DEVELOPMENT AND LIFE-HISTORIES OF TELEOSTEAN FISHES. 869 



over the anal region and at the tapering caudal extremity. In this latter portion 

 embryonic striations or rays (er) appear, and are especially distinct in the upper portion. 



In a fortnight the changes were the appearance of very finely stellate pigment over 

 the corrugated rectum (hg), and between the latter and the urinary vesicle (uv). 

 Smaller stellate pigment-spots proceed along the ventral surface of the gut to the yolk- 

 sac, but they go no further. The same stretch behind the vent along the edge of the 

 muscle-plates. Two or three stellate pigment-corpuscles also appear over the yolk-sac, 

 about midway between the oil-globule and the notochord. In some the yolk has con- 

 siderably diminished, and the oil-globule is thrown rather more to the front. The ridge 

 from the ventral marginal fin goes a considerable distance forward over the yolk-sac. 



In a few days the young fishes exhibited a tendency to lie on their sides at the 

 bottom of the vessel. 



After the lapse of five weeks, the majority of the larvae (PI. XIII. fig. 7) had the tend- 

 ency just mentioned. A well-marked interrupted line of pigment runs from the cardiac 

 region to the anus, passes forward and upward behind it, and is then continued to the tail. 

 The marginal fin is continuous from the anus to the tail; a narrower fin occurs in front 

 of this, and it diminishes about the region of the gall-bladder, which is large and distinct. 

 The dorsal fin again is similar, and deepens only a little in front of the caudal, which in 

 outline is somewhat lobate. The fin-rays are present in the tail, and are at this time 

 better marked in the ventral (anal) than the dorsal fin. They are also distinct in the 

 pectorals. The snout now extends forward about half the diameter of the eye in front of 

 it; and the mandible projects a little further, but is motionless, the animal aerating its 

 gills in its progress through the water. The lateral view of the head much resembles 

 that of the cod or gurnard at a similar stage, but the diagnostic features besides those 

 mentioned are the great length of the body and the median position of the anus. In the 

 tail a hypural thickening has taken place, with a few coils of vessels which show pale 

 blood coursing through them. The large size of the otocysts, and their continuation 

 upward so as nearly to meet in the median dorsal line, is interesting. 



Most perished at the end of April from impurity of the water, but such as survived 

 showed little change in habit and structure. 



Young gunnels, 1^ inch long, having the external features of the adult, were pro- 

 cured in July. 



Lophius piscatorius, L. # — An injured example of the post-larval frog-fish was 

 procured by means of the mid- water net, 15 miles off the Isle of May, on 30th August 

 1886, at a depth of 25 fathoms, on 32 fathoms' ground. Its length is 7 mm. In outline 

 it presents (PI. XIX. fig. 6) a large flattened head and a slender body, the notochord at 

 the tip of the tail being bent upward at the dorsal angle. This curved terminal portion 



* The rarity of the floating ova of this species on the east coast of Scotland is remarkable, for the adult is very- 

 common in stake-nets and trawls. So far as known, the spawn is also uncommon on the west coast, though there and 

 off the south coast it has once or twice occurred recently. A specimen sent to the Fishery Board was stated to be the 

 ova of the cat-fish. Raffaele failed to meet with it in the Bay of Naples. 



