Additional Notes on the Holconoti. 365 
each other, without being able to tell exactly how, from want of 
specimens, ‘l’o set this question completely at rest, it would be 
best to obtain callections from the different tributaries of the Ten- 
nessee, as well as from the main stream, one from the Powells, 
one from the Clinch, one from the Holston, one from the French 
Broad, &c., and from the main river, one from the vicinity of 
Washington, Tenn., or from Chattanooga, another from Florence, 
(the Muscle Shoal being the point, as I am informed by Dr. 
Newman, above which fish do not migrate in the Tennessee, ) 
and another anywhere above its junction with the Ohio, perhaps 
best about Reynoldsburg, at some distance from the Ohio. Who- 
ever will accomplish this survey will have made a highly val- 
uable contribution to our knowledge. 
Appennix.— Additional Notes on the Holconoti. 
Havine lately received a large number of specimens of Holco- 
nott, from California, through the kindness of my friend, T. G. 
Cary, Esq., of San Francisco, Lavail myself of this opportunity to 
make several additions to my first notice of that remarkable family. 
As I had anticipated, the uumber of species belonging to it is rap- 
idly increasing. I have now no less than six distinct species before 
me, presenting even a far wider range of differeuces than I was 
prepared to find among them, which has led me to establish several 
hew genera, besides E:mbiotoca. Respecting the family characters, 
I have to add that there is another space deprived of scales, extend- 
mg along the middle line of the belly, from the sides of the ventrals 
to the base of the anal, undoubtedly a provision to facilitate the 
dilatation of the abdominal cavity during the growth of the aston- 
‘shingly large young of these fishes. It is rather surprising, how- 
Mammalia. Nevertheless the males and females differ widely 
rom one another, in each of the four species of which I have 
thus far been able to obtain both sexes. Thiscircumstance adds 
Steatly to the difficulty of distinguishing and characterizing the 
Pecies. ‘Ihe males are uniformly smaller than the females, con- 
trary to what has been observed in the genus Peeilia, in which 
the males ( Mollinesia) and the females ( Pacilia) differ so much 
48 to have been considered as distinct genera, but agreeing in this 
fespect with my genus Heterandria, in which the males are also 
Smaller than the females. ‘The difference consists chiefly in the 
Peculiar form of the anterior part of the anal in the males, which 
sembles somewhat that of the male of Mallotus villosus, being 
mote rigid and more expanded than in the females. The jaws — 
“f€ more or less protractile. Air bladder large and sim In 
Stoop Seams, Vol. XVII, No. 51.—May, 1854. | : 
