MUGIL CORRUGATUS. 161 



corresponds with the middle point between them and the beginning of the anal 

 fin. 



The caudal fin is large and powerful, but rather lunate than forked ; its lobes 

 being very broad and short. Their longest rays, reaching to the points, are 

 simple : and the rays between these are peculiarly stout and copiously branched, 

 with rows of conspicuous pointed imbricated scales running up between them. 



The scales are very large, quite smooth to the touch, and with apparently entire 

 edges, i. e. to the unassisted senses cycloidal (Agassiz) : yet, when examined with 

 a high power of the microscope, they prove to be neither properly cycloidal nor 

 ctenoidal ; having the edges of the superimposed laminae finely and minutely 

 denticulate or rather crenulate ; being in fact completely intermediate between 

 the two above-named structures.* They are disposed in regular longitudinal 

 rows of from forty-three to forty-five in number, from the edge or axil of the 

 opercle at the upper axil of the pectoral fins, to the base of the caudal fin, where 

 they become smaller, softer, and confused. There are about sixteen or seventeen 

 scales in a vertical line at the first dorsal fin. The elongated scales at the base 

 of the same, and at the fore-axil of the ventral fins, have been already described : 

 there is neither elongated nor pointed scale at the upper axil of the pectoral fins. 



The lateral line is indistinguishable either by the eye or by the structure of 

 its scales from the rows above or beneath its usual place. 



Colour a bluish grey, becoming blackish, dark, and dusky on the top of the 

 head and back, and paler down the sides, which are striped longitudinally in 

 regular straight lines along the middle of each row of scales with ten or eleven 

 narrow equidistant dusky streaks, becoming faint and evanescent on the belly. 

 Each scale in situ appears also bordered near the margin with a dusky crescent. 

 The belly, throat, lower jaw, and cheeks up to the lower edge of the orbit, are 

 pure opaque or milky white. The ventral fins are white, except the first ray, 

 which is somewhat dusky or greyish. All the other fins are dark grey. The 

 upper part of the upper lip is dusky grey or blackish : its lower part is white or 

 flesh-colour. The iris is dark rich brown, varied with golden, and with the inner 

 edge golden. 



The fry have a distinct brassy or metallic yellow spot or patch on the opercle, 

 which they for the most part lose when they attain the length of eight or ten 

 inches. It is, however, now and then retained, though in an evanescent state, 

 in full-sized fishes. 



On opening the abdomen, it seems to be filled with the large and extremely 

 voluminous intestine, which makes three or four volutions, and is singularly and 

 beautifully punctate or reticulated, like fine lace, especially towards the vent. The 

 stomach is rather small, and singularly shaped, being exactly pear-shaped, or coni- 

 cal and clavate at the top. The entrance from the oesophagus is in its middle ; 

 and the ascending branch, or pylorus, which forms its fore or upper part, swells 

 out into a sort of hard gizzard, with thick cartilaginous parietes ; at the top of 

 which, out of a hollow like a navel, issues the intestine, surrounded at its origin by 

 six distinct and large but short finger-like e«m, of a pale colour, and rosy at their 

 pointed tips : the upper part of the stomach being also shining, pale, or whitish. 

 The liver is of moderate size, but short, and of a dark colour. The air-bladder 

 is large, oblong-elliptic, extending the whole length of the abdominal cavity, but 

 adnate throughout to the upper part of the same, from which it is not separable. 

 The whole peritoneum is dark or blackish. 



The intestines are of a very tender substance, easily ruptured ; and, like the 



* See also Annales des Sciences, xi. 347, 3C9 (June 1839) : xiii. 61 (Jan. 1840) ; and xiv. 108 

 (Aug. 1840). 



