268 MB. A. SMITH woodWabd oIs- [Feb. 16, 



The following papers were read : — 



1. Oa Echidnocephalus, a Halosauroid Fish from the Upper 



Cretaceous Formation of Westphalia. By A. Smith 



Woodward, F.Z.S., of the British Museum (Natural 



History). 



[Received January 19, 1897.] 



(Plate XVIII.) 



In 1858 Dr. W. von der Marck ' described a curious eel-shaped 

 fish with well- developed pelvic fins and a separate short dorsal, from 

 the Upper Cretaceous formation of Westphalia. He gave it the 

 generic name of EcMdnocephalus, and in 1863 ^ he added to his 

 description some rather sketchy figures of four specimens; In the 

 last-mentioned year Mr. J. Y. Johnson presented to this Society ^ 

 a description of an existing fish from the seas olf Madeira, remark- 

 ably similar in general aspect to the extinct form ; and for this he 

 proposed the generic name of Halosaurus, noting the aberrant 

 characters which later induced Dr. Giiuther * to make it the type 

 of a distinct family, the Halosauridae. The striking resemblance 

 between these two fishes does not appear to have been hitherto 

 observed ; but, thanks to Dr. Giinther's anatomical investigation of 

 new specimens of Halosaurus obtained by the ' Challeuger ' Expe- 

 dition % it is now possible to demonstrate that the correspondence 

 between the Cretaceous and Eecent forms in question is exact 

 even to some of the most specialized osteological features. I have 

 not yet had the privilege of studying the original fossils referred 

 to by Dr. von der Marck, but there are four very fine specimens 

 from the same formation and locality in tbe British Museum. 

 These form the subject of the following descriptions, and suffice to 

 show very clearly how the strange Halosauroid type was already 

 completely developed before the end of the Cretaceous period. 



The finest specimen showing the head (Plate XYIII. fig. 1) is a 

 little distorted in the anterior part of the abdominal region, and 

 wants the hinder half of the tail. The head is exhibited in direct 

 side-view, but its structure is very difficult to interpret, most of 

 the bones being shown only in impression, while the opercular 

 apparatus is crushed upon the hyoid and branchial arches, and 

 the pterygo-quadrate arcade upon the more external bones. The 

 cranium is long and narrow and much depressed, as indicated hj 

 a fragment of the parasphenoid (pas.) preserved in the orbital 

 region. An impression of the parieto-frontal region suggests 

 that the cranial roof was smooth and gently arched from side to 

 side, without any occipital crest. Below the anterior three- 

 quarters of the skull there is an impression of the pterygo- 



> Zeitschr. deutsch. geol. Gesell. vol. x. (1858), p. 247. 

 ^ Palseontograpbica, vol. xi. (1863), p. 55, pi. viii. figs. 1-3, pi. xiv. fig. 1. 

 3 Proc. Zool. Soc. 1863, p. 406, pi. xxxvi. fig. 2. 

 * OataL Fishes Brit. Mus. vol. vii. (1868), p. 482. 



' A. Giintlier, "Report on the Deep Sea Fishes," 'Challenger' Reports, 

 vol. xxii. (1887), p. 232, pi. Ix. figs 1-8. 



