STUDIES ON AVIAN ANATOMY.— II. 
Geococcyx, Bubo and Aeronaut es* 
MARGARET E. MARSHALL, M. A. 
Introduction. 
This paper is the second in a series dealing with the question of 
the homologies of the Caprimulgi. After a previous study of 
Phalaenoptilus (Proc. Amer. Phil. Soc., 1905) the writer has studied 
those forms most easily obtained, with which the Caprimulgi have 
been compared. They are : a cuckoo, Geococcyx calif ornianus 
(Less.) ; an owl Bubo virginianus palesceus (Stone), and a swift, 
Aeronaut es melanoleucus (Baird). There was not time for the study 
of the entire anatomy of all the birds, so I have examined the ali- 
mentary tract, the central nervous system, the nostrils and pecten 
of the eye, the urogenital system, the musculature of the fore 
limb, and in Geococcyx the pterylosis. 
The material used consisted of the following: two adult female 
Aeronautes, one entire, the other lacking a head; three adult female 
Geococcyx, two entire; and one entire adult female Bubo. 
In order to obviate any misunderstanding in reading the de- 
scriptions which follow, an explanation of the terms there employed 
may not be amiss. In referring to the carina sterni the border desig- 
nated “dorsal” is the line of junction between the carina and the 
body of the sternum, the latter being mentioned as the “lateral sur- 
face.” The term “ventral,” then, means the free border of the 
carina. The names of the crests, projections, and surfaces of the 
humerus are the same as those given by Purbringer (1888), Plate 
I, figures 9, 10, 11, 12. Also the name processus sterno-coracoideus 
is that given by him. 
I wish to express my profound appreciation of the valuable as- 
sistance and ready sympathy of Professor Thos, II. Montgomery, 
Jr., under whose direction it has been my great pleasure to study 
for the past two years. 
A. OBSERVATIONS. 
1. Alimentary tract. 
The tongue in Geococcyx (T., PL I., fig. 10) is long and slender. 
Posteriorly it is bifid and supplied with spines. In Bubo (T., PI. IV., 
* Contributions from the Zoological Laboratory of The University of Texas, 
No. 73. 
