401 



scapularibus conspicue albo terminatis : primario externo nigro versus apicem albo, fascia subapicali 

 nigra, seeundo et tertio nigris ad basin canis et albo terminatis, reliquis canis, versus apicem nigris et 

 albo apicatis, secundariis pallide canis albo terminatis : rostro pallide flavo, mandibula macula subapicali 

 sanguinea : iride flavicanti-grisea : pedibus pallide carneis. 



2 inari similis, sed minor. 



Ptil. Mem. similis sestivali, sed capite et collo pallide fusco striatis. 



Adult Male (Orkneys, summer) . Head, neck, rump, tail, and entire underparts pure -white ; entire mantle 

 or the back, scapulars, and wing-coverts delicate light French grey ; larger wing-coverts, secondaries, 

 and scapulars broadly tipped with pure white; outermost primary almost entirely blackish, white 

 towards the tip, and crossed by a subapieal black band ; the next two grey at the base, black towards 

 the tip, being finally terminated with a large white spot ; the remaining primaries grey, except towards 

 the tip, where they are black, finally tipped with white ; secondaries pale grey, tipped with white ; beak 

 pale yellow, with a large red spot at the angle of the lower mandible ; iris yellowish grey, margins of 

 the eyelids yellow; legs and feet flesh-colour. Total length 23 inches, culmen 2*65, wing 16 - 7, 

 tail 6 - 75, tarsus 2 - 5. 



Adult Female. Similar to the male, but somewhat smaller. 



Young. Similar in plumage to the young of Larus fuscus. 



Winter plumage. Similar to the summer plumage, except that the head and neck are striated with pale 

 brown. 



I have carefully compared examples of the present species in immature plumage and in down with specimens 

 of Larus fuscus and L. marinus, and cannot find any character by which they may be distinguished, 

 except as regards the young of L. marinus, which are larger. Mr. R. Collett, who has also tried to 

 ascertain some sure mode of distinguishing them, writes that " it is almost impossible to distinguish the 

 young of L. argentatus from those of L. fuscus and L. marinus at the same stage of growth, the spots on 

 the head and body being distributed in precisely the same manner in each." 



Obs. Of the Herring-Gull there are three distinct species or races : — Larus argentatus, the range of which 

 is given below ; Larus leucophceus, which is found in Eastern and South-eastern Europe and Northern 

 Africa; and Larus occidentalis, which inhabits Asia and China (extending westwards to the Mekran 

 coast, where it meets L. leucophceus) and the west coast of North America. I am not certain as to 

 whether this last species (L. occidentalis) should not bear the name of L. cachinnans, Pall., as this 

 author clearly refers to a Gull having flesh-coloured legs and a dark mantle in his description of that 

 species ; but he likewise speaks of it as inhabiting the Caspian and Asia, and has evidently confused 

 L. leucophceus and L. occidentalis, and I have therefore deemed it best to retain the name L. occidentalis 

 for the species having the very dark mantle and flesh-coloured legs. In the colour of the mantle L. 

 argentatus is the lightest, and L. occidentalis much the darkest, L. leucophceus being intermediate 

 between the two. As regards measurements all the three species vary very much, as will be seen by 

 the following table. 



I have measured altogether nearly fifty specimens, but have not deemed it necessary to record the measure- 

 ments of each specimen, and have therefore picked out a fair average series of L. argentatus, leaving 

 out those that have not been sexed. The last two specimens of this species on the list were carefully 

 compared with the types of Larus smithsonianus by Dr. Coues, and sent to me as agreeing precisely 

 with them. 



3u2 



