DINOTOPTERUS. RUT 1. DINOTOPTERUS CUNNINGTONT.
Bouleng. ll. ce., Tr. pl. xxxi.
Depth of body 73% times in total length, length of head 35 times. Head extremely flattened, 1} times as long as broad, its upper surface covered with very thin skin and rugose with strive radiating from the occipital region; frontal fontanelle large, 2} times as long as broad, 1 length of head; occipital fontanelle very small; a rather long and narrow occipital process; snout broad, truncate, not projecting beyond mouth; eye small, 3 times in length of snout, 7} times in interorbital Fig.228.
Dinotopterus cunningtoni.
Adult and young, types (Tr. Z. 8. 1906). Z.
width ; nasal barbel 2 length of head; maxillary barbel a little longer than head, reaching posterior third of pectoral; outer mandibular barbels once and $ as long as inner and nearly as long as head. Jaws with bands of minute villiform teeth ; similar teeth form a rather broader crescentic band on the vomer. Gill-rakers very long and slender, closely set, about 110 on anterior arch. Dorsal 53, its distance from occipital process 4 length of head; adipose dorsal low and short, in contact with caudal. Anal 43, separated from caudal by a space equal to twice diameter of eye. Pectoral } length of head; spine rather weak, not
278 SILURIDA.
serrated, a little more than half length of fin. Ventral equally distant from end of snout and from root of caudal. Caudal rounded. Dark brown, almost black, above, pinkish white beneath. Described from a single specimen, 500 millim. long ; the species said to grow to 1290 millim. In a young specimen, 90 millim. long, the head is less depressed and the eyes are proportionally larger. Lake Tanganyika.
1. Type. Mpala. Dr. W. A. Cunnington (C.).
2. Yg. Mbete. 2?
8. PLOTOSUS.
Lacep. Hist. Poiss. v. p. 129 (1803) ; Giinth. Cat. Fish. v. p. 23 (1864) ; Vaill. Bull. Mus. Paris, 1903, p. 119.
Platystacus, part., Bloch, Ausl. Fische, viii. p. 52 (1793). Body elongate, compressed, tapering to a point behind. A short dorsal fin in front, with a pungent spine; a second long dorsal and a long anal, united with the caudal. Pectoral fin with the outer ray spinous; ventral fin with 12 to 14 rays. Head feebly depressed; four pairs of barbels—one nasal, one maxillary, two mandibulars. Kye with free orbital margin. Jaws with a band of obtusely conical teeth ; a group of large granular teeth on the vomer. Gill-membranes free from the isthmus, deeply notched in the middle. A dendritic post-anal apparatus. Air-bladder moderately large, free.
Vertebre 46-81 (16-19+ 30-62). Brachiostegal rays 11 to 13. Coasts of the Indian and Western Pacific Oceans, sometimes entering fresh waters. One species has been found in fresh waters in Kast Africa. 1. PLOTOSUS ANGUILLARIS.
Silurus, sp. d, Forsk. Deser. Anim. p. xvi (1775). Platystacus anguillaris, Bloch, Ausl. Fische, viii. p. 60, pl. ecclxxiii. fig. 1 (1793). Plotosus anguillaris, Lacep. Hist. Poiss. v. p. 129 (1803); Riipp. N. Wirbelth. Abyss., Fische, p. 76 (1835) ; Cantor, Cat. Mal. Fish. p. 264 (1850) ; Peters, Arch. f. Nat. 1835, p. 267; Giinth. Cat. Fish. v. p. 24 (1864); Sauv. Hist. Madag., Poiss. p. 477, pl. xlvii.a. fig. 1 (1891); Pfeff. Thierw. O.-Afr., Fische, p. 29, fig. (1896).
Plotosus ikapor, Less. Voy. Coquille, Zool. ii. p. 132, pl. xxxi. fig. 3 (1830). Plotosus marginatus, Bennett, Life of Raffles, p. 691 (1830). Plotosus lineatus, Cuy. & Val. Hist. Poiss. xv. p. 412 (1840) ; Schleg. Faun. Japon., Poiss. p. 228, pl. civ. fig. 3 (1846).
