832 U. S. p. R. R. EXP. AND SURVEYS — ZOOLOGY GENERAL REPORT. 



This is the smallest of the genus, has the white rump hand conspicuous, the tail slightly 

 rounded, and the interdigital wehs black. 



FREGETTA, Bonaparte. 



Fregetta, Bon. Cons. Av. II, 1855, 197. Tjpe Procellaria tropica, Gould. 

 Ch. — Bill small ; nasal tube short and recurved ; wings very much lengthened ; tail subtruncated ; tarsi very long ; toes 

 muscular for tlieir entire length ; claws small and depressed. Colors, sooty, more or less varied with white. 



The depressed form of the claws will at once distinguish this genus from Thallassidroma. 

 But one species of this genus is found on our coast. 



FREGETTA LAWRENCII, Bonaparte. 



The Black and White Stormy Petrel. 



Thalassidroma fregelta, Lawr. Ann. Lye. Nat. Hist. N. Y. V, 1851, 117. 

 Fregetta lawrencii, Bon. Cons. Av. II, 1855, 198. 

 Sp. Ch. — Head and wings black ; neck, breast and back, dark plumbeous, or dull bluish ash ; wing coverts brown ; the tail 

 white at the base, with the terminal half and the two central feathers black ; abdomen, inside covering of wings, and rump, 

 white ; bill and legs black. Tail even ; claws flattened and of an ovate form. 

 Length, about 8 inches ; wing, 6 ; tail, 3 ; tarsus, 1|. 

 Hab. — Florida coast. 



Prince Bonaparte has conferred my name on the above bird, which I had described as Thai, 

 fregetta. The specimen from which my description was taken was presented to the Academy of 

 Nat. Sciences, Philadelphia ; on a recent visit there I wished to compare it anew with Mr. Gould's 

 specimens of Thai, fregetta, but it could not be found at the time. I have, therefore, concluded 

 to let it stand as named by Prince Bonaparte. 



PUFFINUS, Brisson. 



PvJJinus, Bbiss. Ornithologie, 1760. Type Procellaria piijjinus , L. 

 Cii. — Bill about as long as the head, rather slender, compressed near the end and obliquely grooved on the sides, the tip 

 curved, strong and acute, the lower mandible grooved laterally on the sides ; nostrils basal, with two distinct openings; wings 

 very long and pointed, first quill the longest ; tail rather short and rounded ; tarsi as long as the middle toe and compressed ; 

 toes long and united by a full web ; a straight claw or spur in place of the hind toe. 



These birds are of medium size, and are endowed in a remarkable degree with great powers 

 of flight. They swim lightly and gracefully, and while seeking their food have the habit (like 

 the small petrel.s) of patting the surface of the water with their feet. 



The following diagnosis will serve to distinguish the five species of this genus, found in 

 North America : 



Upper plumage brownish ash, under parts grayish white ; bill yellowish green, tips 

 brownish black ; tail brownish black, graduated ; tarsi and feet yellow ; hind part of 



tarsi and outer toe brown P. major. 



Upper plumage sooty brown, under pale dingy brown ; bill black ; tail blackish brown, 

 graduated ; legs and feet black P. fuliginosus. 



