3l6 CHARADRIIFORMES chap. 



when vast flocks arrive with great regularity, or even to an exact 

 day. In England this occurs at the end of March or beginning 

 of April, the latter part of August or the first week of Septem- 

 ber being as punctually observed for departure. Except for 

 purposes of procreation, or during violent storms, individuals are 

 rarely seen on land, as might be expected from the clumsy 

 style of gait ; yet Puffins and Black Guillemots are fairly 

 good walkers, and the former fly particularly straight and 

 swiftly. Auks either splash along the surface of the waves 

 before diving, or plunge suddenly, and when immersed use their 

 wings much as if flying. The usual voice is a harsh-toned croak 

 or grunt, but in addition Simoi-hynclius is said to chatter, Cydo- 

 rhynchus to whistle ; Ptychorliam'pluis utters a musical ringing- 

 sound, the Little Auk a wild cry, and Black Guillemots a shrill, 

 plaintive note. Fish, crustaceans, worms, and the like, with 

 chance ship-refuse, compose the diet ; the birds frequently dis- 

 gorging it when scared, and sometimes in order to feed the young. 

 The great pear-shaped egg of the Guillemots proper, and the 

 more oval one of the Eazorbill, is deposited on some bare ledge 

 of a cliff, on a stack, or on an island rock. In the case of the latter 

 bird the egg is usually in a crevice, being white or buff with 

 black or brown markings, and generally, if not invariably, green 

 inside. Guillemots' eggs vary from white or buff to brilliant 

 green or blue, and are spotted, streaked, or covered with intricate 

 wavy patterns of black, brown, or rufous ; the same bird prob- 

 ably always producing similar specimens. The Black Guillemots 

 lay two greenish -white eggs with blotches of brown, rust- 

 colour, and grey, under close-packed boulders or in holes low down 

 in cliffs ; that of the Little Auk is pale bluish-green, with or 

 without faint rufous stains, and is found in similar, but commonly 

 much higher, situations ; Synthlihorhamjjlms and various other - 

 forms use burrows in the turf, like Petrels, as an alternative to 

 chinks in rocks; but the first-named produces two buff eggs, spotted 

 with brown and grey, while the remainder lay only one, which 

 is either white, or very indistinctly marked. Of these. Puffins 

 fasliion a considerable nest of dry materials. In some instances 

 at least, both sexes incubate, the period being nearly five weeks. 

 Wlien hatched in holes the young remain there for a considerable 

 time, otherwise they are soon assisted by their parents to reach 

 the sea. Where unmolested. Auks are sufficiently tame ; Puffins, 



