CLASSIFICATIOX OF AGASSIZ AND IMULLER. 



325 



brought together, and tribes tlint are really allied bein;j widely separated. The following classification, which is 

 that of Prolcssor Miiller, slightly modified hy Professor Owen, being founded on the general organizaticn o{ the 

 animals it includos, has more title to be considerej a natural one, and reproseuts the nearest approach to a perfect 

 arrangement which the present state of knowledge admits. 



OnDEtt I.-DERMOPTEPvI. 



Internal skeleton unossified; integument and vertical fins muco-dermoid; vermiform, or abraehial and apodal, 

 no pancreas, no air bladder. 

 Sub-order 1, rnAKTNGoBBANcnii, (or Cirrhostomi.) Gills free, pharyngeal, inoperculato ; no heart. 



Family. — Amphioxldce. Example- — Lancelet. 

 Sub-order 2. MAssiponnANcnii, (or Cyclostomi.) Gills fixed, bursiform, inoperculate, receiving the respiratory 

 Streams by apertures usually numerous and lateral, distinct from the mouth ; a heart. 



Family.— Myxinoidei. iJisampZs.— Myxine or Hag;, Family.— Petromyzontidce. £«anipJe.— Lamprey. 



Obdeb II.— MALACOPTERI. 



Internal skeleton ossified ; external skeleton in most as cycloid, in a few as ganoid, scales ; fins supported by 

 rays, all, save the first sometimes in the dorsal and pectoral, soft or jointed; abdominal or apodal; gills free, 

 operculate ; a swim-bladder and air duct. 



Sub-order 1. Apodes. 



Family. — Symbranchidcs. Example. — Cuchia, 

 Family. — Gymnotida;. 

 Sub-order 2. AsDOMiNiXES. 

 Family .— Heteropygii. Example. — Amblyopsis. 

 Cltipeidcc. Herring. 



Salmonidce. Salmon. 



ScopclldcB. Saurus. 



Characini. Myletes. 



Family. — SiluridcB 



Family.— Murccnidce. 

 Example. — Gymnotus. 



Example. — Eel. 



Fami'y. — Galaxidce. 

 Esocidce 

 MormyridcB 

 Cyprinodohtidce 

 CyprinidiB 

 Example. — Sheat Fish. 



Example, — G alaxia g. 

 Pike. 



Mormyrus. 

 Umber. 

 Carp. 



Obdee III.— PHARTN606NATHI, 



Internal skeleton bony; external skeleton in some as cycloid, in others as ctenoid, scales ; inferior pharyngeal 

 bones coalesced ; swim-bladder without duct. 

 Sub-order 1. Malacoptebtoii. 



Family.— Scomber-esooidce. Example. — Saury-pike. 

 Sub-order 2. Acanthoptebtgii. 



Family. — Chromidv. Example. — Chromis. Family. — Cyclo-Labridie. Example. — Wrasse. 



Family. — Cteno-Labridce. Example. — Pomacentrus. 



Oedeb IV.— AXACAXTIIIXI. 



Internal skeleton ossified ; extei'nal skeleton in some as cycloid, in others as ctenoid, scales ; fins supported by 

 flexible or jointed rays; ventrals beneath the pectorals, or none; swim-bladder without air duct. 

 Sub-order 1. Apodes. 



Family, — Ophididce Example. — Ophidiijm. 

 Sub-order 2. Thobacici. 



Family.— Gadidcc, Example.— doi Family.— Pleuroneclidce. Hxample.—Tlaice. 



Oedeb V.-ACANTIIOPTERI. 



Internal skeleton ossified ; external skeleton as ctenoid scales ; fins with one or more of the first rays unjointed 

 or inflexible spines ; ventrals in most beneath, or in advance of the pectorals ; swim bladder without duct. 



Family. 



PercidcB. 



Sderogenidoe. 



Scicenidce. 



Laby rinthibrancldi 



ilugilida:. 



Notacanthidce. 



Soomberidce. 



Example. 



Perch. 



Gurnard. 



JIaigre. 

 Anabas. 



Mullet. 



Notacanth. 



Mackerel. 



Family, 

 Squamipcnnes, 

 TcEnioidei. 

 Theutyidtc. 

 FistularidcB. 

 Gobiidce. 

 Blenniidce, 

 Lophiidcc. 



Example. 

 Clia;todon. 

 Riband-fish. 

 Lancet-fish. 

 Pipe-mouth-fish. 

 Goby, Remora, and Lump-fish. 

 Blenny and Wolf-fish. 

 Angler. 



Obdeb VI.— PLECTOGNATIII. 



Internal skeleton partially ossified; external skeleton as ganoid scales or spines; maxillaries and pre.inaxiUa- 

 ries fixed together ; swim-bladder without air ducts. 



Family.— SalistincB. E.Tawple.—F\\e-{\sh. Family.— Ostraciones. Example. — Trunk-fish. 

 Family. — Gymnodontes. Example. — Globe-fish , 



