167 



under the eye. After leaving the frontal the canal is pro- 

 tected only by the chain of very slender suborbital ossicles. 

 the posterior of which are sometimes called postorbitals, 

 and the last of which is attached to the frontal. These 

 ossicles are much more conspicuous in the Cod. In one 

 specimen examined there were 18 suborbitals on the ocular 

 side. On the eyeless side the suborbitals are both fewer 

 and larger, nor does the canal take such a wide sweep 

 forwards, and is hence shorter (cp. fig. 29). It leaves the 

 frontal in front almost exactly opposite the exit of the 

 right infraorbital. From this point the canal extends 

 forwards in a slight curve until it reaches the left 

 lachrymal to which the first suborbital ossicle is attached. 

 On the ocular side the lachrymal is quite distinct from 

 the suborbital chain, and in the specimen examined the 

 canal ended by a pore 11mm. behind and below the postero- 

 ventral extremity of the lachrymal. On the eyeless side 

 the canal passes on to the left lachrymal, on which it 

 terminates. There were 5 suborbital ossicles on this side, 

 but three of these were each divided into two. Traquair 

 describes 13 on the ocular side, and 8 on the eyeless. In 

 the sections the right infraorbital canal was not com- 

 pletely developed, the first 7 sense organs being yet 

 unenclosed in a canal, but lodged in small depressions of 

 the skin. The supratemporal and infraorbital canals are 

 therefore the last to be completed. The portion of the 

 canal in line with the " lateral line," and innervated bj^ 

 the R. oticus facialis, contained '■] sense organs on the 

 ocular side, to the last of which attention may be drawn. 

 On the eyeless side anteriorly the canal courses down- 

 wards, but after leaving the lachrymal it turns sharply 

 backwards almost at right angles. The whole canal is 

 completely developed on this side, and is more robust. 

 Its anterior portion has fewer sense organs, but those it 



