352 PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 
DESCRIPTION OF ANEW SPECIES OF NOTIDANOID SHARK (HEX- 
ANCHIUS CORINWS), FROM THE PACIFIC COAST OF THE UNITED 
STATIS. 
By DAVID 8S. JORDAN and CHARLES H. GILBERT. 
Flexanchus corinus, sp. nov. 
Head large, broad, depressed and very blunt anteriorly; the length 
of snout from front of mouth little more than half the interorbital space 
and rather less than the distance from the front of the mouth to angle 
of the mouth. 
No median tooth in upper jaw. Two sharp, slender teeth in front of 
upper jaw, behind which is a row of four others similar but a little larger; 
the two outer larger than the inner, all without basal cusps. Behind 
these are four others similar and still a little larger. These are di- 
rected backward, and should not be considered as functional teeth. 
The first of the large teeth in the upper jaw is larger than the succeed- 
ing teeth. It has a sharp point hooked outward, and a single strong 
cusp on its outer margin, its inner edge not serrate. The second 
tooth, on both sides, has the basal cusp obsolete. The third tooth is 
like the first, but a little smaller. The fourth tooth is slightly serrated 
on the inner margin, and has two strong cusps on the outer at base. 
The fifth and sixth are similar to the fourth, but more strongly serrate on 
the inner margin. The seventh, eighth, and ninth are small, and the 
number of cusps is increased, so that they approach the form of the 
teeth of the lower jaw. 
The median tooth of the lower jaw is very small, with a slight me- 
dian cusp and three cusps on the outer margin, the uppermost the 
largest. The first lateral tooth has six cusps; the first the largest, the 
others progressively decreasing; the long edge of the first cusp is finely 
serrated, but has no basal cusp. The second, third, fourth, and fifth 
teeth are precisely similar in size and form to the first. The sixth and 
seventh are somewhat smaller. In the smaller specimen, from Soquel, 
the inner edge of the teeth is not serrated. Behind the large teeth in 
each jaw is the usual series of small blunt teeth, which in this species 
are little developed. 
Nostrils near the tip of the snout. Furrow of skin at angle of mouth 
reaching half way from the angle of the mouth to the gill-opening. Eyes 
large, % the length of the snout. Spiracles small, far behind the eyes. 
Gill-openings 6. Pectoral moderate, as long as from first gill-opening to 
tip of lower jaw. Ventrals small, reaching past front of the small dorsal. 
Dorsal a little higher than anal, and terminating over the middle of the 
latter fin. Tail long, twice as long as head, a little less than $ the 
total length, little bent upward ; its basal lobe little developed; the scales 
on its upper edge somewhat enlarged. 
