80 



PISCES 



Family 1. Sty lodontidae. Wagner.^ 



Jaws and vomer with several rows of teeth, those of tlie outer row styliform. 

 Vertehral column consisting of hemi-vertebrae or ring-vertebrae. AU fins fringed with 

 fulcra. Caudal fin both internally and externally hemi-heterocercal, the Upper lohe 

 more extensively scaled tlian the lower lobe, Upper Permian to Upper Jurassic. 



Acentrophorus, Traq. Trunk fusiform. Dorsal fin short, opposite tlie 

 Space between the pelvic and anal fins. No enlarged ridge scales. A. varians, 

 Kirkby sp., and other species from Magnesian Limestone, Durham. A. 

 chicopensis, Newb. Trias ; Connecticut Valley, U.S.A. 



Semionotus, Ag. (Ischypterus, Egert.). Trunk fusiform. Dorsal fin large 

 and extended, its liinder part opposed to the anal fin. Dorsal series of pointed 



ridge scales forming a pro- 

 minent crest. Fin fulcra 

 sometimes very large. Scales 

 and head-bones smooth or 

 but feebly ornamented. S. 

 bergeri, Ag., from Keuper of 

 Coburg and Thuringia. *S'. 

 kapß, Fraas (Fig. 143), from 

 Keuper, Haslach, near 

 Stuttgart. Other species from 

 the Bunter, Muschelkalk, 

 Keuper, and Ehaetic of Europe, also from the Upper Karoo Formation of 

 South Africa, the Hawkesbury Formation of New Sout*h Wales, and Trias of 

 Connecticut Valley and New Jersey, U.S.A. 



Fig. 143. 



Semionotus Jcapffi, Fraas. Keuper (Stubensandstein) ; Stuttgart. 

 2/3 uat. size (after O. Fraas). 



Fig. 144. 



Dapedüis pholidotus, Ag. Upper Lias ; Boll, Würteinberg. 1/2 nat. size. 

 B, C, Teeth, nat. size (after Quenstedt). 



Crenilepis, Dammes. Muschelkalk. IIomoeolepis.WsLgner. Upper Lias; Boll. 

 Dapedius, de la Beche (Amblyurus, Ag. ; Aechmodus, Egerton), (Figs. 144, 



- Sträver, J., Fossile Fische aus dem Keupersandstein von Coburg (Zeitschr. deutsch, geol. Ges. 

 vol. XVI.), 18Qi.— Wagner, A., Die Griffelzähner (Stylodontes), (Gelehrt. Anzeig. k. bay. Akad. 

 vol. L.), 1860. — Deecke, W., Ueber Fische aus verschiedenen Horizonten der Trias (Palaeoutogr. vol. 

 XXXV.), l88S.—Netoberry, J. S., Fossil Fishes and Fossil Plauts of the Triassic Rocks (Mouogr. 

 U.S. Geol. Surv. vol. XIV.), 1888.— Schelhvien, E., Ueber Semionotus Agassiz (Schriften Phys.- 

 ökon. Gesellsch. Königsberg), 1901. 



