ICHTHYOLOGY. 



285 



Classifica- attribute to a gigantic harp. It miglit almost have been said 

 tion — that the vessel trembled at those uncertain sounds. For 



Acanthop- gg^^g tj^^g t|,gy increased, and finally formed a loud and 

 universal chorus, the entire length of the vessel, and on 

 either side. In proportion as they ascended the river the 

 mysterious sounds diminished, and finally altogether ceased. 

 The interpreter gave the information that they were pro- 

 duced by a troop of fishes of a flattened oval form, which 

 possess the faculty of adhering firmly to various bodies by 

 their mouths. A similar phenomenon was noticed by the 

 illustrious Humboldt in the South Seas, although he was 

 unable at the time to divine the cause. It would, as Cuvier 

 has remarked, be an object of curious research to discover 

 by what organ these sounds are produced. Lieutenant 

 White need not have left his own country to become 

 acquainted with the loud noises produced by the " Drums" 

 or " Grunts," as Pogonias cliromis is named in the United 

 States. This fish, or a species similar to it in appearance 

 and habits, abounds in the winter and spring on the coasts 

 of Georgia and Florida, and drums so loudly on the bot- 

 toms of vessels that anchor there, as utterly to deprive the 

 sailors of sleep, until several nights' use has accustomed 

 them to the loud and disagreeable noise. The sound is 

 1 better expressed by the word drumming than by any other, 

 and is accompanied by a tremulous motion of the vessel. 

 We caught several ot the fish, and found them excellent 

 food, but their tails were rejected as being full of parasitic 

 filaria. It appeared to us that the uneasiness produced by 

 these parasites might cause the fish to beat their tails against 

 the bottom of the vessel, and that many individuals were 

 emploved in keeping up the sound which continued without 

 the slightest intermission all the night through. The teeth 

 of Plectropoma dentex 

 have been shown 

 60. Fig. 103 

 sents a Sciaenoid 

 group having a 

 dorsal fin. This group 

 corresponds in external 

 appearance with the Per- 

 coids that have a single 



dorsal, being seemingly as much allied to them as to the 

 typical Sciaenoids with the two dorsals, and differing from 

 the analogous Percoids chiefly by the presence of teeth on 

 the roof the mouth, and a few pores on the mandible. The 

 latter character, however, exists in some Percoids also. 



Family VIII.— SCI.'EXID^. 



{Lfs Sciano'ides. Cuv.) With many of the exterior characters of 

 the Percoides, such as a spinous or denticulated operculum, a vari- 

 ously armed preoperculum, scaly body, a simple or double dorsal, 

 or one deeply notched, and the same varieties in the combination 

 of these characters, they have more or less of a peculiar family 

 physiognomy, and differ from the Percoids in having no teeth on 

 the vomer or palatines. The bones of the head and face are often 

 full of muciferous cells or hollows, with external porous openings ; 

 and the face and snout are frequently gibbous. The vertical fins 

 and parts of the head are occasionally scaly. Scales ctenoid, gene- 

 rally obliquely ranged. In their internal anatomy there is more 

 variety than in the Percoids, and their air-bladders especially have 

 branching appendages in many genera. The diagnostic characters 

 are, — denticulations or spines on the opercular pieces ; cheeks not 

 cuirassed by the suborbitar ; mouth little protractile ; vomer and 

 palatines toothless ; seven branchiostegals. 



(a.) Two dorsals, or one deeply notched. 



Genus I. Sci.ena, Cuv. Head convex, with cellular bones. Two 

 dorsals, or one dorsal deeply notched, and the soft part much longer 

 than the spinous one ; a short anal. Preoperculum denticulated ; 

 operculum ending in points. Seven branchiostegals. Otolites larger 

 than in most fishes, and the air-bladders large and complicated. 

 The proper Seiijmae have feeble spines in the anal, and are destitute 

 of canines and barbels. Stomach caecalj tea pancreatic cxca or 

 more. Four species. 



Fig. 103. 

 Diagramma orientate. 



GrENns II. Otolithus, Cuv. Scimn.(e also with feeble anal spines 

 and no barbels, but having long curved teeth or canines among the 

 others. Air-bladder having a horn-like projection on each side in 

 front; four pancreatic cseca. Eighteen species. 



Genus III. ANCVLonoN, Cuv. Otolithes with a very short snout, 

 excessively long canines, and a pointed tail. Two species. 



Genus IV". Couvina, Cuv. iicicen(e with wholly villiform teeth 

 and no barbels, but ditfering from Sciaena and Otolithus in the 

 great size of the second anal spine. Nineteen species. 



