262 



ICHTHYOLOGY. 



Classifica- ami without a conspicuous casque. First dorsal ray elongated into 

 tion — Ma- a fiat cutaneous filament. The palatine teeth a narrow band 

 lacopteri. divided by smooth lines into four patches. Branch iostegals six; four 

 ^ M B -^ or si-x barbels. Five species. 



Gf.nus VIII. Pang.\SICS, Valenc. Four short barbels; no 

 prolongations of the fin rays. Ten branchiostegals. Air-bladder 

 divided into four parts by three contractions. One species. 



Grnus IX. SiLUNDIA, Valenc. A small smooth head, like that 

 of Schilbes. Very small adipose fin ; long anal. Only two small 

 (maxillary) barbels ; teeth of the jaws hooked, and longer than in 

 other Silttrid(B ; a transverse band in front of the roof of the mouth, 

 as in Bagrus. Twelve branchiostegals. Two species. 



Genus X. .Sciades, MUU. and Trosch. A cross band of palatine 

 teeth, and behind them two clusters. 



Genus XI. Ariodes, Mull and Trosch. Palatine teeth forming 

 two separate patches, and sometimes farther back a single tuft 

 only. 



Genus XII. Eutropiu.s, Mull, and Trosch. One confluent band 

 of teeth on the vomer and palatines. Head small ; nape high : the 

 head and adjoining part of the body compressed near the dorsal 

 aspect. Tail long and high, strongly compressed. Anal long; adi- 

 pose fin very small. 



Genus XIII. Arius, Valenc. Teeth on the roof of the mouth 

 disposed in two widely-separated plates, supported fcir the most 

 part by the palatines only, but in some species encroaching on the 

 angles of the vomer. Branchiostegals five to eight, rarely ten to 

 twelve. The teeth may be villiform or pavement-like, the passage 

 to the pavement-like teeth being gradual ; some species have the 

 ordinary nuchal armour of a triangular (interparietal, Cuv.) supra- 

 occipital plate, with the apex truncated, and a small crescentic 

 interspinal plate ; others have a very large separate supraoccipital 

 disk, and the barbels vary in number. On combinations of these 

 diversities of structure several groups are established in the Histoh-e 

 des Poissons, in which fifty-one species are described. Air-bladder 

 in some divided lengthwise into two separate sacs. 



Genus XIV. Osteogeneiosu.s, Bleek. A rayed and an adipose 

 dorsal fin. Conical, acute, curved, crowded teeth on the premax- 

 illaries, and mandibles in many rows ; palatine teeth in two oblong 

 arched plates in the fore part ; the mesial line of the roof of the 

 mouth smooth ; eyes far back. Two premaxillary barbels, bony 

 and rigid. Branchiostegals five. Head cuirassed; gill-openings 

 extremely narrow. Indian Archipelago. 



Genus XV. Batrachocephalus, Bleek. Dorsal fins two, the 

 hinder one adipose. Thick, cylindrical, premaxillary and mandibu- 

 lar teeth in many rows ; vomer and mesial line of the roof of the 

 mouth smooth ; a few crowded cylindrical teeth on the anterior 

 angles of the palatine bones ; eyes above. Read cuirassed ; no 

 barbels. Five branchiostegals. Indian Archipelago. 



Genus XVI. Pimelodus, Lacep. Hoof of the mouth smooth, 

 edentate. Barbels six or eight. Some species want the casque ; 

 others possess it ; it is sometimes continuous with the buckler of the 

 first osseous ray of the dorsal ; sometimes distinct and not continu- 

 ous. Forty-three species are described in the Histoire dcs Poissons. 



The following two genera have been published since the date of 

 I that work : — 



I Genus XVII. Rita, Bleek. Dorsals two, the posterior one 



•• adipose. Conical teeth in the upper jaw pluriserial ; mandibular 



teeth conical in the anterior rows, granular in the posterior ones; 

 vomerino-palatine teeth granular, disposed in two oblong patches in 

 the fore part of the palate. Branchiostegals eight or ten ; barbels 

 six, fleshy, belonging to the nose, premaxillaries, and mandible. 

 Ventrals eight-rayed. (Arius rita, Cuv. and Valenc.) 



Ge.nus XVIII. Bagarius, Bleek. Dorsals two, the posterior 

 one adipose. Barbels eight, on the jaws bony, rigid ; upper jaw 

 teeth pluriserial, acute, placed in a curved quadripartite band; 

 mandibular teeth biserial, with an interior series of canines at the 

 symphysis only ; no teeth on the vomer, palatines, or entoptery- 

 goids. Branchiostegals twelve. Rays of the ventrals six. No air- 

 bladder. 



Genus XIX. Euanemus, Mull, and Trosch. Narrow gill- 

 openings. Body laterally compressed. Cranium covered with skin. 

 Card-like teeth in one band on the upper and under jaw ; none 

 on the vomer or palatines. First ray of the dorsal and pectoral 

 fins spinous ; dorsal fin wl011y anterior and small ; a very small 

 adipose fin ; rays of the ventrals much more numerous than in other 

 Silund<B. Eyes covered with skin. Barbels six. One species E. 

 columbetes. 



Genus XX. Ketengus. Bleek. Dorsal fins two, posterior one 

 adipose. Cuneiform uniserial teeth on the premaxillaries and 

 mandible; vomer and palatines smooth. Head cuirassed; eyes 

 superior. Five branchiostegals ; four fleshy barbels. Strait of 

 Aladura. 



