DUBLIN TJNIVEKSITY ZOOLOGICAL AND BOTANICAL ASSOCIATION. 53 



Great Northern Diver ( Colymbus glacialis). — This fine bird is a regular 

 winter visitant to the bay and river, but as it is of a quieter disposition 

 than the other Divers, it is not so often seen away from its usual fishing 

 haunts, and on that account it appears less common than it really is. 

 They occasionally remain until late in May before taking their departure 

 for their summer haunts, and sometimes assume their summer garb 

 before leaving. On the 24th of May, 1851, in the open bay near Kil- 

 cummin Head, I saw a flock of ten birds, nine of which appeared in full 

 summer plumage ; they looked very beautiful, and although I pursued 

 them in a boat for some time, I was unable to shoot any, or even to get 

 within shooting distance, owing to their immense swimming powers 

 when under water. 



Eed- throated Diver (Colymbus septentrionalis). — This handsome Diver 

 is also a regular visiter to the bay and river; it is of a much more rest- 

 less nature than the Great Northern, and as it is oftener seen on the 

 wing, it comes more frequently under the notice of the observer than 

 the above-mentioned bird. They are also more easily driven to take 

 flight when pursued by a boat than the Great Northern. The Red- 

 throated Diver generally leaves for its summer haunts about the latter 

 end of April, though a few sometimes remain until the beginning of 

 May ; some always assume their summer dress before departing for the 

 north. I shot one in the adult plumage in May, 1851. 



Black- throated Diver (Colymbus Arcticus). — One in the adult summer 

 plumage was seen near Bartra by my brother, Mr. E. H. Warren, in 

 April, 1851 ; he observed it for a long time with a glass, from a distance 

 of 100 yards. 



Common Guillemot ( JJria troile). — Is seldom seen on the river, as its 

 breeding haunts are several miles west of the Bay. Some have been 

 occasionally washed ashore dead, after a gale of wind on the bay side of 

 Bartra. 



Black Guillemot (JJria grylle) Is seldom seen on the river; I have 



seen them in the Killala channel in summer. 



Razorbill (Aha torda). — The foregoing remarks may be also applied 

 to this bird. 



Puffin (Mormon fratercula) I shot a young bird as it was resting 



on the shore, near Beserk Abbey, at the Mayo side of the river. 



Great Cormorant ( Carlo cormoranus). — Of the two species of cormo- 

 rant, this is the most numerous. They fish very far up the river, and 

 even extend their fishing excursions to Lough Conn, where I have seen 

 them in summer. The seasonal moult commences in this species very 

 early : I have seen them exhibiting the white thigh marks the first week 

 in January. 



Green Cormorant (Phalacrocorax graculus). — Is very numerous. 

 They appear to me to be strictly marine in their habits, for I have never 

 seen an individual in fresh water, or fishing any distance up the river ; 

 and, although the tidal part of the river extends about four miles from 

 the bay, they do not fish more than half that distance. A few pairs 

 build on Kilcummin Head, the western boundary of the bay. 



