270 4 



scale-plate, dropping off when macerated. The largest scales are found along the 

 sides of the body, above and below the lateral line; their number of teeth, in 

 specimens of about 50 ctm. length, is 33—37. In each row the middle teeth are 

 largest, the size evenly decreasing towards the margins. The lateral, smaller teeth 

 show basally a small extension, which appears to vanish on the larger and older 

 ones towards the middle. On a scale of about 3 mm. length one of the longest 

 teeth measures 0,352 mm., one of the shortest 0,112 mm. In another specimen of 

 ca. 40 ctm. length, one of the lateral body-scales carries 28 teeth, a scale from 

 near the middle line of the back 14 teeth, and one from the caudal fin 7. In a 

 young specimen of 110 mm. length, scales from the sides of the body show 7 teeth; 

 the scale-plate is 0,336 x 0,304 mm., the middle tooth 0,096 mm. in length; a scale 

 from the middle of the belly in front of the anus carries only 3 teeth, one median 

 and two lateral; the scale itself is 0,282 x 0,iö2 mm., the median tooth 0,0î)6 mm. The 

 median tooth apparently is the oldest, and new teeth are formed in pairs, one on each 

 side of the first etc. in a similar way as G. Winther (58) has shown the scale-teeth to 

 originate in Gobiiis. It would be of some interest to have for examination still younger 

 specimens which might decide if the development begins with a simple scale-plate 

 without any teeth, on which, later, a single, median tooth, appears, next the first pair 

 of lateral ones and so on ; or if perhaps one single tooth is the first to be formed, 

 the appearance of a scale-plate the next step etc. In the latter case some light 

 might be thrown on the origin of the dermal asperities found in two species of 

 Fistalaria; but it has to be remembered that in the latter genus the small booklets 

 or denticles form one piece with their basal enlargement (cfr. below). 



The large scale-plates of Aulosioma are provided with a great number of con- 

 centric striæ, parallel to the margin ; the number seems to be about double that 

 of teeth present; in the small scales of young specimens only 2 — 3 striæ are found 

 running along each margin ^ 



The canal of the lateral line is not inclosed in the scales, but in a system 

 of free, thin, bony tubes; these tubes are uncovered by scales from the postfrontal 

 to about the level of the posterior margin of the ventral fins; from here and further 

 backwards the tubes are sunk between the scales and more or less covered by 

 these, but the tubes will never be found combined or coalesced with the scales. 



Immediately below the skin, in the most superficial part of the muscles, is 

 found a most richly developed system of long, narrow and flat ossifications, pro- 

 bably formed in the outermost layer of the intermuscular ligaments. Corresponding 

 to the arrangement of the lateral muscles these ossifications appear in a double 

 row on each side above the lateral line, from the head to the tail; below the 

 lateral line the trunk shows two double series, the tail only one, as dorsally to 

 the lateral line. In each double row the upper and lower members converge to- 

 wards the tail, meeting at a very acute angle. In the dorsal row the upper anterior 

 member is by far the largest, very much surpassing in size any of the others; it 



