24 Proceedinffs. 



column run together into one ; and this bone, which from its 

 shape is called the ploughshare-bone, supports several feathers 

 of the fan- shaped tail. 



All the characters I have described belong to the groat 

 majority of birds, but I will now briefly describe a bird which 

 is not of the ordinary type. This is an extinct fossil bird, 

 known as the "Archseopteryx," a word signifying "ancient 

 wing." In this bird, the tail, instead of being short and 

 clumped-up into a large bone at the end, is very long, in fact 

 longer than the body, and consists of a series of slender bones, 

 each of which bears a pair of tail-feathers. All the three 

 digits of the hand have claws, and the bones corresponding 

 to the back of the hand are not run together, but free and 

 movable, and more like the Eeptile-haud. Tlie jaw-bones, 

 instead of being cased in horn to form a beak, as in our 

 existing birds, were furnished with shai-p, reptilian teeth. 

 Now, all these featiu'es showed that it was very much like a 

 Reptile, and Prof. Flower goes so far as to describe it as 

 " half-lizard and half-bird." 



There are other birds known, but all extinct and fossilized, 

 ■which also showed that certain parts were very Keptilelike ; 

 and, as we have seen that there are some Reptiles very like 

 birds in some respects, you will see the force of classing the 

 Reptiles and birds together under one heading — that of 

 Sauropsida. 



I must now pass on to the last great division — the Mam- 

 malia, or animals which feed their young ones with milk. The 

 first division, — that of the Monotremes, which approaches 

 most nearly to the reptiles and birds, — is represented by two 

 small animals, of one of which I have a specimen here. It is 

 known as the Duck-billed Platypus, or Ornithorynchus. This 

 curious little beast lives in holes in the banks of streams, 

 paddling about the mud and swimming in the water by 

 means of its webbed and clawed feet, catching the insects and 

 shell-fish. It lays eggs, too, like those of a bird, and sits 

 on them to hatch them. The young one, when it emerges 

 from the shell, is soft and hairless, and one might consider 

 with reason that its Duck's-bill would not be very well 



