146 UPPER CRETACEOUS TELEOSTS 
Median fins and tail. The median fins are shown in the restoration, Text-figure 
66. The dorsal fin has 17 stout rays, and occupies the second quarter of the back. 
The first ray is shorter than the subsequent ones and unbranched, with its basal 
region ornamented. The remainder of the rays are branched and supported by 
elongate proximal radials. The anteriormost proximal radial is expanded anteriorly 
into a large keel-like structure. Traces of the medial radials are visible extending 
between the bases of adjacent fin rays. 
The small anal fin consists of 11 feeble rays and is remote in position. The first ray 
is short and unbranched, the remainder are all branched. None of the proximal 
radials is expanded. 
The caudal fin is supported by four or five centra. Three of the centra are free 
preural centra, the first preural vertebra appearing to be fused with the centrum of 
ural vertebra 1. Ural vertebra 2 may be present as a terminal half-centrum. The 
remainder of the caudal skeleton is indeterminable. 
The fin itself is composed of 17 branched principal rays, and approximately 16 
accessory rays. 
Scales. The entire body is covered with a uniform coat of small scales, regular in 
shape and arrangement and closely packed. The scales are not present on the 
opercular bones but do cover most of the cheek region. Each scale bears a minute, 
longitudinal crest and these crests are continuous, producing a regular longitudinal 
series of parallel ridges along the body. The scales along the course of the lateral 
line are enlarged and thickened with the longitudinal crests becoming much more 
pronounced towards the caudal peduncle. On the peduncle the crests fuse with 
one another to produce a lateral, longitudinal flange. 
Genus HEMISAURIDA Kner, 1867 
Dracnosis (emended). Halecidae in which the head is not deepened but slightly 
elongated ; body shallow and not elongated. Supraorbital absent. Jaw sus- 
pensorium inclined anteriorly. Preoperculum with a greatly extended posterior 
spine. 16 branchiostegal rays. Dorsal fin in the second quarter of the back. 
Pelvics abdominal but smaller than the considerably elongated pectorals. Epi- 
neurals on the first 23 vertebrae. Body completely naked. 
TYPE SPECIES. Hemisaurida neocomiensis Kner. 
REMARKS. The genus was erected by Kner in 1867 to contain the single species 
Hemisaurida neocomiensis. The holotype of this species is a fragment of the head in 
the Geologische Bundesanstalt, Vienna. The specimen is from the Lower Cenomanian, 
Comen, near Trieste. A more complete specimen of this species, lacking the tail 
region and the tip of the snout is also present in Vienna. These are the only speci- 
mens of the type species and both were examined. 
