Nos. IAXD2.] AXATOMY OF SCOMBER SCOMBER. 69 



nected, and is not easily removed without injury to the cartilage. 

 There seems, however, to be no primary connection whatever of 

 the bone with the cartilage such as Sagemehl found in the Chara- 

 cinidae and Cyprinidse. 



The slender, pointed body of the vomer fits into a correspond- 

 ing median depression on the ventral surface of the parasphenoid, 

 the latter bone extending forward between the thin, lateral proc- 

 esses of the vomer almost to its anterior end. The vomer, accord- 

 ingly, only touches the mid-ventral surface of the chondrocranium 

 in that short ungrooved portion of the surface that lies between 

 the anterior end of the parasphenoid and the beak of the rostrum. 



The Nasal (NA) is a long and narrow bone, doubly-curved, 

 somewhat like a tall and slender S. Its posterior half curves in- 

 ward and forward, and lies along the lateral edge of the anterior 

 end of the frontal, directly above the nasal sac. Beyond the 

 frontal the nasal curves downward, outward, and forward, and 

 then inward and forward, its anterior end reaching nearly to the 

 level of the anterior end of the maxillary. In this part of its 

 length it projects beyond the dorso-lateral processes of the eth- 

 moid, and even slightly beyond the anterior end of the chondro- 

 cranium, the ends of the two nasals looking like horns on either 

 side of the rostrum. From near the anterior end of each bone a 

 fibrous band, or sometimes two such bands, descend to the lateral 

 process near the lower ventral edge of the anterior end of the 

 maxillary of the same side of the head, and to the adjoining dorsal 

 edge of the anterior end of the premaxillary, as already described. 



The nasal is traversed its full length by the supraorbital lateral 

 canal, but the anterior organ of this canal is innervated by a 

 branch of the buccalis facialis, and not by a branch of the ophthal- 

 micus superficialis facialis. The one organ so innervated lies in 

 the curved, projecting, anterior end of the bone, and its general 

 position and innervation seem to indicate, as will be more fully 

 explained in describing the lateral canals, that it corresponds to 

 one of the organs found either in the ethmoid or in the antorbital 

 bone of Aniia. If such be the case, the nasal of Scomber is the 

 equivalent of the nasal of Amia plus the antorbital of that fish, or 

 plus that half of the ethmoid of the fish that lies on the cor- 

 responding side of the head. In general position it corresponds 



