ICHTHYOLOGY. 



247 



Classifica- "'^" incisors; behind which there is a second rank in which the 



jJqj^ jj^_ teeth near synipliysis have their crowns somewhat truncated, but 



lacopteri. ^^e lateral teeth are all incisorial, the slopes of the two rows 

 V _ J being on different sides, so that they form a furrow which receives 



^^^ the points of the mandibular teeth. At the symphysis of the 

 mandible there are two interior, very small, compressed, and 

 sharply pointed teeth. No maxillary teeth. Three species, un- 

 known to MuUer. 



Genus XIX. Myleus, Miill. Pre-maxiUaries armed with two 

 rows of teeth ; the exterior ones compressed and incisorial ; the in- 

 terior ones truncated like molars, but with the posterior edge ele- 

 vated and cutting ; mandibular teeth in one row, pointed and inci- 

 sorial on the anterior part of the jaw, but with no conical ones 

 behind them. Body compressed; belly keeled and denticulated; 

 these dermal ossicles forming two rows near the anus. Branchial 

 openings large ; pharyngeal teeth villiform ; dorsal with its pointed 

 interneural spine in front, placed over the interval between the 

 ventrals and anal. Three species. 



Genus XX. Mylesinus, Valenc. Dorsal and anal fins as in 

 Myleus; pre-maxillary teeth five, sharply cutting, standing closely 

 side by side, with their crowns a little dilated, and having a little 

 cusp on each side, so that they may be called tricuspid, though 

 the middle lobe forms most of the cutting edge; the neck of the 

 tooth is narrower; a little behind the two mesial teeth, though 

 in the same row or nearly so, there are three teeth with trun- 

 cated or sloping cusps, which are rather notched than tricuspid ; 

 mandibular teeth twelve on each lirab, in a single row, tricuspid, 

 with the middle cusp oval and elongated ; no conical teeth forming 

 a second row at the mandibular symphysis. Lips thick, fleshy, and 

 densely papillose. One species. 



Genus XXI. Chalceus, Cuv. (TJn/con, Miill.) Pre-maxillary 

 teeth triserial, multicuspid; the anterior ones the smallest, and 

 seeming conical from the sraailness of their lateral cusps ; man- 

 dibular teeth biserial, the front ones large and multicuspid, the 

 lateral ones and those of the anterior rows conical ; behind the 

 symphysis two stronger conical teeth, as in MyUtiis. Body elon- 

 gated, compressed ; belly rounded like that of a Trout, but covered 

 with large scales like a Carp. A great number of pyloric ca}ca. 

 Eleven species. 



Genus XXII. Chalcinus, Miill. Pre-maxillary teeth small, 

 crenulated, multiscupid, biserial; mandibular teeth, biserial like 

 those of Chalceus, multicuspid, and strong anteriorly ; two small 

 conical ones behind the symphysial ones, and an interior lateral 

 row of very small conical ones towards the angle of the* mouth. 

 Body compressed ; edge of the belly trenchant but not serrated. 

 Porsal far back ; anal very long ; and pectorals long and pointed. 

 Three species. 



The genus Alysia of Lowe (Zool. Tr. 1839) probably belongs to 

 some of the preceding genera of C/iammj, but the teeth are not de- 

 scribed with sufficient minuteness to determine its proper place. 



h. M. Valenciennes makes a small group of Serraaalmus, Pygoceu' 

 truSj Pygojyristis , and Catoprion. 



Genus XXItl. Seurasalmus, Lacep. Teeth triangular and 

 trenchant, in a single row on the pre-maxiUaries, palatines, and 

 mandibular; maxillary not entering into the composition of the 

 orifice of the mouth, but lying under the edge of the pre-orbitar, 

 and behind the pre-maxillary. Body compressed, for the most part 

 rhomboidal, the first dorsal and anal ray proceeding from the most 

 prominent points of the upper and under jjrofile ; belly keeled and 

 serrated with a double row of dermal spines before the anus; first 

 interneuralof the dorsal projectingone pungent pointanteriorlyand 

 two posteriorly ; branchial openings pretty large ; four branchio- 

 stegals ; stomach a very large conical sac; from thirteen to twenty- 

 one pyloric cajca. Voracious carnivorous fishes. Ova not dropping 

 into the cavity of the abdomen. 



Genus XXIV. Pygocentrus, Miill. No palatine teeth; pre- 

 maxillary and mandibular bones carrying a single row of trian- 

 gular, trenchant, feebly-crenulated teeth. Maxillary bone as in 

 Serrasalmus, almost hidden behind the pre-maxillary. Body com- 

 pressed ; bellj' trenchant and serrated, the points near the anus 

 being doubled ; branchiostegals four ; caical stomach ; caeca vary- 

 ing from ten to fifteen; air-bladder divided into a small globular 

 anterior one, and a very large second one, which communicates 

 with the oesophagus by a very short canal. Ova not dropping into 

 the cavity of the abdomen. Four species. 



Genus XXV. Pygopristis, Mull. Separated from ryjocen- 

 trvs by the edentate and smooth roof of the mouth, but the jaw 

 teeth are crenulated, and strongly denticulated. Two species. 



Genus XXVI. Catoprion, Miill. and Trosch. Salmonoids, 

 with a serrated belly, having two rows of conical pre-maxillary 

 teeth, and one row of trenchant triangular mandibular ones. One 

 species. 



