DEVELOPMENT AND LIFE-HJSTOEIES OF TELEOSTEAN FISHES. 867 



processes form in a line along the ventral edge of the myotomes, but none exist on the 

 dorsal. The eyes have a greenish iridescence like a diamond-beetle's wing. The noto 

 chord is quite straight at the tip, and its cells are large. The tail-fin presents only a 

 trace of a dorsal enlargement. The nasal capsules form two conspicuous pits. The 

 heart has a small oil-globule below it, and the large oil-globule lies immediately behind 

 the heart — in front of the yolk, which is granular. No blood-vessel occurs in the tail 

 proper, the aorta passing almost to the tip of the chorda, and bending upward and forward 

 into the vein. The blood is comparatively pale, being only faintly pinkish in the 

 heart. The vertical vessels (intervertebrals) running up the sides of the notochord are 

 proportionally large. The branchial bars are cartilaginous. The liver is pale, and bur- 

 rowed with large vascular channels, while the densely folded alimentary canal lies above 

 it. It curves into the posterior region of the yolk-sac, and when the latter is viewed 

 from the ventral surface a folded region of the gut is evident, but no external opening. 



The larval form figured in PI. XV. fig. 2, was supposed to be Montagu's sucker 

 at an early stage, but it differs in the presence of dorsal pigment. Some variation, 

 however, may occasionally occur. On the other hand, several species may have ova and 

 larvae very similar to Montagu's sucker. In this form the regularity of the vitelline 

 vessels and their simplicity, as well as the large size of the cephalic vessels, are noteworthy. 



Centronotus gunnellus, L. — Masses of ova* about the size of a Brazil-nut have more 

 than once been found in cavities (holes of Pholas) at the Pier Pocks, with the parent- 

 fishes coiled beside them. The examples specially dealt with occurred on March 14, 1887. 



The egg-capsules examined were somewhat friable, as all the embryos had escaped. 

 The zona has a finely punctate appearance, and the punctures are most regularly 

 arranged. The lacerated margin, however, presents very fine crossed fibres, probably 

 due to the condition of the specimens, and these fibre-like markings disappear in 

 Farrant's solution. 



The larva measures just over ^ of an inch (ihy)« I* is extremely translucent, 

 and when hatched shows no trace of pigment, save that the pupil is dark (PI. XIII. 

 fig. 6). It is extremely hardy and active, darting through the water in various 

 directions, and again resting on the bottom. The head is blunt and rounded. The 

 auditory organs (au) are very large, the eyes moderately so. The most remarkable 

 features are the extreme length and thinness of the embryo, its eel-like form, the 

 great length of the alimentary canal (g), and the character of the yolk-protuberance 

 (y), which is directed somewhat forward. The latter is not of great size, and the 

 vitelline mass proper is of an elongated ellipsoidal shape with a faint opacity, and 

 having in its anterior ventral part a single oil-globule (og) of crystalline translucency, 

 very slightly tinged with ochre, and surrounded by a thick protoplasmic coat (p); while, 

 from the shortness of the sac, the globule is near the heart. Entirely covering the 

 posterior surface of the yolk is the liver (Ir), which projects as a long cellular process 

 from the abdominal region proper, and insinuates itself between the hypoblastic covering 

 * These ova appear to have been first recognised by Mr Anderson Smith on the West Coast. 



