516 PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 



18GS), three specimens having been dredged at "San Diego in ten 

 fathoms' water ; they here were yellowish, translncent, with a brown 

 streak near the back." — ( Cooper M8S.) It may be that this form belongs 

 to the genus Epiijoniclithys. 



BEANCHIOSTOMA. 



Siinonymy. 



= Brancliiostoma, Costa, Cenni Zoologici Napol., p. 49, 1834. 

 = Ampliioxus, FarreZ/, Hist. Brit. Fishes, [1st ed.,] p. 468,1836. 

 = Brancliiostoma, GUnther, Cat. Fishes Brit. Mms., v. 8, j). 513. 1870. 

 Limax sp. Pallas. 



EPIGOXICHTHYS. 



S2)n07iymj/. 



= Epigonichthys, Peters, Monatsberichte K. Akatl. Wissensch. Berlin, 1870, pp. 322- 

 327. 



NOTE OIV THE iTIVZONT.^ On ITfARSIPOBRAIVCHIATES. 

 BY THEODORE: OILL. 



Inasmuch as it has been stated by Dr. Giinther, in his recent "Guide 

 to the Study of Fishes" (p. 1), that " according to the views generally 

 adopted at present, all those vertebrate animals are referred to the class 

 of fishes" which are below the Amphibians, the following note is added 

 iti connection with the succeding papers. 



The heterogeneity of the combination formerly regarded as the class 

 of fishes is now so evident to any one who has familiarized liimself with 

 the anatomy of the vertebrates that it is unnecessary to detail the points 

 of difference. Suflflce it to state that the differences between the Lepto- 

 eardians, Marsipobranchiates, and typical Fishes at least are far greater 

 than those between any adjoining classes of terrestrial vertebrates. To 

 still confound them in a single class is therefore a taxonomic falsehood, 

 without any justification from either a scientific or "practical" stand- 

 point. The degree of divergence of the branchiferous vertebrates has 

 been aptly recognized by Hiickel, Gegenbaur, Lankester, etc., in their 

 classifications, by the difierentiation of AmpMoxus from all the other verte- 

 brates and of the Marsipobranchiates from all those thereafter remain- 

 ing. AmpMoxus has even been excluded from the true vertebrates 

 by Semper (1874), Hoppe-Seyler (1877), and Balfour* (1880). In the 

 United States there is not a single active ichthyologist who does not 

 admit at least three classes of branchiferous vertebrates — the Leptocard- 

 ians, Marsipobranchiates, and Fishes. The remark of Dr. Giinther, 

 therefore, finds no illustration in the United States, and the exceptions 

 are conspicuous and brilliant even in England^ 



* There is only a nominal diiference between the views of Lankester and Balfour, 

 the former enlarging the term Vertebrata to include the Tunicates, and the latter 

 limiting it to exclude Amj)]iioxus, 



