32 
General Form. — Tlic body is remarkably elongated, the maximum 
depth being contained more than four times in the total length. The head 
and oj)ercular apparatus occujiy about one-fourth of the total length ; and 
the dorsal fin is very high, the length of the anterior ray almost equalling the 
depth of the trunk at its point of insertion. 
Appendicular Skeleton. — The pectoral fins arc placed well above the 
inferior margin of the flank, the remains of about six or eight rays of 
one fin being distinguishable in the type-specimen. The pelvic fins in each 
fossil are unfortunately destroyed ; and only the anterior margin of the 
dorsal is preserved. Very little of the latter is seen in the type-specimen, 
but the anterior ray seems to bo unbroken in the second example under dis- 
cussion, and the dimensions of the fin thus indicated are shown by the 
dotted line (PI. VI., Pig. 3). The anal fin is evidently opposed to the hinder 
portion of the dorsal, and its anterior rays are also much elongated, their 
length being equal to the depth of the caudal region at their point of 
insertion. The caudal fin is of the usual proportions, and consists of more 
than twenty bifurcating rays. The fulcra upon the anterior margin of each 
of the median tins are large and conspicuous, but remarkably slender. 
Squamation. — As in S. australis described above, the scales of the 
middle of the anterior portion of the flank are twice as deep as broad ; 
and at the extremity of the caudal pedicle, small diamond- shaped scales 
distinctly cover an abbreviated upper lobe. 
Remarks. — This species is distinguished by the elongation of the 
body, the depth of the flank-scales, and the extreme tenuity of the large fin- 
fulcra. In the relative length and slenderness of the trunk, it is only 
equalled by S. elongatusA from the Kouper of Stuttgart, and this species 
differs considerably in the characters of its squamation. 
Genus PRISTISOMUS, gen. nor. 
Gen. Char. — Body comparatively deep, but fusiform ; three or more 
series of the flank-scales vertically elongated ; a dorsal and ventral series 
of prominent ridge-scales. Teeth large, styliform, in close series. Paired 
fins moderately developed ; dorsal and anal fins remote, the former partly 
opposed to the latter ; caudal fin robust, scarcely forked. Small fulcra 
present upon all the fins. 
O. Fraas, “ Ueljer Semionotux,” Wtii'tt. .Tahresh., lS(il, Vol. xvii, pp. !)3, !)5, I’l. 1, figs. 4, 
