PROCELLAEIID^ THALASSOGERON 501 



\ 



short dives after its prey. In November the Mollymawk departs- 

 from our shores for its breeding places in the Southern Ocean. The 

 nest, like that of the Wandering Albatros, is a conical elevation 

 built up of moss and earth, and on Kerguelen at any rate there 

 are a great many together, forming a rookery at an elevation of from 

 400 to 500 ft. above the sea. One egg only is laid as a rule, dull 

 white with a cap of rufous specks and blotches at the larger end ; 

 the average size is 4-0 x 3'5. There are in the South African 

 Museum four Albatros eggs from Tristan identified with this 

 species, but these not improbably would be more rightly assigned 

 to Thalassogeron culminatus, which was the species found breeding 

 there by the " Challenger" Expedition. 



Genus II. THALASSOGERON. 



Type. 

 Thalassogeron, Bidgway, Water Birds N. Amer. 



ii, pp. 345, 357 (1884) T. culminatus. 



Closely allied to Diomedea but with the culminicorn much 

 narrower behind the nostrils and separated at that point by 

 membrane from the latericorn. 



Five of the smaller Albatroses are assigned to this genus, the 

 range of which extends throughout the Southern Oceans ; of these, 

 three have been found near the coast of South Africa. 



Key of the Species. 



A. Culmen bright yellow contrasting with the 

 sides of the bill, which are black. 



a. Culminicorn rounded posteriorly : lower 



edge of the mandible yellow T. culminatus, p. 501. 



b. Culminicorn pointed posteriorly ; basal 

 edge but not the lower edge of the mandible 



yellow T. chlororhynchus, p. 503. 



B. Bill generally pale, no contrast between the 



culmen and sides T. layardi, p. 505. 



805. Thalassogeron culminatus. Gould's Yelloiv-nosed 

 Mollymawk. 



Diomedea culminata, Gould, Proc. Zool. Soc. 1843, p. 107 ; id. B. 



Austr. vii, pi. 41 (1848) ; Layard, B. S. Afr. p. 364 (1867) ; Sharpe, 



ed. Layard' s B. S. Afr. p. 773 (1884) ; Green, Ocean Bds. p. 12, pi. 



ii, fig. 4 (1887) ; Shelley, B. Afr. i, p. 169 (1896). 

 Thalassogeron culminatus, Salvin, Cat. B. M. xxv, p. 451 (1896) ; 



Parkin, Ibis, 1900, p. 675. 



