488 ALLIS. [Vor. Il. 
only, arranged, where there are two, across the top of the snout. 
In the 17-inch specimen, which seemed an exceptional one in 
many ways, there were three pores in this group on each side 
of the head, the third pore lying a little in front of, and lateral 
to, the two regular ones. In no other specimen were more than 
two pores found. In the skull there was but one opening in the 
ethmoid corresponding to this group, showing that the division 
of the trunk lies in the dermis entirely above the bone. 
Group 3 lies near the edge of the upper lip, below and in front 
of the nasal tube, and has but one pore, or two lying parallel 
to the edge of the lip. As the trunk of this system issues in 
the dermis between the ethmoid and antorbital, there is no cor- 
responding opening in the skull. 
Group 4 lies near the edge of the upper lip, lateral to and 
below the nasal tube, and usually has two pores in the adult. 
In the 17-inch male there were two pores in the group on each 
side of the head; in the 20}-inch male, two on one side, and 
four, arranged in a square, on the other; and in the 27-inch 
female, three, lying in a line parallel to the edge of the lip. In 
the skull there was a single opening only. 
Group 5 lies back of and lateral to the nasal tube, and below 
the dermal crease which extends from the base of the tube 
toward the posterior nasal aperture. The number of pores in 
this group varies, as does also their arrangement, and they are 
nearly, if not quite, continuous with those of group 7. In the 
17-inch specimen there were eight pores in the group; in the 
204-Inch one, nine; and in the 27-inch one, nineteen. One or 
more of the anterior pores of the group lie close to the dermal 
crease before mentioned, and directly opposite the pores of 
group I, supra-orbital. In the skull there were eight openings 
in this system. 
Group 6 belongs in position to the supra-orbital line, and will 
be described with group 4 of that line, with which it is con- 
tinuous. 
Group 7 lies behind, and lateral to, group 5, considerably 
below the posterior nasal aperture, and immediately above 
group 8. , 
Groups 8 to 11 lie along the upper edge of a deep furrow 
which separates the maxilla from the side of the head. The 
maxilla, when the mouth is closed, shuts under the overhanging 
