274 PROCEEDINGS OF THE ACADEMY OF 



iielle. Orbit 4.2 times in length to opercular margin. The casque 

 rises from the orbits to the dorsal spine. It is keeled obtusely, 

 or roof-shaped, extends on the sides nearly to the lateral line, and 

 is prolonged into a point on each side of and behind the last ray 

 of the dorsal fin. The humeral portion of the clavicle is much 

 enlarged and dilated horizontally, and is produced into a post- 

 humeral (postclavicular) spine which extends to below the dor- 

 sal spine, is sharp-edged, striate, and not serrate. 



The inferior aspect of the scapular arch is a transverse shield, 

 convex in front, concave behind, and gently concave inferiorl}^, 

 two-thirds of its width being composed of the coracoids; the sur- 

 face punctate. The postcoracoid processes are very long, ex- 

 tending to bej'ond the bases of the ventral fins ; they are curved, 

 and the extremities dilated outwards, so as to present with the 

 thoracic portion exactly the form of the Grecian lyre. The huge 

 prickly pectoral spines curving round on each side, and meeting 

 behind the ventral fins, suggest the wreath which often accompa- 

 nies the lyre. The surface of the postcoracoid processes is longi- 

 tudinally striate. A section of the fish in front of the pectoral 

 fins is triangular. 



The preorbital bones are well developed; they form an erect 

 transverse crest of eleven long, sharp teeth, and are toothed late- 

 rally and below. Casque rugulose. 



Radial formula D. I. 4, C. 12, A. 12; Y. 6 ; P. I. 2. The dorsal 

 spine is' quite straight, trigonal in section, and longitudinally 

 grooved. The inferior half in front is furnished with stout spines 

 directed upwards ; behind smooth. The pectoral spines are very 

 large, curved, and extend to the second or third ray of the anal 

 fin. They are spinous, and longitudinally grooved. 



The lateral shields are tw^enty-three in number, and each is fur- 

 nished below its middle with a recurved spine as in Doras. The 

 surface of the plates is granular. Caudal fin truncate. 



Color in front of the dorsal fin dark brown, minutel}' varied 

 with lighter ; a light cross-band from one humeral base to the 

 other, and another between the orbits. Posterior part of the 

 body yellowish, with a dark spot at the base of the dorsal fin ; a 

 band on the middle of the side, and one at the base of the tail. 

 Fins brown-dusted ; dorsal and pectoral spines brown, yellow 

 cross-banded. Inferior surfaces deep brown, except the osseous 

 portions, which are pale brown. 



[January 16, 



