52 UPPER CRETACEOUS TELEOSTS 
largest Dercetis species, Dercetis maximus from the English Chalk (Woodward, 
1903, pl. 15, fig. 2), to the smallest Dercetis gracilis from the Lebanese chalk. 
White and Moy-Thomas (1940 : 102) pointed out that the generic name Lepto- 
trachelus was preoccupied and erected a new generic name, Benthesikyme. Since 
all of the species of Leptotrachelus are now included in the genus Dercetis, Ben- 
thestkyme is treated as a synonym. 
Dercetis triqueter Pictet 
(Text-figs. 22, 23) 
1850 Dercetis triqueter Pictet : 47, pl. 9, figs. 5, 6. 
1850 Dercetis linguifer Pictet : 47, pl. 9, figs. 7, 8. 
1866 Leptotrachelus triquetey (Pictet) Pictet & Humbert : 95, pl. 14, figs. I, 2. 
1887 Leptotrachelus triqueter (Pictet) ; Davis : 620, pl. 38, fig. 1. 
1898 Leptotyvachelus triquetey (Pictet) ; Woodward : pl. ro. 
1901 Leptotvachelus triquetey (Pictet) ; Woodward : 174. 
1903 Leptotrachelus triqueter (Pictet) ; Woodward : 68, text-figs. 15, 16. 
1926 Leptotrachelus tviquetey (Pictet) ; Woodward : fig. 3. 
1940 Leptotvachelus triquetey (Pictet) ; Berg: fig. 215. 
1954 Leptotrachelus triquetey (Pictet) ; Signeux : 642, pl. fig. 4. 
1958 Leptotvachelus triqueter (Pictet) ; Bertin & Arambourg : fig. 1617A. 
1964 Benthesikyme triqueter (Pictet) Danil’chenko : fig. 141. 
1966 Leptotrachelus triqueter (Pictet) ; Lehman : fig. 200. 
Di1aGNosis (emended). Dercetis of standard length up to 22:5 cm. Vertebrae 
between 70 and 73 in number of which 30 are caudal. Anterior precaudal centra 
twice as long as deep. Head equal to approximately one-fifth of the standard 
length and the maximum height of the head equal to one-third of its length. Pre- 
orbital region forms 60% of the total head length. Mesethmoid bluntly bifurcate 
anteriorly. Dorsal fin with 35 rays; anal fin with 8 or g small feeble rays, remote in 
position. Pectoral fin with 11 rays ; pelvic with 8 rays arising behind anterior third 
of the trunk. Scutes of varying sizes, with the precaudal ones heart-shaped ; 
triradiate pattern obscured in many. Intermediate lath-shaped scutes often 
present. 
Ho.totyre. Fragment of abdominal region in the Muséum d’Histoire Naturelle, 
Geneva, from the Upper Senonian of Sahel Alma, Lebanon. 
MATERIAL. Specimens in the B.M.N.H., the Muséum d’Histoire Naturelle in 
Geneva, and the Muséum National d’Histoire Naturelle, Paris. 
REMARKS. The species was originally erected by Pictet as Dercetis triqueter and 
in the same work (Pictet, 1850) he erected a second species, D. linguifer. Pictet 
and Humbert (1866 : 95) synonymised both species under Leptotrachelus triqueter. 
Both holotypes (Dercetis triqueter and Dercetis lingwifer) are in Geneva. That of 
Dercetis linguifer is also a small fragment of an abdominal region and is clearly 
referable to Dercetis triqueter. 
DeEscRIPTION. Neurocranium. The neurocranium is indistinct and _ badly 
preserved in all of the specimens examined. The neurocranium is elongated, 
