1880.] NATURAL SCIENCES OF PHILADELrHIA. 233 



DESCRIPTION OF A NEW SPECIES OF HEMITSIPTERUS FROM ALASKA. 



BY AV. N. LOCKINGTON. 



Hemitripterus cavifrons, nov. sp. 



D. iv-xiv, 1-12. A. 14. P. 20. V. ^. C. 3-12-3. L. lat. 44. 



Head very large and depressed ; abdomen protuberant, so that 

 the depth equals the width ; snout to tip of ascending process ot 

 pre-maxillar}' rising at an angle of about 45^ ; thence to occiput, 

 along the median line of the fish, deeply concave ; from occiput 

 to caudal peduncle regularly arched, the curve reaching its highest 

 point at about the tenth dorsal spine. Outline of anal base 

 corresponding to that part of the dorsal directly above it. 



Depth, 3^ ; greatest width, 3^ ; length of head, 3^ ; length of 

 pectoral rather more than 4 times in the total length, caudal 

 included. 



Axial length of snout, 3f ; longitudinal diameter of orbit, 6f ; 

 interocular width, 2|| times in length of head ; least depth of 

 caudal peduncle rather less than 5 times in greatest depth. 



Anterior nostril on a level with the centre of tlie pupil, and 

 prolonged into a conspicuous tube ; posterior nostril somewhat 

 tubular. 



Orbits elevated considerabl}' above the general surface of the 

 forehead, so tliat the concavity of the inter-ocular area is equal lo 

 about f of the transverse diameter of the eye ; e^^es lateral, some- 

 what elliptical. 



Mouth very large, ver}' slightly oblique ; its width from tip to 

 tip of the opposite maxillaries, li in the length of the head, and 

 exceeding that of the upper jaw by more than one-third. 



Pre-maxillaries not forming the whole of the margin of the 

 upper jaw, the maxillaries entering into it posteriorly. 



Posterior extremity of maxillary considerably behind the orbit, 

 its upper margin not concealed by the pre-orbital in the closed 

 mouth. 



Lower jaw slighth' projecting beyond the upper. 



Several rows of sharp, recurved, cardiform teeth, forming a 

 broad band, in both jaws, also on the vomer, palatines and 

 phar^-ngeal bones. The teeth on the vomer and palatines slightly 

 longer than those on the jaws. 



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