NATURAL SCIENCKS OF PHILADELPHIA. > ': 



1. HaLOOYPTBNA. MICROSOMA, COUPS, NOV. sp. 



Diag. : Halocyptcna rostro, pedibus, alis caudaque nigris; corpore tot< 

 intense fusco-atro, abdomine sensim fuliginoso, tectricibus alarum majoribue 

 dilutioribus; Long. tot. 5.75; alas 4. 75 poll. Ang. et cent. 



Description. Form typical of the genus, as above characterized. Entire 

 plumage deep lustrous brownish black, darkest on the head, neck, back, and 

 upper parts generally ; changing gradually on the abdomen to a fuliginous 

 brown, which is the prevailing tint of the under parts, from the breast back- 

 wards including the under tail coverts. The lesser and medium wing 

 coverts are as dark as the back; as are also the inferior alar tectrices. The 

 greater coverts are considerably lighter ; being with the external borders of 

 some of the tertials dull brownish, with a cast of gray. The remiges and 

 rectrices are pure black. There is no indication of white on the rump or 

 crissum. The bill, feet, and claws are black, as are also the interdigital 

 membranes. 



Dimensions. Total length from tip of bill to end of tail 5. 75 inches and 

 hundredths. Wing from the carpal joint 4.75. Bill from front along culmen 

 .48 hundredths; along rictus .62; height at base .19; width .21; length of 

 nasal tubes .22. Bare portion of tibia; .30; tarsus .90; middle toe and claw 

 .82 ; inner do. .08 ; outer do. .80. Tail to end of central rectrices 2.50 ; to end 

 of outer do. 2.15. ' Difference between central and next pair .15 hundredths-. 



Habitat. South Pacific coast of North America. 



Typical and unique specimen No. 11,420 of Smithsonian Museum Register. 

 Adult female, taken in May, 1861, by John Xantus, at San Jose del Cal 

 Lower California. 



This diminutive species hardly exceeds in size the little G. pelagiea, and is 

 at the same time much slenderer and more delicate in form than that species. 

 The combination of the small size; peculiar form and unifi rm < dors widely 

 separate it from any ether known Petri 1. 



I IV. PROCELLARIA, Linn, emend. 



The genus of which the little pelagiea L. is the type constitutes the fifth 

 and the last one of this short-legged group of Procellariese. It is readily 

 recognizable among all its allies by the combination of its short legs, acui" 

 claws, and square or slightly rounded tail. As to size, it comprehends the 

 very smallest of known natatores ; with hardly the exception of my diminu- 

 tive little Halocyptcna mkrosoma. The bill is small, short compressed, th< 

 sides rapidly converging to the narrow tip ; less than half as long as tb.v 

 skull, a little more than half the tarsus. The wings in length an typical of 

 the section ; reaching beyond the tail. The second primary is longest ; the 

 third a little shorter; the first less than the fourth. The bare proportion of 

 the tibia? is short ; the tarsus is just equal to the middl i toe and claw. The 

 proportions of the toes to each other are as in other genera, already described. 

 The tail is moderately long, full, the feathers broad; > little rounded in 

 shape. In color this genus is usually dark with a white rump and crissum ; 

 though this color does not obtain throughout the genus, if such species as 

 nereis, Gould, and fasciolat a, Tschudi, really belong here. 



The genus I'rocellarid first appears in 1746, in the sixth edition of the Sys- 

 temne Naturae, having as its type the P . pelagiea, Linnaius. Throughout suc- 

 cessive editi -. the same species is invariably made tj ' \ \ : as it also is in 

 the Edition of Gmelin (1788), and in Latham's Index Ornithologicus (1790). 

 I am, therefore, quite at a loss to discover the grounds upon which modern 

 ornithologists have been justifiable in assigning the name Procellaria to such 

 a genus e. g. as that of which glacialis, or antarcticus, or ( oki, are respectively 

 typical. If with Dr. Schlegel we admit but a single genus of Procellarinse, 

 that' will of course be Procellaria; and we shall employ it in its original Lin- 

 nean acceptation. If, however, with almost all ornithologists, we make . 



1884.] 



