— 101 — 



antero-laterally and gives attachment, on its outer end, to the ethmo-maxillary ligament. The latero- 

 posterior, or ventro-latero-posterior, surface of the process gives siipport to a process on the hind end 

 of the nasal bone, the latter bone being strongly bound to the mesethmoid process by fibrous tissues. 



The ECTETHMOID has a body of delicate perichondrial bone, and a stout lateral process 

 which corresponds to the wing and arm together of the bone in Scorpaena. On the ventral edge of 

 this lateral process there is a single large condylar eminence, which gives articulation to the lachrymal 

 alone, the palatine not anywhere Coming into articular relations with the ectethmoid. Lateral to this 

 articular eminence, the ventro-Iateral corner of the lateral process is free. On the antero-dorsal 

 surface of the bone there is a short but relatively large process which projects antero-mesially and gives 

 Support, on its summit, to the lateral end of a lateral process on the hind end of the nasal, this process 

 of the nasal being strongly bound to the ectethmoid process by fibrous tissues. Between this ecteth- 

 moid process and the mesethmoid process, the lateral process of the nasal bridges the hind end of 

 the olfactory depression, lying between the two nasal apertures. In Scorpaena scrofa, as already 

 stated, this nasal process of the ectethmoid of Cottus is apparently represented by an eminence, or 

 short spine, sometimes but not always found on the ectethmoid of that fish. 



The VOMER has a 'short dorsal limb formed of thin bone, of perichondrial appearance, which 

 comes into contact posteriorly with the perichondrial portions of the three ethmoid bones. A raised 

 portion on the ventral surface of the anterior end of the bone bears a band of villiform teeth which 

 extends, uninterruptedly, from one side to the other. 



The PREMAXILLARY has large ascending and articular processes, the former resting on the 

 dorsal surface of the rostral, and the latter articulating with the maxillary, as in Scorpaena. The body 

 of the bone is shorter than in Scorpaena, extending but half the length of the maxillary and ending 

 practically at the hind edge of its own postmaxillary process; the posterior half of the body of the 

 bone of Scorpaena being represented, in Cottus, by tough gristly tissue. The oral surface of the bone 

 of Cottus is furnished nearly its füll length with small villiform teeth. 



The MAXILLARY has a stout, right-angled ascending process which articulates with the 

 premaxillary and, through the intermediation of a päd of semi-cartilaginous tissue, with the dorsal 

 limb of the vomer. The antero-mesial (proximal) end of the ligamentary process is well-developed 

 and gives Insertion to the ethmo-maxillary ligament. The postero-lateral (distal) end of the process 

 is represented by a slight eminence which gives Insertion to the maxillo-mandibular ligament, this 

 ligament having a course, and an Insertion on the articular, similar to that in Scorpaena. Between 

 these two ends the ligamentary process is but slightly if at all developed, but the dorsal surface of 

 the shank of the bone here gives articulation to the enlarged anterior end of the maxillary process 

 of the palatine. The ventral edge of the anterior end of the lachrymal here also comes into slight 

 contact with the maxillary, but the lachrymal is here bound to the palatine alone, and is not supported 

 by, and bound to the maxillary, as in Scorpaena. 



The NASAL has, as already stated, a lateral process on its hind end, this process giving to the 

 Mnd end of the bone an expanded appearance. This expanded hind end of the bone is bound mesially 

 to the mesethmoid process, and laterally to the nasal process on the dorso-anterior surface of the 

 ectethmoid, thus bridging a part of the nasal pit. The bone is traversed by the supraorbital latero- 

 sensory canal and lodges one organ of that line. No part of the canal traverses the process that 

 bridges the nasal sac. 



