MOCHOCUS. 493 Pectoral fin with a strong spine; ventral fin with 7 rays. A cephalonuchal bony shield. Mouth subinferior, small, without labial folds ; small conical teeth in both jaws, none on the palate. A maxillary and two mandibular barbels on each side, the latter branched. Nostrils rather remote from each other, both with a valve, the posterior very large. Eye moderate, without free border. Gill-openings small, confined to the sides. Air-bladder large, free.
Vertebre 33-34 (11-+4- 22-23).
Nile and Lake Rudolf.
Two species :— First dorsal fin much nearer end of snout than root of caudal, with the spine serrated in front and with 7 or 8 soft rays... » 1. M. niloticus, Joann., p. 493. First dorsal fin nearly equally distant from Fall of snout and from root of caudal, with the spine smooth in front and with 6 soft rays . 2. MM. brevis, Blgr., p. 495. 1. MOCHOCUS NILOTICUS.
Joannis, |. e. pl. viii; Giinth. 1. c., and Petherick’s Tray. ii. p. 239 (1869) ; Bouleng. ll. ec. pl. Ixxvi. p. 2.
Rhinoglanis typus, Giinth. ll. ec. pp. 216, fig., and 237, fig. Rhinoglanis vannutellii, Vincig, Ann. Mus. Genova, (2) xix. 1898, p. 254. Depth of body 44 to 5% times in total length, length of head 31 to 4% times. Head depressed, not or but little longer than broad, rugose above, with a large, oval frontal fontanelle; occiput with a low, blunt keel, which is continued on the nuchal shield; eye supero-lateral, 5 to 41 times in length of head, 14 to 14 times in interorbital width. Barbels long and slender, maxillary 14 to 24 times as long as head, reaching posterior third of pectoral spine, base of ventral, or a little beyond ; mandibular barbels shorter, with a few slender simple branches. Occipito-nuchal shield as long as broad or longer than broad, with short, rounded posterior processes. A long pointed humeral process, Anterior dorsal I 7 (rarely 8), much nearer end of snout than root of caudal; spine as long as or a little shorter than head, finely serrated in front ; second dorsal with 10-15 rays, preceded by a few fulcra-like bony scutes, as long as or a little longer than its distance from the first. A series of three or four small bony scutes, ankylosed to the interneural bones, on each side of soft part of first dorsal fin. Anal 9-10. Pectoral spine as long as or a little longer than that of dorsal, finely serrated on
494 SILURID &.
outer border, with 7 (young) to 14 very strong antrorse serre on its inner border, reaching base of ventral or not quite so far. Ventral equally distant from end of snout and from root of caudal, or a little nearer the former, not reaching anal. Caudal deeply emarginate, upper lobe the longer. Caudal peduncle nearly twice as long as deep. Pale Fig.368.
Mochocus niloticus.
Luxor (F. N.).
yellowish or greyish olive above, speckled and marbled with blackish ; two more or less regular dark bands across the back, one under each of the dorsal fins; belly white; dorsal and caudal fins yellowish, dotted or spotted with blackish.
Total length 65 millim, Lower Nile to Bahr-el-Gebel; Lake Rudolf.—Type (Paris Museum) apparently lost.
1-3. Ad. Beni Souef, Low, Nile. L. Loat, Hsq. (C.). 4-13. Ad., hgr., & yg, Near Luxor. *) 14-23, Ad., hgr., & yg. Between Luxor and Agsuan, i 24-27. Ad. & hpr. Assuan * 28. Skel. ” or 29-31. Hgr. Kaka, White Nile. 3
MOCHOCUS. 495 32. Ad. Tonga, White Nile. L. Loat, Esq. (C.). 33-36. Ad. L. No, a 37. Type of Rhinoglanis | Gondokoro. J. Petherick, Esq. (C.). typus.
38-44. Ad. & her. +3 L. Loat, Hsq. (C.). 2. MOCHOCUS BREVIS.
Bouleng. Ann. & Mag. N. H. (7) xviii. 1906, p. 148, and Fish. Nile, p. 390, pl. Ixxvi. fig. 3 (1907).
Distinguished from the preceding by the shorter caudal part of the body, the first dorsal fin being equally distant from end of snout and from root of caudal, or a little nearer the former. Depth of body 3} to Fig.369.
Mochocus brevis.
