3 "Tt i
C~JG
MONOGRAPH!
OF THE
FAMILY UNIONID^E,
OR NAIADES OF LAMARCK,
(FRESH WATER BIVALVE SHELLS,)
OF
NORTH AMERICA,
ILLUSTRATED BY FIGURES DRAWN ON STONE FROM NATURE.
BY T. A. CONRAD,
CURATOR OF THE ACADEMY OF NATURAL SCIENCES OF PHILADELPHIA, HONORARY MEMBER OF
THE GEOLOGICAL SOCIETY OF PENNSYLVANIA.
PHILADELPHIA:
J. DOBSON, 108 CHESNUT STREET.
1836.
da>H
E. G. Dorse y, Printer,
12 Library Street.
TO
CHARLES A. POULSON, Esq.
Member of the Academy of Natural Sciences of Philadelphia, fyc.
THIS BOOK IS DEDICATED,
AS A SLIGHT TRIBUTE OF ESTEEM,
BY HIS OBLIGED FRIEND,
THE A UTHOR.
MONOGRAPH Y
OF THE
FAMILY UNIONIDil
UNIO.
GENERIC CHARACTER.
Shell equivalved, inequilateral: cardinal teeth two
in each valve, irregular, generally striated, simple or
biparted; an elongated lamelliform tooth on the pos-
terior hinge margin of the right valve, and two
similar teeth on the corresponding margin of the left
valve: muscular impressions two principal ones in
each valve.
OBSERVATIONS.
Mr. Say justly remarks, that, "in North America,
the shells of this genus excel those of any other
country in magnitude, beauty, and diversity of spe-
cies." The rivers of Tennessee have furnished the
most beautiful specimens of many species common to
the western waters. The Ohio or Mississippi has
not hitherto furnished a single species existing in
tide waters which flow into the Atlantic; and the
only shell of this character is the Alasmodonta mar-
ginata, Say.
The shells of this genus may be divided into two
groups, the "winged" and "not winged," as Mr. Sow-
erby has proposed for the whole family of Unionid^e.
The former are included in the genus Symphynota, of
Mr. Lea, which we cannot adopt, because, as Fe-
russac justly remarks, "in the same family generic
characters should be taken from the same parts;"
thus the other genera are formed from the absence
or arrangement of the hinge teeth, whilst Symphynota,
without any regard to the hinge, is constructed from
a testaceous connexion of the valves, which Ferussac
observes is "almost an organic character among the
Acephala which have the mantle completely closed
near the hinge margin, at least in young shells."
Dr. Kirtland has made some interesting remarks
on the sexes of this family, in which he has proved
them to be distinct, in the opinion of many concho-
logists; and the sex can be ascertained by the form
of the shell. Almost every species has two promi-
nent varieties of form, one of which is shorter and
more ventricose than the other, which is happily ex-
plained by the observations of the intelligent author
of the essay referred to.*
*Vide Silliman's Journ. vol. xxvi. p. 117.
c"1
i
u
nioJasccatus,Raf
UNIO FASCIATUS.
Plate I.
DESCRIPTION.
Shell elliptical, compressed, yellowish olive, with
broad dark green rays, and a few intermediate nar-
row rays; umbo slightly compressed, little promi-
nent; anterior side short; ligament margin scarcely
curved, slightly declining; posterior margin obliquely
truncated; umbonial slope abruptly rounded; submar-
gin slightly furrowed; basal margin protruding a
little near and behind the middle; within white;
cardinal teeth thick, direct; margin thin, showing the
exterior rays.
SYNONYMES.
U. fasciatus, Raf. Ann. gen. des Sc. Phys. vol. v. p. 28.
Poulson's translation, p. 20. Say, Amei\ Conch. No, 6.
Ferussac, Mag. de Zool.
U. carinatus, Barnes. Sillimairs Journal, vol. vi. p. 126.
Cab. A. N. 8. No. 1020.
OBSERVATIONS.
This shell has been considered a variety of cario-
sus by some conchologists, but it is invariably more
ponderous and compressed, with very different mark-
ings and cardinal teeth. It is most nearly related to
the crassus, Say, but can be distinguished by its
more elliptical outline, much broader and darker rays,
and by the beaks being less nearly terminal. Fe-
russac gives carinatus, Barnes, as a synonyme to
crassus, Say. Common in the western waters. The
figure is from a specimen from the Scioto, given me
by my friend, Dr. William Blanding.
UNIO OVATUS.
Plate II.
DESCRIPTION.
Shell subtriangular, rather thin, compressed ante-
riorly, inflated over the umbonial slope, which is pro-
foundly angulated and subrectilinear; posterior slope
flattened or slightly concave, much wrinkled; umbo
inflated, prominent, sloping anteriorly, distant from
the anterior margin; surface glabrous, olive-yellow;
within bluish; cardinal teeth double in each valve,
very oblique, compressed, elevated.
SYNONYMES.
U. ovatus, Say. Nicholson's Ency. (3d Amer. ed.) art. Conch.
pi. ii. fig. 7. Lam An. sans vert. vol. vi. p. 75.
Cab. A. N. S. No. 1225.
OBSERVATIONS.
