Teleostei — Acan thopterygii. 43 



originally referred to the existing Tetrapterm (Ilistiophorus) certain 

 fragments of snouts from the Chalk, which now appear to be 

 identical with those of a distinct Cretaceous family subsequently 

 discovered — that of the Protosphyrcenidce. An extinct genus, 

 Ccelorhynchus, was also founded upon some extremely slender, 

 longitudinally- ribbed fossils, from the Chalk and Eocene formations, 

 at first supposed to be the snouts of Sword-fishes ; but Prof. W. C. 

 Williamson has examined the microscopical structure of these, and 

 regards them as dermal spines. To Tetrapterm (or Histiophorus) 

 Agassiz also assigned fossil snouts and vertebra? from the Eocene 

 Tertiaries, and the genera Brackyrhynchus and Xiphiorhynclms have 

 since been founded upon Eocene and Crag fossils in Belgium. 



Of the family of Berycidce, a very large series of specimens is Wall-case, 

 exhibited. These Fishes have much the general appearance of the No 18. 

 Perches, but there are large cavities in the head-bones connected z? b |-case, 

 with the sensory slime-canal system, and the pelvic fins have 

 (except in one genus) more than five soft rays in addition to the 

 spine. They are all marine. The living genus Beryx occurs both 

 in the English Chalk and the Upper Cretaceous of Mount Lebanon. 

 Many of the English examples, both of this and allied genera, are 

 but slightly compressed, retaining their original form, and those 

 from the collection of the late Dr. Mantell are especially fine ; 

 several are the type-specimens figured in the works of Agassiz and 

 Mantell; and later acquisitions from Mr. Frederic Dixon's collec- 

 tion are the originals of figures in his well-known "Geology and 

 Fossils of Sussex." Hoplopteryx is a genus with very powerful 

 fin-spines, to which are referred the two English Chalk species 

 commonly known as Beryx ornatus and Beryx superbus, besides other 

 forms from the Cretaceous of Westphalia and Mount Lebanon. 

 Berycopsis (with cycloid scales), Momonotus, and Stenostoma are 

 other genera of the English Chalk. Pseudoberyx (with almost 

 abdominal pelvic fins) occurs at Mount Lebanon, and Sphenocephalies 

 and Acrogaster in the Westphalian Cretaceous deposits. The living 

 surface -dwelling genera Myripristis and Holocentrum are not un- 

 common at Monte Bolca, and the latter has also been discovered 

 in the Miocene of Malta. 



The carnivorous marine family of Scorpmiidce is represented 

 in the fossil state by a species of Scorpcena in the Infusorial Earth 

 of Oran, Algeria, but there are no specimens in the collection. 



The Spar idee, or " Sea-breams," have numerous extinct congeners. Table-cases, 

 They are Perciform Acanthopterygians with a curiously specialized Nos. 55, 56. 

 dentition, the front teeth being usually adapted for piercing and 

 cutting, and those at the sides of the mouth for crushing. Their 

 earliest representatives, from the Cretaceous of Mount Lebanon, 

 appear to be referable to the living genera, Pagellus and Sargus ; 

 and both these fishes are again found in the Tertiaries, the former 

 at Monte Bolca, and the latter in France and at Oran, Algeria. 

 Sparnodus (Fig. 79) is an extinct genus from Monte Bolca, having 

 the teeth somewhat "spaced out" — hence the name. Sargodon, 



