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Show 1886.] POINTS IN THE ANATOMY OF THE CAPRIMULGIDAE. 153 Dr. Gadow, in Bronn's 'Thierreichs' (Bd. vi. Abth. iv. p. 177), has referred to the double condition of the tendon of the tibialis anticus in Podargus; this statement I am able to confirm from my own dissection of that bird; but in the other genera this muscle has a more normal arrangement, being undivided at its extremity. The only other birds in which I have found a similar disposition of the tibialis anticus are the Owls (Strix pratincola); but Dr. Gadow has mentioned Chrysotis as another instance. Steatornis differs from the other genera in having no femoro-caudal muscle ; in the remaining genera the formula on Garrod's system is A X Y 1 . Steatornis therefore agrees with Podargus and AUgotheles in the absence of a biceps slip to the patagium ; while those genera which agree with each other in the possession of a tracheo-bronchial syrinx, viz. Caprimulgus, Nyctidromus, and Chordeiles, have a biceps slip; Steatornis is peculiar in the absence of the femoro-caudal muscle, and in the presence of an expansor secundariorum ; while Mgo-theles appears to differ from its allies in having no caeca, and also in the structure of the patagial tendons. I am unfortunately unable to give any account of the visceral anatomy and myology of Batrachostomus, which I should imagine will be found to agree pretty closely with Podargus. All these facts lend additional confirmation to the generally accepted view that Steatornis is a peculiar type of Goatsucker and needs a special subfamily to itself. It evidently, however, comes nearest to Podargus, Batrachostomus, and A^gotheles ; and the fact that all these genera lay white eggs2 is so far confirmatory of the anatomical resemblances; in the other Goatsuckers the eggs are coloured. A second subfamily will include Podargus and Batrachostomus, while A^gotheles ought perhaps to be regarded as the type of a third subfamily. The remaining genera, Caprimulgus, Chordeiles, and Nyctidromus, belong to the fourth subfamily. The Steatomithinae are at one extreme, and the Caprimulginae at the other; Podargus, Batrachostomus, and AlJgotheles are much nearer to Steatornis than to Caprimulgus, but should be placed in an intermediate position. This view of the affinities of the different genera of Caprimulgidae almost entirely bears out the scheme of classification proposed by Mr. Sclater (loc. cit.). 1 Coll. Papers, p. 346. 2 Cf. P. L. Sclater, P. Z. S. 1866, p. 127. P R O C ZOOL. Soc-1886, No. XI. 11 |