138 Edward Phelps Allis jr., 



From near the hind edge of the anterior nasal tube, a marked 

 maxillary labial furrow begins, and from there extends backward, in 

 a slightly curved line, nearly to the level of the hind end of the gape 

 of the mouth, where it gradually vanishes without turning downward 

 to meet the hind end of the mandibular labial furrow. This latter 

 furrow is strongly developed, and, tui-ning upward at its liind end, 

 vanishes at the angle of the gape, there meeting the hind end of the 

 line of the mouth opening, and forming with it. in ajipearance, when 

 the mouth is closed, a continuous line. 



The maxillary labial furrow cuts downward into the fleshy lip 

 of the fish, and is deepest somewhat anterior to the middle of its 

 length. It lies external to the lachrymal, that bone lying external to 

 the so-called maxillary bone. A shallow furrow, or more properly a 

 deep crease, extends upward into the thick upper lip, from its ventral 

 surface, and separates the ventral portion of the lachrymal from the 

 underlying maxillary. Which one of these two furrows is the homo- 

 logue of the supramaxillary furrow of my descriptions of Amia (No. 2) 

 I am unable to determine. The shalloAV furrow that extends upward 

 into the thick lip fro-m its ventral surface would certainly seem to 

 be the homologue of a much deeper furrow found in much the same 

 place in Scomber (No. 9), and there lying between the lachrymal 

 externally and the premaxillary and maxillary together internally; the 

 premaxillary of Scomber extending backward the full length of the 

 maxillary, and lying in part ventral to it and in part external to it. 

 This furrow, in Scomber, I considered as the homologue of the supra- 

 maxillary furrow of Amia; for it is evident that if the lachiymal of 

 Amia were to acquire the backward extension that it has in Scomber 

 it would lie external to the maxillary exactly as it does in Scomber. 

 The presence of a premaxillary in Scomber, extei'nal to the maxillary, 

 however, obscures the relations. On the other hand the maxillary 

 labial furrow of Conger seems most evidently the homologue of the 

 maxillary labial furrow of Polypterus, which furrow may perhaps be 

 (No. 6) the homologue of the supramaxillary furrow of Amia. The 

 possible total absence of a maxillary bone in Conger, to which I have 

 once made reference (No. 6) and of which I am now quite fully con- 



