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ligament, running forward from its jjoint of origin on the ectethmoid, has its insertion on the palatine 

 cartilage, the process of the lachrymal thus being developed in supporting relation to it. The aecond 

 ethmo-palatine ligament is, as already stated, a slender and delicate one that arises from the ventral 

 surface of the ectethmoid. Eunning forward from there, parallel to but at a certain distance from 

 the larger ligament, it also is inserted on the hind end of the palatine cartilage. 



The lachrymal is traversed by the infraorbital latero-sensory canal and lodges three organs 

 of that line. 



The second infraorbital bone is a large and almost "parallelogrammic bone. The Striae on its 

 outer surface radiate mainly from a point that lies near the ventral quarter of the bone directly super- 

 ficial to the latero-sensory canal that traverses the bone, but partly also from a second point that 

 lies slightly antero-ventral to the first one, and also directly superficial to a portion of the latero- 

 sensory canal; these two points apparently representing the centers of ossification of two bones, 

 here fused but found separate in a 63 mm specimen of Lepidotrigla examined in serial sections. i) 



In the hind edge of the bone, at about its ventral third, there is a more or less pronounced 

 angular incisure. Dorsal to this incisure the hind edge of the bone abuts against the anterior edge 

 of the preopercular, overlapping it but slightly at any place. Ventral to the incisure, the bone also 

 abuts against the anterior edge of the preopercular, but it there also rests upon the lateral edge of 

 the posterior process of the quadrate, the attachment to this latter bone being particularly strong, 

 much stronger than to the preopercular. The point of the incisure lies in the line, anteriorly produced, 

 of the dorsal and largest preopercular spine, and fits against a pointed portion of the anterior surface 

 of the outer edge of the jjreopercular. From the point of the incisure, and extending backward across 

 the outer surface of the preopercular to the base of its dorsal spine, there is a slight but distinctly 

 evident tuberculated ridge, this ridge being also continued forward across the second infraorbital 

 bone. Ventral to the ridge, both the preopercular and second infraorbital incline slightly downward 

 and inward, the ridge thus separating two somewhat inclined surfaces. In my large specimens this 

 ridge is but slightly indicated, while in the small ones it is quite jjronounced. 



The infraorbital latero-sensory canal enters the second infraorbital bone on its outer surface 

 near the middle point of its dorsal edge, this point lying at the anterior edge of the orbit. Posterior 

 to this point there is a depressed region on the outer surface of the dorsal edge of the bone, the de- 

 pression lodging the ventral portions of the third and fourth infraorbital bones. From the point 

 where the canal enters the outer surface of the second infraorbital bone it runs downward and for- 

 ward in the line of the Striae on the outer surface of the bone until it r«aches the principal point from 

 which those Striae radiate. There it sends a long primary tube backward nearly to the hind edge of 

 the bone, and itself turns gradually forward to leave the bone at its anterior end and enter the 

 lachrymal. The primary tubes that arise from the canal as it traverses the bone all open on its outer 

 surface ventral to the longitudinal striated ridge just above described. The bone lodges four organs 

 of the infraorbital line. 



The third and fourth infraorbital bones are relatively small. The third bone has the shape 

 of an elongated rectangle, occupies the larger part of the depressed region along the dorsal edge of 

 the second infraorbital bone, and forms the ventral edge of the orbit. The fourth bone is somewhat 



') Siiice the completion of the manuscript these two bones have also beeil found separate in a medium-sized speeimen 

 of Trigia hirundo. 



Zoologica. Heft 57. 17 



