate i. A few details 

 concerning the external characters are, however, not entirely clear. 

 In the photograph reproduced the posterior border of the flipper 

 appears to be entire, while in the one from which the tracing was 

 made it is evidently notched and angled at the distal extremity. 

 There is a similar doubt as to the exact outline of the flukes. 



With the specimen and photographs Mr. Hoy sent these notes on 



the freshly killed animal : " Length, 7 ft. 6 in. ; girth, several inches in 



front of dorsal fin, 4 ft. 6 in. ; total number of vertebrae, 45 ; color, 



back blue-gray, belly white ; eyes very small ; ears like pin pricks ; 



blowhole rectangular, at depth of one inch it divides into two 



passages ". 



0-3 ')') 



In the type the dental formula is ~ -'^"' = 129. The individual 

 ^ 33—31 



variation in the number of teeth may eventually be found to be as 

 great as in Inia, where the range, according to Flower, is from 104 

 to 132 (Trans. Zool. Soc. London, Vol. 6, p. 95, 1867). The smaller 

 size of the teeth and the apparent specialization of the entire dentition 

 for seizing and grasping rather than for strength make it appear 

 probable that the average number will prove to be greater than in the 

 South American animal. Further material will be required to show 

 whether such is actually the case. 



