on some rare British Birds. 267 
light and darker brown NM rne more Bnet and et 
at the smaller end. aAA 
Is PARASITICUS. 
Found on Eia Isle of Glass, or Scalpa, most plentifully. 
Several varieties were examined, and confirmed the remark, 
that there is no external mark of distinction between the sexes. 
Nest upon the slope of a marshy hill, composed of dried grass. 
Eggs very light brown, marked imegnlariy with deep-seated dark 
brown blotches. : 
: LARUS TRIDACTYLUS. 
On the Isle of Glass, Troup Head, Fowls heaugh, near Mon- 
trose, Isle of Bass, in the Forth. 
Nest composed. of dried conferva. Eggs white, with black 
and brown spots. The young are brought to Edinburgh market, 
with the gannet, and sold as articles of food. 
Larus MARINUS. 
Observed on the Isle of Glass, 
Te lau ARGENTATUS. - bos 
-Plentiful at Tester! idum ey, in the Firth of Clyde; n no other 
gulls, not even the mottled a" of their own species, on the 
island. | 
2 LARUS FUSCUS. | 
About a mile South of Troup Head, also on South Ronaldsha, 
Pentland Skerrie, and Copinsha. On many remote rocks were 
mottled varieties of gulls, but none any where near us — 
places. 
| 2x2 E oko 
