. Key to North American birds [microform] : containing a concise account of every species of living and fossil bird at present known from the continent north of the Mexican and United States boundary. Birds; Ornithology; Oiseaux; Ornithologie. Srntrlliite tarsus, of u rat-binl. !i Fio. 11. h. Sriitrllfiti- tnrsu's, of a l)i(;p<in; «. reticulate tardus, of it plover. § 81. AViiEN an unfeathered tarsus shows on its front surface no divisions of the podotheca, or only two or three divisions close by the toes, it is said to be ioo^erZ, and the podotheca is said to be yi/.s-erZ. (Fig. 9
. Key to North American birds [microform] : containing a concise account of every species of living and fossil bird at present known from the continent north of the Mexican and United States boundary. Birds; Ornithology; Oiseaux; Ornithologie. Srntrlliite tarsus, of u rat-binl. !i Fio. 11. h. Sriitrllfiti- tnrsu's, of a l)i(;p<in; «. reticulate tardus, of it plover. § 81. AViiEN an unfeathered tarsus shows on its front surface no divisions of the podotheca, or only two or three divisions close by the toes, it is said to be ioo^erZ, and the podotheca is said to be yi/.s-erZ. (Fig. 9.) This con- dition chiefly occurs in higher Osrines, ind is supposed by many, particu- larly German ornithologists, to indicate the highest typo of structure; but it is also found in some wtiter birds, as Wilson's stormy petrel. It is not a very common modilication. Among North American birds it only occurs in the following cases: — Genera Tardus (1), Cinclus (5), iSaxicoIa (6), Sialia (7), liegulus (9), Chainoca? (11), Myiadestes (52) and Oceaniles (307) ; and even these birds, when young, show scutella, which disappear with age, by progressive fusion of the acrotarsial podotheca. § 82. The Cuus, when bare below, may i)resent scutellation either before or behind, or both, as is seen in many waders where the cms is largely naked; often again, the crural podotheca may consist of loose, softish, movable skin, not obviously subdivided: sometimes it is truly reticulate, as in the genus Heferoscehis (221). § 83. The TAiisrs, in general, may be called subcylindrical ; it is often quite circular in transverse section ; very rarely thicker across than fore-and- aft (as in penguins) ; but very often thicker in. the reverse direction. When this transverse thinness becomes noticeable, the tarsus is said to be. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations
Size: 1352px × 1848px
Photo credit: © Library Book Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1870, booksubjectbirds, bookyear1872
