20 
RICHARDS. 
chamber. This view shows very clearly the course of the 
chorda tympani nerve forwards and outwards around the 
Fig. 4. 
neck of the hammer, and also shows, alas, but too dis- 
tinctly, the line of accidental fracture through the mem- 
branous tegmen just mentioned. The rounded surface 
of the promontory is also well shown. 
Before closing this paper I desire to express my sincere 
thanks to Dr. B. Alexander Randall, of Philadelphia, who, 
while recently on a visit to this city, most kindly volun- 
teered to take for me a number of photographs of the 
specimen. Two of these photographs were selected by me 
for use in this paper, and engravings from them are given 
in Fig. 2 and Fig. 4. These two views were exceptionally 
difficult subjects for the camera, and, as usual, the process 
of engraving does imperfect justice to the excellence of 
the photographic work. Fig. 1 is from a photograph 
made by Thomas of 717 Sixth avenue, and Fig. 3 from 
one made under my supervision by the photographer at 
the College of Physicians and Surgeons. I desire also to 
express my thanks to Prof. Allen of the Central Park 
Museum, and to other gentlemen connected with that insti- 
tution, for kind attention and courteous assistance offered 
on the occasion of my visits there. 
