﻿POSITION OF THE PALiEONISCIDJS. 



35 



sions of Holostei and Chondrostei were adhered to, and Palceoniscus, and its allies 

 Amblypterus, Eloniclithjs, Pygopterus, Acrolepis, and Cheirolepis, were very properly brought 

 together in one family, that of the Ileterocerci monopterygii, which was placed in the 

 order Holostei. Unfortunately this family still contained a number of heterogeneous 

 elements, for, in addition to such forms as Platysomus and Eurynotus, several other 

 genera (Euynathus, Conodus, MegalicJttliys), still further removed from the Palceoniscidce, 

 are introduced. 



In 1852 Vogt published a classification of the Ganoids 1 having some points of interest. 

 /■Family Cephalaspida. 



Sub-order Loricata 



Sub-order Rhombifera 



I 



Sub-order Cyclifera . . | 



Here the Palseoniscoid fishes are included along with the Dapedii in the family 

 Monosticha of the sub-order Rhombifera ; and in this classification we find the term 

 Palceoniscidce (Palseonisciden) used for the first time, though only to indicate a sub-family in 

 which were also included Platysomus and Eurynotus. Unnatural as was the association of 

 these fishes in one " family " with the Dapedii, we must, nevertheless, consider the insti- 

 tution of the term " Palceoniscidce " to be a step in advance, though the Platysomids might 

 also with advantage have been excluded. In Mr. Dallas's ' Handbook of the Animal 

 Kingdom' we find the term " Palceoniscidce" raised to one of family importance. 



The classification employed by Pictet in the second edition of his ' Traite de Paleon- 

 tologie' (Paris, 1854) is in the main very similar to that of Vogt; the Hoplopleuridce 

 being, however, added as a distinct primary division of the Ganoids. Among the 

 Phombifera the family of Zepidosteidce is constituted to include both the Monisticha and 

 Disticha of Vogt, and in the subdivision of this assemblage into " tribes " the Palceo- 

 niscidce are again unmercifully broken up, as may be seen below : 



2e. Famille Lepidosteides. 



Ire Tribu. Lepidosteides homocerques a machoires prolongees (Jspidor/iynckus, 

 Belonostomus, Prionolepis) . 



1 ' Zoologische Briefe,' vol. ii, Frankfurt, 1852. 



Acipenserida. 

 Spatularida. 

 Acanthodida. 

 Polypterida. 

 Dipterida. 



Monosticha I Sub-family Palgeoniscid; 



,• , I Dapedidse. 

 JJisticna 1 



Pycnodontida. 



Holoptychida. 



Ccelacanthida. 



Amida. 



