St. Andrews Murine Laboratory. 183 



the egg up to a stage when a liypural thickening occuired in 

 the tail, which also presented fin-rays. At this stage ^ '' a 

 well-marked interrupted line of black 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 con- 

 tinuous from the anus to the tail; a narrower [preanal] 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 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 in 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 large size of the 

 otocysts and their continuation upward so as nearly to meet 

 in the median dorsal line is another interesting feature. At 

 this stage they are fully 12 millim. in length. It may further 

 be noted that the ventral median line of black pigment ceases 

 before reaching a line from the pectorals, an oblique bar on 

 each side, forming a A with the apex directed forward, 

 occurring at this region, only a short streak of pigment 

 existing in the middle line in front. No trace of ventral fins 

 is apparent. 



Lately (23rd May) the trawl-like bottom tow-net brouglit 

 up a remarkably transparent fish about 35*5 millim. in length 

 which gives us an intermediate stage between the foregoing 

 and those which resemble the adult, though perhaps they only 

 exceed this specimen by a few millimetres. The gunnel at 

 this stage appears to live on the bottom, and probably hides 

 amongst the sand like the young Jnguilla, to which at first 

 sight it has a close resemblance. 



1'he proportions of this translucent fish differ materially 

 from the earlier form. Thus the eye is much less in propor- 

 tion to the size of the head and the latter occupies much less 

 bulk in proportion to the body. Nevertheless the eyes seemed 

 to be large and prominent in life when viewed from above. 

 The eye has a silvery lustre laterally, emerald and dark olive- 

 green when viewed from above. Ventrally a black pigment- 

 line begins on the hyoid and continues along the median line 

 to the anus, just as in the earlier form, except that in front 

 it now passes between the separated limbs of the A -shaped 

 arrangement. A line of the same pigment-dots behind the 



* M'Intosli and Priuce, Trans. R. Soc. Edin. vol. xxxv. p. 869 (1890), 



