GEOLOGY IF NATIONAL MUSEUM — MERRILL. 275 



foot bones showing the development of the horse from the primitive 

 Eohippus to the modern living form, (2) one of the common land 

 tortoise (Stylemys nebrasensis) showing the growth stages from the 

 smallest to the large adult specimens, and (3) a collection repre- 

 senting the fauna of the Pleistocene period, which immediately pre- 

 ceded the present-day animals. While far from complete in its rep- 

 resentation, it gives an idea of the character and kind of animals 

 that lived at that time. Of special local interest are two collections 

 from near-by sources. These are (1) a series of remains, chiefly 

 shark and cetacean, from the Miocene formations near Chesapeake 

 Beach, Md., and (2) a strikingly varied series of mammalian remains 

 from a limestone cavern on the line of the Western Maryland Kail- 

 way, near Cumberland. Of the first there are several almost complete 

 skulls and two skeletons of the long and short snouted dolphinlike 

 cetaceans; a rare and the most perfect example of the squalodon 

 yet discovered; and several representatives of the whalebone whales. 

 There is also a considerable series of sharks' teeth, which are the only 

 portions of these animals which are sufficiently bonelike to have been 

 preserved. These fragmental remains well illustrate the character 

 of the aquatic animal life during Miocene times, when this portion 

 of the Maryland coast was depressed beneath sea level. The second 

 collection to which reference is made is from a limestone cavern 

 which was cut through in the process of railway construction. From 

 the stalagmitic and clayey matter occupying the bottom of this cave 

 there were secured more or less fragmentary bones and skeletons of 

 between 40 and 50 species of mammals, ranging in size from that 

 of a small bat to an elephant. Among these are many identified with 

 forms now living, but others extinct and of a type not now inhabit- 

 ing North America. There are included in the collection remains 

 of bats, mice, wood rats, rabbits, porcupines, woodchucks, skunks, 

 weasels, martens, badgers, mountain lions, lynxes, wolverines, bears, 

 peccaries of a species much larger than any now living, tapirs, horses, 

 and antelope, the nearest living representative of which is an African 

 species, and mastodons. The assemblage of so numerous and varied 

 a series in one common burying ground can seemingly be accounted 

 for only on the supposition that this cave at some earlier period was 

 connected with the surface by a sink hole through which poured a 

 stream of water carrying the carcasses of dead animals which had, 

 perhaps, been drowned during a period of flood. The collection, 

 only a few examples of which can be exhibited, is of exceptional 

 interest in that it shows the changes which have taken place in the 

 character of the animal life within a very recent period. Other 

 objects of interest in this hall are the peccary (Platygonus), bear 

 (Ursus), wolverine (Gulo), and wolf (Canis), together with skulls 

 representing several species each of the extinct bison, muskox, horse, 



