lxxviii 
INTRODUCTION. 
Family PHAETHONIDiE. Tropic-birds. 
Genus PHAETHON, Linn. Tropical seas. 
Gen. char. — Bill as long as the head, broad, and dilated at the base ; with the culmen elevated, curved, and 
the sides much compressed to the tip, which is entire and acute ; the lateral margins more or less serrated ; the 
nostrils basal and lateral, with the opening linear, partly closed by a membrane, and exposed. Wings long and 
pointed, with the first quill the longest. Tail moderate and graduated, with the two middle feathers lengthened 
and linear. Tarsi shorter than the middle toe, strong, and covered with small scales. Toes long ; the outer toe 
longer than the inner; the three anterior ones and the hind toe all united together by a broad membrane; the 
claws small, compressed, and acute. 
Order TUB IN ARES. 
Family PROCELL ARIIDiE*, Petrels. 
Genus DIOMEDEA, Linnaeus. Colder parts of both Hemispheres, but more especially in the 
Southern Ocean. 
Gen. char. Bill longer than the head, very robust, straight ; the sides compressed and longitudinally grooved, 
with the tip greatly curved and acute ; the lateral margins dilated and curved ; the culmen broad, convex, and 
rounded ; the lower mandible weak, compressed, with the tip truncated ; the nostrils placed near the base, in the 
lateral groove, covered by a tube which is short, widening and spreading anteriorly from the side of the bill, with 
the aperture somewhat rounded and open in front. Wings very long, very narrow, with the second quill the 
longest. Tail short and rounded. Legs short, strong, with the tarsi one fourth shorter than the middle toe, and 
the inner toe the shortest. The two lateral toes margined exteriorly by a narrow membrane ; the web between the 
toes full and entire ; the hind toe and claw entirely wanting ; the claws short and obtuse. 
Genus PELECANOIDES, Lacep. Southern Hemisphere. 
Gen. char. — Bill shorter than the head, broad at the base, and much depressed ; the sides swollen, grooved, 
and gradually compressed towards the tip, which is lengthened, compressed, arched, and acute ; the lower mandible 
broad at the base and suddenly compressed at the tip, which is, with the gonys, arched and acute ; the sides longi- 
tudinally grooved and deep ; beneath is placed a membranous pouch, capable of extension ; the nostrils basal, one 
fourth the length of the bill, flattened above, and forming two lengthened, sublinear, exposed apertures, placed side 
by side on the surface. Wings very short, with the first two quills nearly equal and longest. Tail short and 
rounded. Tarsi rather shorter than the middle toe, laterally compressed, and covered with small scales. Toes long ; 
the outer nearly as long as the middle toe ; the hind toe and claw wanting. 
Genus PRION, Lacepede. Southern Hemisphere: generally observed between 30° and 70° 
south latitude. 
Gen. char. — Bill the length of the head, broad or very broad at the base, depressed above; culmen nearly straight, 
laterally swollen, but gradually compressed towards the tip, which is arched, elevated, compressed and acute; the 
lateral margins dilated near the base, with a series of very fine laminae running along the whole length internally 
rather above the margin ; the lower mandible broad at the base, gradually compressed towards the tip, which is 
* Upon a closer study of the subject, I have decided on recognizing a larger number of groups in this Family than were 
admitted iuto my first edition, or into my ‘ Manual,’ published in 1882. This will add to the total number of genera indicated 
at p. xxxvii ; but as none of these are endemic it will not affect my general argument. 
The late Mr. Forbes, in his excellent account of the Petrels, in the ‘ Yoyage of the Challenger ’ (Zool. vol. iv. pp. 1-64) 
recognized a separate family under the name Oceanitidm, embracing the four closely allied genera Garroclia, Oceanites, Pelago- 
droma, and Fregetta, which form together a very compact section. I prefer, however, to retain the whole of these natural groups 
under the general denomination of Procellariidse, leaving the proposed divisions to take rank as subfamilies. 
