632 LAEtfS ARGENTATU^, HEEEING GULL. 



tenoid or dilatores ffloUidis, and the consirictores glottidis, having the ordinary form and 

 disposition. 



The larynx thus composed is a flattened, tapering organ, situate between the apd- 

 hyals, near the base of the hyoid, supported by the uro-hyal, which runs along its infe- 

 rior surface. It measures seven-teuths of an inch in length ty about half au inch in 

 breadth at its widest part posteriorly. It is connected with surrounding parts by con- 

 densed cellular tissue ; by the prolongation into it of the mucous membrane of the 

 mouth, and by various muscles. 



The trachea measures nine inches in length. It is not of uniform width thronghout, 

 hut superiorly it is broad and flattened, having much the'sLape of a trai sverse section 

 of the larynx; while as it proceeds downward it becomes smaller and almost perfectly 

 cylindrical. The rings are there also much denser and more resisting, so that the tube 

 is much less compressible below than above. The tracheal rings ai'e about one hun- 

 dred and forty in number. As usual, they are alteruately broader from right to left; 

 the increased width on the right of one riug being compensated for by the narrowness 

 of the next, at the same point of its circnmference. 



The aterno-tracheal muscles arise from the sternum, just above the sterno-coracoid ar- 

 ticulation ; reach the tr.achea an inch or so above the inferior larynx, and run as narrow, 

 flattened bands, one on each side of the windpipe, quite to the thyroid cartilage; being 

 then continued on to the hyoid bone, lorming the thyro-byoids. These muscular band# 

 arc well developed. . Snjall fibrous oti'scts proceed from the supra-clavicular fascia to 

 the trachea at its termination, and, with others from the intra-clavicular air-cell, pro- 

 ceeding to the posterior part of the lower larynx, aid to hold the parts in situ. 



The lower larynx does not differ in any essential points from that of Stercm-arius, 

 already described in sufficient detail. The bronchial half rings are twenty-four in 

 number. They are all of equal width at all points of their circumference, and thin and 

 delicate, except the first one, which is larger aud stouter, and bears to the lower larynx 

 ranch the relation that the cricoid does to the upper. 



My earlier experiences with this Gull were along the coast of Labra- 

 dor, in 1860 ; it is there the most abundant representative of its family, 

 spending the summer and breeding plentifully on the mossy islands, and 

 retiring southward in September. On approaching one of the breeding- 

 grounds where, from a distance, numerous birds could be observed 

 sitting on their nests, or walking leisurely about, we soon .gave au 

 alarm, when all would rise on wing, with loud screams, and circle high 

 over head. The nests were found scattered irregularly over the ground, 

 with little choice as to situation, except that the birds seemed to rather 

 prefer moss-covered rocky places, and dry, bare spots ; the grassy patches 

 being generally appropriated by Eider Ducks. The numbers of Ducks 

 and Gulls on any island were u.sual]y complementary, there being more 

 of the latter than of the former on the bare islands, and conversely. 

 The Gulls' nests were large and bulky, com[)osed of dry grass, moss, and 

 lichens, gathered into a heap, with a slight cavity, as if merely result- 

 ing from the weight of the birds. The eggs, in all the instances that 

 came under my observation, were three in number; in other respects 

 they showed the great variation customary in this family. They aver- 

 aged about 2.80 in length by about 1.90 in width. Some were light 

 bluish or greenish, others deep brownish-olive ; while the dark markings 

 were of every size and shape, very irregularly distributed. Early in 

 July eggs were found in every stage of development, though injiiost 

 instances the embryos were advanced. At the same time many newly- 

 hatched birds were caught skulking beneath stones or scrambling over 

 the luxuriant moss. These downy nestlings are curious objects, like 

 soiled carded wool, variegated with anguhir, dusky markings. On 

 being caught they would squeal loudly, and fight with spirit. Placed 

 on water they swam easily, and seemed quite at home. They fed freely 

 from the first on tish and pork scraps. 



Terrestrial nidiflcation is the rule with this species, as.it is throughout 

 the family ; yet there are authentic accounts — as that given by xVndu- 

 boji — of their nesting in colonies in trees. During the summer, in Lab- 

 rador, the principal food appears to be the lance tish {MaUotus vUlosusj, 



