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Show 1897.] ANATOMY OF PHAETHON. 289 could find no aftershaft; there are 12 rectrices ; the pollex is clawed. The bird is aquincubital. The anatomy of the soft parts of this bird has been briefly touched upon by Brandt in the memoir already cited, where the tongue, palate, and larynx are figured. The presence of two carotid arteries, the muscular formula of the leg, and one or two other muscles have been referred to by Garrod'. I am not aware, however, to what species these notes refer, and, as will be seen presently, specific differences are apparently marked in the internal organs. The specimen of the bird wdiich I dissected had bad the intestines removed. I find, however, from a M S . note of Garrod that the intestines of an individual dissected by him were 3 | feet long, the large intestine only f inch, and the casca " buttons." Tbe left lobe of the liver is the smaller, and there is a gall-bladder. The Pectoralis primus was not very markedly two-layered. Mr. Forbes found a specimen dissected by himself (? species) to have a single-layered pectoralis. It has the second insertion on to the flat common Biceps tendon found in so many Steganopodes. I found no Pectoralis ahdomlnalls. Fig. 1. Origin of Biceps in Pelecanus (left-hand figure) and Phalacrocorax (right'hand figure). (After Fiirbringer.) Cor., Coracoid ; C, coracoidal head of Biceps; A, attachment of humeral head to Humerus; B, its prolongation to Coracoid. The Biceps (fig. 1) is fashioned like that of Phalacrocorax, not like that of Pelecanus and still less like the Biceps of Sula and Fregata; the humeral head in fact is a narrowish tendon attached to but still distinct from (by reason of its greater thickness) the wide thin tendon which is the coracoidal head of the muscle; the former has also, as shown in the drawing (fig. 1, A ) , a short special tendinous attachment to the head of the humerus. The muscular slip to the patagium (Biceps slip) arises from the humeral head of the Biceps. The Pataglalls muscle in part performs the function of a deltoid; 1 " O n certain Muscles in the Thigh of Birds &c," P. Z. S. 1873. p. 628 &c. " Notes on the Anatomy of Plotus anhinga;' P. Z. S. 1876, p. 335 &c. PROC ZOOL. Soc-1897, No. XIX. 19 |