OCR Text |
Show 1887.] ANATOMY OF CERTAIN AUKS. 45 the bodies of both of them. I will at once observe, however, that the form of the heart is quite different in these two birds, being not only smaller in S. antiquus than it is in the Marbled Auk or Murrelet, but apparently longer, and decidedly more pointed in the former than it is in the latter, wherein it is a thicker organ with a bluntly rounded apex (fig. 2). Fig. 1. Fig. 2. Fig. 1. Anterior aspect of the lower larynx, heart, and viscera of Synthliborham-phus antiquus. f fat overlying in front of the lower larynx; s.t, sterno-trachealis muscle of the left side; h, heart; I, right lobe of liver ; V, left lobe of liver ; g, gizzard. Fig. 2. Same parts and aspect of the corresponding organs in Brachyrhamphus marmoratus; lettering the same as in fig. 1, with t.l, the left tracheo-lateralis muscle. The figures are drawn life-size by the author, and are from the specimens of the Murrelets lent by the Smithsonian Institution. Extraordinary differences are to be observed in the livers of these two Murrelets, both as regards form and size. In each the left lobe is rather the larger, and descends somewhat further into the abdomen. But in S. antiquus the hepatic lobes are considerably |