PLOTOSUS.—REUTROPIUS. 279 Plotosus castaneus, Bleek. Nat. Tijdschr. Ned. Ind. ii. 1851, p. 490. Plotosus arab, Bleek. Atl. Ichth. ii. p. 98, pl. xev. fig. 2 (1862) ; Day, Fish. Ind. p- 483, pl. exii. fig. 4 (1878).
Depth of body 6$ to 8 times in total length, length of head 41 to 5 times. Snout rounded, feebly projecting beyond mouth, its length equal to interorbital width ; eye supero-lateral, 5 to 6 times in length of head ; lips papillose; teeth large. Nasal and inner mandibular barbels 3 to } length of head, maxillary and outer mandibular 2 to 2. Gillrakers rather long, closely set, about 20 on lower part of anterior arch. Dorsal I 4-5, 85-100; anal 70-80; spine strong, serrated in front and Plotosus anguillaris.
Indian Ocean (after Day, Fish. Ind.). 3.
behind, 4 to } length of head. Pectoral about } length of head, with strong but short spine serrated on both sides. Ventral 1$ to 1% times as distant from caudal as from end of snout. Dark brown, usually with two or three bluish-white longitudinal streaks on each side, at least in the young.
Total length 250 millim.
Indian Ocean and Western Pacific, as far north as Japan. 1-2. Ye. Gulf of Suez. R. MacAndrew, Hsq. (P.).
3-5, 6. Her. & yg. Zanzibar. Sir L. Playfair (P.).
7. Her. Rodriguez. G. Gulliver, Esq. (P.).
8. Skel. ?
9. EUTROPIUS.
Miill. & Trosch. Hor. Ichthyol. iii. p. 6 (1849) ; Giinth. Cat. Tish. v. p. 52 (1864); Bouleng. Poiss. Bass. Congo, p. 266 (1901), and Fish. Nile, p. 306 (1907). Body moderately elongate, strongly compressed, the precaudal region short. Dorsal fin short, with a spine and 5 or 6 branched rays; a very
280 SILURID&.
small adipose dorsal fin; anal fin much elongate. Pectoral fin with an outer spinous ray. Ventral fin with six rays, inserted under the dorsal fin or behind the vertical of the latter. Four pairs of barbels—nasal, maxillary, and two mentals or mandibulars. Nostrils widely separated. Eye large, with free border. Jaws with a band of villiform teeth; a band of villiform vomero-palatine teeth. Gill-membranes free, deeply notched. Air-bladder large, free.
49-55 vertebree (11-15+36-39). 9 or 10 branchiostegal rays. Nile and Tropical Africa.
Synopsis of the Species.
I. Snout projecting more or less beyond border of mouth. A. Base of dorsal exactly above base of ventrals ; maxillary barbel longer than outer mandibular; spine of dorsal at least as long as head ; pectoral longer than head, reaching origin of anal ora little beyond ; anal 52-63. 1. E. congolensis, Leach, p. 281. B. Base of dorsal entirely or partly in advance of base of ventrals; spine of dorsal not longer than head ; pectoral not reaching anal. 1, Maxillary barbel longer than outer mandibular. a. Anal with more than 50 rays.
Anal 59; pectoral spine feebly serrated on inner side; nasal barbel much longer than eye 6 DAY eho tole e Bee Vcr hoon 8 2. EH. banguelensis, Blgr., p. 282. Anal 54-69 ; pectoral spine strongly serrated on inner side; nasal barbel not longer thanvey6\.> yo. tae, ss) Mopac 3. E. niloticus, Riipp., p. 283. Anal 52-53 ; pectoral spine feebly serrated on inner side ; nasal barbel not longer than EV SPE PMR he BA LIE, Oi, NM 4, E. grenfelli, Blgr., p. 286. b. Anal with not more than 50 rays.
