104 
DAVIS: NOTE ON CHLAMYDOSEL ACHUS. 
length. They are about an inch longer than the pectorals, the reverse 
of what is usual amongst sharks : each is broadly rounded, twice as 
long as wide, and ends in an acute point behind the neck. The anal 
fin is nearly eight inches in length and three in breadth, the lower 
margin is cui-ved and the posterior extremity forms an acute angle. 
The tail is without a pit at its root, and the fin is not divided into 
lobes by a notch at its lower border. The upper portion of the fin 
is not more than three- sighths of an inch in height : the lower 
portion is little short of three-and-a-half-inches in its greatest depth, 
and with its filamentary extremity is not far from twelve inches in 
length. 
The teeth are arranged in fifty-one rows with six in each row. 
There are thirteen in each ramus of the upper jaw and twelve on 
each side of the lower jaw, and in the latter there is also one median 
row on the symphysis. All the teeth ai e small, the largest is barely 
a quarter of an inch across the tips of the cusps, and the smallest is 
less than one-sixteenth : they consist of three long, slender, very 
sharp, subconical cusps, separated by a pair of rudimentary denticles 
or buttons, on a broad backward-extended base. The anterior teeth 
are largest and they decrease in size backwards. Behind the teeth 
pi oper, on each jaw there is a patch of scales similar to those on the 
lips at the angle of the mouth. Anteriorly the cusps are bent over 
backwards towards the base, those behind are nearly or quite erect, 
the points are bent slightly upwards or forwards. On each side the 
median cone and on the inside of the lateral ones a slight ridge runs 
from the base to the apex. A small ljutton is situated between the 
central and each lateral cusp, and behind these a ridge extends 
backwards over the base which ends in a pair of prongs extending 
beneath the base of the next tooth in the row to the extent of one- 
third of its length. In the posterior rows of teeth, their bases are 
somewhat distorted, the median cusp is considerably'' longer than the 
lateial ones. The buttons disappear in plications. For a descrip- 
tion of a tooth of the twelfth or thirteenth row that of Cladodus 
mirabilis, Agass, is not far out of the \vay ; in fact it agrees so well 
hat, if considei-ation was limited to that particular tooth, one could, 
thave little hesitation in naming the new species Cladodus auguineus 
