RAZORBILL. 3' 5 



markings are usually very bold and large, most numerous 

 about the larger end of the egg, where they frequently 

 form an irregular zone. One variety has the markings 

 of a streaky character ; another and rarer variety is 

 almost spotless. No shade of green or blue is ever dis- 

 played externally on the eggs of this species. Average 

 measurement, 2*9 inches in length, by 1*9 inch in breadth. 

 Incubation, performed by both sexes, lasts from thirty 

 to thirty-three days. 



DIAGNOSTIC CHARACTERS : The eggs of the Razorbill 

 are never so acutely pear-shaped as those of the Guillemot, 

 being blunter and broader for their length. They can 

 only possibly be confused with those of the Guillemot, 

 but from which they may be readily distinguished by 

 the clear pea-green tinge of the interior of the shell when 

 held up to the light ; those of the Guillemot always being 

 yellowish-white, except in such varieties where the green 

 or blue exterior overpowers it. As previously remarked, 

 however, the eggs of the Razorbill externally never 

 exhibit green or blue tints. 



Family ALCID^E. Genus FRATERCULA. 



PUFFIN. 



FRATERCULA ARCTICA (Linnaus). 

 Single Brooded. Laying season, May and early June. 



BRITISH BREEDING AREA: Except on the south of 

 England, where it is only sparingly dispersed, and the 

 east of England, where it is not known to breed south of 

 Flamborough, the Puffin is widely and generally dis- 

 tributed round the British Islands, in some places, as 