Genus XXVII. Hydrocyon, Cuv. Salmonoids, with large and 

 strong teeth implanted in a single row on both jaws; these teeth 



are conical, slightly compressed, and have cutting edges; roof of Classifica- 

 the mouth smooth. Body elongated ; sides flattened in the middle; tion — Ma- 

 belly rounded like the back; intestines very short, with a consi- lacopteri. 

 derable number of pancreatic CEeca (thirty-five to forty). Bran- '^^^^^^■Z 

 chiostegals four. One species. 



Genus XXVIII. Cynofotamus, Valenc. Differ from Hydro- 

 cyon in having two rows of pointed pre-maxillary teeth, those of 

 the exterior row very short ; interior row containing four large 

 canines ; maxillary on the side of the orifice of the mouth like that 

 of a trout, edged by a row of very small conical teeth ; mandible 

 armed at the end by eight canines ; and a second interior row ia 

 composed of very small teeth ; palate destitute of both teeth and 

 granular eminences. Branchiostegals five. 



Genus XXIX. CYNODON.Spix. Salmonoids, with granular teeth 

 on the palate ; pre-maxillaries, maxillaries, and mandible armed by 

 a single row of pointed conical teeth, among which there are enor- 

 mous canines, the largest being near the symphysis, those of the 

 mandible entering corresponding holes in the palate. Body much 

 compressed at the pectorals ; belly frequently compressed ; anal 

 very long and scaly. Pectorals pointed and laid along the body, de- 

 scending to a right angle with the longitudinal axis when they act. 

 Stomach remarkably large. Carnivorous. Three species. CynO" 

 don scomberoides, Val., is the genus Hydrolycue of Miiller. 



Genus XXX. Xiphorynchus, Agass. Differs from Cynodon 

 in having a single row of pointed teeth on the palatines, as well as 

 on the jaws. Carnivorous fish. Twelve pancreatic caeca or there- 

 abouts. Five species. 



Genus XXXI. Aqoniates, Mull. Intermediate between Hy 

 drocyon, which is remarkable for long canines, and Tetragonop* 

 terus, which has two rows of pre-maxillary teeth, some of them 

 tricuspid. This dentition distinguishes Agoniates from Cynopo- 

 tamus. One species. 



Genus XXXII. Xiphostoma, Spix, Snout conical and elon- 

 gated by the extension of the pre-maxillaries, palatines, nasal and 

 prefrontal, and the dorsal aspect of the ekuU wholly covered by a 

 granular engraved casque. The elongated pre-maxillaries and the 

 mandible are furnished with numerous minute teeth, set closely 

 side by side in a single row, their points recurved like a small fish- 

 ing-hook ; palatines wrinkled and rough, with odontoid granula- 

 tions. Body slender, elongated, and round. Dorsal very far back 

 beyond the ventrals. Pancreatic casca very considerable in number. 

 Five species. 



Genus XXXIII. Salanx, Cuv. (Leucosoma,Gra.j.) Body slen- 

 derly fusiform, the thin end of the spindle being the anterior one ; 

 jaws equal, the cleft of the mouth horizontal, slightly arched in the 

 middle ; maxillary curving over the corner of the mouth, and send- 

 ing a slip in front of the end of the pre-maxillary, forming a consi- 

 derable part of theborder of the orifice ; jire-maxillaries armed with 

 a single series of small teeth, with four tall, subulate, recurved 

 canines among them on each bone, the space nearest the symphysis 

 have only a row of small ones ; maxillary edged with a pectinated 

 row of short teeth ; mandibular teeth on the sides of the bone 

 smaller and more numerous than those of the upper jaw ; tip of the 

 mandible toothless, but close to it there are three strong teeth, whose 

 points when the jaws are close pass through a rhomboidal mem- 

 branous space near the point of the snout ; palatine bones set with 

 a row of fine teeth, but there are no teeth on the vomer, which does 

 not project. Ventrals about the middle of the fish ; dorsal in the 

 middle of the posterior half, the anal still nearer the caudal fin, and 

 the adipose fin corresponding to the posterior part of the anal. One 

 species. 



Genus XXXIV. Hydropardus, Reinh. Teeth on the pre- 

 maxillaries, elongated maxillaries, and mandible, unlserial, caninei 

 and conical ones intermixed ; the anterior mandibular teeth received 

 into pits in the palate ; palatine teeth minute, granular ; pharyn- 

 geal teeth villiform. Body elongated, compressed ; belly keeled. 

 Scales small. Gill-openings extremely large; five branchiostegals; 

 internal rakers of the branchial arches having the form of small 

 osseous tubercles, studded with the finest spines ,• ventral pie none \ 

 dorsal fin over the anal, which is exceedingly long, and has a scaly 

 base. (An. 1850.) 



Genus XXXV, Gonostoma, Rafin. Pre-maxillaries short, not 

 passing the eye; the maxillary completing the upper half of 

 the mouth, as in the ClupeidcB or Sahnonidae ,■ teeth large, conical, 

 and sharply pointed, widely set on the jaws, with very small ones 

 in the intervals; palatines and entopterygoids covered with minute 

 raduliform teeth, and there are rough spots on the tongue ; pharynx 

 very narrow, the superior pharyngeal teeth resembling the teeth of 

 a harrow, in two groups, the anterior group composed of three teeth 

 larger and longer than the rest; fourteen branchiostegals, sub- 

 orbitar very delicate ; dorsal placed far back ; free recurved spines 

 on the sides of the tail. Ovarian sacs shut. One species. 



Genus XXXVL Ciiauliouus, Bloch, {Astronesthes, Richardson. 

 P/uenodon, Lowe, Ann. Nat. Hiat.,x.y\i, 52.) Mouth formed nearly 



