250 



ICHTHYOLOGY. 



Classifica- 

 tion — Ma- 

 lacopteri. 



Genus I. Stomias, Cuv. Elongated scaly fish, having some- 

 what of the form of Scombereso.t, but with a short high head and a 

 barbel depending between the limbs of the mandible. Dorsal and 

 anal opposite near the caudal; ventrals in the posterior quarter of 

 the fish before the vertical fins. Scales thin, fornung hexagonal di- 

 visions in the skin, not imbricated. Mouth cleft far past the eye, 

 which is near the end of the very short snout ; upper border of the 

 mouth formed by the premaxillaries and maxillaries ; mandible pro- 

 jecting beyond the snout ; strong conico-subulate curved teeth on 

 the premaxillaries and mandible, with very small teeth on the part 

 of the maxillary, which passes beyond the premaxillary ; small 

 teeth exist between the tall ones ; the tongue is toothed in the same 

 manner, and the branchial rakers are in the form of long, hooked 

 teeth. Branc'hiostegals seventeen ; pretty large gill-openings. Ali- 

 mentary canal a long straight tube, without a stomachal dilatation ; 

 no pancreatic ca?ca ; ovaries, two long sacs ; a long, slender air-blad- 

 der. One iMediterranean species. 



The want of an adipose fin seems to be the only character that 

 separates this fish from Ckauliodus, and other Scopdini. 



Genus II. Microstoma, Valenc. General form of -S/om/a.«, but 

 less elongated, with a small head and a very small mouth, wholly 

 anterior to the proportionally enormous eye. The anal behind the 

 dorsal, and neither of them so far back as in Stomias. Upper half 

 of the orifice of the mouth formed by the small premaxillaries 

 and maxillaries, both without teeth ; a few vomerine teeth, none on 

 the palatines, nor on the tongue or pharyngeals, but the branchial 

 rakers are long and pointed. Branchiostegals four. Intestine and 

 air-bladder as in Stomias; pseudobranchiae crested. One Mediter- 

 ranean species. The specimen in the Paris Museum is the same 

 with Risso's, but the imperfect descriptions of the latter giving it 

 an adipose fin, led MuUer to believe them to be different. 



The Chirocentres, says M. Valenciennes, approach Esox, and even 

 Ci/prinus, by the absence of pancreatic caeca, but they depart from 

 these families to place themselves near the Clupeoids by the junc- 

 tion of the premaxillaries and maxillaries. It is a family of only 

 one species, forming the 



Genus III. Chirocentrus, Ouv. Body compressed, elongated ; 

 belly trenchant, not denticulated. Dorsal far back on the tail, op- 

 posite to the anal ; pectorals pointed with a long styloid bone in the 

 axilla covered with scales; ventrals excessively small. Pharyngeal 

 teeth strong and curved ; two mesial premaxillary teeth horizontal ; 

 upper jaw formed of small premaxillaries soldered to dentiferous 

 maxillaries which have two supplementary pieces as in Ciupea, one 

 of them hidden under the preorbitar scale bone, the other extend- 

 ing beyond the corner of the mouth ; teeth very fine and short on the 

 palatines, two pterygoid bones, the tongue, the branchial arches, 

 and the pharyngeals. Stomach ceecal ; intestine short, with the in- 

 terior mucous coat forming a long spiral valve ; no pancreatic 

 caeca ; swim-bladder long, slender, with interior imperfect trans- 

 verse partitions, and an air-tube going to the stomach. Branchio- 

 stegals eight. 



Genus IV. Notopterus, Valenc. Body greatly compressed, 

 very thin towards the tail. Snout obtuse, with little projection, the 

 nasal bone scarcely passing the turbinal ; two small premaxillaries 

 placed transversely at the extremity of the nasal, and suspending 

 the free maxillaries, the latter a single bone (not of several as in 

 the Clupeida:)', limbs of the maxillaries having a deep, oblong, dor- 

 sal cavity, with two trenchant edges carrying teeth ; jaws armed 

 with minute raduliform teeth, also the palatines; a small spot 

 on the end of the vomer, an oval surface on the presphenoid ; 

 and very long crooked ones on the edges of the tongue. The 

 foremost two suborbital scale bones are serrated on their edges, 

 and also the edges of a large hollow on the inferior limb of 

 the preoperculum, which hides entirely the smooth interoper- 

 culum ; operculum large, and suhoperculum wanting; as in the Si- 

 luri. Large muciferous cavities in the cranium, on which there 

 are five longitudinal ridges, namely, a mesial interparietal one and 

 two lateral ones on each side; the suprascapula is also cavernous, 

 and pierced for the passage of raucoducts. Dorsal very small ; anal 

 very long and united to a small caudal ; ventrals united to one 

 another, but scarcely perceptible from their minuteness. A genital 

 papilla behind the anus. Belly very much compressed, and edged 

 by a double series of denticulations. Scales small, covering the 

 body, the gill-covers, and part of the cheeks ; lateral line straight. 

