Birds of Celebes: Laiidae. §93' 



ORDER LARI. 



The systematic position of the Gulls — whether they should be placed 

 nearer to the Plovers or to the Petrels — is not yet decided; perhaps an inter- 

 mediate position would be most correct. They have the following characters 

 whereby they may be distinguished as an order. They are of more or less ex- 

 clusively natatorial habits, feeding chiefly upon fish, and furnished with webbed 

 feet (in some genera the webs much indented) , differing, especially by the former 

 point, from the Charadriidae ; the young are covered with down and spotted, and 

 are able to leave the nest at an early age; the eggs are richly spotted, and do 

 not apparently exceed 3 in number; the nostrils are schizorhine — Avherein 

 they difl'er from the Tuhitiares and Steganopodes; further from the former by the 

 shape of the tongue, coracoid, furcula and hypotarsus, etc. Gadow), from the 

 latter by the hind toe, when present, not being webbed and joined on to 

 the other toes; the bill is simple, not furnished with a nail at the tip or ser- 

 rations or lamellae at the edges; the wing is long, the ulna exceeding the 

 humerus — whereby they difl'er from the Ducks, as well as by their eggs, young, 

 and various osteological characters. 



FAMILY LARIDAE. 



Mr. Howard Saunders divides the Lari or Gaviae into two families, 

 Laridae and Stercorarudae , the former being distinguishable by their "bill with- 

 out a cere; sternum with two notches on each side of the posterior margin; 

 toes partially or fully webbed; claws feeble or moderate". He subdivides the 

 Laridae into Sterninae, Rhynchopinae and Larinae; the Sterninae have a straight, 

 tapering bill with both mandibles of about equal length, whereas in the Larinae 

 the tip of the maxilla turns down over the mandible, while the bill of Rhijnchops 

 is of abnormal appearance, the lower mandible projecting considerably beyond 

 the upper one. 



GENUS HYDROCHELIDON Boie. 



These small. Marsh Terns are distinguishable from the other Terns by 

 their having the feet webbed only about as far as the first joint of the middle 

 toe, and the feet do not appear to be used for swimming. There are four 

 species, generally of dusky plumage. 



■i- 380. HYDROCHELIDON LEUCOPTERA (Meisu. Scli.). 



White-winged Black Tern. 



a. Sterna leucoptera (I) Meisner & Schinz, Vog. Schweiz 1S15, 264; (11) Naum., Vog. 

 Deutschl. X, 214, t. 257 (1840); (3) Stejn., Bull. U. S. Nat. Mus. 1885, Nr. 29, 

 316; (4) Ens. & Worces., B. Menage Exped. 1894, SI. 



