96 



PISCES 



CLASS I 



Family 5. Saurodontidae. Cope (non Zittel). 



Skull laterally compressed ; jaws powerful, and bearing a single row of compressed, 

 knife-like teeth, with nutrient foramina or notches below the internal alveolar border ; 

 a presymjjhysial bone present and without teeth. Cretaceous. 



The two genera constituting this family, Saurocephalus, Harlan (non Ag.), 

 and Saurodon, Hays (Daptinus, Cope), differ from the Ichthyodectidae in the 

 presence of a presymphysial bone and in the form and manner of succession 

 of teeth. In the first-named genus the crowns of the teeth are short and 

 compressed, with nutrient foramina below the alveolar border on the inner 

 face of the jaw ; and in Saurodon the inner margin of each dental alveolus 

 is deeply notched. Upper Cretaceous ; New Jersey and Kansas. 



Family 6. Clupeidae. Herrings. 



Trunk elegantly fusiform. Supraoccipital bone separating parietals, and otic 

 region prominent; cheek plates reduced; premaxilla very small; maxilla large, 

 entering the gape, with two supramaxillaries ; dentition feeble. Opercular apparatus 

 complete, but few branchiostegal rays, and no gular plate. A single dorsal fin, nearly 

 median, without adipose dorsal. Scales thin and cycloid, without bony layer. Lower 

 Cretaceous to Kecent. 



Diplomystus, Cope. Abdomen compressed to a sharp edge, and bordered 

 with large ridge scutes ; back between the occiput and dorsal fin armoured 

 with smaller ridge scutes. D. dentatus, Cope, and other species finely preserved 

 in the Eocene Green River Shales of Wyoming, U.S.A. Smaller species in 



the Upper Cretaceous 



of Mount Lebanon 

 (D. brevissimus, Blv. 

 sp.) and Brazil, and in 

 the Oligocene of the 

 Isle of Wight. Living 

 in the rivers of New 

 South Wales and 

 Chili. 



Scombroclupea, 

 but finlets spaced out between the small anal and the 



^^^^j^^^^\3 



Fig. 172. 



Clupea ventricosa, H. v. Meyer. Lower Miocene 

 near Ulm, Wurteinberg. 



Unterkirchberg, 



Kner. As Clupea, 

 forked caudal fin. 

 S. macrophthahna, 

 Heckel sp., from 

 Upper Cretaceous 

 of Mount Lebanon 

 and Comen, Istria. 

 Clupea, Linn. 

 Herrings. (Fig. 

 172.) Abdomen 

 compressed to a 

 sharp edge, and 

 bordered with large ridge scutes ; no dorsal scutes. 

 jaws and palatines, larger on the vomer and hyoid. 



Meletta sardinites, Heckel. 



Fm. 173. 

 Lower Oligocene 



Radoboj, Croatia (after Heckel). 



Teeth minute on the 

 Dorsal fin small and 



