DIOMEDEA. 
The only man who had ever dared to consider that the Albatroses 
included more than one genus was Reichenbach, who, in his Nat, Syst. Yog., 
indicated : — 
Dio7nedea Linne 
Phoehastria Reichb. 
Thalassarche id. 
Phoebetria id. 
. . Type D. exulans. 
„ D. brachyura. 
. . „ D. melano'pTiris. 
„ D. fuliginosa. 
Coues included the first three in Dimnedea and admitted Phoebetria as 
distinct. The first two were members of his group of Albatroses, while he 
considered D. melanopTiris a typical Mollymawk. 
When Forbes worked on the Anatomy of the Petrels, he noted the Molly- 
mawks as a distinct genus, and used Reichenbach’s generic name, admitting 
“ three good genera,” Phoebetria, Diomedea, and Thalassarche (which he spelt 
Thalassiarche). 
Baird, Brewer, and Ridgway, in the Water-Birds of North America, 
introduced Thalassogeron for the allies of D. culminata Gould, noting that 
D. melanophris was a typical Diomedea, whereas D. culminata had the 
culminicorn posterior to the nostrils, separated from the latericorn by a bare 
piece of skin. The three genera Diomedea, Thalassogeron, and Phoebetria were 
accepted, and this disposition was followed by Salvin in the Cat. Birds Brit. 
Mus., Vol. XXV. 
Rothschild, who has made a special study of these birds, questioned 
the advisability of recognising Thalassogeron, as almost all stages between 
Diomedea and Thalassogeron as regards bill-characters could be found. Con- 
sequently in the Monograph the following note is given as an apology for the 
retention of the genus Thalassogeron : “ The above characters (for separating 
the genera of Albatroses) are taken from Salvin’s ‘ Catalogue,’ but I have 
examined several species of Thalassogeron and Dio^nedea, which were almost 
inseparable generically. - Mr. Pycraft, however, has found some osteological 
characters which he considers to be sufficient for their separation. He sends 
me the following note on the subject : ‘ Thalassogeron may be readily distin- 
guished from Diomedea, in so far as cranial characters are concerned, in the 
much greater width of the interorbital region of the frontals, and in the greater 
width of the palatine ends of the pterygoids. These characters sharply define 
Thalassogeron from Diomedea, but Diomedea melanophrys presents in all other 
respects an extremely close resemblance to Thalassogeron, so much so as to 
make it probable that this species has been wrongly placed in the genus 
Diomedea. Like Thalassogeron, it presents a peculiarly inflated lachrymse, 
and this seems to be met with in no other member of the genus Diomedea. If 
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