The great depression of the posterior slope distin-
guishes this species from the cardium, Raf. Old
shells are produced posteriorly. It varies consider-
ably in form; some specimens are compressed, others
very ventricose, with rather broad radii over the
whole disk. This variety is so dissimilar to the
specimen figured, that I propose to designate it by
a distinct name, terming it variety ornatus; it is com-
mon in the rivers of South Alabama. The species is
common in the western waters.
:
•
i ' ^V
Unto ovatuti >S'«-<j-
.3
• ■ .
f
/ Unio c/aua, Laitt.^ £.Unio decisus, Lea.
UNIO CLAVA.
Plate III. — Fig. 1.
DESCRIPTION.
Shell cuneiform, very oblique; posterior side pro-
duced, compressed, with an oblique furrow rapidly-
widening from the umbo; ligament margin arcuate,
very oblique; umbo elevated, narrowed, inclining for-
wards; beaks curved to a point, terminal; epidermis
wrinkled, olive-yellow or brownish, with interrupted
rays over the umbo, disappearing with age; within
white, very iridescent posteriorly; cardinal tooth in
the left valve nearly parallel with the ligament mar-
gin.
SYNONYMES.
U. clava, Lam. An. sans vert. vol. vi. p. 74.
U. scalenius, Raf. Ann. gen. des Sc. Phys. vol. v. p. 43. pi.
lxxxi. fig. 24, 25. Poulson's trans, p. 47.
U. modioliformis, Say.
Cab. A. N. S. No. 1117.
OBSERVATIONS.
A beautiful species when perfect, and common in
the western rivers. With age the posterior side be-
comes greatly produced and compressed, and gene-
rally furnished with irregular indentations. Allied to
U. oviformis, nob. and decisus, Lea.
B
6
UNIO DECISUS.
Plate III.— Fig. 2.
DESCRIPTION.
Shell cuneiform, oblique; anterior margin obtusely
rounded; posterior side produced, somewhat com-
pressed, with a very oblique indistinct furrow, and
irregular indentations, frequently obsolete; extremity
angular; beaks nearly terminal, eroded; umbonial
slope rectilinear, subangulated; epidermis finely wrin-
kled inferiorly, reddish-brown with obsolete brown
narrow rays; within white.
SYNONYMES.
U. decisus, Lea. Trans. Amer. Philos. Soc. new series, vol.
iv. p. 92, pi. xii. fig. 23.
U. taitianus, ib. vol. v. p. 39, pi. iv. fig. 11. variety.
Cab. A. N. S. No. 1733.
OBSERVATIONS.
This species much resembles the preceding, but
can always be distinguished by its broader and less
oblique umbo, uniform absence of green rays, and
by its rectilinear umbonial slope, but more especially
by the posterior extremity, which is never so nearly
on a line with the base as in the former shell, which
with age is greatly produced and compressed, whilst
the present species, when old, never becomes so;
the cardinal teeth, also, are very different. Com-
mon in the Alabama river, and has hitherto been
found only in the state of Alabama.
UNIO REFLEXUS.
Plate IV.— Fig. 1.
DESCRIPTION.
Shell suboval, thick anteriorly; middle of the disks
with a single row of distant elevated tubercles, about
four in number; umbo not very prominent, subme-
dial; umbonial slope subcarinated; posterior side
slightly furrowed and emarginate at base; posterior
slope flattened, with transverse undulations; poste-
rior extremity truncated; within white; cardinal teeth
large, direct, much sulcated.
Var. A. disks covered with small tubercles.
Var. B. epidermis blackish, nacre purple.
SYNONYMES.
U. reflexus, Raf. Ann. gen. des Sc. Phys. vol. v. p. 40.
Poulson's trans, p. 40. Say, Amer. Conch. No. 6. Fernssac,
Mas;, de Zool.
U. cornutus, Barnes. S'dliman's Journ. vol. vi. p. 122.
Cab. A. N. S. No. 1750.
OBSERVATIONS.
Allied to the U.Jlexaosus, but approaches nearest
to U. gibbosus, Raf., yet may always be distinguish-
ed from that species by its suboval outline, and the
regularity and prominence of its tubercles. The
two varieties I found in the Alabama river. The
figure represents a tuberculated specimen. The
species preserves its distinctive characters in very
8
remote localities, specimens from south Alabama
perfectly resembling others from the waters of Indi-
ana.
UNIO FLEXUOSUS.
Plate IV.— Fig. 2.
DESCRIPTION.
Shell subtriangular, bifurcated, swelling and sub-
nodulous in the middle; posterior side with a wide
oblique furrow; umbonial slope obtusely carinated;
umbo flattened, prominent; epidermis with numerous
slender rays; within white, cardinal teeth direct,
sulcated; lateral teeth short and thick.
SYNONYMES.
U. flexiiosus, Raf. Ann. gen. des Sc. Phys. vol. v. p. 40.
U. foliatus, Hildreth. Silliman's Journ. vol. xiv. p. 248, fig.
16.
Cab. A. N. S. No. 1050.
OBSERVATIONS.
A specimen of this shell in Mr. Poul son's cabinet
was labelled by Rafinesque, whose description, un-
der the name we have adopted, entirely accords with
the species before it has attained its profound bifur-
cation.
