1876.] MR. H. SAUNDERS ON THE STERNIN/E. 669 



with the smaller species, of which, moreover, I have never seen a 

 specimen except from the Marquesas ; and I have therefore been 

 compelled to give a name to it. The larger species is also found at 

 the Marquesas. 



The nesting of Gygis is peculiar, the single egg of clay-white mottled 

 with brown being placed on the cavity of the branch of a tree, or in a 

 fork of two branches, and on the points of the coral reefs — anywhere, 

 in fact, where it will lie. In these babits Gygis shows another affinity 

 with Anous, of which it seems to be a highly specialized offshoot. 



" Sterna nivea " of F. D. Bennett (Whaling Voy. i. p. 370, 1840), 

 from the Caroline Islands, might be either of these species ; and I 

 can find no description of " Gygis napoleonis" Bp. 



Genus Angus, Leach. 

 Anous stolidus, Linn. 



Sterna stolida, Linn. Svst. Nat. i. p. 227 (1766); id. Amcen. 

 Acad. iv. p. 240; Gmelin,"S. N. i. 2, p. 605 (1788). 



Sterna fuscata, Linn. Svst. Nat. i. p. 228 (1766), ex Brisson, vi. 

 p. 220, t. 20. fig. 1 ; Gme'l. S. N. p. 605 (1788), juv. 



Sterna pileata, Scop. Del. Faun, et Flor. Insubr. i. p. 92.no. 73, 

 ex Sonn. Voy. p. 125, pi. 85 (1/86). 



Sterna senex, Leach, in Tuckey's Exped. to the Congo, App. 

 p. 408 (1818), obtained by Cranch. 



Anous niger, Steph. in Shaw's Gen. Zool. xiii. i. p. 140, pi. 17 

 (1825) — type of Anous, Leach (adult). 



Anous fuscatus, Steph. in Shaw's Gen. Zool. xiii. i. p. 140 

 (1825), juv. 



Anous spadicea, Steph. in Shaw's Gen. Zool. xiii. i. p. 143 

 (1825), juv. 



Megalopterus stolidus, Boie, Isis, 1826, p. 980. 



Sterna unicolor, Nordm. in Erin. Verz. v. Thier. & PA. p. 17 

 (1835). 



Anous stolidus, Gray, List Gen. Birds, p. 100 (1 841) ; Blyth, Cat. 

 B. A. S. Bengal, p. 293; Gould, B. Australia, vii. pi. 33*(1848); 

 Cassin, U.S. Expl. Exp. p. 391 (1858); Finsch & Hartl. Faun. 

 Centralpolyn. p. 234 (1867), Vug. Ost-Afrika's, p. 835 (1870); 

 Scl. & Salv. P. Z. S. 1871, p. 566 (Neotrop. Laridfe) ; Coues, B. 

 N.W. Am. p. 710 (1874). 



Anous rousseaui, Hartl. Beitr. Orn. Madagasc. p. 86 (I860). 



This well-known species, a straggler to the British seas, ranges from 

 the Gulf-coast of North America to the shores of Australia, through- 

 out Polynesia, and occurs, in fact, in all tropical waters. There 

 appears to be no constant difference between individuals from the 

 most distant localities ; and this similarity applies to its habits and 

 breeding, its single egg being deposited on a nest of sea-weed placed 

 on mangrove bushes, in the fork of a tree, or even on the bare rock. 



In the British Museum there is a specimen from Dalrymple Rock, 

 Chatham Island, one of the Galapagos group, which is of a uniform 

 sooty brown. It is evidently an immature bird ; and I am therefore 



Proc. Zool. Soc— 1876, No. XLIV. 41 



