182 LAEID^. 



Sterna hirundinacea, Less. 



(Plate XIII. fig. 9.) 



Sterna eassinii, Abbott, Ibis, 1861, p. 166. 



Sterna hirundinacea, Saunders, Zool. ' Challengei- ' Exped. ii. pt. viii- 



p. 135 (1880); Sclater, t.c. p. 151 (1880); Scl. ^ Huds. Argent. 



Orn. ii. p. 19G (1889) ; Saunders, Cat. Birds B. M. xxv. p. 52 



(1896) ; Sharpe, Hand-l. i. p. 134 (1899). 



The eggs of Cassin's Tern vary in shape from a narrow to a broad 

 oval, but the smaller end is always markedly pointed. The ground- 

 colour is also very varied, being pale green, creamy buff, reddish buff 

 or olive-bufF. The markings consist of spots and blotches of blackish 

 brown and pale inky-purple. One example in the Collection is 

 white, with a few markings of the latter colour only. Specimens 

 measure from 1-75 to 2 in length, and from 1-3 to 1-45 in breadth. 



1. Riode Janeiro, 6th June (J'. Foww.c/). Saunders Coll. 



17. EUzabeth Island, Straits of Magel- Voy. H.M.S. 'Challenger.' 

 Ian, Jan. 



3. Elizabeth Island, Nov. Dr. Coppinger [P.]. 



4. Falkland Islands (C. C. Abbott). Gould Coll. 



5. Falkland Islands (C. C. A.). Gould Coll. 



3. Falkland Islands (C. C. A.). Saunders Coll. 



2. Falkland Islands (C. C. A.). Salvin-Godman Coll. 



2. Falkland Islands {Dr. Decme). Saunders Coll. 



3. Falkland Islands. McCormick Bequest. 



Sterna fluviatilis, Naum. 



Sterna hirundo, Thien. Fortpflanz. ges. Vog. tab. Ixxxiv. fig. 1, a-in 



(1845-54); Baedeker, Eier Eur. Vog. tab. 7. fig. i (1855-63); 



Hevjitson, Eggs of Brit. Birds, ii. p. 480, pi. cxxxiii. fig. iii (1856) ; 



Baird, Brewer ^- Ridgiv. Water Birds N. Am. ii. p. 295 (1884); 



Seebohn, Brit. Birds, iii. p. 280, pi. 46 (1885) : id. Eqqs of Brit. 



Birds, p. 102, pi. 29. figs. 1, 3 (1896). 

 Sterna wilsonii. Boss, Nat. Hist. Rev. 1862, p. 289 ; id. Canad. Nat. vii. 



p. 154 (1862). 

 Sterna fluviatilis, Dresser, Birds Eur. viii. p. 263 (1871) ; Leqr/e, Birds 



Cetjl. p. 1015 (1880) ; Saunders, Cat. Birds B. M. xxv. p. 54 (1890) ; 



Sharpe, Hand-l. i. p. 135 (1899). 



The large series of eggs of the Common Tern embraces almost 

 every type to be found amongst the eggs of the Terns. They vary 

 in shape from broad, blunt ovals to pointed ovals and some ex- 

 amples are pyriforra. The ground-colour varies from a pale greenish 

 white or bluish white to different shades of buff. The markings, 

 consisting of spots and blotches of blackish brown and underlying 

 grey or pale purple, are distributed over the shell in an infinity of 

 patterns. The eggs measure from 1-47 to 1-85 in length, and from 

 1-15 to 1-3 in breadth. 



3. North America (7'. iJf. i>Ve«t'er). Saunders Coll. 



1. North America. H. F. Walter, Esq. [P.]. 



2. Hudson's Bay. Gould Coll. 



5. Slave Lake, Canada, June. B. R. Ross, Esq. [P.]. 



4. Hog Island, Virginia {Dr. Hitz : Salvin-Godman Coll. 



Henshaw Coll.). 