This singular species, when young, is smooth, and
simply emarginate behind the middle. It approaches
nearest to U. gibbosus, Raf. Not uncommon in the
western rivers.
IVnU) rej[(Jiis,Kaf^
Z.Uni.o fLexuosu3,R<ij.
9
UNIO PHILLIPSII.
Plate V.— Fig. 1.
DESCRIPTION.
Shell subovate, with concentric furrows; anterior
side smooth; disk with a single row of irregular
tubercles in the centre, some of which are elongated
and grooved; posterior side narrowed, with a wide
furrow and a few small tubercles; umbonial slope
straight, carinated and tuberculated; posterior slope
concave, indistinctly tuberculated; ligament slope
rectilinear, oblique; extremity direct, emarginate;
basal margin swelling centrally, emarginate behind;
mnbo prominent, rather broad, flattened at the sum-
mit; beaks retuse; epidermis yellowish-brown, with
indistinct filiform rays over the umbo; within white;
cardinal teeth rather small, direct, double in each
valve.
OBSERVATIONS.
This handsome species is allied to U. (/iiadrahis,
Raf., but is very distinct, the young shell having
broad smooth and retuse beaks, whilst the young of
the quadrulus has the beaks narrowed, tuberculated,
pointed and curved forwards. The specimen figured
is from the Wabash, and is in the cabinet of Mr.
John Phillips, who called my attention to it as a
distinct species, and I have dedicated to him a small
tribute of respect for his talents and scientific zeal.
10
UNIO METANEVRUS.
Plate V. — Fig. 2.
DESCRIPTION.
Shell suboval, thick, ventricose; anterior side tu-
berculated, except near the margin, which is smooth;
disk with an oblique furrow; umbonial slope very
prominent, broad and rounded, with numerous tu-
bercles, some of which are very large; posterior slope
wide, concave, or angular, with oblique slightly re-
curved series of rib-like tubercles; umbo slightly
prominent; beaks retuse; ligament margin oblique,
rounded at the extremity; posterior margin emargi-
nate; epidermis yellowish-brown, with interrupted
green rays; within white, much thickened anteriorly.
SYNONYMES.
U. metanevra, Raj '. Ann. gen. des Sc Phys. vol. v. p. 39.
Ferussac, Mag. de Zool.
U. nodosus, Barnes. Silliman's Journal, vol. vi. p. 124, pi. vi.
fig. 7.
Cab. A. N. S. No. 1754.
OBSERVATIONS.
A common species in the western and southern
rivers, easily recognised, when in perfection, by its
swelling umbonial slope: very old specimens much
resemble U. stapes, Lea, but are much larger.
U4c™_-^
■' ! ! i '■-' '
~s-
). I'Jiin ph.ill.lp.yii , Co/i. "Z-. Vnio MrAaneuru s, Haf-
pec. f#3S.
11
UNIO MORTONI.
Plate VI. — Fig. 1.
DESCRIPTION.
Shell suborbicular, not thick, ventricose; disk flat-
tened, or slightly furrowed from beaks to base, co-
vered with irregular tubercles; anterior margin sub-
truncated; posterior margin straight, direct; ligament
margin subarcuate, oblique, forming an angle with
the posterior margin; umbo with an oblique furrow,
prominent; beaks rather retuse, decorticated; umbo-
nial slope angular, slightly arcuate; posterior slope
flattened; epidermis yellowish brown, with fine crowd-
ed wrinkles; within white; anterior margin not thick-
ened; cardinal teeth compressed, very prominent,
oblique.
Cab. Ji. N. S. No. 1874.
OBSERVATIONS.
This pretty species is common in Bayou Teche,
Louisiana; but I have seen it from no other locality;
it approaches nearest to the quadruhis, Raf., but dif-
fers greatly in size, convexity, and want of a distinct
furrow from beak to base. It is dedicated to my
friend Dr. S. G. Morton, whose exertions have fur-
nished a splendid collection of American and foreign
fresh water shells to the Academy of Natural Sci-
ences.
12
UNIO FRAGOSUS.
Plate VI. — Fig. 2.
DESCRIPTION.
Shell suborbicular, ventricose, with an indistinct
narrow furrow, and two approximate series of very
prominent irregular tubercles, anterior ones largest;
umbonial slope angular; posterior slope slightly con-
cave, with a few narrow rib-like tubercles, more pro-
minent near the margin; posterior margin direct,
slightly emarginate; ligament slope straight, slightly
oblique; umbo narrow, prominent; beaks much in-
curved, pointed, tuberculated; epidermis brown, with
two or three broad, widely interrupted green rays.
OBSERVATIONS.
This fine spocies approaches quadridus, Raf., but
is much more ventricose, has more prominent tuber-
cles, and is very distinct. I am indebted to Dr.
Blanding for the splendid specimen represented by
the figure; it is from the Scioto river, Ohio.
/. Unlo MortonL, Con. %.vn\o jranosus, Conrad.
Die. 1S3S
HHBSSBsS
<--.:■ .■-.*f-->,;^-"- -
•.
N
-r
r^r*" - " i .
■
('"/a co.rtatu*, fia/;
17
UNIO COSTATUS.
Plate VII.
DESCRIPTION.
