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caual, of the frontal spine of Scorpuena, but it does not lie at tlie hind end of the frontal, that 

 Position being held by the penultiniate serratnre of the line. Whether this latter serrature 

 represents a part of the frontal spine or not, I can not determine, but it apparently does. The 

 spine on the parieto-extrascapular must then be a parietal spine, and there is no nuchal spine. 

 Starting from or slightly postero-lateral to the frontal spine, and running at first postero-laterally, 

 and then posteriorly, near the lateral edge of the dorsal surface of the skull, there is another 

 ridge, which corresponds in position to the lateral row of spines of Scorpaena. This ridge lias 

 a wavy or bluntly serrated edge and sometimes terminates, at the hind end of the suprascapular, 

 in a small spine. 



Emery ('85) has given a figure of the skull of the adult Peristedion in which the spines that 

 I have just described are roughly shown, with the exception of the mesethmoid and ectethmoid spines. 

 which are neither shown in the figure nor mentioned in the text. The spines are also shown by the 

 same author in two figures of larvae of Peristedion of different ages, the skull of the youngest larva 

 being said to so greatly resemble the skull of the adult Scorpaena that Emery calls that larva the 

 scorpaenoid stage of the fish. At these two stages of Peristedion the spines are all very large, and a 

 Single spine on the nasal, and a single large spine on the frontal represent the several spines on those 

 bones of the adult. A spine is also shown on the pterotic of the youngest larva, this spine being wholly 

 wanting in the adult. Similarly, a spine is said by Emery to be found on the nasal of the young of 

 Trigla hirundo, and to wholly disappear in the adult. 



The dorsal surface of the skull of Peristedion, between the fronto-parietal serrated ridges, 

 and posterior to the frontal commissure, is perfectly flat, lies in a horizontal position, and corresponds 

 to the region of the subquadrangular groove on the Vertex of Scorpaena. Lateral to the ridge that 

 bounds this surface, on either side, the dorsal surface of the skull is a flat surface that slopes rapidly 

 down ward at an angle of approximately 30" to the vertical plane. Between the orbits the dorsal 

 surface is concave. A low rounded ridge, on either side, here marks the course of the supraorbital 

 latero-sensory canal, the two ridges converging forward, in nearly straight lines, toward the median 

 spine on the mesethmoid. In the preorbital region the lateral edge of the dorsal surface of the skull 

 lies, as it does in Trigla, in the level of the ventral surface of this part of the skull: and the line of 

 this edge, prolonged posteriorly, falls, in Peristedion, nearly into the line of the lateral edge of the 

 postorbital part of the dorsal surface of the skull. 



The posterior surface of the skull resembles that of Trigla but is steeper. and hence shorter 

 than it is in that fish. The hind edge of the secondarj' skull is ^harp and finely serrated, and slightly 

 ventral to this edge, and parallel with it, there is a slight but sharp ridge which projects posteriorly 

 and forms a little shelf which gives support to the anterior edges of the anterior row of the bony 

 plates of the body. The middle portion of the shelf is formed by the supraoccipital, its lateral 

 portion, on either side, being formed by the parieto-extrascapular and suprascapular. Beneath the 

 ridge, or shelf, there is a slight median vertical ridge which represents the spina occipitalis. This 

 little shelf in Peristedion is apparently simply the ventral edge of the somewhat thickened hind end 

 of the secondary skull of the fish. Ventral to it there is a low and rounded transverse ridge which 

 represents what I have described in Scorpaena and Trigla as the hind edge of the primary skull. 

 Between tliis ridge and the little shelf that represents the hind edge of the secondary skull, there is 

 a shallow groove which, although it here lies definitely on the hind surface of the skull, evidently 

 represents the supratemporal fossa. 



