OCEANIC MAMMALS 481 



half of the back. The teeth are large, conical, and spaced, 

 usually about eight to nine in each tooth row. The animal 

 thus bears a superficial resemblance to a blackfish, but the 

 head is less globose, and the pectoral fin is shorter, about one- 

 eighth or a ninth instead of a fifth of the total length. 



In 1927 a school of no less than 126 came ashore at Dornoch 

 Firth, off Sutherlandshire, Scotland, and their skeletons were 

 secured by the British Museum to form the basis of a compre- 

 hensive study. In the few years following other schools were 

 stranded at such distant parts of the world as the Ligurian 

 Sea, the coast of Malaga, Ceylon, Tasmania and New South 

 Wales, Zanzibar, and the coast of South Africa near Cape- 

 town. 



Instead, therefore, of being an extinct or rare species as 

 at first believed, this large porpoise proves to be common, fre- 

 quenting the temperate and tropical seas of the world. A social 

 species, it may gather in schools of considerably over a hundred, 

 old and young, and is believed to subsist chiefly on squid. 

 What drives these "suicide squads" to become stranded in 

 such numbers is uncertain. Various ideas have been advanced, 

 but the true reason is difficult to fathom. Ordinarily they seem 

 to keep well off from land but perhaps may at times follow in 

 schools of their favorite food animals, whether fishes or squids, 

 and coming too near land in shallow shelving coastal waters 

 get panic-stricken and drive on to the beach. Hitherto they 

 have served no economic use, for their appearance is too un- 

 dependable to make it worth the effort to hunt them. 



Family ZIPHIIDAE: Ziphioid Whales 

 BEAKED WHALES OF THE GENUS MESOPLODON 



The whales of this genus are so rarely stranded or captured, 

 or preserved in museums, that very little is known of them 

 beyond the general appearance and anatomy of the occasional 

 specimen that has fallen into the hands of a naturalist. It is 

 believed that they are relatively few in numbers and represent 

 a waning group, once more numerous but now slowly dying 

 out. Many fossil remains have been referred to the genus. 

 Nevertheless, more likely it is their solitary habits and pelagic 

 life, and the infrequency of their visits to near-shore waters, 