Shell suboval, slightly ventricose anteriorly; disk
with profound oblique undulations, numerous and re-
curved behind the umbonial slope; umbo narrow,
slightly prominent, oblique, nearly terminal; ligament
margin elevated, nearly straight; epidermis yellowish
brown, sometimes blackish brown, much wrinkled
posteriorly; within white, iridescent posteriorly,
waved on the margin; cardinal teeth very thick.
SYNONYMES.
U. costatus, Raf. Ann. gen. des Sc. Phys. vol. v. p. 49. pi.
lxxxii. fig. 13, 14. Poulson's trans, p. 57. Say, Amer. Conch.
No. 6. Ferns. Mag. de Zool.
U. undulatus, Barnes. Silliman's Journ. vol. vi. p. 121, pi. 2.
OBSERVATIONS.
This shell very nearly approaches U. plicatus, Say,
and some varieties can scarcely be distinguished
from it. It has, in general, more undulations, a much
less prominent umbo, is less ventricose, and has often
a yellowish epidermis, which is not the case with the
plicatus. Not uncommon in the western waters, and
in the Alabama river; very large and fine in the
rivers of Tennessee.
18
This species in some of its varieties so nearly re-
sembles U. heros, of Say, when the latter is old and
eroded on the umbones, that Mr. Say at one time
considered them identical; the young shell of the he-
ros, however, was found to be so entirely dissimilar
to the young of the costatus, that the specific differ-
ence was obvious to the most careless observer, and
Mr. Say in his synonymy retains his species. This
circumstance should induce those naturalists who
live in favourable situations to study the young of
every species, for as Mr. Lea has justly observed,
they are the most certain guides to specific distinc-
tions; when the umbones and beaks are perfect, most
species will exhibit very nearly the prominent cha-
racters of the very young shells, and hence the ne-
cessity of procuring cabinet specimens of the most
perfect description, if we would effectually trace the
species and make ourselves acquainted with their
affinities.
20
UNIO PARVUS.
Plate IX.— Fig. 1.
DESCRIPTION.
Shell oblong or elliptical, with prominent concen-
tric lines, and slightly contracted from beak to base;
inflated posteriorly and the basal margin dilated and
rather abruptly ascending to the extremity, which is
narrow, obtuse, and much above the line of the base;
umbo when not decorticated, profoundly sulcated;
umbonial slope undefined; posterior slope with a sub-
marginal, slightly prominent line; ligament margin
not oblique; posterior margin obliquely truncated
above; within white; cardinal teeth very erect.
SYNONYMES.
U. parvus, Barnes. Silliman's Journal, vol. vi. p. 1T4.
Cab. A. N. S. No. 1872.
OBSERVATIONS.
A small species, without any prominent character,
yet very distinct. It approaches nearest to U. lieno-
sws, nob. but that species is always more or less
radiated and generally pink or purple in the interior;
the parvus is white within and rarely rayed. Inhabits
western rivers generally from Bayou Teche in Louisi-
ana to Fox river in the North Western Territory.
An elegant specimen from the Scioto river is dark
olive-green and distinctly rayed; and the acutely an-
gulated ridges on the beaks are very perfect.
..--i-'-rT i
z
/( I. V n,o jjvjou;,, Iirrrju V 2. I Kl I r;.',-, /.,,,;
21
UNIO GLANS.
Plate IX.— Fig. 2.
DESCRIPTION.
Shell ovate-elliptical, thickened anteriorly; surface
with numerous concentric lines; anterior side short;
posterior side subcuneiform; umbo slightly prominent;
beaks undulated; umbonial slope undefined; epidermis
generally dark brown, sometimes rayed; within dark
purple, except on the anterior margin; cardinal teeth
prominent, direct.
SYNONYMES.
U. glans, Lea. Trans. Amer. Philos. Soc. new series, vol. iv.
pi. viii. fig. 12.
Cab. A. N. S. No. 1168.
OBSERVATIONS.
This does not appear to be an abundant species,
yet it is occasionally found in the waters of Ohio,
Tennessee and Alabama. In the latter state I met
with it only in the tributaries of the Tennessee river.
The purple nacre and white anterior margin will al-
ways distinguish this species from any other, which
resembles it in form. Another peculiarity is the
posterior tooth of the left valve pointing to the pos-
terior extremity, which causes the teeth to diverge
greatly. It most resembles U. lienosus, nob. and U.
parvus, Barnes. The figure represents the largest
and best specimen I have seen, and the only one that
is distinctly rayed; it is from the Harpeth river,
Tennessee.
22
UNIO SILIQUOIDEUS.
"'Plate X. — Fig. 1.
DESCRIPTION.
Shell ovate-oblong or elliptical, ventricose, mode-
rately thick; surface glabrous, olive-yellow, with nu-
merous green rays varying much in size; anterior
side not very short, margin regularly rounded; liga-
ment margin straight, not declining; posterior ex-
tremity angulated; umbonial slope undefined; beaks
with flexuous undulations; within bluish-white; cardi-
nal teeth oblique, lateral teeth slightly decurved pos-
teriorly.
SYNONYMES.
U. siLiquoiDEus, Barnes. Silliman's Journ. vol. vi. p. 269.
U. inflatus, lb. p. 267.
Cab. Jl. N. S. No. 1055.
OBSERVATIONS.
