MKMOmS OF TUE NATIONAL ACADEMY OF SCIENCES. 



129 



iflithyologry, but let us hoiie tliat few could reason so and that museums may not become obstacles 

 to the advuucenuMit of science, but be used for its furtherance only. 



The National Museum of the United States may be the lirst in which provision is made for the 

 thorough study of systematic ichthyology. The imlicy itf havinj,' a skeleton of every species has 

 been recofini/ed by its enlightened director, J^r. (loode, and we may hope that before many 

 years have i)assed a collection may be formed which will be worthy of a national museum and may 

 serve to put ichthyology on a sound basis. 



Meanwhile i'chtiiyology is still a crude and inchoate science. The present list has been jue- 

 pared as a check list and adjuvant to the use of the collection. ISIany families have been allocated 

 in their positii.ns simply bewiuse they have been placed there before and because equal doubts 

 would he involved in placing them.elsewhere. In many cases, it is certain that the general con- 

 ceptions of their relations (if so positive a term may be applied to what are vague reiterations of 

 I)ast utterances) are baseless, but the indications furnished by the exterior is insuflHciont to justify 

 positive conclusions. Until the anatomy or at least the osteology of every family and subfamily 

 is known, much doubt must remain as to the proper allocation of such groups. 



In order to furnish clews to the literature, the names of the proposers and modifiers of family 

 terms are appended, and the dates will enable the student to obtain the desired result by use of the 

 recognized channels of information. The names of authors inclosed within parentheses are of 

 those who have given the name in more or less difll'erent forms or with different ranges of characters ; 

 those in open space are of such as have given the forms adopted and also essentially the same limits. 



In the family names derived trom compounds with -'<«-, the shorter termination^^itrfo; is 

 adopted rather than — podidw. (Compare the alternative or poetical forms -uXuituq, gen. r.olur.ou^ 

 0ioi-ou^, gen. dtdi-ou, etc.) Thus Lcpldopidwxs used instead of Lcpidopodidw. 



In names derived from compounds with azat/ia and similar words the termination — ida: is also 

 employed, as Ginghjmosiomidn: As this is contrary to almost universal usage among naturalists, 

 I can not do better than cite, in this connection, the words of the scholarly Hermannsen.* 



Class MYELOZOA (Is. Geoflr. St. Ilil., Bona- 

 parte, 1856), or LEPTOCAEDIANS. 



Order AMPHIOXI (Bou., 1846). 



1. BRAScmosTOJiiD.E Boll., 1816. 



Class MAKSIPOBKANCUII or MYZONTS. 



Order HYPEROTRETA (MuUer, 1844). 



2. Heitatuemid.e Gill, 1892=Bdellostomid.e Gill, 



1872. 



3. MvxiNiu.K (R.af., 1810) Gill, 1872. 



Order HYPEROARTIA (Muller, 1844). 



4. MOUDACIID.K Gill, 1892. 



5. Petromvzontid.e Risao, 1826. 



a. retromyzontina (Bon., 1832) Gill, 1892. 

 6. Geotrinw Gill, 1892. 



Class SELACHIANS. 

 Order OPISTHRARTHRI (Gill, 1882). 



fi. Ciu.AMVDosKi.AciiiD.K Gariiiaii. 1.H84. 



7. IlKXA>-caiD.i; Gill, 188.j=Xotidanid.e (M. II.). 



Order PROSARTHRI. 



8. llETEKODONTID.B QiU, (1862) 1872=Cestuacion- 



TID.E (Agass., 1883) Owen, 1846. 



Order TECTOSPONDYLI. 



9. EcniNORniNiD.E Gill (1862), 1872. 

 ■ 10. OxYNoTii).*: Gill (1862), 1872. 



11. StjUALiD.E (Bon., 1832) Gill, 1888=Spinacid.e. 



12. Dalatiidjj Gil], 1892=Scymnid.e (Miiller anil 



Henle, 1815). 



a. Sonmoaiittr Gill, 1888. 



b. Dalatiinw Gill, lS92=/Sc!/mniii(i: (Hon., 1837), 



Gill. 



* Vocabula composita Graec.-c originis, quorum tcmiiualis radix generis nentralis, in n cx-ieus, genitivo urof 

 flectitur, nonnisi adjectiro sensu adliibentur. Hinc si neutralia nuniero plurali ol)veniunt, ut Adeloderma, C'rico- 

 stoma, terminentur genitivo orum; sin autem singular! numcro, ut Amphiilesnia, Cycldstoma, fominini erout 

 generis, ct declinal>imus „ Cyclostoiuie." — Docuniento sint vetorum nomiua onTflaKuiepfiu, rpiaro/ioc, a6ea/io(. 



"Omni vel specie rectac rationis, qui Pleurotomam similiatiue vocaliula uuutralis generis habent. Conferatur 

 ^CiiiTOfUc." — iIcrmana.seD, Indicis Genorum Malacozoorum I'riiuordia, vol. i, 1846, p. xiii. 



S. Mis. 109 9 



