of the District of Montreal. 407 



only other species of this orenus met with on this continent does 

 not visit us. It is a peculiarly northern sea bird, never met with 

 beyond the sea coasts. 



Fam. II. Longipennes. 

 Genus Sterna. 



Gen. char. Bill as long or as longer than the head, compres- 

 sed, slender, more or lest acuminate with sharp edges ; upper 

 mandible, curved at the tip, never hooked, and equal in lencrth to 

 the lower ; nostrils in the middle of the bill, longitudinally cleft 

 and pervious ; legs and feet slender and small, with a naked space 

 above tlie knee ; tarsus shorter than the middle toe ; the 3 front 

 toes webbed ; hind toe very short barely touching the ground ; 

 wings long, acuminate; 1st primary longest; tail of 12 feathers 

 long and forked. 



^S'. Hiinindo ? The Great or Common Tern. 



v.s.p. Bill fine orange, faintly delineated with black, near the 

 tip, which is pale lake ; irides deep hazel ; legs and feet black. 



Dorsal aspect. Crown, occiput, including the eye, black, des- 

 cending for a short distance down the nuchal region, the remain- 

 der of which, with the rump and tail, is white ; mantle pearl co- 

 lour ; the three first primaries greyish black, the others hoary 

 pearl colour, all of them with a faint streak of white, running 

 longitudinally along the inner vanes ; shafts white ; lower eyelid 

 white. 



Ventral aspect white. 



1st primary longest, the others graduated ; the tail moderate 

 furcate; length from the lateral tail feather to the tip of the bill 

 20 inches; alar expanse 4G inches; the specimen a female, 

 length of bill from the rictus 3j inches; length of the tarsus If 

 inch. This bird diflers in several particulars from the S. Rirundo 

 of Nuttall, so much so that I feel almost inclined to rank it a se- 

 parate species, were it not for the risk of multiplying species. 

 The points in which they difl'er are the following : 



S. Hirundo. S. Hirundo ? 



Crown and occiput wholly black, Crown and occiput wholly black 



including the eyes. including the e3"e, lower eye- 



lid white. 

 Mouth bluish white or pale lead Mouth pearl colour. 



colour. 

 Tail greatly forked. Tail moderately forked.. 