The species which most resembles this appears to
be the radiatus, which for comparison we figure upon
the same plate. Young specimens differ constantly
from the radiatus in having a straw-coloured highly
polished epidermis, and much undulated beaks; are
more inflated, have the anterior side longer and the
margin more regularly rounded. The sexual varie-
ties are far more strongly marked, some specimens
having almost the form of U. cariosus, whilst the ra-
diatus offers comparatively slight differences of out-
line. Old shells become thick and much inflated, and
23
resemble in form the U. teres, Raf. common in the
western rivers. I did not observe it in Alabama.
Mr. Say, in his synonymy of the western species,
has given the siliquoideus as a synonyme of U. cariosus,
considering it a mere variety of that species, and
more strangely merges the radiatus in the same. We
have seen abundance of both the latter and cariosus,
in the Schuylkill and Delaware, but never any varie-
ties of either which could for one moment have led us
to confound the two species. Mr. Lea informs us
that a specimen of the siliquoideus in the Garden of
Plants at Paris, is labelled luteola of Lamarck; this
name we should have adopted if Ferussac had not
referred Lamarck's specimen of luteola to cariosus, of
Say, which we presume to be correct, as that distin-
guished naturalist is well acquainted with those
species which are common in the United States.
In Bayou Teche there occurs a beautiful species
allied to this if it be not a variety; it is distinguished
by a darker epidermis, with distant and dark green
rays of nearly uniform size. We have not seen many
specimens, but a figure of it will be given when its
characters shall be determined and its affinity with
the siliquoideus clearly ascertained.
24
UNIO RADIATUS.
Plate X. — Fig. 2.
DESCRIPTION.
Shell oblong-ovate, thin, slightly compressed on
the anterior side; surface with fine wrinkled lines
and distinct furrows; olive, with numerous green rays,
varying in size; anterior side short and narrowed;
margin abruptly rounded; posterior side dilated; liga-
ment margin elevated, slightly curved; anterior basal
margin slightly contracted; umbonial slope undefined;
posterior extremity subtruncated; within yellowish or
salmon coloured, and thickened anteriorly; bluish and
highly iridescent posteriorly.
SYNONYMES.
U. radiata, Lam. An. sans vert. vol. vi. p. 73.
Barnes. Silliman's Journ. vol. vi. p. 265.
Mya radiata, Spengl. Gmel.
U. virginiana, Lam. An. sans. vert. vol. vi. p. 79.
U. oblongata, Wood. Suppl. Index. Test.
Cab. A. N. S.No. 1116.
OBSERVATIONS.
A common species in the tide waters of the middle
states, and very abundant in those of Virginia, but it
has not been found in any of the tributaries of the
Mississippi, except the Ouisconsin river, where,
according to Mr. Barnes, it was obtained by Mr.
Schoolcraft. This naturalist remarks that it inhabits
Saratoga lake.
10
t.Unio Siltuuoideus, Barnes r. X. t/nio radiatus , La mirrri.
//
0 'pactorosus, 0
■>, Onto frrzctoltis, Jittf.
25
UNIO PECTOROSUS.
Plate XL— Fig. 1.
DESCRIPTION.
Shell elliptical, inflated, moderately thick, yellow-
ish or olive, with unequal green rays, the larger rays
having distant dark spots; anterior side compressed,
extremity acutely rounded; ligament margin parallel
with the base; umbonial slope angular; umbo broad,
prominent, summit obtusely rounded; beaks distant
from the anterior extremity; within white, with a
wide greenish margin; cardinal teeth thick, promi-
nent, direct; cardinal plate dilated.
SYNONYME.
U. pectorosus, Nob. New fresh water shells, p. 37. pi. vi. fig. 1.
May, 1834.
U. perdix, Lea. Trans. Amer, Philos. Soc. new series, vol. v.
p. 72. pi. xi. fig. 31. Sept. 1834.
Cab. A. N. S. No. 2102.
OBSERVATIONS.
This shell has so nearly the outline of U.fasciolus,
that I have figured both on the same plate for com-
parison. It diners from that species in the rays,
dilated cardinal plate, &c. It is allied to U. ovatus,
Say, but is much more elongated. The specimen re-
presented has double cardinal teeth in each valve, but
the character is not permanent. It is in the splendid
collection of Mr. Poulson, and was found in the Har-
peth river, Tennessee. I obtained a few specimens
D
26
on the bank of Elk river, Alabama, in which the epi-
dermis was dark and the rays obscure. Mr. Lea
compares it with the crassus, Say, but we cannot
find any point of resemblance.
UNIO FASCIOLUS.
Plate XL— Fig. 2.
DESCRIPTION.
Male. Shell elliptical, inflated, yellowish, with nu-
merous unequal flexuous green rays; anterior margin
regularly, not obtusely rounded; posterior extremity
angulated; ligament margin slightly declining; umbo
wide, prominent; beaks retuse, distant from the an-
terior extremity; umbonial slope obtusely rounded;
within white; cardinal teeth prominent, diverging;
margin horn-coloured, shewing the exterior rays.
Female. Short ovate; posterior side dilated; umbo
narrower and more oblique; ligament margin elevated.
SYNONYMES.
