NOTICES OF NEW BOOKS. 237 



exposition of the chief characteristics which distinguish Croco- 

 diles from Alligators ; and in the chapter on " Spiny Animals," 

 the author explains in what respect the spines of Porcupines 

 differ from those of Hedgehogs. Thus in the Hedgehogs 



" the spines, in place of terminating in sharp points, by which they are 

 but loosely attached to the skin, like those of the Porcupine, the spines of 

 the Hedgehog terminate interiorly in small knobs, which are placed 

 beneath the skin, and may thus be compared to pins stuck through a piece 

 of soft leather. Beneath the skin lies a layer of muscle known as the 

 panniculus camosus ; and it is by the action of this muscle on their heads 

 that the spines are raised from a recumbent to a vertical position when the 

 creature rolls itself up into a ball — an action of which all Porcupines are 

 quite incapable. In the Porcupine the spines are most developed on the 

 middle line of the head and back, the hinder part of the body, and on the 

 short tail. But while those on the body are solid throughout and pointed 

 at each end, the spines at the extremity of the short tail are in the form 

 of hollow quills inserted by narrow stalks. It is these hollow quills that 

 make the loud rattling sound heard when a Porcupine is walking. . . . 

 Although the owner is unable voluntarily to eject the latter, their pointed 

 bases render them easily detached, and Leopards, which habitually feed ou 

 Porcupines, are found to be actually bristling with their quills." 



We may supplement this remark with an observation of 

 Dr. Hart Merriam, to the effect that the American Panther, or 

 Puma (which usually preys upon Deer), is either particularly fond 

 of Porcupine, or else is frequently forced by hunger to make a 

 distasteful meal. It is certain, he says, that " it destroys a great 

 many Porcupines, and it often happens that a Panther is killed 

 whose mouth and lips, and sometimes other parts also, fairly 

 bristle with the quills of this formidable rodent " (Trans. Linn. 

 Soc, New York, 1882-84). 



In his chaper " On the Extinction of Animals," Mr. Lydekker 

 would have done well to have referred to an excellent paper on 

 this subject by Mr. Frederic A. Lucas, published, with several 

 good illustrations, in the * Eeport of the U. S. National 

 Museum,' 1888-89 (pp. 609-649). In this essay an account is 

 given of several species not mentioned by Mr. Lydekker, such 

 as the West Indian Seal, Monachus tropicalis ; the Californian 

 Sea Elephant, Microrhinus angustirostris ; the Pacific Walrus, 

 0. obesus ; the European Bison, B, bonassus ; the Californian 

 Vulture ; and the Tile -fish, Lopholatilus chameleonticeps. Some 



