— 98 — 



orbital to the postfrontal, the canal here forming a continuous suborbital ring, instead of being 

 interrupted as in Scorpaena. The orbital edges of the lachrymal and two suborbitals are broadened 

 to form a flat, curved and delicate suborbital shelf. 



The lachrymal articulates, by its dorsal edge, with the ectethmoid. Its ventro-anterior corner 

 rests upon, and is firmly bound to the ligamentary process of the maxillary, the dorso-mesial portion 

 of its anterior edge resting upon the dorsal surface of the maxillary process of the palatine! At the 

 hind end of this surface of contact with the palatine a short stout ligament connects the two bones. 

 Posterior to the point of attachment of this ligament, between it and the articular surface for the 

 ectethmoid, the large anterior primary tube of the main infraorbital canal opens on the external 

 surface of the bone. The second and third tubes of the main infraorbital canal issue from that canal 

 as it traverses the lachrymal, the fourth tube issuing between the lachrymal and first suborbital, 

 as in Scorpaena. The anterior edges of the second and third tubes, one or both, are produced in 

 short sharp spines, these being the only spines on the infraorbital chain of bones. The fifth tube 

 opens on the lateral surface of the second suborbital bone, and the prolonged hind end of the dorsal 

 edge of this tube reaches and is bound to the preopercular. The sixth tube lies between the dorsal 

 edge of the second suborbital and the ventral end of the first postorbital, the seventh tube lying 

 between the two postorbitals, and the eighth tube between the second postorbital and the postfrontal. 



The hyomandibulo-palato-quadrate apparatus does not difier in any important respect from 

 that of Scorpaena. The opercular process of the hyomandibular is not so long as in Scorpaena. The 

 preopercular has five spines on its hind edge; but the second spine from the dorsal edge of the bone, 

 instead of the first one, is the longest, and there is no supplementary spine either at the base of this 

 spine or at the base of the dorsal spine, as there is in Scorpaena. The quadrate has a posterior process, 

 the posterior surface of which is applied against and firmly bound to the ventral end of the preoper- 

 cular. On the inner surface of the quadrate there is a symplectic groove which lodges the ventral 

 portion of the symplectic. The metapterygoid has lateral and mesial flanges on its hind edge, both 

 of which are connected with the anterior edge of the hyomandibular, as in Scorpaena: but these 

 flanges of Sebastes do not meet to form a dorsal Prolongation of the hind edge of the bone, and there 

 is no continuation of the flanges along the dorso-anterior edge of the bone, as in Scorpaena. The 

 ectopterygoid and entopterygoid difier but little from those of Scorpaena. The palatine is relatively 

 shorter than in Scorpaena, and its ventral process is not so tall as in that fish. The opercular, sub- 

 opercular and interopercular are as in Scorpaena. 



The mandible has articular, angular and dentary elements, closely resembling those of Scorpaena. 



III. Cottus octodecimospinosus. 



The skeleton of the head of Cottus octodecimospinosus difiers considerably, in several important 

 respects, from that of Scorpaena and Sebastes. 



1. SKULL. 



The skull as a whole is relatively low and flat, and the brain case is relatively long, occupying 

 nearly one half the length of the skull. The bones of the skull are all much thinner and more delicate 

 than those of Scorpaena and Sebastes, the brain case being little more than a thin shell of bone. 



