432 PUFFINIDZA. 
O. homochroa, Coues, which may also occur within our limits, is a small Petrel and 
is more sooty and less chocolate-brown underneath than the foregoing species, and it 
has a decided ashy shade on the head and fore part of the body, and the upper tail- 
coverts have a cinereous tinge. The lower under wing-coverts are also not so white. 
Long. tota circa 6°8, ale 5°65, caude 3:2, culm. 0°6, tarsi 0°85. (Descr. femine adulte 
ex Farallon Is. Mus. Rothschild.) | 
Fam. PUFFINIDA, 
For this family Salvin enumerates the characters as follows:—* Nostrils united 
externally, or nearly so, above the culmen; margin of the sternum uneven; distinct 
pterygoid processes; manubrium of furcula very short; coracoids short, wide at the 
base and divergent; first primary the longest, or not shorter than the second.” 
The Puffinide, which are entirely oceanic in their distribution, are divided into two 
subfamilies, the Shearwaters (Puffinine) and the Fulmars (Fulmarine). None of the 
latter have, as yet, been found in Central America. 
Subfam. PUFPFININ. 
The members of this subfamily are distinguished by the absence of lamelle on the 
sides of the palate, whereas all the Fulmarine have more or less well-developed lamelle. 
Hight genera of Puffinine are recognized by Salvin in the ‘ Catalogue of Birds.’ 
PUFFINUS. 
Puffinus, Brisson, Orn. vi. p. 131 (1760) ; Salvin, Cat. Birds Brit. Mus. xxv. p. 368 (1896). 
The true Shearwaters of the genus Puffinus have the tarsus distinctly compressed, 
with the anterior edge sharp. ‘The nasal tube is low, both nostrils being visible from 
above, directed forwards and slightly upwards. ‘The tail-feathers are twelve in number. 
The distribution of the genus is world-wide, and about twenty species are recognized. 
In addition to the three here enumerated, two others, P. opisthomelas and 
P. creatopus, may visit the islands off the Mexican or Central-American coast, but there 
is no direct evidence of either of them having been seen within these limits. 
1. Puffinus cuneatus. 
Puffinus cuneatus, Salv. Ibis, 1888, p. 353'; Cat. Birds Brit. Mus. xxv. p. 371°; Seebohm, Ibis, 
1891, p.191°; Anthony, Auk, xv. pp. 39‘, 316°; xvii. pp. 247-252, t.8°; Nelson, N. Amer. 
Fauna, no. 14, p. 277; Oates, Cat. Eggs Brit. Mus. i. p. 152°. 
Puffinus knudseni, Stejneger, Pr. U. 8. Nat. Mus. xi. p. 93°. 
Brunneus, alis caudaque nigricantibus, hac longa cuneata; pileo vix saturatiore brunneo, loris et facie laterali 
paullo cinerascentioribus ; genis albis cinereo marmoratis ; corpore toto subtus albo, colli lateribus 
_ brunneis dorso concoloribus, corporis lateribus et axillaribus cinerascenti-brunneis ; subcaudalibus 
