THE DHAGONKT FAMILY. 179 



T \j inch to 4- inch in length have been obtained by the mid- 

 water net in St Andrews Bay during August. Thus they still 

 retain their pelagic habit, but a few are found near the rocks, 

 shewing a tendency to assume the adult habitat. 



The smallest (^ inch) are mainly conspicuous for a large head 

 and trunk and a long whip-like tail. The lower jaw projects 

 at an angle (Plate VII, fig. 7). ' Head and body are speckled 

 with brownish-black pigment-corpuscles, which attain their 

 greatest development on the ventral surface of the abdomen 1 / 

 The predominance of a dark coloration on the under surface 

 is rarely found amongst fishes, this part being usually white 

 or pale, as it is also in the adult dragonet. When the little 

 larva has nearly doubled its length ( inch) the head has become 

 flatter, and by a growth outwards of the cheeks, the eyes are 

 carried towards the top of the head, so that they look upwards 

 more than laterally. The upper jaw has grown forwards and 

 the arch of the mandible has increased. The dark pigment 

 on the under side is more prominent than before. At a 

 little over ^ inch in length, the same coloration obtains. 

 The head and trunk are still broad when seen from above. 

 A side view shews the fish to have a fusiform outline. The 

 embryonic continuous median fin has broken up into two 

 dorsals, a tail fin and an anal. The pectoral and ventral fins 

 approach those of the adult in shape, no marked hypertrophy 

 taking place in either pair. There is a spine upon each gill- 

 cover which, at the stage of about J inch in length, becomes a 

 formidable armature. By this time also the ventral fins have 

 gained greatly upon the pectorals, being markedly longer. 



Shortly afterwards (Plate VII, fig. 8) the adult characters 

 have been mostly assumed. The peculiar protrusible mouth is 

 conspicuous. The paired fins are pale, except for a mass of 

 dark pigment at the fleshy base of the pectorals. The lower 

 surface ' is still coloured with black pigment/ and dark bands 

 extend over the greenish back, one behind the head, and 

 three across the trunk. ' The figure here referred to is from 

 a sketch made some days after confinement in a glass tank 

 in the laboratory, hence the coloration is modified. The 



1 Researcites, p. 86-4. 



122 



