Zoological Society, 155 



two in number, are very large, followed on each side by two false 

 molars, and four true molars. In Echinops, as in Erinaceus, the feet 

 have five toes ; the thumb of the fore-feet is small and seated on the 

 wrist/ the other toes are small, and armed with feeble, compressed, 

 hooked claws, the last toe the smallest : the toes of the hind-feet 

 resemble those of the fore-feet, and the inner and outer are the 

 smallest. The snout, ears, tail, and spiny covering of the upper sur- 

 face of the body, as in Erinaceus. 



The skull, as compared with that of Erinaceus, was proportion- 

 ally very inferior in size ; it was more level above, and narrower, 

 the cranial cavity being contracted, and the muzzle shorter. The 

 occipito-parietal ridge was elevated, the zygomatic arches were 

 almost obsolete. The palate was narrow, and the posterior foramina, 

 which in the hedgehog are large open fissures, were reduced to mi- 

 nute orifices. The pelvis was very narrow, and the pubic bones 

 were separate in front. 



The vertebral formula was as follows : 



Cervical 7 



Dorsal 15 



Lumbar 7 



Sacral 2 



Coccygeal 8 ? 



The ribs consisted on each side of 8 true and 7 false. 

 Mr. Yarrell exhibited a recently preserved example of a new spe- 

 cies of Swan, closely allied in external appearance to the well-known 

 Domestic Swan, but having the legs, toes, and interdigital mem- 

 branes of a pale ash-grey colour, which in the Cygnus olor, 111., are 

 deep black. Mr. Yarrell observed, that this species had been known 

 to him for some years past as an article of commerce among the 

 London dealers in birds, who receive it from the Baltic, and di- 

 stinguish it by the name of the Polish Swan. In several instances, 

 these swans had produced young in this country, and the cygnets 

 when hatched were pure white, like the parent birds, and did not 

 assume at any age the brown colour borne for the first two years 

 by the young of all the other known species of White Swans. 

 Mr. Yarrell considered that this peculiarity was sufficient to entitle 

 the bird to be ranked as a distinct species, and in reference to the 

 unchangeable colour of the plumage, proposed for it the name of 

 Cygnus immutabilis . 



During the late severe weather, flocks of this swan were seen 

 pursuing a southern course along the line of our north-east coast, 

 from Scotland to the mouth of the Thames, and several specimens 

 were obtained. The specimen exhibited was shot on the Medway, 

 where one flock of thirty, and several smaller flocks were seen. 



