104 



PISCES 



CLASS I 



Sub-Order 3. ACANTHOPTERI. Muller. 



Some of the rays of the pelvic and median fins spinous, not articulated. Pelvic 

 fins usually advanced far forwards. Lower pharyngeals separate. 



In the existing fauna the Acanthopteri form by far the most numerous 

 group of fishes. 



Family 1. Berycidae. 



Trunk short, compressed, and rather deep, with ctenoid or cycloid scales, rarely 

 naked. Head bones ridged to form large mucous-cavities ; orbits large and lateral ; 

 mouth usually oblique, the jaws and generally also the palate with small pointed teeth. 

 Operculum more or less serrated or ridged. Pelvic fins thoracic, with an anterior 

 spine and more than five divided rays. Upper Cretaceous to Recent. 



The living Berycidae are marine fishes, most of them inhabitating consider- 

 able depths. 



Hoplopteryx, Ag. (Fig. 182). Head short. Dorsal fin deep, with a few 

 spaced spines in front ; anal fin Avith four or five spines. Scales large and 



Fig. 1S2. 

 Hophpterys zipjiei, A<;a:ssiz sp. Lower Pliiiier ; Welilowitz, Bolieiiiia. V:t "at. size (after Fritsch). 



Ctenoid. Common in the Upper Cretaceous. H. lewesiensis, Mant., from the 

 English Chalk, and other species originally referred to the surviving genus 

 Beryx. 



Sphenoccphalus, Ag. Upper Cretaceous, Westphalia. Pycnosterinx, Heckel. 

 Upper Cretaceous, Mount Lebanon. 



The two surviving genera, Holocentrum and Myripristis, Cuv., are repre- 

 sented by extinct species in the Upper Eocene of Monte Bolca. 



Family 2. Percidae. Percbej-. 



Trunk elongated, with ctenoid scales. PremaxiUa, mandible, vomer, ami palatine 

 with pointed teeth .• six or seven branchiostegal rays. Peine fins thoracic with an 



