25 
cleft —26. 
21 a, Scales evident between eyes —22. 
(20a) b. No scales between eyes — 25. 
22 a. Ventral fins united in front — Mugilogobius devisi 
(21a) McCulloch & Ogilby : De Vis' goby. 
b. Ventral fins separate — 23. 
23 a, Second dorsal with 9 (not more than 10) rays. Gill-cover 
(22b) and body striped — Mogurnda (Krefftius) australis 
(Krefft) : Striped gudgeon. 
b. Second dorsal with 11-13 rays. Gill-cover striped, body 
blotched or mottled — Trout gudgeons, 24. 
24 a. General appearance typically dull, blotched brown on 
(23b) grey. Scale count from upper limit of gill cover to tail 
over 36 — Mogurnda mogurnda (Richardson), 
b. General appearance typically bright, with purples, blues, 
and greens over grey. Scale count from upper limit of 
gill-cover to tail less than 36 — Mogurnda mogurnda 
adspersus (Castelnau). 
25 a. Second dorsal fin with not more than 10 rays. (Median 
(21b) fins usually banded) — Carassiops compressus (fCrefft) ' 
Carp gudgeon. 
b. Second dorsal fin with more than 10 rays. (Tail usually 
yellow to Grange) — Carassiops galii Ogilby : Firetail 
gudgeon. 
26 a. Anal fin with single leading bony spine — 27. 
(20b) b. Anal fin with two or more spines — 31, 
27 a. Anal fin long, extending from level of first dorsal to hinder 
(26a) limit of second dorsal fin — Melanotaenia nigrans 
(Richardson) ; Crimson-spotted jewel fish, 
b. Anal fin short, corresponding in size and levels with 
second dorsal fin — 28. 
28 a. Origin of second dorsal fin behind that of anal; first dorsal 
(27b) with leading edge very much longer than trailing edge. 
(White mark -on nape, and commonly black mark at base 
of second dorsal — Pseudomugil signifer Kner : Blue-eye. 
b. Origins of second dorsal and anal fins at same level; first 
dorsal with spines not differing greatly in length — 29. 
29 a. Body stocky, slightly compressed — Craterocephalus 
(28b) marjoriae Whitley. 
b. Body elongate and round in section —30. 
30 a. Body showing three or ma e obvious interrupted black 
(29b) longitudinal lines below a prominent median lateral line 
— Craterocephalus stercusmuscarum (Gunther) : Spotted 
silverside. 
b. Body never showing m.ore than one such interrupted line 
below the lateral line — Craterocephalus fluviatilis 
McCulloch : Silverside. 
3t a. Body blotched. Mouth powerful and oblique, extending 
(26b) to below level of eye — Glossamia gillii (Steindachner) : 
Gill's percelle. 
b. Body uniformly olive-green above, silver below. Mouth 
small and weak, not reaching level of eye — 32. 
32 a. Jaw margins with minute but discernible teeth — Mugil 
(31b) cephalus Linnaeus : Hardgut mullet, sea mullet or river 
mullet. 
b. Jaw margins toothless — Trachysloma petardi (Castelnau) : 
Fresh water mullet. 
