196 LONG-WINGED SWIMMERS — LONGIPENNES. 



could be seen at one time. The sailors collected enormous numbers of their eggs, 

 the birds screaming unceasingly. AVhenever a Pelican or a Turkey Buzzard passed 

 near they assailed the intruder by hundreds, and drove it fairly out of sight. The 

 Ivazor-bill forms no other nest than a slight hollow in the sand. The eggs are always 

 three, having a pure-white ground, largely blotched and patched with very dark 

 umber, with here and there a large spot of an obscure purplish tint. The young 

 are at first of the same color as is the sand on which they lie ; and are not able to fly 

 until Ave or six weeks after being hatched. 



If this bird is shot at and wounded, and then falls into the water, it is easily 

 secured, as it cannot dive. At such a time its cries excite the sympathy of its fellows, 

 who crowd around it as Terns do under similar circumstances. 



Specimens of the egg of the Eazor-bill in the Smithsonian collection, from Hog 

 Island, Va., and from Florida, vary in their length from 1.70 to 1.80 inches, and in 

 their breadth from 1.30 to 1.40. Their ground-color is a pale buff or buffy white ; 

 the markings are large, longitudinal, and of a conspicuous blackish broAvn, intermin- 

 gled with subdued spots of umber and lavender-gray. The ground-color of South 

 American examples is a very deep drab. 



Family- LAEIDJ^. — The Gulls and Terns. 



Chae. Bill moderately compressed, or sometimes nearly cylindrical, its cover- 

 ing entire; the tip of the maxilla overhanging, or at least meeting, that of tlie 

 mandible ; the culmen more or less curved, but never arched terminally — some- 

 times nearly straight throughout ; symphysis of the mandible usually forming more 

 or less of an angle, this, in most cases, prominent in proportion to the relative depth 

 of the bill ; nostrils sub-basal, perforate ; legs and feet of proportionate size. Tail 

 extremely variable in form and length. 



Although including among its very numerous members great extremes of size 

 and form, the family Laridce as here restricted is not divisible into more than two 

 sub-families ; and these are so nearly imited through certain forms as to be really 

 more artificial than natm-al. They may, with considerable difficulty, be defined as 

 follows : — 



Larinae. Depth of the bill through the angle decidedly greater than through the middle of the 

 nostrils ; terminal jiortion of the culmen decidedly curved ; mandibular angle frequently 

  prominent, always distinct. Tail even, excejjt in Xema (forked) and Rhodostcthia (wedge- 

 shaped). Size extremely variable, but usually medium or large ; sometimes very large. 



Sterninae. Depth of the bill through the angle (symphysis of tlie lower jaw} less than through 

 the middle of the nostrils ; terminal portion of the culmen slightly curved, or nearly 

 straight ; mandibular angle seldom prominent. Tail forked, except in Anous (graduated). 

 Size extremely variable, but usually small ; never very large. 



In probably no other group of l)irds are there so many and great extremes of form connected 

 by imperceptible transitions, as among the Laridce. Owing to this fact, the genera are exceed- 

 ingly difficult of definition, uidess restricted to the smallest possible number, some of those thus 

 comprehended containing a considerable number of " sub-genera," many of which are almost, if 

 not quite, sufficiently different in form or size to be of generic distinctness. The genus Larus, for 

 instance, in its most comprehensive sense includes both the gigantic L. marinus and the pigmy 

 L. minutus ; the latter smaller than many Terns, the former approaching an Albatross in size ; while 



