ORDER TELEOSTEI. 



01 



ence of mucous-bearing cavities in the head, and by the pelvic fins 

 having (except in Monocentris) a single spine, and more than five 

 rays. This family is one of the oldest of the suborder, being abun- 

 dantly represented in the Chalk. The fossil genera, which may be 

 noticed in alphabetical order, are as follows — viz., Acrogaster, from 

 the Upper Cretaceous of Westphalia ; Berycopsis, from the Creta- 



Fig. 944. — Xiphias. Greatly reduced. 



ceous of England ; Beryx, in which there is one dorsal fin with 

 several spines, is represented by a single species in the European 

 Chalk, and by two species in the Chalk of the Lebanon, while it is 

 also living at the present day ; Holocentrum, from the Middle 

 Eocene of Monte Bolca, the Miocene of Malta, and tropical seas 

 of the present day ; Homonotus, from the Cretaceous of both Eng- 

 land and the Lebanon ; Hoplopteryx (fig. 945), in which the spinous 

 portion of the dorsal fin is greatly developed, and there are also four 



Fig. 945. — Hoplopteryx lewesiensis ; from the Upper Chalk of Sussex. Reduced. 

 (After Mantell.) 



large spines in advance of the anal, is known from the Upper Cre- 

 taceous of both Europe and the Lebanon ; Myripristis, from the 

 Middle Eocene of Monte Bolca, and now found in tropical seas ; 

 Pristigenys, from Monte Bolca ; Pseudoberyx, from the Chalk of the 

 Lebanon, characterised by the almost abdominal position of the 

 pelvic fins ; Sphenocephalies, from the Upper Cretaceous of West- 



