2278 PLOVERS, SANDPIPERS, SNIPE, JACANAS, GULLS 



the neck, and forked on the upper back; and the oil gand is tufted. In their 

 down-clad and active young, these birds resemble the plovers, but the down is of a 

 more complex type. The first toe is raised above the level of the others, with 

 which it is not connected by membrane; and the nasal apertures in the skull are 

 schizorhinal, while the external nostrils are elongated, and placed rather low down 

 on the sides of the base of the beak. In the general structure of the palate, as well 

 as in the presence of a process on the outer side of the humerus (see figure in Vol. 

 III. p. 1467) , the gulls resemble the plovers. Rarely, if ever, exceeding three in num- 

 ber, the eggs are spotted or scrolled with dark markings on the light colored 

 ground. 



Gregarious and noisy in their habits, the gulls and terns are chiefly frequenters 

 of the coasts, although many of them may be found on inland waters, while all 

 may be driven inland by stress of weather. Even in England gulls may be seen 

 following the plow in search of worms; and in parts of Argentina, as in the 

 Colina district, at a distance of some two hundred miles from the sea, they appear 

 to dwell permanently inland, nesting in the lagunas. In Britain, while some 

 species breed on coast cliffs, others nest on islands and inland lakes, grassy downs, 

 and peat mosses. All the members of the group are birds of powerful and sustained 

 flight, and are capable of floating in the air with scarce a movement of their wings, 

 while they are equally at home on the surface of the water, where their webbed 

 feet enable them to swim with facility. The terns are, however, more essentially 

 aerial and aquatic birds than the gulls, their short legs not being well adapted for 

 walking on land. In the neighborhood of the sea the food of all these birds con- 

 sists mainly of fish and refuse, but when inland they consume worms, insects, the 

 eggs and young of other birds, and the offal from slaughterhouses. Although the 

 group as a whole has a cosmopolitan distribution, it is noteworthy that in the great 

 area lying between South America and the neighborhood of Australia and New 

 Zealand not a single gull is to be met with, although terns are abundant. Along 

 the southern shores of Australia, and also in New Zealand, a large, dark-mantled 

 gull (Larus patificus) makes its appearance as an isolated form. Geologically, the 

 group appears to be one of the oldest of the existing orders of birds, remains of an 

 extinct genus (Halcyorms} occurring in the London Clay, a formation belonging to 

 the lowest division of the Tertiary period; while other forms, which have been 

 assigned to the existing genus Larus, occur in beds pertaining to the lower portion 

 of the Miocene period. According to the classification adopted by Mr. Howard 

 Saunders, the order may be divided into two families, the first of which is again 

 split up into three subfamilies. 



THE TERNS, SKIMMERS, AND GULI<S 

 Family 



Including the three groups above named, each of which represents a subfamily, 

 the present family is characterized as follows: The beak has no cere at its base; 



