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dicate that the bone of Scorpaena, up to and including this process, is the equivalent of the entire 

 premaxillary in those fish.es in which the maxillary lies, in Sagemehl's terminology, lateral to the 

 premaxillary. This, however, requires investigation. 



The other two processes of the premaxillary both arise from the proximal end of the bone, 

 and, in the descriptions of many fishes, are both included under the term ascending process. But 

 one of them only is properly that process, the other being a greatly developed articular process. 



The ascending process, properly so-called, is directed dorso-posteriorly, and is a long, thin, 

 pointed, plate-like piece of bone which lies in a plane that crosses obliquely and perpendicularly 

 the extreme proximal end of the premaxillary. Its internal surface is presented ventro-postero- 

 laterally and its mesial and larger part rests upon and is firmly attached by connective tissue to the 

 corresponding half of the grooved dorsal surface of the cartilaginous rostral, its mesial edge touching, 

 throughout nearly its entire length, in the mid-dorsal line, the corresponding edge of its fellow of 

 the opposite side. The external surface of the process is presented antero-dorso-mesially, and so 

 forms, with its fellow of the opposite side, a Y-shaped longitudinal groove on the dorsal surface of 

 the anterior end of the snout. This groove is wide antero-ventrally, but tapers dorso-posteriorly 

 to a narrow end. The antero-ventral end of the groove is filled with a päd of tough fibrous tissue 

 which extends downward between the anterior ends of the two premaxillaries and binds them strongly 

 but loosely together. The dorso-posterior end of the groove lodges a similar but smaller päd of tissue, 

 and this päd gives attachment to a stout ligamentous band which here crosses the outer surface of 

 the two ascending processes. This ligament, from here, runs downward and laterally, on either side. 

 passes ventral to the nasal bone, between it and the ethmo- maxillary ligament, and is inserted on 

 the base of the maxillary process of the palatine. A branch of this ligament runs antero-ventro- 

 laterally to the antero-mesial corner of the articular process of the premaxillary and then laterally 

 to the mesial (proximal) end of the ligamentary process of the maxillary, having an attachment at 

 each of these points; while a smaller branch of the ligament runs backward and laterally, and is 

 inserted on the anterior surface of the mesethmoid process. The function of this latter branch of the 

 ligament is evidently simply to fix a limit to that anterior motion of the rostral that accompanies 

 the protrusion of the premaxillaries. the main ligament holding the rostral down upon the dorsal 

 surface of the snout. 



The articular process of the premaxillary arises from the bone immediately lateral (distal) 

 to the ascending process. It is a relatively large plate of bone which lies in a plane that begins at 

 the antero-lateral edge of the base of the ascending process, at an acute angle to the plane of that 

 process, and from there runs postero-laterally across the dorsal surface of the body of the bone. At 

 the point where its antero-mesial edge joins the antero-lateral edge of the ascending process, there 

 is a marked but rounded angle in the antero-lateral edge of the latter process. The external surface 

 of the articular process is flat and smooth. On the postero-lateral portion of its internal surface 

 there is a large flat articular eminence which gives articulation to a part of the articular head of the 

 maxillary, in a manner that will be later described. 



In an earlier work ('98) I came to the conclusion that the ascending process of the premaxillary 

 of teleosts is primarily an independent bone, and that this independent bone is represented in the 

 median dermal ethmoid of Amia, and probably also in bone 2 of Huxley's descriptions of Esox. This 

 conclusion, in so far as it regards the dermal ethmoid of Amia, seems confirmed by the conditions 

 found in Lophius, Sphyraena, Salmo, Elops, and other fishes that I have been led to examine in this 



