PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 517 



The progress toward the recognition of the class of Myzonts or Mur- 

 sipobranchiates is indicated in the following synonymy : 



THE CLASS OF MYZONTS, OR MAESIPOBRANCHIATES. 



Synonyms as class names. 



< Pisces, A7-t€di, Genera Piscium, 1738. 



X Pisces, Hnnaus, Systema Natmiv, ed. x, t. 1, p. 239, 17.58; ed. xii, t. 1, p. 419, 1760.* 



< Pisces, Gmelin, Liun. Systema Natune, t. 1, p. 1126, 1788. 



< Ichthyoderes (Iclitliyodera), Geoffroy St. Hilaire, LatreiUe, Families Nat. du Regne 



Animal, p. 107, 1825. 



< Pisces, Costa, Ceuni Zoologici Napol., p. 49, 1834. (lucludes the genus BrancMos- 



toma <^ class Leptocardil — in the class.) 



< Myzontes, Agassiz, Contrib. to Nat. Hist, of U. S., v. 1, p. 187, 18.57. 



~ Marsipobranchia, Hilclcel, Generelle Morphologic der Organismeu, B. 2, p. cxx, 18GG. 



= Dermopteri, Cope, Proc. Acad. Nat. Sci. Phila., [v. 20,] p. 2.56, 1868. 



= Cyclostoma, Gegcnhaur, Grundrissder vergleich. Auat., p. 577, 1870. 



= Cyclostomata, O.Schmidt, Haudbuch der vergleich. Anat., 6. Aufl., p. 259, 1872. 



= Dermopteri, Coj)e, Proc. Am. Assoc. Adv. Sci. 1871, v. 20, p. 320, 1872. 



= Marsipobranchiates, Gill, Arrangement Fara. Fishes, pp. ix, 25, 1872. 



= Marsipobranchiates, Jordan, Man. Vertebrates Northern U. S., p. 199, 1876. 



= Myzonts (Marsipobranchii), Wilder, Proc. Am. Ass. Adv. Sci., v. 24, § B, p. 185, 1870. 



> Hyperotreta, t Lanlester, Quart. Jouru. Micr. Sc. v. 17, p.—, 1877. 



> Hyperoartia, t Lankester, Quart. Journ. Micr. Sc, v. 17, p. — , 1677. 



Synonyms as subclass names. 



= Marsipobranchii, Bonaparte, Nuovi Annali delle Sci. Nat., t. 2, p. — , 1638; t, 4, p. 



277, 1840. 

 = Marsipobranchii, il/M7?er, Abhandl. K. Alcad. Wiss. zu Berlin, 1844, p. — , 1846. 



< Dermopteri (Owen), Gill, Cat. Fishes E. Coast N. A., p. 24, 1861 (Not Dermopteres, 



Dum., q. = Salmonid;B.) 



< Holocrania, Huxley, Proc. Royal Soc. London, v. — , 1874; Ann. and Mag. Nat. Hist., 



(4,) v. 15, p. 225, 1875. 



NOTE ON THE BDEEI^O.^TOilIID.E AND MVXINID^. 



BY THEODORE OILL. 



In 18712, in ray "Arrangement of the Families of Fishes," I have rec- 

 ognized two families iti the order Hyperotreta, and recently have com- 

 municated to Professors Jordan and Gilbert a new generic name for 

 the many-gilled species. I herewith give diagnoses of the family and 

 genera. The distinctions in each case, from the nearest allies, are so 

 evident that the groups do not really need justification. Kevertheless, 

 as others have thought differently, it is not superlluous to add that 

 characters analogous to such as have been used to differentiate the fam- 

 ily and genera would be regarded as of great systematic value in the 



* The genus i/^/J^JHe was referred to the class Vermes. 



t These "classes" are regarded as constituents of a "grade" (" Cyclostoma") con- 

 trasting with another (Guathostoma) including all the vertebrates with jaws. 



