PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 517 



The progress toward the recognition of the class of Myzonts or Mar- 
sipobranchiates is indicated in the following synonym^' : 

THE CLASS OF MYZONTS. OR MARSIPOBRANCniATES. 

Synonyms as class names, 

Pisces, Artedi, Genera Piscimu, 1738. 

X Pisces, Lhuwns, Systema Naturjc, eel. x, t. 1, p, 239, 17.58; ed. xii, t. 1, p.419, 17GG.* 
Pisces, Gmelin, Lion. Systema Natnne, t. 1, p. 112G, 1788. 

< Ichtbyoderes (Iclithyodera), Geoff roy St. Hilaive, LatrelUe, Families Nat. du Kegue 

Animal, p. 107, 1825. 

< Pisces, Costa, Cemii Zoologici Napol., p. 49, 1834. (Includes the genus Branchios- 

tonia class Leptocardii — in the class.) 

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

= Marsipobrauchia, IldcJcel, Generelle Morphologic der Orgauismeu, B. 2, p. exx, 18GG. 
= Dermopteri, Cope, Proc. Acad. Nat. Sci. Phila., [v. 20,] p. 25G, 1808. 

= Cyclostom.t, Gegenhanr, Gniudrissder vergleich. Anat., p. 577, 1870. 

= Cyclo.stomata, O. Schmidt, Haiidbneh der vergleich. Anat., G. Anti., p. 259, 1872. 

= Dermo[)teri, Cojjc, Proc. Am. Assoc. Adv. Sci. 1871, v. 20, p. 320, 1872. 

— Marsiimbrauchiates, Gill, Arrangement Fam. Fishes, pp. ix, 25, 1872. 

= Marsipobrauchiates, Jordan, Man. Vertebrates Northern U. S., p. 199, 187G. 

= Myzonts (Marsipobranchii), Wilder, Proc. Am. Ass. Adv. Sci., v. 24, $ B, p. 185, 187G. 
> Hyperotreta, t Lanlester, Quart. Jouru. Mier. Sc., v. 17, p. — , 1877. 

]> Ilyperoartia, t Lankester, Quart. Jouru. Mier. Sc., v. 17, p. — , 1877. 

Synonyms as suhelass names. 

= Marsipol>ranchii, Bonaparte, Nuovi Auuali delle Sci. Nat., t. 2, p. — , 1838; t, 4, p. 
277, 1840. 

= Marsipolirauchii, J/aRe?-, Abhandl. K. Akad. Wiss. zu Berlin, 1844, p. — , 1846. 
Dermopteri {Oiven), Gill, Cat. Fishes E. Coast N. A., p. 24, 18oI (Not Dermopteres, 
Dnm., q. = Salmonidie.) 

Holocrania, Huxley, Proc. Royal Soc. Loudon, v. — , 1874; Ann. and Mag. Nat. Hist., 
(4,) V. 15, p. 225, 1875. 



NOTE ON THE ISDEEEOl^TOHID.E ANI> HVXlNIHdE. 

BV THEOBOBE OllLE. 

In 1872, in iny ^‘Arrangement of the Families of Fishes,” I have rec- 
ognized two families in the order llyperotreta, and recently have com- 
municated to Professors Jordan atid Gilbert a new generic name for 
the iiiauy-gilled species. 1 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. Nevertheless, 
as others have thought difiereiitly, it is not siii)erfiiious to add that 
characters analogous to such as have been used to difierentiate the fam- 
ily and genera vould be regarded as of great systematic value in the 

*The gemis Alyxine was referred to the class Verme.s. 

t These “classes” are regarded as eoustitnents of a “grade” (“Cyclostoma”) con- 
trasting with another (Guathostoma) including all the vertebrates with jaws. 



518 PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 



classes of selacliiaos and true fislies, and the ouly comprehensible reason 
why they should not be so regarded in the present case is because the 
species are few in number. Inasmuch, however, as the function of tax- 
onomy is to express morphological truths, and not the quantities under 
which a given type is manifested, such reasons appear to be very iusuth- 
cient. 

The synonymy of the order Hyperotreta is appended. 

HYPEEOTRETA. 

Synonyms as orders. 

Cyclostomi, />o«a2>rti'/e, Giorn. AccacL diScienze, v. 52 (Saggio Distrib. Metod. Ani- 
mali Vertebr. a Sangue Freddo, p. 41), 1832. 

Helmiutboidei, Nuovi Anualidelle Sci. Nat.,t. 2, p. 133, 1838; t. 4, p.277, 

1840. 

= Hyperotreta, Mnller, Abbandl, K. Akad. Wiss. zu Berliu, lf-44, p. — , 184G. 

