358 
A. M. REESE 
in the other Chimaeroids could not be determined by the figures 
of either Garman or Dean. 
The subrostral canal (figs^ 1, 3, 4, sr) has the appearance, when 
seen in a ventral or an anterior view of the head, of a letter Y. 
The stem of the Y, and the two branches, are each about five 
millimeters in length, in a fish of average size. Each branch of 
the Y begins in an enlargement at the point of union of the rostral 
and suborbital; it thence passes ventrad and mediad to meet its 
fellow in an enlargement at the dorsal end of the stem of the Y; 
this stem which, of course, lies in the median plane, extends ven- 
trad to the enlargement at the point of union of the two angular 
canals. 
In C. monstrosa the course of the subrostral is the same as has 
just been described, except that, if Garman's figures be accurate 
in this detail, the enlargements are not in the same position. The 
course of the subrostrals in the other Chimaeroids could not be 
determined from the figures and descriptions at hand. 
THE STRUCTURE OF THE CANALS 
Although numerous workers have described the structure of 
the lateral line organs in other fishes, no one, apparently, has 
described the anatomy of these organs in C. colliei; and the 
work of Solger (79) and others upon C. monstrosa leaves much to 
be desired. 
According to Garman ('88) the chief structural difference be- 
tween the canals of the Chimaera and those of the other genera 
of the Holocephali is that in the former genus they have the form 
of an open canal, while in the other genera they are tubular in 
structure. According to the method of development of these 
canals it would seem, then, that, in this respect, at least, the genus 
Chimsera is more primitive than the other genera of the group. 
As viewed from the surface there appear to be two types of 
canal; the common form that is seen in the lateral line proper 
(figs 1, 2, I) and most of the cephahc canals; and the form that 
has the previously m^entioned enlargements, and is represented 
by the canals on the anterior region of the snout (fig. 1). The 
