TRIASSIC FISHES FROM SPITZBERGEN 
2 2T 
Squamation. 
The scales are of about the same shape and arranged in the same way as in 
B. renterskioldi. Most of them are consequently wider than high, and this is especially 
the case towards the dorsum and on the ventral side. Their anterior covered area is in 
general wide and their antero-dorsal corner is not infrequently somewhat produced 
upwards. Their dorsal margin has a well developed or in certain cases even a long 
articulatory spine, and their medial surface is furnished with a broad vertical ridge, at 
least on the scales of the abdominal region. Their posterior margin is serrate. 
The scale sculpture resembles also on the whole that of B. reuterskioldi. The striae 
pass off as in this species and anastomosations between them are similarly unusual. 
Finally, tubercles or shorter striae occur in both species between the anterior ends of 
the longer striae, and, in addition, the fine folds on all the striae. The only difference 
that can be shown seems to consist in the fact that the striae are relatively coarser in 
B. reuterskioldi than is the case here. 
The number of striae is rather great on the highest, anterior scales, but decreases 
according as the scales diminish in hight. The character of the striation on some scales 
from the anterior part of the lateral surfaces of the abdominal region is shown in 
PL 29, fig. 2 and it is noteworthy that the striae on these scales grow very fine as they 
approach the posterior margin, and that a number of equally fine shorter ones are 
inserted between their posterior ends. The striae of the latter category are, however, 
only to be found on the scales iii the most anterior vertical rows. The shape and the 
sculpture on the scales of the ventral side is shown as a negative in PI. 29, fig. 3 . 
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Remarks. — It is evident from the description just given that the differences 
that can be observed between the specimens described in this connection and B. reuterskioldi 
are of rather slight importance. It is probable, however, that a number of additional 
differentiating characters would be found if we had a more complete material at our 
disposal. 
As it is thus impossible at present to decide whether in the remains described 
here we are concerned with a variety of B . reuterskioldi or a new and independent species 
closely related to this, I have merely placed them under the heading Boreosomus sp. 
Geological occurrence and localities. — All the specimens included under 
the heading Boreosomus sp. come from the upper Saurian horizon. The localities of the 
finds are as folows: Cape Svea, Mt Congress, Mt Tschermak, Mt Marmier and Mt Viking. 
Boreosomus? scaber n. sp. 
(PI. 24, fig. 4; PI. 26, fig. 3; PI. 35, fig. 4). 
Under this name I include a fragment of a smaller fish* P. 8yy, and a large number 
of detached scales. 
I shall begin my description with specimen P. 8yy and afterwards pass on to the 
detached scales. 
Specimen P. 8yy consists only of a portion with connecteed scales from the caudal 
region or the transition between this and the abdominal region (PL 24, fig. 4). The 