= Hyperotreti, Bonayarte, Cat. Metod. dei Pesci Europei, pp. 92,* 1840. 

Cyclostoniata, Fitzinyer, Sitzuugber. K. Akad. der Wissenscb. (Wieu), B.67, 1, Abtb., 
p. 57, 1873. 

BDELLOSTOMIDJE. 

Synonymy. 

= Bdellostomidse, Gill, Arrangemeut Families Fisbes, p.25, 1872. 

Petromyzoutid® gen. Bonaparte, etc. 

JMyxinid® gen., Giinther, Putnam, etc. 

Hyperotreta with the branchial apertures separate (C-11) and lateral, 
debouching directly on the sides. 

POLISTOTREMA. 

Synonymy. 

= Polytrema, Girard, Report U. S,. Naval Expd. to Cbili, v. 2, p. 251, 1854, (provis- 
ional name, not of Ferussac, 1822, nor Ri.sso, 182G.)* 

— Polistotrema, Gill with Jordan Gilbert, Proc. U. S. Nat. Mas., v.4,p. 30, 1881. 
Gastrobrancbns sp., Lacvpede. 

Ileptatrema sp., Cuvier, 

Bdellostoma sp., Midler, Girard, Giinther, Putnam. 

Bdellostomids with an increased number of branchim (about 10 or 11 
on each side) and the base of the tongue between the seventh or 
eighth pair of gills. 

*“It is to be regretted that Duineril’s aiipellation of Ileptatrema, by referring to a 
point of organic structure subjected to variations, could not be retained to designate 
tbese fisbes generically. If that name be restricted to the species provided with seven 
respiratory apertures, then eacli species would constitute a genus by itself; that 
Avitb six of tbese apertures ought accordingly be called Hexatrema ; tbeu Ileterotrema 
when six are observed on one side and seven on tbe other ; Ileptatrema when seven ; 
and finally Polytrema for tbe species described farther on. 

“Considering, however, the structure of tbe mouth, both internally ami externally, 
we would not hesitate in uniting them all under the well appropriate name of i>dtZZo«- 
toma, suggested by Professor Muller.” — Girard, op. cit. 



PEOCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 519 



Two species have been indicated, but whether they are really dis- 
tinct remains to be established. Both are represented in the U. S. Nat. 
Mns., but the Chilian form is in very poor condition. 

POLISTOTEEMA DOMBEYII. 

Synonymy. 

1798— Gastrobranchus Dombey, LacepMe, Hist. Nat. des Poissons, t. 1, p. 531, pi. 23. 
1829 — Heptatremes Dombeyii, Cnrier, Regue Animal, 2. ed., t. 2, p. 405. 

1834 — Bdellostoma Dombeyii, MiiUer, Al)bandl. Akad. Wiss. zu Berlin, p. 80. 

1851 — Bdellostoma Dombeyii, Gray, Cat. Specimens Fishes in Brit. Mus., i»t. 1, p. 149. 
1854 — Bdellostoma polytrema, Girard, Proc. Acad. Nat. Sei. Phila., v. 7, p. 199. 

1854 — Bdellostoma i>olytrema, Girard, Report U. S. Naval Exped. to Chili, v. 2, p. 
252, pi. 33. 

1870 — Bdellostoma polytrema, Gunther, Cat. Fishes. Brit. Mus., v. 8, p. 512. 

1874 — Bdellostoma polytrema, Putnam, Yroc. Bost. Soc. Nat. Hist., v. IG, p. IGO (156). 
1881 — Polistrotrema Dombeyi, Gill with Jordan and Gilbert, Proc. U. S. Nat. Mus., v. 3, 
p. 458, 1881. 

polistotre:ma stoutii. 

Synonymy. 

1878 — Bdellostoma Stoutii, Lockington, Am. Nat., v. 12, p. 793. 

1881 — Polistotrema Dombeyi pt.. Gill with Jordan and Gilbert, Proc. U. S. Nat. Mas., 
V. 3, p. 4.58 ; v. 4, pp. 18, 29, 1881. 

Hah i fat. — Cal ifor n i a. 

“Eleven gill openings on each side; ten teeth on the anterior and 
nine in the posterior series. 15i inches long. Eel River, Humboldt 
County. 

“ It is rather singular that this fish, which is abundant in Eel River, 
and is sold for food, and also occurs in this harbor, should hitherto have 
escaped notice. I believe it to be the only species of its genus hitherto 
found on the Pacific coast of North America; and it differs from BJelh 
ofitoma pohjtrema, a species which occurs along the coast of Chili, both 
in the number of the gill openings and that of the teeth, B. polytrema 
having fourteen of the former and twelve of the latter in each series.” — 
Bochinyton.'^^ 

A specimen was received, 1866, at the Smithsonian Institution from 
Dr. Canfield, and on comparison with B. polytrema could not be satis- 
factorilv diagnosed. 

