1878.] MR. R. COLLETT ON CERTAIN GOBIOID FISHES. 325 



teeth, which project very little beyond the jaws. Only the inner- 

 most part of the lower jaw is entirely toothless. These teeth make 

 their appearance very early in the young. In a young specimen 

 of scarcely 14 millims. length, some very minute (microscopical) 

 teeth are already visible in the front part of the lower jaw, although 

 they cannot with certainty be seen in the upper. In specimens 

 of the total length of 23 millims. there are some small teeth visible 

 in both jaws ; and on being dried, one may see that some of them are 

 already developed ; still they continue to be minute until the speci- 

 mens have reached their full length. 



The teeth of the female undergo no special alteration the whole 

 of their life through, but continue daring the spawning-season in the 

 same state as before ; but in the males, on the other hand, these 

 minute teeth of young specimens begin to disappear towards the 

 spawning-season, and are replaced by a set of long and cylindrical 

 ones. These long teeth do not proceed from the minute teeth, but 

 constitute an entirely new set, which shoot forth at the same time 

 as the orignal set disappears. In the specimens wherein the organs 

 of generation are still not fully mature, both sets of teeth are visible 

 for a short period at the same time, the new set only half deve- 

 loped. 



Finally, during the spawning-season all the minute teeth of the 

 male have almost entirely disappeared, and are replaced by the 

 new, long, and almost straight teeth, situated at a remarkable dis- 

 tance from each other, and chiefly to be found on the front part 

 of the jaws. In the lower jaw their number is 4, or sometimes but 

 3, on each side ; they are not particularly pointed, but almost cylin- 

 drical, only slightly curved, and placed almost vertically upon the 

 outer edge of the jaw. At a little distance below and inside the 

 last of these teeth, on each side, is found a sharp, curved tooth 

 (caniue) directed backwards and almost in the form of a claw. In 

 the posterior half of the jaw the prolonged teeth are missing, a few 

 of the minute teeth of the young period still remaining here. 



In the upper jaw the number of the long teeth is 5 on each side, 

 of which a few (1-2) are also to be found behind the middle of the 

 jaw. In the upper jaw there is also found, inside the ordinary row 

 on each side, the curved canine, which is directed backwards ; this 

 canine is placed further in front than the opposite one in the lower, 

 or nearly at the point of the jaw. There may further be found in 

 the posterior part more or less remaining of the original minute teeth, 

 whilst these only exceptionally are found at the point of the jaw. 



The fins. — The first dorsal fin has 5 rays, and is a little higher 

 in the full-grown males than in the females, without, however, 

 reaching the height of the body. . All the rays are about evenly 

 high, undivided, feeble, and rather closely set. This is one of those 

 fins which appear latest, and is entirely wanting in specimens of a 

 total length under 16 millims., wherein all the remaining fins have 

 already got their rays. In individuals of the total length of about 

 22 millims. this fin is found with extremely feeble and short spines, 

 which are often difficult to detect. 