U. fasciolus. Raf. An. gen des Phys. Sec. vol. 5. p. Poul-
son's trans, p. 28. Say. Amer. Conch. No. 6.
U. multiradiatus, Lea. Trans. Amer. Philos. Soc. new series,
vol. 3. p. 48. pi. ix. fig. 15.
Cab. .d. N. S. No. 1429.
OBSERVATIONS.
Distinguished by its numerous unequal green
undulated rays; without these the female might be
\%
, ii :. ( i, ', .Unto -Ala
27
mistaken for U. cariosus. Old shells are very thick
and ponderous, and Mr. Poulson has a line specimen
of this description. Had the Baron de Ferussac seen
this, we think he would not for a moment have deemed
it a variety of U. subovatus. Mr. Phillips has two
fine specimens, male and female; the former is repre-
sented.
UNIO CONGARiEUS.
Plate XII. — Fig. 1.
DESCRIPTION.
Shell elliptico-rhomboidal, thin, somewhat flattened
at the sides; epidermis olive or reddish-brown, with
numerous green rays, sometimes obsolete; umbones
flattened, broad; summits obtusely rounded, slightly
prominent; umbonial slope profoundly angulated;
ligament slope slightly oblique; posterior slope much
depressed, with oblique, irregular, undulated lines;
within white, highly iridescent; cardinal teeth oblique;
lateral teeth elongated, slightly curved.
SYNONYME.
U. congar;£us, Lea. Trans. Amer. Philos. Soc. new series, vol.
4. p. 72. pi. vi. fig. 4.
Cab. A. N. S. No. 2101.
OBSERVATIONS.
Inhabits the eastern waters of South Carolina. I
found it also at Augusta, Georgia, in great numbers.
28
It certainly approaches U. niger, Raf.; the young of
the latter resembling it so much, as to lead to the
inference that they may be varieties of one species,
occasioned by difference of locality. Specimens from
Augusta resemble the m^er more than those from the
Congaree river; and in Flint river, Georgia, is a va-
riety of the latter, differing only from the congarceus
in being rather larger and more ponderous.
UNIO MASONI.
Plate XII. —Fig. 2.
DESCRIPTION.
Shell suboval, thin; umbones broad, inflated, disks
slightly flattened near the umbonial slope; beaks dis-
tant from the anterior margin; ligament margin ele-
vated; umbonial slope angulated; epidermis oliva-
ceous, polished, wrinkled inferiorly; summits decor-
ticated; within white, cardinal teeth oblique, rather
thick.
SYNONYME.
U. masoni, Nob. New fresh water shells, p. 34. pi. 5. fig. 2.
Cab. A. N. S. No. 2100.
OBSERVATIONS.
Inhabits Savannah river, at Augusta. When the
description was originally published, I had seen only
13
' nio cot? emeus, HUdretL i cutULus, C.
29
the young shell, but subsequently, in examining a
number of specimens of U. cougar (Bus from the same
locality, an adult specimen was discovered, which has
served for the figure and description. It is in Mr.
Phillips's cabinet. The outline of the young shell is
represented for comparison with that of U. cougar teas.
Mr. Poulson's cabinet.
It is dedicated to Mr. William Mason, whose dis-
coveries have much advanced our knowledge of
American conchology.
UNIO COCCINEUS.
Plate XIII. — Fig. 1.
DESCRIPTION.
Shell oblique, subtriangular, compressed, slightly
waved; epidermis blackish-brown, with crowded
wrinkles; anterior side very short; posterior side sub-
cuneiform, much compressed, extremity truncated;
umbo slightly flattened; basal margin not much ar-
cuated posteriorly; posterior margin slightly sinuous,
oblique, rounded above; umbonial slope abruptly
rounded; summits prominent, eroded; within salmon
colour, rarely white; cardinal teeth double in each
valve, direct.
SYNONYME.
U. coccineus, Hildrcth.
Cab. A. Ar. S. No. 2104.
30
OBSERVATIONS.
This shell, in having a slightly undulated disk, ap-
proaches the mytiloides, Raf., but is very distinct. It
is well known in the collections by the name we have
adopted, but we are informed that Dr. Hildreth has
not published his description of it. I have figured a
fine specimen from Mr. Hyde's cabinet. This na-
turalist observes that the species inhabits Mahoning
river, near Pittsburg, and that of the very many
specimens he has received, none has perfect beaks.
UNIO CATILLUS.
Plate XIII.— Fig. 2.
DESCRIPTION.
Shell oval orbicular, slightly oblique, moderately
thick, convex, dark chestnut-brown, with crowded
wrinkles; anterior margin obtusely rounded or sub-
truncated; posterior margin rectilinear, nearly direct,
extremity rounded; umbonial slope roimded; umbones
inflated, narrow, prominent; ligament margin rectili-
near, oblique, angular posteriorly; summits slightly
flattened; beaks much incurved, pointed, slightly tu-
berculated; lunule short ovate; within rosaceous;
cardinal teeth thick, direct, profoundly sulcated; la-
teral tooth of the left valve very thick, that of the
right valve compressed, and rising from a very broad
plate or base projecting on either side; cardinal plate
profoundly dilated.
Cab. A. N. S. Xo. 2103.
31
OBSERVATIONS.