Genus XXI. CALOPtiTsrs, MiiU. and Trosch. No palatine teeth ; 

 a row of stronger teeth on the upper jaw and mandible, behind 



which, on the one or the other, a row of smaller teeth. The end of Classifica- 



the first dorsal and pectoral ray simply jointed, not denticulated ; tion Ma- 



a long adipose fin. Six barbels ; narrow gill-opening ; seven lacopteri. 

 branchiostegals. A very small swim-bladder, which is bordered v. j 



behind with an elegant fringe of cfecal processes. Two species. ^ 



Genus XXII. Erethistes, .Mull, and Trosch. Narrow gill- 

 openings. Head big, broad, pointed anteriorly, rough. Besides the 

 occipital process there is always another like it. The scapular girdle 

 has a long bony process above the pectoral, and another beneath it ; 

 mouth small. Card-like teeth in the upper and under jaw ; none 

 on the palatines. A moveable spine forming the first ray of the 

 dorsal and pectoral fins ; an adipose fin ; anal small. 



Genus XXIII. Auchenipterus, Valenc. Siluroid with an 

 adipose fin. Head small ; teeth almost imperceptible. Branchi- 

 ostegals five ; no teeth on the roof of the mouth. Dorsal very far 

 forward, or on the nape. Casque united by suture with the dilated 

 bucklers of the first and second interspinals covering the nape to 

 the dorsal, as in Doras and Si/nodontis. Seven species. 



Genus XXIV. Trachelyopterus, Valenc. No adipose fin, 

 yet allied to Schilbes and Pimelodus. Barbels six. Villiform teeth 

 on the jaws, none on the roof of the mouth. A solid, osseous casque, 

 united, as in Auckenipterits, and coming near the dorsal, owing to the 

 shortness of the supraoccipital plate, and the completely obsolete 

 chevron. Pectorals attached under the throat. One species. 



Genus XXV. Hypophthalmus, Valenc. An adipose fin. No 

 teeth; eyes near the ventral aspect. Fourteen branchiostegals. 

 Dorsal fin small, well back, with a bony ray ; a strong ray in the 

 pectoral also ; ventrals small; anal long. Six barbels. Three species. 



Genus XXVI. Agexeiosus, Lacep. Maxillary barbels only, 

 and very short; in one species denticulated and resembling horns. 

 Eyes depressed as in Hupophthahmis. Branchiostegals eleven. A 

 bony ray in the dorsal and pectoral ; a moderately long anal. 

 Three species. 



Genus XXVII. Synodontis, Geoffroy St Hilaire. Remarkable 

 among the Siluroids having an adipose fin, for the arming of the 

 head, which shows much affinity with that of Auchenipterus and 

 Doras. Supraoccipital plate large, united by a long transverse 

 suture with the greatly dilated interneural buckler, which is further 

 prolonged along the base of the dorsal by its junction with three 

 interneural plates; very wide strong pointed coracoids attached to 

 the suprascapulars which form the lateral angles of the helmet. 

 Enormous strongly-toothed pectoral spines ; a high pointed and 

 trenchant dorsal spine. Snout short, terminated by the nasal which 

 supports very small premaxillaries covered with finely villiform 

 teeth. Mandible composed of two short .slender limbs, and carrying 

 in front a bundle of teeth that, individually, are very thin lancets, 

 each supported on a stalk as fine as a hair, and terminated by a 

 small recurved and gold-coloured hook. This dentition resembles 

 that of Salttrias. 



Genus XXVIII. Doras, Lacep. Pimelodi with the lateral line 

 cuirassed by keeled bony plates, each ending in a spine. Head 

 armed as in Auchenipterus, and the coracoid similarly formed. The 

 very thick dorsal and pectoral spines are strongly toothed. In some 

 the snout is depressed, and the mouth at its extremity is furnished 

 with two broad villiform bands of teeth on the jaws; in others, the 

 mouth is a round hole under a conical snout, and having small 

 groups of mandibular teeth only. Ten species. 



Genus XXIX. Calliciithys, Linn., Gronov. Pmctorfi cuirassed 

 on the lateral line like the Doras, and with an adipose fin; but the 

 lateral shields are narrow, embrace the whole height of the fish, 

 and form two rows, somewhat tiled and crossing in the middle. Head 

 covered with a helmet ; mouth small, almost toothless ; two barbels 

 at each corner of the mouth. Three branchiostegals. Dorsal and 

 pectoral spines often feeble. No air-bladder; intestine frequently 

 doubled back ; stomach globular and small. Ten species. 



Genus XXX. Arges, Valenc. Teeth bifid, and slightly curved 

 at the points, ranged in rows on the jaws and producing a sort of 

 harrow which no other Siluroid, nor any other fish, is known to 

 possess. Koof of the mouth smooth and edentate ; two maxillary 

 barbels, and papillae at the nostrils. First dorsal small, with 

 a weak ray in front ; adipose fin long ; ventrals well forward. 

 Four branchiostegals. Two species. 



Genus XXXI. Brontes, Valenc. An Arges without the adi- 

 pose fin. No casque. Eyes, two minute points on the top of the 

 head. Branchiostegals four. One species. 



Genus XXXII. Astroblepus, Ilumb. An apodal resembling 

 otherwise, e.Kternally, Brontes; having a depressed head ; eyes above. 

 A single dorsal; no adipose fin. First rays ending in filaments. 

 Four branchiostegals. One species. 



Genus XXXIII. Clarias, Gronov. Helmet extending to the 

 temples and cheeks ; the supraoccipital point more or less rounded, 

 in some semicircular. Nape exposed ; no predorsal buckler. 

 Teeth on the jaws and arc of the vomer. Head depressed, obtuse. 

 Body long; caudal truncated. Anal long and low ; dorsal without 