HEPTATREMA. 

Synonymy. 

= Heptatrema, Diime’rilfide authors; * (possibly in his “ Dissertation sur les Poissons 
Cyclostomes,” which I have not seen.) 

= Les Heptatremes, Dumeril, Cuvier Eegne Animal, 26 ed., t. 2, p. 40.5. 1829. 

= Bdellostoma, Aliiller, Abhandl. K. Akad. Wiss. zu Berlin, 1834, p. 79, 1836; 1838, 
p. 173, 1839; 1841, p. Ill, 1844. 

<( Bdellostoma, Girard, Report U. S. Naval Exped, to Chili (provisional name), v. 2, 
p. 251, 1854. 

*This genus was not proposed in the “Zool. Anal.” as Gray and Girard indicated, 
nor in the 1st ed. of Cuvier’s Regne Animal. 



520 PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 



^ Hexatreiua, Girard, Report U. S. Naval Exped. to CLili (provisional name), v. 2, 
p. 251, 1H54. 

^ Heterotrenia, Girard, Report U. S. Naval Exped. to Chili (provisional name), v. 2, 
p. 251, 1854. 

> Heptatrenia, Girard, Report U. S. Naval Exped. to Chili (provisional name), v. 2, 
1). 251, 1854. 

Bdellostomids, with typically 7 (sometimes 0) pairs of branchial aper- 
tures and the base of the tongue between the anterior pair of gills. 

MYXINID^E. 



Synonymy. 

= Missinidi, Bafmesque, Indice dTttiologia Siciliaua, p. 49 (order), 1810. 
<[Cyclostomia, llafinesque, Analyse de la Nature, p. 94, l8l.5. 

= Sucenrs, Ciirier, Regne Animal, t. 2, p. 116, 1817. 

= Dii)orobranchia, LatreiUe, Fam. Nat. du Regne Animal, p. 112, 1825. 

<^Myxinidie, Gray, List Spec. Fish Liit. Mns., jiart 1, Choudroi)teygii, p. 145, 1851. 
Myxinidie, Bonaparte, Cat. iletod. dei Pesci Europei, pp. 9*, 92’^, 1846. 

Myxinoitlei, Bleeker, Enum. sp. Piscinui archipel. Indico, p, xxxiii, 1859. 

<( ]\Iyxinidje, Gnuther, Cat. Fishes Brit. Mas., v. 8. p. 510, 1870. 

= Myxini<l?e, GiU, Arrangement Fam, Fishes, p. 25, 1872. 

Gastrohranehi, Fitizinyer, Sitznugsher. K. Akad. der Wi.ssensch. (Wien), B. 67, 1. 
Ahth., j). 58, 1873. 

Hyperotreta with the branchial sacs (G pairs) oi)eiiing by duets con- 
fluent behind into one which opens below on each side of the median 
line. 

MYXININ^E. 

Synonyms as subfamily. 

= Myxinia, Rafincsqiie, Analyse de la Nature, p 94, 1815. 

= Gastrohranchiui, Bonaparte, Giorn. Aecad. »li Scienze, v, 52 (Saggio. Distrib. Metod. 

Animal. Vertebr. a Sanguo Freddo, p. 41), 1832. 

= Gastrobranehini, Bonaparte, Nuovi Aunali delle Sc. Nat., t. 2, p. 133, 1838; t. 4, p. 
277, 1840. 

= Myxinnii, Bonaparte, Cat. Metod. dei Pesci Europei, p. 92*, 1846. 

MYXINE. 

Synonymy. 

IMyxine, LinnoEus, Syst. Nat., t. 1, p. — ,* 1758. 

Myxine, Betzins, K, Vet. Acad. Nya llandl. Stockholm, v. 11, pp. 110-114, 1790. 
Gastrobranehus, Bloch, Allg. Natnrgescliichte der Fisehes, t. 12, p. 66, 1795. 
Gastrobranchns, Bloch, Systema Ichthyologiic, ed. Schneider, j), 534, 1801. 

Myxine, Miiller, Abhandl. K. Akad. Wissenseh. Berlin, 1834-1843 (passim). 

For the most recen^ahd important information respecting’ the species 
of this genus, the ‘‘Notes on the genus Myxine, by F. ^Y. Putnam” 
(Proc. Boston Soc. Nat. Hist., v. IG, pp.127-135, 1874), should be con- 
sulted. 



Myxine is referred by Linuasus to the class Vermes. 



