OSTEOLOOICAL SPECIMENS ARRANGED ACCORDING TO THE 

 CLASSES OF VERTEBRATA, IN THE ASCENDING ORDER. 



Class PISCES, Fishes. 



The specimens of this class are arranged according to the following Orders : 

 Order I. DERMOPTERI. 



Endo-skrieton unossified ; exo-skeleton and Yrrtiral fiiis mucodennoid ; vermiform, or abrachial and 

 apodal ; no pancreas ; no air-bladder ; no oviducts or tpenn-ducU ; peritoneal outlet*. 



Suborder I. CIRROSTOMI. 



Gills free, pharyngeal, inoperculate ; no heart. 



Faui. Amphioxida. Example, Lancelot. 



Suborder H. CYCLOSTOMI. 



Gills fixed, bursifonn, inoperculate, receiving the respiratory streams by apertures usually numerous 

 and lateral, distinct from the mouth ; a heart. 



Fam. Myxinida. Example, Myxine. 

 Petromyzontida. Lamprey. 



Order II. MALACOPTERI. 



Endo-skeleton oaanVd ; exo-skeleton, in most as cycloid, in a few as ganoid scales ; fins supported 

 by rays, all of which, sare sometimes the first ray in the dorsal and pectoral, are soft or jointed , 

 abdominal or apodal ; gills free, operculate ; a swim-bladder and air-duct ; peritoneal outlets in many. 



Suborder I. APODE8. 

 Fam. Mwrtandte. Example, Eel. 



