I. THE LORICATI. 



I. Scorpaena. 

 1. SKULL. 



The complete skeleton of the liead, and the skull proper (neurocranium) of Scorpaena scrofa 

 are show in Figs. 1 — 9. As is well known, the orbits are large; the interorbital wall simple; the dorsal 

 surface of the skull, between the orbits, deeply concave and traversed longitudinally by two prominent 

 ridges; and on the vertex there is a subquadrangular groove which is slightly broader than it is long, 

 and which is bounded on either side, and both anteriorly and posteriorly, by ridges. 



The two longitudinal ridges between the orbits mark the course, on either side of the head, of 

 the supraorbital latero-sensory canal. Each of these ridges turns postero-laterally at its hind end 

 and is there joined by the transverse ridge that forms the anterior boundary of the groove on the vertex, 

 the Single ridge formed by these two ridges united then immediately turning posteriorly andterminat- 

 ing in a pronounced spine. This spine lies not far from the hind edge of the frontal, at the anterior 

 end of the ridge that forms the lateral boundary of the groove on the vertex, and it projects backward, 

 or backward and laterally above the opening of the seventh, or terminal tube of the supraorbital latero- 

 sensory canal, that opening lying immediately lateral to the lateral bounding ridge of the groove on 

 the Vertex. Emery ('85) has called this spine the frontal spine, naming it after the bone on which it 

 lies, and I adopt this term rather than the term tympanic, given by Jordan & Gilbert ('83) to the 

 corresponding spine in Scorpaena porcus. 



The tympanic spine of the Scorpaenidae, as defined by Eigenmann and Beeson ('94) in their 

 descriptions of the Sebastinae, is said to always overarch a mucous pore, to always lie near the outer 

 border of the frontal, and to be always present and homologous throughout the group. The coronal 

 spine, as defined by the same authors, is said to be developed in but few species, to lie on the frontal, 

 nearer the mid-dorsal line than the tympanic, and directly in front of the parietal ridge. The frontal 

 spine of Scorpaena scrofa thus has the relations to the supraorbital latero-sensory canal of a tympanic 

 spine, while in other respects it has the position of a coronal spine, as that spine is shown both in Jordan 

 & Gilberts' diagram of the cranial ridges of Sebastodes (1. c. p. 653) and in Cramer's ('95) figures 

 of Sebastodes introniger and Sebastodes auriculatus. The relation to the supraorbital canal is, 

 however, so typical that the spine, in Scorpaena, is certainly a tympanic and not a coronal one. It 

 lies at the hind end of the interorbital ridge on the frontal, that ridge thus appearing as a cranial 

 spinous ridge; but this relation of the spine to the ridge, though apparently usual in the group, is not 

 constant, as will appear when the spine is described in Scorpaena porcus. 