This species has been sent from the west, under
the name of coccineus, but is so very distinct that I
should not otherwise have compared it with that
species. It approaches nearest to the polltus of Say,
and obliqims, Lam., but the peculiarity of the teeth
and greatly dilated cardinal plate, as well as many
other characters, forbid a union with either. Mr.
Hyde informs me that a great number of specimens
in his possession, from the Scioto river, shew the in-
terior to be generally of a rose colour or purple, oc-
casionally nearly white, and rarely salmon. Of the
latter Mr. Hyde possesses a specimen more beauti-
fully coloured than any Unio I have seen — it will be
figured in a future number. The figure is from a
specimen in the cabinet of Mr. Phillips.
UNIO PRODUCTUS.
Plate XIV.— Fig. 1.
DESCRIPTION.
Shell narrow-elliptical, produced, moderately thick,
slightly ventricose, somewhat contracted near the
middle; anterior side short, dilated, margin obtusely
rounded; basal margin sinuous; posterior side ros-
trated; extremity rounded, much above the line of the
base; ligament margin parallel with the line of the
base; umbonial slope obtusely carinated; umbo decor-
ticated, not elevated above the dorsal line; within
32
purplish; cardinal teeth thick, direct; lateral teeth
thick.
OBSERVATIONS.
On a passing glance this shell would certainly be
mistaken for U. jiasutus, but the thickness of the shell,
the dilated anterior side, and thick, direct, lateral
teeth, will sufficiently distinguish it. The disk pos-
teriorly has several small plicae or undulations simi-
lar to those of U. grayanus, Lea, but as only one
specimen can be examined this character may prove
inconstant.
In the cabinet of Mr. Phillips. I found it on the
shore of Savannah river, at Augusta, and supposed
it to be a variety of nasutus, but comparing it with
that species from South Carolina and Florida, it was
found to differ materially, and to form a link between
it and the rectus.
UNIO LANCEOLATUS.
Plate XIV.— Fig. 2.
DESCRIPTION.
Shell narrow-elliptical, thin, ventricose, yellowish,
smooth and polished; disks slightly flattened; ante-
rior side somewhat compressed, not very short, mar-
gin regularly rounded; umbonial slope regularly
rounded, inflated; posterior side produced, extremity
//
. UjiW>f>rodurtu.fjC.%.-(f.Un^oL k » ■ '"" ' -
■■.
i
33
angulated; beaks not prominent; ligament margin
short, elevated; within pale salmon colour; lateral
teeth slightly recurved.
SYNONYME.
U. lanceolatus, Lea. Trans. Amer. Philos. Soc, new series,
vol. iii. pi. 3. fig. 2.
Cab. A. N. S. No. 1105.
OBSERVATIONS.
Inhabits Tar river, N. C, Mr. Lea. Mr. Hyde
has received specimens from the Rappahannoc at
Fredericksburg, Va. It approaches nearest in out-
line to U. productus and ?iasatus, but cannot be easily
confounded with either.
UNIO RECTUS.
Plate XV.
DESCRIPTION.
Shell profoundly elongated, thick; anterior side
short; posterior side rostrated, cuneiform; extremity
angular, compressed; umbo inflated, but not promi-
nent, obtusely rounded; disks slightly contracted in
the middle; ligament margin nearly rectilinear; epi-
dermis dark green or olive-brown, smooth, frequently
with broad green rays; within pink in the middle;
cardinal teeth small, direct, double in each valve.
SYNONYMES.
U. rectus, Lam. An. sans vert. vol. vi. p. 74.
E
34
U. latissima, Raf. An. gen. des Sc. Phys. vol. 5. p. 31. Poul-
son's trans, p. 25.
U. PRiELONGirs, Barnes. Silliman's Jour. vol. vi. p. 261.
Cab. A. N. S.No. 1112.
OBSERVATIONS.
This shell resembles in outline U. ?iasutus, Say, U.
lanceolatus, Lea, and U. teres, Raf. With the latter
it has most affinity. It is a common western species,
found as far north as the Ouisconsin, and inhabits
the Alabama river near Claiborne. The figure was
taken from a fine male specimen in Mr. Poulson's
cabinet.
UNIO CRASSUS.
Plate XVI.
DESCRIPTION.
Male. Shell ovate, thick, yellowish, with brown
rays, obsolete inferiorly; umbo broad, flattened; beaks
obtuse, nearly terminal; umbonial slope angulated;
posterior side cuneiform; posterior dorsal margin
arcuate; basal margin dilated behind the middle; pos-
terior extremity angular; within salmon colour or
white, with a horn-coloured margin; cardinal teeth
direct, thick, very prominent, subtrifid.
Female. Shell oval quadrate, ventricose, posterior
side dilated; posterior margin widely truncated, di-
rect; umbo oblique and terminal.
M
Unio crass us
35
SYNONYMES.
U. crassus, Say. Nich. Enc. (Amer. ed.) art. Conch, pi. i. fig.
8. old male.
U. crassidens, var. c. Lam. An. sans vert. vol. vi. p. 71.
U. LIGAMENTINA, ib. p. 72.
U. ellipticus, Barnes. Silliman's Jour. vol. vi. p. 259. male.
U. suborbiculatus, Hildretli. Silliman's Jour. vol. xiv. female.
U. abruptus, Say. Amer. Conch, pi. 17, female, var. A. male.
U. cYCL^ps, Raf. Contin. of Monog. p. 2, female.
Cab. A. N. S. No. 358.