Type (F. N.):
41 times in total length, length of head 3 to 34 times. Occiput and nuchal shield slightly tectiform, but without a keel. Maxillary barbel reaching extremity of ventral or a little beyond. First dorsal I 6, the spine without any serration and always shorter than head; second dorsal with 9-16 rays. Anal 9-10. No scutes at sides of soft rays of first dorsal fin. Pectoral spine reaching root of ventral, with 6 to 10 very strong serve on inner side. Caudal peduncle only a little longer than deep. Coloration as in MM. niloticus, but pectoral, ventral, and anal fins with some brown spots. Total length 31 millim, White Nile. , 1-15. Types. Fashoda. LL. Loat, Esq. (C.). 16, Type. L. No. »”
496 SILURIDZ.
34. DOUMEA.
Sauvage, Bull. Soc. Philom. (7) iii. 1878, p. 96, and N. Arch. Mus. (2) iii. 1880, p. 41; Bouleng. Ann. & Mag. N. H. (7) vi. 1900, p. 526. Body elongate, feebly depressed, with extremely slender candal peduncle. ‘Two short dorsal fins, the anterior entirely in advance of the ventrals and formed of one simple, thickened but articulated, and 6 branched rays, the second much smaller, opposed to the anal, and formed of fine rays partly concealed in adipose tissue ; pectoral and ventral fins large, horizontally expanded, the outer ray much thickened but not ossified, formed of very numerous articles angularly bent and produced on the outer side into a fringe imbedded in the thickened integument ; ventral with 6 rays. No cephalo-nuchal shield. A maxillary and two mandibular barbels on each side, verrucose like the lips. Nostrils remote from each other, both with a valve. Eye small, without free border. Mouth small, inferior, surrounded with thick papillose lips; small pointed preemaxillary teeth; mandibular teeth few or absent ; palate toothless. Guill-openings narrowly interrupted at the isthmus, the membrane forming an uninterrupted transverse fold. Air-bladder absent. Vertebre 37 (17+20). 6 branchiostegal rays.
Cameroon to Augola.
Two species :— Head 12 to 13 times as long as broad, snout 12 to 1% times as long as postocular part of head ; space between the two nostrils on each side equally distant from end of snout PMOL IHROIN OVO. =o 6 96 6 elo No 6 ‘c 1. D. typica, Sauv., p. 496. Head 1} times as long as broad, snout 1} times postocular part of head; posterior nostril nearerieyejay ees) ai seule ss. eo aangolensis Dlor saps 4 9n'. 1. DOUMEA TYPICA.
Sauy. ll. ce. pl. iii. fig. 1; Bouleng. t. ¢. p. 527, and xii. 1903, p. 440. Depth of body slightly less than its width, 74 to 9 times in total length. Head strongly depressed, with slightly rugose vertex and occiput, covered with a thin skin, 1% to 13 times as long as broad, 5 to 54 times in total length; snout pointed, projecting a little beyond mouth, 1% to 1? times as long as postorbital part of head ; space between the two nostrils on each side equally distant from end of snout and from
DOUMEA. 497 eye; latter directed upwards, 63 to 8 times in length of head, 1} to 2 times in interorbital space. Maxillary barbel { to 3 length of head, mandibular barbels shorter still. Occipital process narrow, nearly 3 times as long as broad, narrowly separated from interneural shield. First dorsal I 6; first ray as long as or a little longer than head; border of fin slightly concave. Anal II 6-7. Pectoral usually not reaching ventral ; latter extending beyond origin of anal. Caudal deeply notched, Fig.370.
Doumea typica.
S. Cameroon. §.
crescentic, lower lobe the longer. Caudal peduncle a little depressed, about 4 total length. Brownish above, whitish beneath. Total length 160 millim.
Upper Ogowe, South Cameroon.—Type, in Paris Museum, examined. 1-11. Ad. & her. Efulen, 8S. Cameroon. G. L. Bates, Esq. (C.). 12. Skel. Kribi R., am a 13. Ad. Ja R., Fe AS 2. DOUMEA ANGOLENSIS.
Bouleng. Ann. & Mag. N. H. (7) xviii. 1906, p. 347. Depth of body 103 times in total length, head 53 times. Head smooth above, 14 times as long as broad; snout obtusely pointed, projecting beyond mouth, 1} times as long as postorbital part of head; space between the two nostrils nearer eye than end of snout; eye 8 times in length of bead, twice in interorbital width. Mavxillary barbel 3 length of head, mandibular barbels a little shorter still. Occipital process half length of snout, widely separated from interneural shield. Dorsal I 6, first ray nearly as long as head. Anal 17. Pectoral not VOL. IE. 2K
498 SILURIDA., reaching ventral; latter just reaching origin of anal. Caudal peduncle 2 total length. Yellowish brown above, whitish beneath ; ill-defined dark bars across the back; a dark streak from the end of the snout to the eye; two dark transverse bars on the dorsal, anal, pectoral, and ventral fins.
Total length 70 millim.
Benguella.
Fig.371.
Doumea angolensis.
Type.
