2 GUIDE TO THE FOSSIL MAMMALS AND BIRDS. 



The series begins on the right-hand side of the entrance to 

 Gallery No. 1 and is continued round this Gallery to the 

 left-hand side of the same entrance. The peculiar ]\Iammalia 

 of the Orders Edentata, Marsupialia, and Monotremata are 

 placed in Gallery No. 2. Many of the larger specimens are 

 necessarily mounted (jn separate pedestals or in separate 

 cases, not in their exact systematic position hut as near tlie 

 allied fossils as possible. 



Boxe-Beds. 



Case A. Most of the fossil remains of ]\Iammalia are obtained 



Pier-case 2. 1'rom " bone-beds " or great accumuhitions of Ijones, wliicli 

 have been formed by tlie deatli and rapid Ijurial of large 

 troops of animals, or Ijy the washing together of portions of 

 skeletons by streams and cuiTcnts. In the Island of Samos, 

 for example, there is an extensive It me-bed of Lower Pliocene 

 age, which seems to have resulted from the destruction of 

 herds of quadrupeds by a fall of volcanic dust from some 

 neighbouring eruption. In Greece there are several bone- 

 beds also of Lower Pliocene age, which must have accumu- 

 lated rapidly in lakes or temporary pools. These have ))een 

 excavated especially at Pikermi, near Athens, and a fine slali 

 from one of them, presented by Mr. Alexander Skouses, is 

 shown in a special Case A, near Talde-case 1. In this small 

 specimen (Plates II, III) tliere are remains of carnivores, 

 antelopes, gazelles, the three-toed horse {Hi'pparion), and 

 two birds, crowded together in red marl, which was originally 

 mud washed down from the neighbouring marble-range of 

 Pentelieon. ]\lany of the bones are in natural associatitm 

 (as, for instance, those of one bent leg oi. Hij)parioii), sliowing 

 that parts of the skeletons were l)uried rapidly before all 

 the ligaments and muscles which held them together had 

 decayed. At Olivola, in the CaiTara Mountains, Italy, there 

 is an Upper Pliocene torrent-deposit filled with bones and 

 pebbles ; and good examples of this are shown in I'ier-case 2 

 (top shelf). In many places, in the deposits left by rivers, 

 there are great collections of bones Ijrought together Ijy 

 eddying currents, such as those discovered in the valley of 

 the Thames during the working of brick-fields at Ilford and 

 Crayford. There are also numerous fissures, especially in 

 limestone districts, largely filled witli accumulations of 1 tones 

 which have fallen or been washed into them. When these 

 Ijones are mingled with angular fragments of rock and 



