118 



Actinopterygii Percomorplii. 



Wall-case, 

 No. 17. 



Table-case, 

 No. 55. 



; Wall-case, 

 ' No. 18. 



The Trichiuridaa ("Hair-tails," "Scabbard-fishes," etc.) 

 differ most prominently from the preceding family in the 

 powerful character of the jaws, which are armed with strong 

 teeth, some usually much larger than the others. Representa- 

 tives of the existing Lepidopus occur in the Eocene Slates of 

 Glaris, and also in the Upper Miocene of Licata, Sicily. Owing 

 to imperfections in the specimens, the former were originally 

 placed in a distinct geiias, Anenchelum, and the distortion of the 

 fossils led to an undue multiplication of the so-called species. 



Hemithyrsites and Trichiurichthys are scaly extincC forms 

 from the Upper Miocene of Licata, Sicily, but there are no 

 examples in the collection. 



Next to the Trichiuridee are arranged the fragmentary 

 remains of Xiphiidae or " Sword-fishes." These, as is well 

 known, are remarkable for the great length of the cuneiform 

 snout ; they are the largest of Acanthopterygian Fishes. The 

 generic determinations of the fossil forms are still very doubtful, 

 but a series of typical fragments is exhibited from the English 

 Eocene. 



Of the family of Berycidae, a very large series of specimens 

 is exhibited. These fishes have much the general appearance 

 of the Perches, but there are large cavities in the head-bones 

 connected 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 Cre- 

 taceous 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 collection 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), Uomonotus, and Stenostoma are 

 other genera of the English Chalk. Pseudoberyx (with 

 almost abdominal pelvic fins) occurs at Mount Lebanon, and 

 SplienocepTialus and Acrogaster in the Westphalian Cretaceous 

 deposits. The living surface-dwelling genera, Myripristis and 

 Holocentrum, are not uncommon at Monte Bolca, and the latter 

 has also been discovered in the Miocene of Malta. 



The carnivorous marine family of Scorpaenidae 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 col- 

 lection. 



