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line of cartilage that caps the dorsal edge of that bone, and the body of the frontal, immediately 

 postero-mesial to the flange, resting upon the dorsal surface of this same line of cartilage. Postero- 

 internal to this large flange and slightly postero-lateral to the antero-mesial end of the line of ali- 

 sphenoid cartilage, a short narrow and pointed process projects downward from the ventral surface 

 of the frontal, lies against the internal, postero-mesial surface of the cartilage, and may even extend 

 ventral to the cartilage, there lying against the corresponding surface of the alisphenoid. This little 

 process of the frontal, and the large flange -like process of the same bone, thus clasp and hold between 

 theni the dorsal end of the alisphenoid, in a manner similar to that described by me for these same 

 bones in Scomber. From the hind edge of the little process a delicate ridge runs postero-mesially 

 toward the postero-mesial corner of the frontal. It corresponds to the flange that, in Scomber, forms 

 the lateral boundary of the post-epiphysial cartilage, that cartilage being reduced, in Scorpaena, to a 

 narrow band along the anterior edge of the supraoccipital. Postero-lateral to the alisphenoid, the 

 greatly diminished flange of the frontal overlaps slightly, or abuts against, the dorsal edge of the 

 sphenotic. 



The lateral edge of the frontal, at and posterior to its postorbital corner, rests upon the dorsal 

 surface of the sphenotic, the mesial corner of its hind edge resting upon the dorsal surface of the 

 supraoccipital, and the hind edge of the bone articulating by suture with the anterior edges of the 

 pterotic and parieto-extrascapular. Adjacent to the sphenotic and supraoccipital bones the frontals 

 each rest upon small cartilaginous remnants of the chondrocranium; and between these cartilages 

 and the related bones, they form part of the roof of the cranial cavity, covering a large median opening 

 in the roof of the chondrocranium formed by the fusion of the anterior ends of the lateral fontanelles. 

 This median opening is open anteriorly, there being no cartilaginous epiphysial ridge to form its 

 anterior boundary; Sagemehl's statement that this ridge is found in all teleosts thus not being correct. 



The frontal is traversed by the supraorbital latero-sensory canal and lodges five organs of that 

 line, two of these organs, the 4th. and 5th. of the line, lying relatively close together, without an 

 intervening primary tube, as will be fully explained when describing the canals. The position of that 

 part of the canal that lies between the orbits is marked by a strong ridge, already several times referred 

 to as the frontal or interorbital ridge. A similar ridge marks approximately the position of the fourth 

 tube of the line; that tube running mesially and slightly backward to meet, in the middle line, its 

 fellow of the opposite side. The hind edge of this ridge forms the anterior boundary of the groove 

 on the vertex. 



That part of the cranial cavity that is enclosed between the anterior halves of the ventral 

 flange-like processes of the frontals corresponds to the fore-brain recess of my descriptions of Scomber, 

 but, in Scorpaena, the cranial cavity is so large, relatively to the brain, that the fore-brain lies wholly 

 posterior to the recess, reaching, approximately, only to the anterior edge of the basisphenoid. The 

 olfactory nerves there pierce the membranes that close the orbital opening of the brain case, and, 

 enclosed in a membranous tube, traverse the orbit. The fore-brain recess of the adult Scorpaena 

 thus lodges no portion of the brain, being simply filled with fatty tissue. 



POSTFRONTAL. 



The postfrontal is a small flat bone which lies directly upon, and is quite firmly bound to, the 

 posterior portion of that part of the dorsal surface of the sphenotic that is not covered by the frontal 

 and pterotic. Along its anterior and lateral edges, narrow strips of the sphenotic appear, and form 



Zoologiaa. Heft 57. 5 



