175] OSTEOLOGY OF LORICATI — GUTBERLET 



INTRODUCTION 



The suborder Loricati is characterized by the extension of the 

 third suborbital bone across the cheek to the preopercle. This group 

 has a wide range of variation and Gill has divided it into several families 

 of which the rock fishes, or Scorpaenidae, are more generalized and the 

 sculpins, or Cottidae, are the most specialized. The family Hexagrammi- 

 dae comes between the two extremes, being more nearly related to the 

 Scorpaenidae than to the Cottidae. 



The purpose of this paper is to make a comparative study of the 

 osteology of these forms in order to determine their relationship. Allen 

 (1905) states that there are many points of resemblance to the Cot- 

 tidae to be found in their osteology, visceral organs, and vascular 

 systems, and that Ophidon is about as closely related to Scorpionichthys, 

 a sculpin, as it is to Hexagrammos, and should be regarded as a type of a 

 distinct family. For this study Ophidon elongatus and Hexagrammos 

 decagrammus of the Hexagrammidae and Scorpionichthys marmoratus 

 of the Cottidae were selected. The material was collected at Monterey 

 Bay, California, by Mr. William F. Allen under whose direction the 

 work was carried on at the Zoological Laboratory of the University of 

 Illinois. 



OPHIDON ELONGATUS 

 The Cranium 



Except for a few ridges and grooves, the entire dorsal surface of 

 the skull (Fig. 1) is flattened. On the anterior half there is a median 

 rectangular groove which extends from between the posterior boundaries 

 of the orbits to the median ridge of the ethmoid. Posterior to the groove 

 the parietals form a ridge on either side, extending laterally and poster- 

 iorly, from the median line to the lateral edges of the epiotics. These 

 ridges are continuations of the long rounded ridges of tlio frontals which 

 form the sides of the rectangular grooves. The surface of the frontals, 

 posterior to the orbits, is somewhat porous and lias striatious which pass 

 caudad and mesad from the edge of the orbits toward the parietals 



The temporal fossa is formed by the pterotics, frontals, parietals 

 and epiotics. It extends caudad from the latero-posterior edge of the 



