SUB-CLASS I 



SELACHII 



3!> 



I: 



of other species (so-called Climaxodus, etc.) from Upper and Lower Carboni- 

 ferous of England, Scotland, Ireland, and 

 North America. 



Fissodus, St. John and Worthen. Car- 

 boniferous Limestone ; North America 

 and Scotland. 



Glossodus, M'Coy ; Mesolophodus, Sm. 

 Woodw. Carboniferous Limestone; 

 Ireland. 



Polyrhizodiu 



Fig. 77. 

 magnus, M'Coy. 



Tooth in front 



size. 



)• 



Fig. 78. 



Poll/rhlZOdus, M Coy (DactyloduS, view (.4), and transverse section|(£), i/ 2 nat. siz 

 \ /-r,. r-~\ m m i vi Carboniferous Limestone ; Armagh (after M'Coy 



Newb.), (Fig. 77). Teeth robust, with a 



tumid crown tapering to a transverse cutting edge, and the root much sub- 

 divided. P. magnuSj M'Coy, and other species from the Car- 

 boniferous Limestone of 

 Ireland, England, Russia, 

 and North America. 

 Ctenoptychius, Ag. 



i allopristoaus pec- r J > o 



tinatus, Ag. sp. (oai (Ctenopetalus, Harpacodus, 



Measures ; Scotland. v , . t\ • ' c< 



Petalodopsis, Davis ; ber- 

 ratodus, de Koninck. Teeth small, 

 antero-posteriorly compressed, with sharp 

 serrated ed<re. Coal Measures and Car- 

 boniferous Limestone ; England, Scot- 

 land, Ireland, Belgium, and North 

 America. 



Callopristodus, Traquair (Fig. 78). 

 As Ctenoptychius, but root subdivided. 

 C. pectinatus, Ag. sp., from the Coal 

 Measures of England and Lower Car- 

 boniferous of Scotland, also from Coal 

 Measures of Nova Scotia. 



Peripristis, St. John (Pristodus, Davis). 

 Lower Carboniferous ; Great Britain and 

 U.S.A. 



Family 4. Squatinidae. M. and H. 

 Angel-fishes or Monk -fishes. 



Triad: broad and depressed. Pectoral 

 fins large, separated by a cleft from the 

 head, so that the branchial openings are 

 still directed laterally. Teeth pointed and 

 conical, ivithout lateral denticles. Two 

 dorsal fins on the tail, without spines. Skin 

 covered with small placoid scales. Jurassic 

 to Recent. 



Fig. 7:'. 



Squatina nlifera, Miinst. sp. 

 derma, Praas). Upper Jurassic 



uatina acou ! 

 Eichstadt, Bavaria. 



(Original in Palaeontological Museum, .Munich.) 



The single genus Squatina, Aldro 

 vandi (Phina, Klein; Thou mas, Miinst. 

 Phorcynis, Thioll. ; Scaldia, Le Hon; Trigoni lus, Winkler), (Figs. 79-81), first 

 appears in the Upper Jurassic and survives in the existing fauna. Complete 

 skeletons of S. alifera, Miinst. sp. ; S. speciosa, Meyer ; and S. acanthoderma, 



