MUSTELUS MEGALOPTERUS.— Smith. 



Pisces. — Plate II. (Male.) 



M. supra viridi-brunneus, purpureo-tinctus, infra subochreus, regionibus ante pinnas pectorales et post 

 ventrales rubro-umbratis ; corporis lateribus brunneo-purpureis. Oculis cupreo-viridi-flavo-niten- 

 tibus. 



Longitudo 4 ped. 4 unc. 



Colour. — Hind-head and back as far as the first dorsal fin, greenish brown 

 glossed with purple — the colour is unequal as to depth, on the hind-head 

 it is lightest, and is there slightly shaded with ochre yellow ; anterior and 

 lateral parts of the head greyish purple, faintly freckled or clouded with 

 vermillion red ; back, behind first dorsal fin, purplish grey, slightly clouded 

 with clove brown ; sides of body, light brownish purple ; under surface, from 

 tip of lower jaw to caudal fin, ochry yellow of various tints, the parts im- 

 mediately behind the ventral fins, and those in front of the pectorals, 

 highest coloured, and freely mottled with vermillion red. Pectoral and 

 ventral fins, purplish grey shaded with brownish red, the latter are besides 

 faintly clouded with vermillion red ; the remaining fins between greenish and 

 purplish grey — the first dorsal, nearly pure grey at its base, and the caudal 

 has an obscure ochry stripe in the direction in which it is traversed by the 

 vertebral column. Eyes a bright greenish yellow, with a strong metallic 

 lustre. 



Form, &c. — Anterior portion of body robust, and sub-triangular, with an 

 acute carina extending between the hindhead and the anterior edge of the first 

 dorsal fin ; posterior portion of body slender, somewhat cylindrical, and with 

 the rudiments of a carina between the first and second dorsal ; the surface harsh 

 and rough, arising from the skin being every where closely covered with small 

 triangular and carinated scales, — the carina is central, forms the apex of the 

 scale, and projects slightly over the base of the scale next in succession. 

 Head, above somewhat flattened, below and on the sides rather convex ; 

 hind-head broad, nose rather narrow and inclined to pointed ; teeth small, 

 three-sided, and with three distinct angles; the apical portion of each 

 slender, slightly prolonged, and acute at the point. Eyes, deeply set, pupil 

 linear and oblique, nictating membrane large ; post-ocular spiracles rather 

 large, oval, and situated directly behind the outer canthus ; the two last 

 branchial, opening, situated above and behind the anterior margin of pectoral 

 fin, appendages long and rather slender. 