Anal 46-50 ; pectoral spine moderately serrated on imuer side, 1% Ve) ee) tee, 0D. ME bersensisStdrewps28te Anal 38-45 ; pectoral spine feebly serrated on botaisides! sey. (2 9. |. SGnen tee Gs naclauwiblon wpe2oee 2, Maxillary barbel not longer than outer mandibular ; anal 52-62. Maxillary barbel longer than the nasal ; caudal peduncle a little deeper thanlong . . . 7. E. mentalis, Blgr., p. 288. Maxillary and nasal barbels subequal . . . 8 E. mandibularis, Gthr., p. 290.
EUTROPIUS. 281 IT. Lower jaw extending forward quite as far as the snout, or projecting a little beyond latter ; base of dorsal entirely or partly above that of ventrals. A. Maxillary barbel longer than the outer mandibular ; nasal barbel not longer than eye.
Analtoc meee eee oc. eee, OF By bocagi, Guimates p00. B. Maxillary barbel not longer than outer mandibular ; nasal barbel longer than eye.
Anal 45; maxillary barbel a little shorter than mandibular ; pectoral reaching ventral . 10. Z. laticeps, Blgr., p. 291. Anal 50-60 ; maxillary barbel not or but little shorter than outer mandibular ; pectoral [p. 291. not reaching ventral . . . . . . . 11. £E. depressirostris, Peters, Anal 63-70; maxillary barbel about half as long as outer mandibular. . . . . . 12. EF. moebii, Pfeff., p. 293. 1. EUTROPIUS CONGOLENSIS.
Stlurus congensis, Leach, in Tuckey, Exped. R. Zaire, p. 409 (1818). Eutropius congensis, Giinth. Cat. Fish. v. p. 52 (1864). Eutropius congolensis, Bouleng. Poiss. Bass. Congo, p. 268 (1901). Depth of body 4 to 43 times in total length, length of head 5 to 6 Fig.230.
Eutropius congolensis.
1 Type. 3.
times. Head 1+ to 1} times as long as broad; snout broad, projecting beyond mouth, 2 to 24 times as long as eye in adult, as long as eye in young; eye perfectly lateral, 4 (young) to 7 times in length of head,
282 SILURIDA.
2 (young) to 4 times in interorbital width; width of mouth a little less than interorbital width; vomero-palatine teeth forming an uninterrupted band, which is as broad as or a little broader than the band of premaxillary teeth. Nasal barbel 4+ to ? length of head, maxillary barbel 2 to $#; inner mandibular barbel about 4 length of outer, which is inserted behind it and measures about 4 length of head. Gill-rakers moderately long, widely set, 7 to 9 on lower part of anterior arch. Dorsal I 6, exactly above ventrals, 2 to 24 times as distant from caudal as from end of snout; its spine slender, feebly serrated behind, as long as or a little longer than head, produced into a filament. Anal 52-63, 4 or 5 anterior rays simple, the following gradually decreasing in length. Pectoral reaching origin of anal or a little beyond, its spine rather feebly serrated on inner side, as long as or a little longer and stronger than that of dorsal. Caudal deeply forked, with pointed lobes. Caudal peduncle as long as ora little longer than deep. Silvery, back brownish ; fins uniform whitish (or pink); a more or less distinct dark blotch on each side above the pectoral fin, corresponding to the thinner skin over the air-bladder ; young sometimes with a dark lateral band. Total length 420 millim.
Congo.
1. Type. Lower Congo. Capt. Tuckey (C.).
2. Ad. Yelala, nr. Matadi, L. Congo. M. P. Delhez (C.). 3. Ad. Monsembe, Upp. Congo. Rey. J. H. Weeks (P.).
4-9, Ad.,hgr.,& yg. Stanley Falls. Rev. W. H. Bentley (C.). 10. Skel. 3? bP) 2. EUTROPIUS BANGUELENSIS, sp. n.
