632 LARUS ARGENTATUS, HERRING GULL, 



tenoid or dilatores glottidis, and .the constrictores glottidis, Laving the ordinary form and 

 disposition. 



Tlio larynx thus comi)osod is a liattened, tapering organ, sitnato between the apo- 

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

 rior surface. It measures seven-tenths of an iuch in length by about half an inch iu 

 breadth at its widest part iwsteriorly. 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 throughout, 

 but superiorly it is broad and liattened, having much the shape of a transverse section 

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

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

 is much less compressible below than above. The tracheal rings are about one hun- 

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

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

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



The sterno-trachcal muscles arise from the sternum, just above the steruo-coracoid ar- 

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

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

 then continued on to the hyoid bone, forming the thyro-hyoids. These muscular bamls 

 are well developed. Snuill fibrous offsets proceed from the supra-clavicnlar 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 hu\vnx, aid to hold the parts in situ. 



The lower larj^nx does not differ in .any essential points from that of Slercorarius, 

 already described iu 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 and stouter, and bears to the lower larynx 

 much 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 an 

 alarm, when all would rise ou 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 ])atches 

 being generally api)ropriated by Eider Ducks. The numbers of Ducks 

 and Gulls on any island were usually complementary, there being more 

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

 The Gulls' nests were large and bulky, composed 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; iu other respects 

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

 aged about 2.80 in length by about 1.00 iu 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 developauMit, though in most 

 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 angular, dusky markings. On 

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

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

 from the tirst on fish and pork scraps. 



Terrestrial uidification is the rule with this species, as it is throughout 

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

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

 rador, the principal food appears to be the lance-tish {Mallotus villosus)^ 



