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Show 1881.] MR. W. A. FORBES ON THE GENUS CONOPOPHAGA. 437 in Galyptomena, and in Hadrostomus, Tityra (just), and Lipaugus, but in none other of the Pipro-Cotingidse. The only Tyrannine bird in which I have observed it is Arundinicola leucocephala. From the character of its skull nothing very definite can be predicated of Conopophaga, except that it clearly has no relation to Furnariine forms. In its visceral anatomy, myology, pterylosis, and other characters I have detected no deviation from the ordinary Passerine structure. The typical arrangement of the tensor patagii brevis tendon is somewhat concealed, as in Pteroptochus and Hy-lactes (cf. Garrod, P.Z.S. 1876, p. 510), by the muscular fibres at the origin of the extensor metacarpi muscle. There is no trace of a vinculum in the deep flexor tendons of the foot. The arterv of the leg is the sciatic. In the tarsi the anterior scutes, about six in number, extend round to the posterior margin exteriorly, leaving the internal plantar space covered by a smooth skin, with no signs of scutes or scutellse. In its possession of an "exaspidean"1 tarsus, Conopophaga differs from all other forms of Tracheophonaa, and resembles Oxyrhynchus, the Tyrannidse, and Pipridae alone of Passerine birds. The Tracheophone syrinx of Conopophaga aurita has been briefly described and figured by Muller2; and from that species C. lineata does not essentially differ. I find, however, that in this latter species the commencement of the tracheal syrinx is less abrupt than is depicted by Muller, the few preceding tracheal rings, particularly posteriorly, becoming gradually less and less deep as they approach the membranous part. The last tracheal ring is deeper and stronger than its predecessors, and is incomplete in the middle line behind. The first bronchial semiring is considerably stronger than the second one, and bears the processus vocalis, which extends upwards for about two rings. The last tracheal and first two bronchial semirings are less closely connected together than in Midler's figure. The tracheal syrinx forms a somewhat dilated tympanum. As regards the muscles, m y observations agree with Midler's as to there being no intrinsic muscles, as the lateral tracheal muscle stops at the commencement of the membranous part of the trachea, from which place also the stemo-tracheales diverge. This syrinx of Conopophaga does not exactly agree with that of any other Tracheophone group. In that it possesses processus vocales it resembles that of the Furnariidse and Dendrocolaptidse described by Muller (Pteroptochus, Hylactes, Formicarius, and Grallaria), and differs from Thamnophilus and Hypocnemis. In the absence of any intrinsic muscle it resembles Grallaria and Hylactes, as described by Garrod, as well as Chama?za, Pteroptochus, and Formicarius. In Furnarius, Dendrocolaptes, &c. this muscle is always present, and double. But in both Grallaria, Hylactes, and the others the stemo-tracheales muscles arise from the end of the vocal process. In Conopophaga, on the other hand, they leave the trachea before reaching that process. 1 As defined by Sundevall, I. c. p. 57. 2 L. c. p. 39, pi. vi. fig. 12. Garrod's ed. p. 32. |