SEMIONOTIDJE. 
93 
pedicles, but obtuse. Pin-fulcra very large, the principal dorsal 
fulcra more than half as long as the anterior dorsal fin-rays ; pelvic 
fins arising much nearer to the anal than to the pectorals; dorsal 
and anal fins deeper than long. Scales smooth, very few serrated, 
but those of the lateral line and sometimes a few anterior flank- 
scales faintly notched on the hinder margin. 
Form. Sf Log. Lower Kimmeridgian (Lithographic Stone): Bavaria 
and S.E. Prance. 
P. 470. Type specimen described and figured by Agassiz: Solen- 
hofen. There are some inaccuracies in the description, 
and the original figure is very inadequate. The cranium 
is exposed from the right side, the facial bones being 
destroyed or displaced; and the right operculum is 
observed above the occiput, with two branchiostegal rays, 
displaying the inner aspect. One of the rays partly 
overlaps the operculum, and thus produces the false 
appearance of a downwardly descending process of the 
latter bone in Dinkel’s figure. So far as preserved, the 
cranial roof is remarkably smooth, but there are distinct 
traces of a few rounded tuberculations in the parietal 
region; and at the extremity of the snout there is the 
premaxilla of the right side, with a single series of five 
obtuse teeth and a stout process ascending from its 
internal lateral extremity to the ethmoidal region of the 
cranium. There are ossifications in the otic capsule, and 
the long, slender, apparently toothless parasphenoid meets 
an expanded dentigerous vomer in front. One of the 
hyomandibular elements occurs displaced above the head, 
and is shown to be comparatively slender, with a superior 
expansion and a large posterior process for the support of 
the operculum. The pterygo-palatine arcade of the left 
side is partly seen below the parasphenoid, and that of 
the right side (“ maxillaire inferieur gauche ” of Agassiz) 
is displaced further beneath and backwards, both exposed 
from the oral aspect; there are several series of teeth on 
these bones, very large in the front half, but becoming 
comparatively insignificant behind. Immediately in ad¬ 
vance of the right pterygo-palatine element is the dentary 
bone of the right side, with a single regular series of 
obtuse teeth; and still further forwards are remains of 
other dentigerous bones, regarded by Agassiz as the 
maxillae and premaxillae. Some of the fin-rays and fulcra 
of the pectoral, dorsal, and caudal fins are well shown; 
