48 A. E. HEFFOED. 



truding on each side, has a yellowish brown tint ; there are pale yellow 

 chromatophores on the head and similar pigment, but of more intensity, 

 in the pectoral region. The thickness and opacity of the head causes 

 the otocysts to be hardly visible. The course of the red blood 

 corpuscles along the circulatory system from the yolk to the body of 

 the larva can be very easily seen. 



Gohius 20ciganellus, Gm. L. 



Some eggs, together with a fish of this species, were taken on a stone 

 between tide-marks on the shore of Rum Bay on 3rd June. The ova 

 have been described by Holt and Byrne (13, p. 46) as regularly 

 fusiform in shape, about twice as high as wide and with rather sharply 

 pointed ends ; by which characters they are distinguishable from the 

 eggs of all other British species of goby. The above-mentioned autliors 

 give 1"84 to 1*9 mm. as the length. An egg which I measured at a 

 late embryo stage was 2"3 mm. long and 0"74 mm. wide, while a second 

 was slightly longer. The yolk was of a greyish brown colour and was 

 darkened by the presence of many small oil-globules. When the 

 embryo is advanced in development, the eyes become extremely 

 conspicuous, showing abundant black pigment and a bronze-green 

 lustre. The oval swim-bladder with strongly marked dendritic chroma- 

 tophores and some yellow pigment over the dorsal side of it is plainly 

 visible. This is the only really conspicuous pigment on the embryo at 

 this stage. The large bean-shaped otocysts contain relatively small 

 otoliths. 



The newly hatched larva (Fig. 7) has a total length of 4-8 mm., the 

 pre-anal length being 2'2 mm., so that the anus is just anterior to the 

 median. The head is somewhat rounded and the lower jaw slightly 

 projecting. The large, oval swim-bladder is a conspicuous object mid- 

 way between otocysts and anus. The gut is straight and has a slight 

 ventral dilation below the hinder end of the swim-bladder. As in the 

 embryo, the most conspicuous pigment is above the swim-bladder 

 (black and yellow) and in the eyes, which are black with blue, green, 

 and gold tints. There is a continuous row of black chromatophores 

 from the throat to the anus along the ventral contour, the largest one 

 with well-marked dendritic rays being below the above-mentioned 

 bulge in the gut ; the terminal one below the anus is also very pro- 

 nounced. Except above the swim-bladder there is no peritoneal pig- 

 ment nor any other chromatophores anterior to the anus. Post-anal 

 ventral pigment consists of a discontinuous series of black dendritic 

 chromatophores (about six or less in number) extending to the hypural 

 region, the largest of which is situated in the centre of the post-anal 



