156 ZOOLOGY. 



the snout being remarkably blunt, and either perpen- 

 dicular, or more or less convex in different individuals. 

 The body is nearly cylindrical, protrudes on either side 

 of the abdomen, and tapers finely at the tail. The 

 summit of the head and trunk presents a plane surface, 

 until about the posterior third of the back, whence 

 arises a hump, or spurious fin, of pyramidal form, and 

 entirely composed of fat. From this embossed ap- 

 pendage, an undulating series of six or eight similar 

 but smaller elevations occupies the upper margin, or 

 ridge of the tail, to the commencement of the caudal 

 fin. The pectoral fins, or paddles, are placed but a 

 short distance behind the head. They are triangular in 

 shape, and diminutive as compared with the size of the 

 whale : in a Cachalot sixty feet long, I did not find 

 them exceed three feet in length by two in breadth. 

 The integuments covering their upper surface are 

 frequently marked with longitudinal embossed ridges, 

 corresponding in number and situation to the bony 

 fingers within. Being connected to the trunk by a 

 ball and socket joint, these members possess a free 

 movement, which can be exercised either in a vertical 

 or horizontal direction. 



The tail-fin, or ee flukes," is both the principal organ 

 of progression and a powerful weapon of defence. Its 

 average horizontal spread, in the adult female, is twelve 

 feet : in a male, sixty feet long, it measured nineteen 

 feet across. Each segment of its posterior, or free 

 border is thin and convexly crescentic ; (not waved, as 

 in the dolphin and porpoise families ;) and each half 

 overlaps the other at the central notch, or " crutch." 

 Owing to the flexibility of the tail, the movements of 

 this fin are exceedingly extensive ; whilst its power may 

 be estimated by the gigantic bundles of round tendons 

 which pass on either side the loins to be inserted into 