 Branchiostegals seven, erroneously stated in the ^^Regne Animale^' to 

 be only one. Stomach compressed, globular, witli the cardia and 

 pylorus in front, one over the other. Ova not shut up in an ovisac, 

 but dropping into the abdominal cavity. Air-bladder multilocular, 

 having numerous interior partitions, and some exterior contrac- 

 tions, with two long posterior horns ; and two little horns that, pro- 

 ceeding from the fore-part of the bladder attached to the cranium, 

 pass under the acoustic sacs which contain the otolite, onwards to the 

 third tubercle of the brain — a unique circumstance in fishes. Three 

 species. 



Notoptrrtis is considered by M. Valenciennes to be the type of a Classifica- 

 peculiar family. tion— Ala- 



Genus V. Arapaima, Miill. (Sudis^ Cnv.; nonKafin.; Vastres, lacopteri. 

 Valenc.) Body more or less rounded, covered by a mosaic <. ^ _^ y 

 veork of osseous scales, which extend over the vertical fins. 

 Anal and dorsal short, and far back. Head formed of deeply sculp- 

 tured bones, with mucous cells, clothed in a thick skin; large 

 cheek bones ; mouth pretty large, bordered above by the premax- 

 illaries and maxillaries, both cari-ying teeth, and below by the 

 mandible, toothed in the same way; small raduliform teeth cover 

 the palatines, the pterygoids, the vomer, the presphenoid, the 

 lingual bone, and all the budy of the os hyoides ; and there is a plate 

 of teeth on the internal surface of the mandible ; the presphe- 

 noidal and palatine teeth vary with the species. Air-bladder said 

 to be cellular like the lungs of a fowl ; two valves at the arterial ori- 

 fice of the ventricle, and no muscular bulb. About six species in 

 the rivers of South America. 



Genus VI. Heterotis, Ehren. A large cuirassed head, 

 clothed in mucous skin, and hard mosaic scales on the body, give 

 this genus a resemblance to Sudis, but the vertical fins are not 

 scaly. The teeth stand in a single row on the jaws, they are re- 

 curved with a rounded point; no teeth on the palatines, vomer, or 

 presphenoid, but there are groups of straight conical teeth on the 

 pterygoids and dilated part of the hyoid bone. Two long, thick, pan- 

 creatic caeca. A cellular air-bladder enters into rings formed by 

 the parapophyses of the caudal vertebra;, as in the Exocccti. Two 

 species, Africa. 



Genus VH. Butirinus, Com. {Albula, Gronov.) Has the 

 general aspect of some of the Indian Cyprinoids. Body regu- 

 larly fusiform, with a conical head, and pointed snout, passing the 

 end of the mandible a little. Dorsal in the middle of the length, 

 its hinder third opposite the ventrals, the anal half-way between 

 the latter and the largely-forked caudal. Head naked. Body 

 covered with large, hard, firm scales; furrows on the cranium per- 

 ceptible through the skin. Fine card-like teeth on the jaws, 

 palatines, front of the vomer, and pharyngeals ; and what is charac- 

 teristic of the genus are small, cup-shaped, hemispheric patches of 

 teeth, covering apart of the presphenoid, and another on each ptery- 

 goid. The convex tongue fits into the canal formed by these three 

 bones, and its surface is also covered with granular teeth. Intes- 

 tines like those of the Clupcidce. Stomach large, cEccal ; pancre- 

 atic caeca twenty-two ; hexagonal cells in the mucous coat of the 

 rectum; ovarian sacs opening on each side of the anus. A long 

 air-bladder, having its thin membrane enveloped in an exterior fib- 

 rous sac, communicates with the stomach by a short tube. Nine 

 species. 



The Butirines, says M. Valenciennes, are undoubtedly allied to 

 the Clupeoids by their large air-bladder and numerous pancreatic 

 CJeca, and the want of teeth on the maxillary, but they are kept 

 apart from that family by the absence of a keeled denticulated 

 belly. 



ERYTHRINID^. 



A small family established by M. Valenciennes of several 

 genera whose true place in the system has been much 

 canvassed. Eri/thriiius is stated by the ichthyoloj^ist just 

 named, to present in its skeleton a resemblance to the Sal- 

 monidce in the adjustment of tlie bones of tlie tace, to the 

 Cf/prinidce in the size of the lateral occipital foramina, to 

 the Clupeidce in the parieto-occipitiil foramina, and in the form 

 of the basi-occipital, which differs totally from that of the 

 Cyprinoids in wanting that vaulted dilatation to which the 

 median pharyngeal plate is attached in that family ; but 

 again it possesses Cyprinoid characters in the union of the 

 first vertebra; and in the existence of the Weberian ossicles, 

 connecting the air-bladder with the auditory organs, though 

 not exactly in the same way as in the Ci/prinidce, 



Family X.— ERYTHRINID^. 



Eri/thro'idcs, Valenc. Body moderately thick ; back and belly 

 rounded ; head large ; snout obtuse ; upjier arch of the mouth formed 

 of the smalt premaxillaries, with the maxillaries articulated to their 

 extremities, both crowded with small conical teeth, as is also the 

 mandible. Villiform teeth cover the palatines and pterygoids, and 

 form an arched plate on the roof of the mouth, separated from its 

 fellow on the other side by a smooth vomerine line ; pharyngeal 

 teeth also villiform. Entire cheek covered by bony suborbitar 

 scales, followed by two temporal plates which are characteristic of 

 the family. Stomach conical, siphonal ; pancreatic caeca numerous ; 



