BLACK GUILLEMOT 491 
Nest.—Karly in April this bird seeks for its breeding- 
quarters, the quietude of rock-fissures in cliffs of very 
varying altitudes, though never at a great height above 
the sea-level. It keeps ‘apart from the throngs of Common 
Guillemots, Razorbills, and Kittiwakes, nevertheless, I have 
seen all four species breeding within the confines of one 
small island. [ have found the nesting-cavity in a deep 
hole at the base of a cliff only a few feet above the sea-level. 
This Guillemot also breeds under masses of loose stones, 
especially on low, flat islands, I have records of odd pairs 
nesting on the mainland of the Dublin coast, as well as on 
Lambay Island and Ireland’s Eye, though along the east 
side of Ireland it breeds but sparingly. 
Colonies, strictly speaking, are not formed; yet in very 
favoured localities—such as along the Galway coast—where 
the great solid rocks are freely fissured, several pairs may 
be found breeding in close proximity. The eggs are laid in 
May and are two in number. The eround- colour is white ; 
in some specimens very faintly shaded with bluish- oreen, 
and the blotches vary from light to dark brown 
Both sexes incubate, 
The young quit their nest about the middle of July and 
appear to be sufficiently matured to look after themselves 
almost as soon as they take to the water. According to 
some observers the parent-birds continue to feed them for 
some time afterwards. 
In an adult male were remains of Portunus arcuatus (a swimming 
crab), some of these creatures being almost entire: the largest measured 
14 mm. across the carapace (body-shell), the smallest 10 mm., also 
fragments of larger crustaceans too broken up to allow of identification : 
several pieces of Litho-thammia (a stony weed) were present. 
The stomach of an adult female contained the greater part of a 
Hermit-crab (Pagurus bernhardus), with no shell surrounding it and 
with one of the large claws missing, probably pulled off, as the bird tried 
to extract the crab from its shell. Portwnus was also found, the largest 
carapace measuring 17 mm. 
The stomach of another adult female contained Pagurida, several 
forms of Brachyura, and remains of other unidentified crustaceans. The 
gizzard of a young male contained Portunus arcuatus in large quantities, 
also the claw of a Pagurid, the claw of Procellana longicornis, and the 
remains of Galathea squamifera. All these birds were obtained from 
the same locality, viz., Ballynakill Bay, co. Galway, and on the same 
date, April 13th, 1900. I was surprised to find no fish present in the 
stomachs, and from the nature of the food it seems obvious that these 
Guillemots must have descended to a considerable depth to pick the 
creatures from the floor of the sea or from submerged rocks. 
