240 DR. J. MUEIE ON THE ORGANIZATION OP THE CAAING WHALE. 



of the cranium and its supeiincumbent nodosity. The under surface of the chin deepens 

 towards the throat ; and the contour from this point ventrally towards tlie tail is a 

 nearly uniform, narrowing, sweeping line. The dorsal antero-posterior curve almost 

 corresponds to the abdominal one, excepting where interrupted by the back-fin. To- 

 wards the caudal extremity the perpendicular depth is but moderate. Opposite the 

 dorsal fin the body insensibly narrows, which narrowing steadily increases the nearer it 

 approaches the root of the caudal fin, and becomes laterally compressed. 



The subjoined measurements of our female give the relative total length in a straight 

 line, and curvilinearly following the dorsal arch, in distances between various points. 

 From these data it follows that the amount of arching of the back and projecting mass 

 of the snout is longer by about one foot and a half than is the body taken in a hori- 

 zontal parallel straight line. 



ft. in. 



Length from the snout to the fork of the tail 10 10 



Distance from the projecting upper lip to the blow-hole, following curve 111 



From the blow-hole to the anterior root of the dorsal fin 2 9^ 



Dorsal fin in length at its base 1 94 



Distance from the posterior root of dorsal fin to tail's root .... 4 9 

 Tail from root to fork 10 



The dorsal fin is a prominent feature in the profile outline of the animal. It is large, 

 falcate-shaped, and very much laterally compressed near and at its upper free margin. 

 The anterior upper smooth border forms the segment of a wide arch whose summit is 

 perpendicular to the posterior attached root of the fin. Behind, it terminates in an 

 almost hook-like manner. The posterior inferior border is deeply emarginate. This 

 fin is situated in front of the middle of the body. Measured from the centre of the fin 

 itself, the distance between it and the front of the truncated snout is six inches less 

 than from the same point backwards to the root of the tail, while it is eighteen inches 

 less when the measurement is carried to the fork of the tail-fin. 



The dimensions of the dorsal fin are : — greatest length or that continuous with the 

 upper curved border to the hooked tip, 2 feet li inch ; length of the base in a straight 

 line, 1 foot 9^ inches ; greatest vertical height, 8^ inches 



In relation to the body, the low-set position, and the peculiarly narrow, tapering, 

 scythe-shape of the pectoral fins, in contrast with the blunt globose snout, render the 

 Pilot Whale at once as remarkable as it is characteristic among the Cetacea. Each 

 pectoral extremity or fin is thin and knife-like on the edges. The length, taken in a 

 straight line, is 1 foot 10^ inches; but the measurement following the curve of the 

 anterior border equals 2 feet 3^ inches, whereas the posterior border in its curve is only 

 1 foot 6^ inches. Their position is about the posterior third of the distance between 

 the snout and the anterior end of the dorsal fin. 



In shape the tail seems uncommonly like that of the Porpoise. It nevertheless 



