1886.] POINTS IN THE ANATOMY OF THE CAPRIMULGIDE. 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 dis- 
section 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 men- 
tioned Ohrysotis 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 AXY’. 
Steatornis therefore agrees with Podargus and Aigotheles 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 go- 
theles appears to differ from its allies in having no ceca, 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 gotheles ; and the fact 
that all these genera lay white eggs* is so far confirmatory of the 
anatomical resemblances; in the other Goatsuckers the eggs are 
coloured. A second subfamily will include Podargus and Batracho- 
stomus, while 4gotheles ought perhaps to be regarded as the type 
of a third subfamily. The remaining genera, Caprimulgus, Chor- 
deiles, and Nyctidromus, belong to the fourth subfamily. 
The Steatornithine are at one extreme, and the Caprimulgine at 
the other; Podargus, Batrachostomus, and digotheles are much 
nearer to Steatornis than to Oaprimulgus, but should be placed in 
an intermediate position. 
This view of the affinities of the different genera of Caprimulgidee 
almost entirely bears out the scheme of classification proposed by 
Mr. Sclater (Joc. cit.). 
1 Coll. Papers, p. 346. 
2 Cf. P. L. Sclater, P. Z.8. 1866, p. 127. 
Proc. Zoou. Soc.—1886, No. XI. 1l 
