220 
ERIK A : SON STENSIO 
lengthened in the longitudinal direction of the fish. It is noteworthy that in this case 
the sculpture on the whole maxillary is developed in the same way and is not, as in 
B. reuterskidldi, stronger on the anterior part. 
Dentition. 
The dentition is fairly weak. The teeth are of two kinds: pointedly conical and 
very bluntly conical, almost spheroid. The former variety is found on the maxillary 
and the dentalo-splenial, where they are arranged in two longitudinal rows, a lateral 
and a medial one. As usual the teeth of the medial row are considerably longer and more 
robust than those of the lateral one. On these stronger teeth can be observed a bright 
little enamel cap. 
The bluntly conical teeth are almost Colobodus-like in appearance, as, like those of 
Colobodus, they posess the little verruca that obviously corresponds to the enamel 
point on the pointedly conical ones. They have, however, no striation radiating from the 
verruca, as is the case in Golobodus. Teeth of this type are only found on a loose fragment 
of bone which may probably have formed part of a pterygoid, or of the parasphenoid. 
The sensory canals of the head. 
Only some smaller parts of the mandibular canal are preserved and show that the 
sensory canals were fairly fine, and that they opened outwards with long simple tubules. 
The number of these cannot be etablished. 
The skeleton of the unpaired fins. 
The dorsal fin {D, PI. 29, fig. 1) is preserved in specimen P. 120 and is situated 
there far forward, its distance from the head'being only about 10 cm, while the height 
of the body in the most anterior part of the abdominal region is, as has been mentioned, 
about 12 cm. It is fairly well developed, is triangular in shape with height and length 
about equal and consists of about 3 o rather coarse, closely situated lepidotrichia, jointed 
throughout; each of these has on the posterior half of the lateral sides a number of 
fine, often confluent, longitudinal striae of ganoine. The anterior half of the lateral sides, 
on the other hand, is without ganoine and is smooth. Nothing is preserved of the fulcra. 
Of the caudal fin there is only a fragment of the dorsal lobe present (P. 122), 
which has already been noticed by Woodward 1912 (p. 293). This fragment is interesting 
inasmuch at it shows undoubtedly that we are concerned with a heterocercal fish. 
Otherwise it gives us no further idea as to the exact form or size of the fin. The lepido¬ 
trichia are on the whole densely jointed and coated with a smooth layer of ganoine. 
The skeleton of the paired fins. 
The shoulder girdle is represented, in its present state of preservation, only by 
very indistinct remains of the supracleithral and the cleithral, both of which have a very 
fine sculpture, consisting of short, horizontally running striae, or, if the term is preferred, 
somewhat lengthened tubercles, oriented in the longitudinal direction of the fish. 
The pectoral fin {Pc, PI. 29, fig. 1) is very incompletely preserved. It is only re¬ 
presented by some proximal parts of lepidotrichia, which appear to be unjointed. 
