tion with large teeth of various forms. The air-bladder is divided by con- 

 striction into two or three portions, and communicates by a duct with the 

 oesophagus. 



If the pharyngeal bones are of any value in classification, the Cypri- 

 noids appear to be entitled to distinction as a suborder of the Teleo- 

 cepbali. The differences between the form of the pharyngeal bones 

 of this group and those of the Acantkopteri seem to be certainly of much 

 greater value than the difference between those of the latter and the Pha- 

 ryngognathi. The form in both of those are the same, and the only dif- 

 ference is the separation or coalescence of the lower bones. The pharyn- 

 geal bones of the Cyprinoids, on the contrary, have a very different form 

 from those of either of the other orders. Other anatomical peculiarities 

 appear to justify us in the separation of the group from the other Physos- 

 tomi of Midler. We have accordingly bestowed on it the name of Even- 

 tognathi in allusion to the development of the pharyngeal jaws. 



No true marine representatives of the Cyprinoids can be said to exist. 

 The Hudsonius amarus of Girard,* Leitciscus chryso-pterits of Dekay,f a 

 fish of doubtful genus, and some of the Northern Oatostomit are found in 

 brackish or salt water, but they can only be regarded as exceptional ex- 

 amples, and scarcely as true marine fishes. They have consequently been 

 excluded from our catalogue. 



Order APODES Kaup \ 



The body is always anguilliform, or extremely elongated ; the skin is 

 generally naked, rarely covered with minute scales imbedded in the epi- 

 dermis. The branchiae are pectinated. The supramaxillaries and inter- 

 maxillaries are small or rudimentary. Teeth are planted on the palatine and 

 vomerine bones. With the vomer, the nasal and ethmoid bones are coal- 

 escent.ll The ventral fins are always absent; the pectorals often; the 



* " Researches upon the Cyprinoid Fishes inhabiting the fresh waters of the 

 United States west of the Mississippi valley, from specimens in the Museum 

 of the Smithsonian Institution. By Charles Grirard, M. D.," p. 46, ib. in Proc. 

 of the Acad, of Natural Sciences, 1856. 



f " Zoology of New York, or the New York Fauna," by James E. Dekay. 

 Partiv. Fishes, p. 211, pi. xxx. fig. 95. 



X Note in the Ichthyology of the voyage of the Erebus and Terror, by Sir 

 John Richardson, p. 58. 



The Rynchana Greyi, mentioned by Sir John as an instance of a purely 

 marine representative of Cyprinoids, is a member of a very different family 

 (Gronorhynchoidae Val.) and belongs to the genus Gonorhynchus of Grronovius, 

 as was afterwards acknowledged by its describer. 



Catalogue of the Apodal Fish, in the collection of the British Museum, by 

 Dr. Kaup, Professor of Natural History, Darmstadt, London, 1856. 



Article "Ichthyology," by Sir John Richardson, in the recent edition of 

 the ' ' Encyclopaedia Britannica. ' ' 



Ichthyology of the Erebus and Terror, by Sir John Richardson, pp. 78, 114.' 



|| The skull of the representatives of the genus Murcena is thus described by 

 Sir John Richardson : 



