202 RECouns of the austiialtan museum. 



Colour. — Blne-grej', the upper surface usually washed with brown and 

 bearing a few small widely scattered black spots ; lips, throat, and 

 abdominal region bluish white. Many specimens have a number of short 

 black cross-bars on the middle of the sides, which are most developed in 

 specimens of medium size and tend to disappear in larger ones. Produced 

 portion of the spinous dorsal blackish, the basal portion like the back and 

 occasionally with a few small black spots. Soft dorsal bi^ownish-blue, 

 and sparsely spotted with black. Caudal bluish-grey, the inferior rays 

 white, and witli numei-ous black spots arranged in iw-egnlar transverse 

 series. Anal and ventrals yellowish-white. Pectorals dark grey, with a 

 broad lighter border and some black spots on the base. 



Described from eight examples 68-140 mm. long from the Burnett 

 River Heads ; the figure represents one of these 136 mm. long. 



Synonymy. — We have examined the eight co-types of (^ohiosoiiia 

 gntfnlatnm, Macleay, and find them similar to the specimens described in 

 all details ; in Macleay's figure, the angulated muscle-bars are too pro- 

 nounced, their appearance being exaggei^ated by contraction due to the 

 effects of their preservative fluid. The type of G. punctularnvi, De Vis, 

 cannot be found in the collection of the Queensland Museum ; its brief 

 description suggests that it is synonymous with S. vlridli^, the differences 

 noted between it and G. guttnlatuDi being apparently of little value. 

 Castelnau's description of his Apocryptes macrophthahniis from Port Darwin 

 leaves little doubt that that species also is synonymous with ;S'. I'iridis. 



Habits. — These little fishes frequent mud-flats and mangrove swamps, 

 and so soon as the receding tide leaves the flats uncovered, the}^ emerge 

 from the holes in which they lie concealed during the prevalence of the 

 flood. They traverse the mud with astonishing rapidity, their powerfial 

 pectoral, ventral and caudal muscles enabling them to leap and bound 

 over its yielding surface in search of the small creatures on which they 

 subsist. They can extrude or retract the eyes at will, and we are informed 

 by Dr. Bancroft that they can partly raise themselves upon their ventral 

 fins and tail so as to gain a wider outlook. He also notes that they hold 

 the spinous dorsal fully erect when moving over the mud. Dussumier^ 

 observed these fishes in the delta of the River Ganges, and wrote: — 

 " They are abundant on the mud-flats, over which tliey ski]> in pursuit of 

 small crustaceans; when an attempt is made to capture them they bury 

 themselves with great celei'ity in the mud, oi- if that be to hard they hurriedly 

 seek a crab-hole, in which to take i-efnge ; when they are in the water 

 they frequently raise the head above the sui'face." Refei-iiiig to this 

 latter peculiarity Dr. Bancroft writes : — " When pursued it skips into 

 the water, swims a few feet, and then protrudes its head witli its goggle- 

 eyes thrust forth to their full extent ; and from this point of vantage, it 

 stares impudently at its would-be captor." AVriting of an allied species, 

 BoleopJitludinns 2)ectin'iro.'itris, Jordan*^ says : — " The animal has the power 

 of skipping along over the wet sands and mud, even skimming with gi-eat 

 speed over the surface of the water. It chases its insect prey among 

 rocks, leaves and weeds, and out of the water is as agile as a lizai'd." 



" Cuvier & Valenciennes — Hist. Nat. I'oiss., xii., 18157, ]■>. '2\',\. 

 ■* Jordan — (luide Study of Fislins. ii., 1905, p. 465. 



