396 
BULLETIN OF THE UNITED STATES FISH COMMISSION. 
17. BRACHYISTIUS ROSACEUS Jordan & Gilbert. 
Cymatogaster • rosaceus Jordan & Gilbert, Proc. U. S. N. M. 1880, 303 (San Francisco). 
Brachyistius rosaceus Jordan & Gilbert, Proc. U. S. N. M. 1880, 456 (San Francisco, California) ; 
Jordan & Jouy, Proc. U. S. N. M. 1881, 10 (San Francisco); Jordan & Gilbert, Proc. U. 
S. N. M. 1881, 51 (San Francisco, California) ; Jordan, Cat. Fish. N. A., 96, 1883; Eigen- 
mann & Eigenmann, Ann. New York Acad. Sci., vi, June, 1892 (San Francisco). 
Micrometrus rosaceus Jordan & Gilbert, Syn. Fish. N. A., 589, 1883 (San Francisco). 
Habitat : Off San Francisco in deep water. 
12. CYMATOGASTER * Gibbons. 
Cymatogaster Gibbons, Proc. California Acad. Nat. Sci., in Daily Placer Times and Transcript, 
San Francisco (aggregatus and minimus) May 18, 1854, fide Agassiz (not Cymatogaster 
Gibbons, May 30, 1854, Holconotus) ; Gibbons, Proc. Acad. Nat. Sci. Phila., v. 7, 106 
( sine desc.), June, 1854 (not Cymatogaster Gibbons, Aug., 1854); Gill, Proc. Acad. Nat. 
Sci. Pkiia. 1862, 275. 
Micrometrus t Gibbons, Proc. California Acad. Nat. Sci., in Daily Placer Times and Transcript, 
San Francisco (sine desc.), May 30, 1854, fide A. Agassiz (first species aggregatus ); Gib- 
bons, Proc. Acad. Nat. Sci. Phila. 1854, 125; Jordan & Gilbert, Syn. Fish. N. A., 588, 
1883 (sp.). 
Holconotus Girard, Proc. Acad. Nat. Sci. Phila. 1885, 322 (not Holooonotus Agassiz, 1854). 
Metrogaster Agassiz, mss. (fide A. Agassiz) ; A. Agassiz, Proc, Boston Soc. Nat. Hist., v. 8 (128), 
133, 1861. 
Ditrema sp. Gunther, 1862. 
Sema\ Jordan, Bull. U. S. Geol. and Geog. Survey, iv, No. 2, 1878 (signifer). 
Type : Cymatogaster aggregatus Gibbons. 
The name Cymatogaster was first published by Gibbons, May 18, 1854, and applied 
to two new species, Cymatogaster aggregatus and Cymatogaster minimus. Since these 
two species belong to two quite distinct genera the name can be used for but one of 
them. A few days later (May 30), Gibbons applied the name Micrometrus to the same 
two species. On June 21 he restricted the name Cymatogaster to pulchellus, a nominal 
species not known at the time (May 18) the name was first proposed. The later use 
of the name is entirely untenable, since Cymatogaster was a name preoccupied by 
its use of May 1 8, just as much as if it had been used for a genus of reptiles fifty years 
before. This seems self-evident and it ought not to be necessary to defend this view. 
Cymatogaster , if used at all, must be used for aggregatus or minimus. The same is true 
of Micrometrus. 
The first species to be eliminated from these two under a separate generic name 
was minimus. Girard described a species, trowbridgii=minimus, under the new generic 
name Abeona , thus restricting both Cymatogaster and Micrometrus to the only other 
species of the original Cymatogaster , viz, aggregatus. 
There seems, then, no other way out of the difficulty than to retain the name Cyma- 
togaster aggregatus , to which it was restricted by Dr. Gill in 1862. 
* Cymatogaster: Kvpa(aroc), foetus, and yaaryp, belly, alluding to the viviparity common to the 
whole family, first sp., C. aggregatus. 
+ Micrometrus: M ispog, small, and perpov measure (quasi size), referring to the comparatively small 
size of the representatives of the genus, first sp., M. aggregatus. 
t Sema: or/pa, a banner, in allusion to the high fins. 
