of the Fishery Board for Scotland. 



233 



viz., from 9 to 11 mm., whereas preparations of Gobius niger imme- 

 diately after hatching measure only about 5 mm., often less. The eyes 

 are large and silvery, abutting on the maxillary margin, and no trace of 

 the choroidal fissure remains. The silvery hue of the eyes is present in 

 the newly-hatched larvae, in which also the choroidal fissure is indicated. 

 The marginal fin shows no rays until the caudal is reached, the whole 

 of the latter region being furnished with well-developed embryonic rays. 

 Moreover, inferiorly, hypural elements form a thickened region. In the 

 newly-hatched Gobius niger only very fine embryonic rays occur in the 

 tail, and they do not proceed so far forward. The notochord is straight 

 in both. The pectoral fins are large and fan-shaped. In one an exten- 

 sion of the marginal fin dorsally occurred in front of the tail, but no rays 

 were present, and the condition may have been accidental. The myotomes 

 along the sides are very distinctly indicated. No swim-bladder is yet 

 visible. A marginal fin also occurs along the ventral edge of the 

 abdomen, and traces of this are visible in the larval black goby. The 

 abdomen is translucent — with a solid opacity (yolk) in front, beneath which 

 lies a small yellowish oil-globule. The vent is prominent and opens 

 about the middle of the body, though in one or two it is in front of the 

 middle line. In this respect it appears to agree with the newly-hatched 

 form above mentioned. 



The head is large, the snout short, and the upper arch of the gape, 

 therefore, is high, the elongated mandible having to bend upward at the 

 tip. The dental margin is quite smooth. The opercular region covers 

 branchial arches, which show a papillose or crenate margin in those 

 specimens procured in March.* The otocysts are large, and lie close behind 

 the eyes. 



The arrangement of the pigment in the examples is as follows : — Over 

 the faintly-yellowish mid-brain are from 5 to 10 isolated black specks, 

 three being median, the others grouped in rows at the sides. Then, after 

 an interval a median-dorsal row commences, two chromatophores broad, 

 and tapers off to one, terminating before the next row is reached. The 

 latter consists of a regular and well-marked series of chromatophores 

 on each side of the dorsal (marginal) fin, and extending to the base of 

 the caudal. A similar arrangement occurs ventrally, for, after a short 

 series in line appears, behind the vent, a row of isolated black chromato- 

 phores occurs on each side of the anal (marginal) fin. Black pigment- 

 corpuscles are grouped along the roof of the abdomen in the usual 

 position, and extend to the vent. A streak of similar pigment also runs 

 on the ventral surface from the cardiac region backward in the middle 

 line. In the newly-hatched black goby black pigment-corpuscles are 

 scattered over the ventral surface of the yolk-sac, and a marked belt 

 occurs at the region of the anal fin in front of the caudal. 



In the post-larval examples, probably of the freckled goby {Gobius 

 minutus), about 3 mm. in length — the black pigment is chiefly grouped 

 along the ventral surface — from the hyoidean region to the tail. A row 

 also occurs along the roof of the abdomen, and a large black chromato- 

 phore at the angle of the mandible on each side. At this stage the 

 chromatophores form a double row in the posterior half of the abdomen 

 to the vent — after which they occur as a single row of widely-radiating cor- 

 puscles, then at a spot in front of the caudal pass up on the sides of 

 the body to meet the golden-yellow area on the dorsum. A few of the 

 same yellow corpuscles appear also toward the ventral border, and near 

 the vent. The air-bladder is conspicuous, and the eyes are greenish-silvery. 



An interesting account of a form considered by Mr Holt to be a post- 

 larval black goby from the West Coast of Ireland was given in 1891,* 

 * Trans. Roy. Soc. Dub., iv. (ser. ii.), p. 441. PI. 47, fig. 12. 



