COMPARATIVE OOLOGY OF NORTH AMERICAN BIRDS. 



467 



The following table compiled from Coues's Key (rev. ed.) and Ridg- 

 way's Manual will fairly present the oologieal characters of this group. 



Oology of North American TuMnares. 



Species, etc. 



Generai characters, the Alba- 

 trosses. 



Coues. 



D. albatnis 



Phoebetria fuliginosa - 



PROCELLAKIIDiE 



Fulmarus glacialis. . . 



Puffin us p ii flit) us. (Manx Shear- 

 water.) 



Oceanodroma leucorhoa, Leach's 

 Petrel. 



Single egg, on the ground, near- 

 ly equal ended; white: both 

 sixes incubate. 



Egg single, white, with rough 

 brittle shell, resembling" a 

 hen's egg in size and shape 

 (p. 778). 



Egg single, dead white, smooth. 

 2.35 X 1.60 (p. 786). 



Egg single, white: nest in bur- 

 rows in the ground (p. 781). 



Ridgway. 



Egg single, ovate or elliptical 

 ovate, white, sometimes speckled 

 or sprinkled on large end with 

 reddish brown (p. 50). 



Egg white, minutely sprinkled 

 with brown on larger end (p. 53). 



Egg single, white (unless adventi- 

 tiously stained) (p. 53). 



Passing next to the Auks (Alcje) we find Dr. Sharpe briefly referring 

 to them as follows : " Egg single, white when in a burrow, otherwise 

 of varied and beautiful color and markings when laid on a rock" 

 (loc. cit., p. 71), and Coues states it differently, inasmuch as he says u eggs 

 few or single, plain or variegated " (Key, p. 797.) Ridgway agrees with 

 Sharpe, declaring the u egg single," though "variable as to form and 

 color " (Manual, p. 8). ( 'ones, in describing the egg of Alle, again finds 

 an exception to Sharpe's diagnosis, for he says the "single egg v laid 

 by that bird is pale greenish-blue (Key, p. 811), but confirms his state- 

 ment given above that Auks lay more than a single egg, in his descrip- 

 tion of Uria grylle, and he remarks of that species, the Common Black 

 Guillemot, that the " eggs, 2 to 3, sea-green, greenish-white or white, 

 spotted and blotched most irregularly with blackish-brown, and with 

 purplish shell markings" (Key, p. 815). According to this authority 

 then an Auk may lay as many as 3 eggs, and another species may lay 

 a blue unmarked egg. The Great Auk, probably now extinct, and one 

 of the most ancient types of the suborder Alcje, laid, as we know, a 

 single egg, which was a milk Avhite, spotted and blotched with dark 

 brown. In form the eggs of Auks assume some modification of the 

 ovate, but are never ellipsoidal or spheroidal. We take it then, judg- 

 ing from such premises, that these birds stand much higher above the 

 reptiles than do any of the Ostrich types. It would seem that this sub- 

 ject will bear its share of thorough revision, for as I write these lines I 

 ascertain through the kindness of Capt. Bendire, who has kindly given 

 me access to the superb collection of birds' eggs of the V. 8. National 

 Musem, that Alle alle normally lays '2 eggs, and that they are of a very 

 pale greenish-blue, almost white. They are very uniform, both in form 

 and color, and the collection contains eight or ten sets of them. This 