Genus V. Johnius, Bloch. Considered by Cuvier to be like 

 C'orvina and Otolithus, a subdivision of Scimna, and distinguished 

 chiefly by the second anal spine being weak and shorter than the 

 soft rays of that fin. Eighteen species. 



Genus VI. Leiostomus, Cuv. Johnii in having a small anal 

 spine or feeble denticulations in the preoperculum ; but the teeth 

 of the jaws so fine as to be with great diflficulty seen; pharyngeal 

 teeth pavement-like. Scales ciliated. Horns of the air-bladder 

 smaller and more slender than in Otolithus. Two species. 



Genus VII. Larimus, Cuv. One of several anomalous Sciaenoid 

 forms, which have cliaracters different from those of the foregoing 

 groups. Two dorsals. Villiform teeth. Forehead not arched ; snout 

 short; preoperculum slightly denticulated. Stomach csecal, narrow; 

 eleven pancreatic caeca; air-bladder large, simple. Two species. 



Genus VIII. Nebris, Cuv. Sciaenoids with two dorsals. Villi- 

 form teeth. Profile nearly straight ; snout short ; mandible ascend- 

 ing. Limb of the preoperculum membranous, and merely striated, 

 and the fins all more or less scaly. One species. 



Genus IX. Lepipterus, Cuv. Sciaenoids with villiform teeth, 

 prolonged snout, profile rather concave, and very scaly vertical 

 fins. One species. 



Genus X. Boridia. Cuv. Corvincg with smooth blunt teeth on 

 the jaws. One species. 



Genus XI. Conodon, Cuv. Sciaenoids distinguished from the 

 others by having a row of conical teeth on the two jaws. One 

 species. 



Genus XII. Eleginus, Cuv. Sciaenoids with an entire pre- 

 operculum. llouth small. Anal long. Two short conical horns in 

 the fore part of the air-bladder. Three species. 



Genus XIII. Eques, Bloch. Resemble Scicena, Corvina, Johnius, 

 in their convex snout, scaly throughout, like the rest of the 

 head; in the mucous pores and pits of the lower jaw; in the up- 

 per jaw being able to retire under the edge of the preorbitar ; 

 in the length of the second dorsal, and the shortness of the anal, 

 both of them scaly as well as much of the caudal. Teeth villiform, 

 and not elongated like those-of the Chcetodons. In Eques the body 

 is compressed, and by the convexity of the nape assumes a cunei- 

 form outline. Branchiostegals seven. Faint crenatures on the pre- 

 operculum; the bony frame of the operculum ends in two flat points. 

 The first dorsal is high and peaked with mostly flexible rays; second 

 dorsal low and long; caudal rhomboidal ; ventrals longer than the 

 pectorals. A small membrane in front of the snout, with a pit on 

 each side between it and the high preorbitar. A small pore beneath 

 the mandible on each side of the median line, A large silvery air- 

 bladder ; caecal stomach ; four pancreatic caeca. Three species. 



Genus XIV. Umbrina, Cuv. Sciaenoids having one barbel un- 

 der the mandibular symphysis. Thirteen species. 



Genus XV. Lonchorus, Cuv., Bloch. Umbrince with two 

 mandibular barbels and a pointed caudal. Two species. 



Genus XVI. PoaoNiAS, Lacep. Umbrinm with many small man. 

 dibular barbels. Lower pharyngeal teeth and middle upper ones 

 large like those of Labrus. Two species. 



Genus XVII. Micropogon, Lacep. Scijenoids with a prominent 

 nape like Corvina. Moderate-sized anal spine, and very small and 

 numerous barbels. Distinct denticulations on the ascending limb of 

 the preoperculum, those at the angle being larger ; operculum end- 

 ing in two flat points. Membrane at the end of the snout four-lobed. 

 Mouth moderately protractile ; pretty broad bands of villiform 

 teeth; pharyngeal teeth villiform, the middle ones being larger, 

 with obtuse summits. Under the mandible at the symphyses two 

 large pores and three small ones ; three or four little barbels 

 attached to the limb of the mandible. Scales slightly rough and 

 oblique as in the Sciaenoids in general. Dorsal spines not very 

 strong ; slender ventral spine, and the anal spine shorter than the 

 soft rays ; caudal nearly even at the end. Three species, America. 



(b.) A single dorsal ; preoperculum always denticulated. 



Genus XVIII, H.emulon, Cut, Body oblong, pretty high an- 

 teriorly, somewhat compressed. Profile descending almost in a 

 straight line, and forming a snout that projects tolerably, Preor- 

 bitar large, but not denticulated, covered with skin and scales, 

 joining the cheek as in the ftcianw in general, and forming a ledge 

 under which the moderately protractile upper jaw retires. Lips 

 fleshy. Mandible articulated under the eye, having an oval pit 



