296 Proceedings of the Royal Physical Society. 



the south-west side owing to want of time. Barrington does 

 not appear to have observed them in 1886. 



Sterna macrura (Naum.) — Arctic Tern. — Not noted by 

 Swinburne. Observed by ourselves on the northern penin- 

 sula; and Barrington found nests and a colony of about 

 thirty pairs, one bird from which was " shot to make sure." 



Larus argentatits, Linn. — Herring Gull. — Swinburne saw 

 several pairs ; we found a few ; and Barrington found "several 

 breeding, but not so common as the next species." 



Larus fuscus, Linn. — Lesser Black-Backed Gull. — Swin- 

 burne " did not notice any Lesser black-backed gulls," though 

 he had " no doubt they were there," but neither did we meet 

 with the species on the island. Barrington marks them as 

 " plentiful, breeding at the south side," and also includes the 

 next species ; so there is no doubt that all three of our 

 common large gulls inhabit the island. 



Larus marinus, Linn. — Great Black-Backed Gull. — Swin- 

 burne mentions the large colony " breeding on the low point 

 at the west end of Ptona." We found them " apparently in 

 a colony, but did not reach the nesting locality ; " and Bar- 

 rington says, " Plentiful, breeding in larger numbers than I 

 have seen it anywhere on the British coasts." 



Eissa tridactyla (Linn.) — Kittiwake. — Large numbers on 

 north side of Sulisgeir, and also on the north-west side of 

 Eona (Swinburne), where we also observed a " very good 

 colony." Barrington enters it as " Abundant, breeding in 

 great numbers." 



F'ldmctrus glacialis (Linn.) — Fulmar Petrel. — Not recorded 

 by Swinburne ; not seen by us ; but Barrington has the note 

 — "A few seen between Butt"of Lewis and Bona, passing 

 singly, one specimen circling round the highest cliff in Eona." 



Puffinus angloruni (Temm.) — Manx Shearwater. — Swin- 

 burne saw the species within a few miles of the island, but 

 searched for the nest there in vain. We did not meet with 

 a single specimen during all the time we essayed to reach 

 North Eona. Barrington observed it off the Butt of Lewis, 

 but not near Eona. 



Procellaria leucorrhoa (Vieill.) — Leaches' Petrel. — Swin- 

 burne's notes we need not reproduce here, and our own we 



