TRIASSIC FISHES FROM SPITZBERGEN 
I X 
which is probably also the case between those of the middle and posterior transverse 
rows. For practical reasons, however, I have grouped here under the heading «teeth 
of the anterior transverse rows» all those teeth that have somewhat distinct lateral 
cones,, while the rest are described as belonging to the middle and posterior transverse 
rows. It is true that it sometimes happens (cf. A. anningiae Woodward, 1889a, p. 2 g3, 
text fig.; Pl. XIV, fig. 4, PI. XV, fig. 1) that small lateral cones are found developed 
even on the teeth of the middle and posterior transverse rows, but in the species under 
consideration there seems to be no risk of this being the case, as the sculpture on 
the teeth of the anterior transverse row is, as we shall see, developed in another way 
than in those of the posterior and middle ones. 
I take the teeth P. 98 a, P. 99 a—e (PI. 2, figs. 1—7) and one tooth from Horn 
Sound as belonging to the anterior transverse rows. To this category I have also 
referred the tooth P. 98 b, though not without hesitation. 
The tooth P. 9 8 a (PI. 2, fig. 1) is defective at one end, otherwise it is well preserved. 
In its present state of preservation it is 10 mm long. Its greatest height is about 7 mm. 
If it has been developed symmetrically there seems to be no reason why it should 
not have belonged to the unpaired symphyseal row. 
Seen from the lateral or medial side the crown is much bent in the way that its 
distal outline is convex from end to end, while its basal one, on the other hand, is 
concave (PI. 2, figs. 1 b, c). Another special characteristic of the crown is the low and 
blunt, but nevertheless powerful principal cone and the distinct lateral cones, four of 
which are preserved on one side of the principal cone and one on the other. The 
appearance of the crown as seen from above is shown in PI. 2, fig. 1 a. 
From one end of the crown to the other there passes off over all the cones a 
longitudinal crista (PI. 2, fig. 1 a) and over the principal cone a distinct transversal 
crista is also developed. The . latter crista reaches both on the lateral and the medial 
surface of the tooth almost entirely to the basal border of the crown, in the neighbour¬ 
hood of which it is ramified. Laterally of the longitudinal crista (PI. 2, fig. 1 c) this 
ramification is considerably stronger than medially of it (PI. 2, fig. 1 b). Apart from 
these cristae the principal cone has no ornament. Anterior and posterior to this cone 
both on the lateral and the medial surface there is on the basal half of the crown a 
rather coarse vertical striation. None of the striae on the lateral surface reach the 
longitudinal crista, but there is a fairly smooth interspace between their distal ends 
and that crista; on the medial surface, on the other hand, there is for each lateral 
cone a stria longer than the other ones, extending from the basal margin of the crown 
to the longitudinal crista. Short fine striae issue from this crista both on its lateral 
and medial side, without becoming attached to the longer ones described, which are 
mainly developed on the basal halves of the crown (PI. 2, fig. 1 a). 
The root is high, especially its middle part, but rather thin in comparison 
with the height. It is bent in the same way as the crown, though not quite so 
much. The lateral and the medial surface meet basally, forming a rounded angle, 
so that one cannot speak of any real basal surface. — A cross section through 
this tooth, clearly showing this and the relation between the root and the crown, is 
seen in text fig. 4 A. 
