Chap. 



ZlPIIIOir) WIIALKS. 



135 



gelatinous slime which they discharged from the surfaces of 

 their bodies when drawn on board. The slime forms masses 

 of a jelly-like substance. 



The villages between Simons Bay and Wynberg have fences 

 made of various bones of whales. A whale fishery was formerly 

 carried on here, but no longer pays. An extremely interesting 

 and very rare whale is occasionally procured at the Cape. It 

 is a Ziphioid, Afesoplodon Layardii. The Ziphioids are a group 

 of the toothed whales and allied to the sperm whale. They 

 have the bones of the face and upper jaw drawn out and 

 compressed into a long beak-like snout which is composed of 

 solid bone, hard and compact like ivory. The upper jaw is 

 devoid of teeth, having lost them in the process of evolution ; 



I Skull of Mesoplodon Layardii. 2 Lower jaw; a small cap of dentine on the tooth. 

 3 Top of lower jaw seen from the front, showing; the ring formed by the 

 teeth. Copied from the British Museum Cat;ilogue of Seals and Whales. 



and the lower jaw, which is lengthened and pointed to 

 correspond with the upper, retains but a single pair of teeth. 



In the species in question, AlesoplodoTi Layardii, these two 

 teeth in the adult animal become lengthened by continuous 

 growth of the fangs into long curved tusks. These arch over 

 the upper jaw or beak, and crossing one another above it at 

 their tips, form a ring round it and lock the lower jaw, so that 

 the animal can only open its mouth for a very small distance 

 indeed. The tusks are seen always to be worn away in front 

 by the grating of the confined upper jaw against them. How 



