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ESPECIALLY MYCTOPHOIDS 95 
scales of the row but becomes progressively more pronounced posteriorly until, on 
the tail peduncle, it is an extremely prominent flange. 
Genus PALAEOLYCUS von der Marck, 1863 
DiacGnosis (emended) : Enchodontidae in which the body is elongated and no 
deeper than the depth of the head at the occiput. Vertebral number approximately 
73 of which 40 are caudal. Pectoral fins greatly enlarged, pelvics excessively 
reduced. Anal fin greatly extended with 50 rays occupying one-third of the total 
body length, its origin being in advance of the dorsal fin. Dorsal fin itself much 
reduced in extent and positioned midway along the body. Mid-dorsal scutes not 
greatly reduced, 5 or 6 in number and almost overlapping. 
TYPE SPECIES. Palaeolycus dreginensis von der Marck 
Palaeolycus dreginensis von der Marck 
(Text-fig. 43) 
1863 Palaeolycus dveginensis von der Marck : 31, pl. 4, fig. 7. 
1954 Palaeolycus dreginensis von der Marck ; Siegfried : 13, pl. 5, figs. 1, 2, 2a. 
Siegfried lists earlier references. 
Diacnosis. As for genus, only species. 
HoLotyre. Number 808 in the Paldontologisches Institut der Westfalische 
Wilhelms-Universitat, Miinster, from the Upper Senonian of Sendenhorst, West- 
phalia. 
MaTeERIAL. The holotype and specimen number 8438, both from Sendenhorst 
and both in Minster. 
Remarks. Of the two specimens examined, the second specimen, number 
8438, was the more complete and was the specimen used by von der Marck in his 
second work (1885 : 251). Neither specimen is complete by any means so that the 
following description is deficient in many features. No other specimens of the 
species are known to the author. 
DEscRIPTION. Neurocranium. Little of the neurocranium is preserved, and what 
is observable is merely an impression in the matrix. The frontals appear to occupy 
a large proportion of the roof of the skull and are produced laterally as the upper 
border of the orbit. The sphenotic projects ventro-laterally from beneath the 
frontal at the hind end of the orbit and presumably the neurocranium attains its 
maximum width between the extremities of the sphenotics. The postero-lateral 
neurocranial region inclines ventrally and the presence of a vertical crest of bone is 
indicated in the pterotic region. The crest demarcates the dilatator fossa laterally 
and the post-temporal fossa medially, both fossae being unroofed. The neurocranial 
bones are unornamented except for the presence of raised ridges of bone running in a 
longitudinal direction above the orbit. The extent of the cranial cavity region is 
reduced, and is shorter than the diameter of the orbit which itself occupies at least 
