THE, NAUTILUS. 103 
introduced before Rangia for the same genus of Mactroid bivalves. 
Nevertheless, the former name must give place to the latter, because 
it had been previously used in zoology for a different genus. Ever 
since Mr. Dall communicated to me the results of his investigations, 
Thad a dim recollection of having seen the name used in another sense, 
and that Rangia would have to stand, but could not recall any cir- 
cumstances connected with it. Having had occasion recently to 
refer to the Plectognath fishes, I recalled that the name Gnathodon 
had been given to a combination of the genera Tetrodon and Dio- 
don, because neither of the latter was applicable to all the forms of 
the composite genus. It was Goldfuss in 1820 who thus used the 
name in his “ Handbuch der Zoologie.” I have not access at pres- 
ent to a copy of Goldfuss’ work,’ but have verified my recollection 
by reference to Cuvier and Valenciennes’ “ Histoire Naturelle des 
Poissons,” (I, 226), where, in a summary of the work, the name is 
thus mentioned “ Gnathodon (Diodon Tetrodon.)”’. Of course, the 
name is not active in ichthyology, and, also of course, it is not 
recorded in any of the Nomenclators of zoology, but, in accordance 
with the law “once a synonym always a synonym,” the previous 
application of the name in ichthyology precludes its use in con- 
chology. 
A NEW VARIETY OF OLIVELLA. 
BY JOONBEOERD: 
Some months azo, I received from my friend, Mrs. E. M. Gay- 
lord, of Alameda, Cal., a suite of Olivella which had been found 
by her in a box of shells that apparently came direct from the 
Gulf of California. 
All of the associated species were well known Gulf shells, and as 
the Olivella were in the same fresh condition as the rest, there was 
no reason to doubt that the entire lot had been secured simultan- 
‘Handbuch der Zoologie, von Georg August Goldfuss, Nuernberg, 1820, be- 
ing the Zweite Abtheilung of the Dritter Theil of Dr. G. H. Schubert's Hand- 
buch der Naturgeschichte. Gnathodon appears on page 100, is suitably 
diagnosed, and includes as sections Orthragoriscus Schn., Diodon L. and 
Tetrodon L.—Eb. 
