2310 TUBE-NOSED BIRDS, DIVING BIRDS, PENGUINS 



one on the lower mandible. With the annual molt both the sheath of the basal 

 half of the beak and the warty red skin at the angle of the mouth are shed. In 

 Europe the breeding range of this species extends from Cape North to the 

 mouth of the Tagus, while in winter the birds wander as far south as Gibraltar, 

 and thence pass up the Mediterranean to the Italian coasts. On the opposite side 

 of the Atlantic the winter range reaches as far south as New York. 



Essentially oceanic in their habits, puffins are gregarious at all seasons, and 

 fly rapidly somewhat after the manner of ducks. Swimming easily, and diving 

 with the expertness characteristic of the family, they feed chiefly on the fry of fish; 

 while their single egg is laid either in a burrow in the ground or among the deep 

 clefts of rocks. In color, the egg is dull white, faintly spotted with gray and 

 brown, and in the presence of these markings it forms one of many exceptions to 

 the general rule that eggs laid in holes are white. From this circumstance, Mr. 

 Seebohm suggests that these birds have only taken to laying in burrows compara- 

 tively recently; the faintness of the markings of the eggs being perhaps indicative 

 that they are in the course of disappearance. 



THE DIVERS 



Family 



In common with 

 the grebes, the divers 

 (Colymbus) differ from 

 the auks (and thereby 

 from all other birds) in 

 that the crest of the 

 tibia is prolonged up- 

 ward to unite with the 

 kneecap, or patella, 

 thus forming a spike- 

 like projection at the 

 extremity of the bone, 

 which must afford a 

 most efficient lever for 

 the muscles in the act 

 of swimming. The 

 two families are further 

 characterized by the 

 saddle-like form of the 



articular surfaces of the vertebrae of the back, by the presence of a small 

 first toe, and the absence of bare tracts on the sides of the neck, while the 

 metatarsus is compressed and knife-like. In the divers the three front toes are 

 fully webbed, and furnished with sharp claw-like nails; the number of primary 



GREAT NORTHERN DIVER. 



