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The levator arcus palatini is a strong muscle which arises from the small roughened surface 

 on the dorso-lateral corner of the sphenotic. Eunning almost directly downward it spreads forward 

 and backward, its deeper fibers being immediately inserted on the external surface of the dorso-anterior 

 portion of the hyomandibular. The more superficial übers of the muscle are inserted in part on the 

 dorsal edge of the lateral flange on the hind edge of the metapterygoid, but in larger part they run 

 downward between that flange and the mesial one and have their insertions on the latter flange, in 

 the membrane that extends from that flange to the anterior edge of the hyomandibular, and also 

 partly on adjoining portions of the hyomandibular. 



The adductor arcus palatini is a broad sheet of muscle that has an origin and insertion similar 

 to that of the muscle in Scorpaena. The surface of origin begins posteriorly on the external surface 

 of the narrow bridge of bone that forms the external wall of the trigcmino-facialis Chamber, runs 

 downward onto the ascending process of the parasphenoid and then, turning forward, extends along 

 the ventro-lateral surface of the parasphenoid nearly to the anterior end of that bone. Running 

 ventro-laterally the fibers of the muscle have their insertion in a long line that begins on the inner 

 surface of the anterior edge of the dorsal portion of the hyomandibular and extends forward along 

 the dorsal edge of the metapterygoid, and then onto the entopterygoid and the palatine cartilage and 

 bone, the line of insertion passing along the dorso-mesial edge of the metapterygoid instead of crossing 

 the internal surface of that bone, as it does in Scorpaena. The small entopterygoid lies upon the 

 internal surface of the ventral edge of the muscle and gives Insertion to certain of its fibers. 



The adductor hyomandibularis, and the dilatator, adductor and levator operculi have already 

 been sufliciently referred to when describing the opercular bones. 



5. LATERO-SENSORY CANALS. 



The latero-sensory canals of Trigla differ in no essential particular from those of Scorpaena. 

 As in that fish, the primary tubes branch repeatedly after they leave the bones to which they are 

 related and enter the overlying dermal tissues, large and complex dendritic Systems being formed. 



The lachrymal lodges three sense Organs of the main infraorbital line, the large second infra- 

 orbital bone, four organs, and the third and fourth bones one organ each. This makes nine organs 

 in all in this part of the line of Trigla, which is two more than is found in Scorpaena, and one more 

 than is found in Cottus even when counting the small supplemental organ in the second infraorbital 

 bone of that fish. 



The postfrontal lodges one sense organ innervated by the oticus lateralis, and the pterotic 

 two Organs innervated by the same nerve. The two organs in the pterotic are without intervening 

 primary tube, and are probably, as already explained, in process of condensation into a single organ. 

 The pterotic also lodges a post-preopercular sense organ, innervated by a branch of the supratem- 

 poralis lateralis vagi, this organ not being found in Scorpaena but being found in Cottus. 



The lateral extrascapular, suprascapular and supraclavicular each lodge one organ of tlie main 

 line, the organs in the first two bones being innervated by branches of the supratemporalis lateralis 

 vagi, and the organ in the supraclavicular by the next following and single branch of the nervus lineae 

 lateralis vagi. 



The supratemporal canal forms a cross-conmiissure with its fellow of the opposite side, and 

 contains two organs, onelying in the lateral extrascapular and the other in the parieto-extrascapular, 

 both innervated by branches of the supratemporalis lateralis vagi. 



