176 LARIDJE. 



Hydrochelidon fissipes, Baedeker, Eier Ear. Voj. tab. 32. fig. 3 (1855- 



63) ; Saunders, Ibis, 1871, p. 399. 

 Hydrochelidon nigra, Dresser, Bi>'ds Enr. viii. p. 327 (1876) ; Saunders, 



Cat. Birds B. M. xxv. p. 17 (1896) ; Sharpe t Hand-l. i. p. 133 



(1899). 



The eggs of the Black Tern vary from a pointed oval form to 

 pyriform. The ground-colour ranges from pale buff to brownish 

 buff, and this is heavily blotched and spotted with reddish brown and 

 blackish brown. With few exceptions, these markings cover quite 

 half the surface of the shell and are often confluent, especially 

 over the broader half. The underlying markings are numerous 

 and of a dull grey colour. Specimens measure from 1'3 to 1'4G in 

 length, and from -9 to 1/05 in breadth. 



2. Coto del Ptey, Spain (Lord Lilford}. Saunders Coll. 



4. South Spain. Lord Lilford [P.]. 

 14. Valkenswaard, Holland, 26th May Saebohm Coll. 



(H. Seebohm}. 



18. Valkenswaard ( W. Bridges}. Saunders Coll. 



18. Holland (T. Baker}. Salvin-Godman Coll. 



5. Holland. Lord Lilford [P.]. 

 14. Kassarien Ptiver, Esthonia Seebohm Coll. 



(Russoiv}. 



2. Garde See, Pomerania, 26th May Seebohm Coll. 

 (H. Seebohm}. 



12. Garde See, 30th May (H. S.). Seebohm Coll. 



Hydrochelidon surinamensis (Gm.}.\ 

 (Plate XIII. fig. 5.) 



Hvdrochelidon nigra surinamensis, Baird, Breioer fy Ridyw. Water Birds 



N. Am. ii. p. 318 (1884). 

 Hydrochelidon surinamensis, Saunders, Cat. Birds B. M. xxv. p. 20 



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



The eggs of the American Black Tern are absolutely undistin- 

 guishable from the eggs of II. leucoptera and H. nigra. 



1. Little Slave Lake, Canada (S.Jones: Salvin-Godman Coll. 

 Henshaw Coll.}. 



13. Chicago ( C. E. Aiken: Henshaw Salvin-Godman Coll. 



Coll.). 



Genus PHAETHUSA, Wagler. 



Phaethusa magnirostris (LicJit.}. 

 (Plate XIII. fig. 8.) 



Sterna magnirostris, Thien. Fortpflanz. ges. Voy. tab. Ixxxii. fi?. 6 



(1845-54). 



Thalasseus magnirostris, Scl. fy Salv. P. Z. S. 1866, p. 200. 

 Phaethusa magnirostris, Scl fy Huds. Argent. Orn. ii. p. 194 (1889) ; 



Saunders, Cat. Birds B. M. xxv. p. 23 (1896) ; Sharpe, Hand-l. i. 



p. 134 (1899). 



