APPENDIX I. 
49 
CC. The muscles which surround the poison glands. 
DD. A portion of the poison glands exposed. 
EE. A pair of muscles which rise from the neck, and terminate in the head. 
F. One of a pair of muscles which bring the head back. 
GG. The skin divided in the middle line of the back dissected from the muscles, and turned on each 
side. 
HH. The intercostal muscles. 
II. The muscles which bring forward the skin of the back upon the neck to form the hood. They 
arise from the ribs, and are inserted into the skin. 
KK. Muscles which raise the ribs : they originate from that part of the rib near the spine, pass over 
two ribs, and are inserted into the rib below near its extremity. 
LL. Muscles which raise the ribs ; arising from one rib and passing over the next, to be inserted into 
the rib below. 
MM. The intercostal muscles. 
Fig. 5. A front view of the neck. The parts are dissected to shew the mode in which the ribs lie in their 
depressed state ; also the muscles by which they are depresssed, and those which bring the skin 
back into its natural state. 
AA. The two portions of the lower jaw separated from each other, and turned aside. 
BB. The poison fangs. 
CCC. The ribs in their depressed state lying over each other on the side of the spine. 
DDD. The ribs on the opposite side in their extended state: their extremities become the boundary 
of the hood, and give it an oval form. 
EE. A pair of muscles which bring the head forward upon the neck. 
FF. The intercostal muscles. 
GG. The muscles which bring the ribs downwards upon the spine. 
HH. The muscles which bring the skin backwards from the neck : they have their origin from the 
points of the ribs, and are inserted into the lower edge of the abdominal scuta. 
II. The abdominal scuta divided in the middle line of the belly. 
KK. The muscles which go from the lower edge of one scutum to the lower edge of the scutum over 
it, to bring the scuta closer together, and make them overlap. 
LL. An internal view of the skin of the snake beyond the abdominal scuta. 
No. II. 
Observations on the Orifices found in certain Poisonous Snakes , situated between the JVostril and 
the Eye. By Patrick Russell, M.D. F. R. S. With some Remarks on the Structure of 
those Orifices , and the Description of a Bag connected with the Eye\ met with in the same 
Snakes. By Everard Home, Esq. F.R.S. 
Read before the Royal Society, February 2, 1804. 
In the description of the Fer-de-lance, or yellow snake of Martinico, the Count de la Cepede has remarked 
an orifice on each side of the head, between the nostril and the eye, which had by some naturalists been con- 
ceived to be the external organ of hearing ; but not having an opportunity himself to ascertain the fact by 
dissection, he recommends it as an interesting object for future investigation.* 
* Hist. Nat. tom. ii. p. 122. 