1. Type. Interior of Benguella, 4000-5000 ft. Dr. F. C. Wellman (P.). 35. PHRACTURA.
Peltura (non M.-Edw.), Perugia, Ann. Mus. Genova, (2) x. 1892, p. 972. Phractura, Bouleng. Ann. & Mag. N. H. (7) vi. 1900, p. 527, and Poiss. Bass. Congo, p. 333 (1901).
Body elongate, depressed, with extremely slender caudal peduncle ; a series of imbricate scutes * along each side of the back and belly from the dorsal and ventral fins to the caudal peduncle, which may be entirely surrounded by these scutes. ‘wo short dorsal fins, the anterior entirely in advance of the ventrals and formed of one simple, flexible, and 6 or 7 branched rays, the second opposed to the anal and adipose, with fine soft rays ; pectoral and ventral fins large, horizontally expanded, without spine, but with thickened, simple outer ray as in Doumea; 6 ventral rays. No occipito-nuchal shield. Mouth small, inferior, surrounded with large papillose lips; no mandibular teeth; small conical premaxillary teeth ; a maxillary and two mandibular barbels on each side; nostrils rather remote from each other, both with a valve; eye small, *Expansionsofprocessesoftheyertebre.
PHRACTURA. 499 without free border. Gill-openings narrowly interrupted at the isthmus. Air-bladder absent.
Vertebree 385-36 (16-17 4-18-20). Niger, Cameroon, Ogowe, Congo.
Synopsis of the Species.
I. Occipital process not reaching interneural shield; snout about 4 length of head.
A. Posterior nostril nearly as distant from eye as the anterior from end of snout. 1. Occipital process 3 to 4 times as long as broad. Eye 10 to 11 times in length of head, 24 to 3 times in interocular width; maxillary barbel 3 length of head; caudal peduncle } total ees: Sartre Tapas a ete yan i lame Covepacrug.. 499), Hye 6 to 7 times in renee of head, twice in interocular width ; maxillary barbel } length of head; caudal peduncle # to a total NENG Ce Os Sle lo dg 16 ep dan timer lellines pian OLD): 2. Occipital process about twice as long as broad ; maxillary barbel 4 to 3 length of head.
Bye 6 to 7 times in length of head, twice in interocular width ; caudal peduncle } to # total Len'ot hyrepanse) ci) nea vie i Sci) ) Oo Lesonevecauda, Dior. 502. Hye 6 to 7 times in length of Hee twice in interocular width ; caudal peduncle 3 to 2 fotallengthy 2 ojy eye ss . . . . 4. P. intermedia, Blgr., p. 503. Eye 53 times in length of Hen 1 times in interocular width; caudal peduncle ? total L@AGWR 6 jo kao Vek BPeolls “6. ol bool! 6 eed olonenuendir Tellers jog SUE. B. Posterior nostril close to the eye ; head rugose above, with strong ridges ; caudal peduncle 3 totallength. . . . . . 6. P. ansorgii, Blgr., p. 504. II. Occipital process in contact with interneural shield ; snout more than 4 length of head; maxillary barbel 4 length of [p. 505. head ; caudal peduncle } total length . 7. P. scaphirhynchura, Vaill., 1. PHRACTURA BOVEI.
Peltura bovei, Perugia, Ann. Mus. Genova, (2) x. 1892, p. 972, fig. Phractura bovei, Bouleng, Ann. & Mag, N. H. (7) vi. p. 528, and Poiss. Bass. Congo, p. 334 (1901).
Depth of body 8 or 9 times in total length, length of head 6 to 64 2K 2
500 SILURIDA, times. Head 14 times as long as broad ; skull a little rugose, covered with thin skin; snout a little longer than postocular part of head, pointed, projecting beyond mouth; space between the nostrils equally distant from end of snout and eye; latter directed upwards,:10 or 11 times in length of head and 25 to 3 times in the interocular width; maxillary barbel 3 length of head, reaching or nearly reaching gillopening, mandibular barbels much shorter. Occipital process 3 times as long as broad, not reaching interneural shield. Dorsal I 7; first ray Phractura bovei.
Lower Congo.
longest, } longer than head; second dorsal very small. Anal II 7. Pectoral longer than head, as long as or a little longer than the ventral; latter nearly reaching the anal. Caudal with crescentic notch. Caudal peduncle depressed, 3 total length. 23-24 dorsal and 19 ventral scutes, the last 5 united on caudal peduncle. Uniform yellowish brown in spirit.
Total length 110 millim. ' Lower Congo.—'Type in Genoa Museum.
1. Ad. Lower Congo. Brussels Museum (E£.).
2. PHRACTURA LINDICA.
Bouleng. Proc. Zool. Soc. 1902, i. p. 268, pl. xxviii. fig. 3. Depth of body 74 to 8 times in total length, length of head 5 to 54 times. Head 1} to 12 times as long as broad, nearly smooth above, covered with papillose skin; snout } length of head, obtusely pointed,