66 UPPER CRETACEOUS TELEOSTS 
material have been studied. The original descriptions of d’Erasmo (1946 ; 1952) 
together with the body fragments in Bologna have convinced me that only one species 
is represented. A small head region, also from Comen, in Bologna, was noticed by 
d’Erasmo (1946 : 82). He ascribed this specimen to the genus Leptotrachelus, and 
indicated that it had affinities with the species Leptotrachelus hakelensis. It almost 
certainly is a specimen of Rhynchodercetis gortanit. 
Due to the lack of material, only a few features are described. All the features 
are well shown by the two specimens from Comen, one in the B.M.N.H. number 
P.10913, and the other in Ljubljana. Both specimens are of the mid-trunk region 
and exhibit both precaudal and caudal vertebrae. 
DescripTION. Vertebral column. Selected vertebrae are shown in Text-figures 
30 A-C. Approximately 59 vertebrae are exhibited in the Ljubljana specimen, 
of which 39 are precaudal. (The type specimen of Rhynchodercetis acutissimus has 
80 vertebrae in all, of which 30 are caudal.) Anterior to the dorsal fin the specimen 
is flattened dorso-ventrally due to the prominent transverse processes having 
prevented twisting of the body during fossilization. However further back the 
dorsal fin and the pelvic fins have overriden this effect and the remainder of the body 
is preserved normally by lateral compression. The body was obviously long and 
very thin, and the precaudal region is characterized by the presence of two pairs of 
Fic. 30. Rhynchodercetis gortanii (d’Erasmo). Selected vertebrae. (A) Ventral view of 
precaudal vertebrae 26 and 27. (Bs) Lateral view of precaudal vertebrae 42 and 43. 
(c) Lateral view of precaudal vertebra, 50 and caudal vertebrae 1 and 2. (pb) Lateral 
view of caudal vertebra 15. 
enormous transverse processes per centrum. The transverse processes are long and 
acutely pointed, but are flattened and extended where they contact the centrum. 
The anterior pair of transverse processes is almost twice as long as the posterior pair. 
The length of the anterior processes increases posteriorly and they attain their 
greatest length at about the 26th precaudal vertebra, (i.e. assuming that 80 verte- 
brae are present of which 50 are precaudal). The greatest length of the anterior 
transverse processes is in excess of the length of the centrum supporting them. The 
posterior pair of transverse processes are set at 90° to the long axis of the centrum 
