FISHES SCIAENIDAE — LEIOSTOMUS LINEATUS, 



99 



The upper surface of the head is almost uniform purplish brown ; the posterior edge of the 

 opercular apparatus being provided with a dark patch, not unlike what is observed in Pomotis 

 and allied genera. An obscure or hazy light fascia extends from the origin of the second dorsal 

 to the lower part of the abdomen, where it is lost in the uniform yellowish tint which predominates 

 over the belly. The fins assume the dark hue of the body, even the ventrals ; the pectorals 

 alone being of a greyish olive. 



List of specimens. 



LEIOSTOMUS, L a c e p . 



Gen. Char. — Body elongated, more or less subfusiform. Head moderate, anteriorly rounded ; snout thickish, and protruding 

 beyond the lower jaw. Mouth large, inconspicuous, velvet-like teeth upon the jaws. Palate toothless. Opercular apparatus 

 smooth ; edge of preopercle slightly denticulated, if at all. Branchial apertures continuous under the throat. Two dorsal fins, 

 contiguous at their base ; anterior one spinous. Anal fin provided with two small spines. Posterior margin of caudal fin 

 concave or subconcave. Insertion of ventrals situated posteriorly to the base of the pectorals. Upper surface of the head 

 cheeks, and opercular apparatus scaly. Scales of body of moderate size. 



Syn.— Letoslomiis, Lacep. Hist. nat. des Poiss. IV, 1819, 269.— Cot. & Val, Hist. nat. des Poiss. V, 1830, 140.— De" 

 KAT, New T. Fauna, IV, 1842, 69.— Storer, Synops. 1846, 69. 



This genus is very closely allied to Amhlodon, from which it chiefly dififers by the inconspicu- 

 ousness of its maxillary teeth, and which are likewise more uniform. The small anal spines 

 constitute another not less important feature. The shape of the caudal fin we consider also 

 quite valuable in the diagnoses of these two genera. 



LEIOSTOMUS LINEATUS, Ay res. 



Tlie Ijlttle Bassi or Cog^ard. 



Plate XXII 0, Figs 1—4. 



Spec Char. — Mouth large ; posterior extremity of maxillary extending to a vertical line intersecting the posterior rim of the 

 pupil. Superior and posterior edge of the opercle terminating into two flat apines. Extremities of pectorals nearly even with 

 the tips of the ventrals. Scales large. Greyish brown above ; greyish silvery beneath, with oblique waving lines of umber 

 brown. 



Stm.— Letosfomus Uneatus, Atres, in Proc. Cal. Acad. Nat. Sc. I, 1855, 25 — Grd. in Proc. Acad. Nat. Sc. Philad. VIII, 

 1856, 135. 



The head constitutes a little less than the fourth of the total length. The mouth is large, 

 for, the posterior extremity of the maxillary extends to a vertical line which would intersect the 

 posterior rim of the pupil. The snout itself is thickish and rounded, and projects beyond the 

 lower jaw ; the gape of the mouth being nearly horizontal. The eye is subcircular, its hori- 

 zontal diameter entering about five times and a half in the length of the side of the head. The 