Depth of body 32 times in total length, length of head 5 times. Head 14 times as long as broad; snout broad, projecting slightly beyond mouth, longer than eye, which is 5 times in length of head and 3 times in interorbital width; width of mouth a little less than interorbital width; vomero-palatine teeth forming an uninterrupted band, which is as broad as the band of praemaxillary teeth. Nasal barbel 2 length of head, maxillary 3, inner mandibular 4, outer mandibular 4. Gill-rakers moderately long, widely set, 9 on lower part of anterior arch. Dorsal I 6, entirely in advance of vertical of ventrals, twice as distant from caudal as from end of snout; its spine slender, feebly serrated behind, the rigid part as long as head, the whole ray 13 times as long as head. Anal 59, 4 anterior rays simple, fourth nearly as long as head. Pectoral reaching ventral, its spine feebly serrated on inner side, as long as and
EUTROPIUS. 283 but slightly stronger than that of dorsal. Caudal deeply forked Caudal peduncle 13 times as long as deep. Body and fins uniform brown, back darker.
Eutropius banguelensis.
Dypes se Total length 300 millim.
Lake Bangwelu.
1. Ad. L. Bangwelu. F. H. Melland, Bsq. (P.). 3. EUTROPIUS NILOTICUS.
HAypophthalmus niloticus, Riipp. Beschr. n. Fische Nil, p. 6, pl. i. fig. 1 (1829). Chilbé zérégé, Rifaud, Voy. Egypte, pl. exciv. no. 4 (1830). Schilbe hasselquistiz, Cuv. & Val. Hist. Poiss. xiv: p. 377 (1839). Bagrus schilbeoides, Cuv. & Val. t. ce. p. 389. Bagrus adansonii, Cuy. & Val. t. c. p. 391, pl. eecexiv. Eutropius niloticus, Giinth, Cat. Fish. v. p. 52 (1864), and Petherick’s Tray. ii. p- 225 (1869) ; Bouleng. Fish. Nile, p. 306, pl. lv. fig. 1 (1907). Hutropius obtusirostris, Giinth. Cat. t. ¢. p. 53. Eutropius adansonii, Giinth. Cat. t. c. p. 54; Steind. Sitzb. Ak. Wien, Ix. i. 1870, p. 985, pl. v.
Eutropius altipinnis, Steind. Notes Leyd. Mus. xvi. 1894, p. 57, pl. i. fig. 1. Depth of body 3 to 43 times in total length, length of head 5 to 6 times. Head 11 to 13 times as long as broad; snout broad, projecting slightly beyond mouth, as long as or a little longer than eye in adult, a
284 SILURIDZ.
little shorter in young; eye perfectly lateral, 3 (young) to 5 times in length of head, 14 (young) to nearly 3 times in interorbital width ; width of mouth a little less than interorbital width; vomero-palatine teeth forming an uninterrupted band, which is nearly as broad as or narrower than the band of premaxillary teeth. Nasal barbel as long as or shorter than eye; maxillary barbel shorter than head ; inner mandibular barbel about half length of outer, which is inserted behind it and measures about } to 3 the length of the maxillary barbel. Gill-rakers moderately long, widely set, 7 to 11 on lower part of anterior arch. Dorsal I 5-6, partly or entirely in advance of vertical of ventrals and 2 to 23 times as distant from caudal as from end of snout; its spine slender, feebly serrated behind, 2 to once length of head, produced into a short’ Fig, 232.
Eutropius niloticus.
Upper Nile (F. N.). wI- ° filament. Anal 54-69, 4 or 5 anterior rays simple, the following gradually decreasing in length. Pectoral reaching or not ventral, its spine strongly serrated on inner side and stronger than and nearly equal in length to that of dorsal. Caudal deeply forked, with pointed lobes. Caudal peduncle 14 to 1} times as long as deep. Silvery or pale brownish, darker green or olive on the back; a blackish or green illdefined blotch on each side above the pectoral fin; dorsal and pectoral fins sometimes blackish.
Total length 400 millim.
Nile System and rivers of West Africa, from the Senegal to the Ogowe.—Types in the Senckenberg Museum, Frankfort (Main). 1. One of the types. Egypt. Dr. Riippell (C.).
2-3. Hgr. Nile. +