OBSERVATIONS.
Closely related to U.fasciatiis, Raf., but can be dis-
tinguished from that species by fewer and narrower
rays, generally distinct only over the umbones; by a
lighter coloured more polished epidermis; more pro-
minent teeth, and the prevalence of a salmon co-
loured interior. Common in the rivers of Ohio,
Indiana, and Illinois, but appears to be rare in the
more southern states. I could not find it in the
rivers of Alabama. The specimen figured was pre-
sented by Dr. Blanding.
UNIO VIRIDIS.
Plate XVII.— Fig. 1.
DESCRIPTION.
Shell elliptical or subovate, ventricose, thin; disks
slightly flattened anteriorly, much inflated over the
umbonial slope; lines of growth prominent; ligament
margin elevated; posterior slope dilated; posterior
36
extremity truncated, direct; epidermis with green
rays, obsolete anteriorly, distinct and very unequal
posteriorly; umbo slightly prominent; beaks with an-
gular furrows, pointed; within white, iridescent; car-
dinal teeth compressed, oblique, that of the left valve
double or trifid; lateral teeth of the left valve imper-
fectly divided.
SYNONYME. •
U. viridis, Raj. An. gen. des Sc. Phys. vol. v. p. 27. Poulson's
trans, p. 19.
Cab. A. N. S. No. 2105.
OBSERVATIONS.
The first specimen of this species which came
under my observation, was found in the Schuylkill
river, near Philadelphia, by Mr. Hyde, who kindly
offered me the use of it, as I supposed it to be unde-
scribed. Comparing it, however, with a single valve
from the Kentucky river, in Mr. Poulson's cabinet,
it proved to be of the same species with that speci-
men which was labelled viridis by Ratine sque. Mr.
Hyde has received specimens from a small stream
near Lancaster, and from the Juniata river. One
from the latter locality has been selected for the figure
and description. It is allied to U. heterodon, but can-
not be confounded with that species.
f?
i. bum viTtdiSjRxLf. Z.Unt'i ocfiva.ce.us, Say.
UNIO OCHRACEI
Pi
DES
oil el! I, thin
■
sen un>
•uperior mar
not oblique; umbo ml tenor exi
igular; umboni;
jundly arcuate: phite,
■ ■ •. ■
A. i
rosac
SYNON
-eus, Say. Nich. Enc. (Am
>; :
OBSE]
common in the
n& inhabits most tide s nori an-
er. Variety A. is very abundant in Jai
irginia, where I found vast numb
i -here by seines us-
37
UNIO OCHRACEUS.
Plate XVII.— Fig. 2.
DESCRIPTION.
Shell elliptical, inflated, thin; epidermis smooth
and polished, rugose posteriorly, yellowish, with nar-
row green unequal rays; anterior side narrowed, and
the superior margin elevated and connate; ligament
margin not oblique; umbo inflated; posterior extre-
mity angular; umbonial slope angular; basal margin
profoundly arcuate; within white, rarely pale rose or
salmon; cardinal teeth very oblique, much compressed,
bifid in the right valve; single or imperfectly divided
in the left; lateral teeth arcuate.
Var. A. Reddish brown; rays obsolete or want-
ing; within rosaceous.
SYNONYMES.
U. ochraceus, Say. Nich. Enc. (Amer. ed.) art. Conch, pi. ii.
fig. 8.
Symphynota ochracea, Lea. Trans. Amer. Philos. Soc, new
series, vol. iii. p. 69.
Var. A. Mytilus fluviatilis, Gmel. Lister, tab. 157. fig. 12.
Cab. A. N. S. No. 1063.
OBSERVATIONS.
Very common in the Schuylkill and Delaware
rivers, and inhabits most tide waters north of Savan-
nah river. Variety A. is very abundant in James
river, Virginia, where I found vast numbers of shells
brought ashore by seines used in the shad fishery in
38
the month of March. So accurately does the above
mentioned variety agree with Lister's figure and de-
scription, that I cannot doubt the identity. The
species is, perhaps, most closely allied to U. cariosus,
its common associate in the Delaware and Schuylkill.
The specimen figured has a double cardinal tooth in
each valve.
UNIO NASUTUS.
Plate XVIIL— Fig. 1.
DESCRIPTION.
Shell elongated, compressed, thin; disks slightly
flattened; anterior side short; posterior side rostrated,
tapering, angular at the extremity; umbo not promi-
nent; beaks small, eroded; umbonial slope profoundly
oblique, angulafed; ligament margin rectilinear, ele-
vated; posterior superior margin profoundly oblique
and slightly concave; within bluish, iridescent, rarely
purple or salmon; cardinal teeth compressed and
oblique, double in each valve.
SYNONYMES.
U. nasutus, Say. Nich. Enc. (Amer. ed.) art. Conch, pi. iv.
fig.l.
U. rostrata, Valenc.
Lister, tab. 151. fig. 6.
Cab. A. N. S.No. 1123.
OBSERVATIONS.
A common species in the tide waters from Florida
m
^%^~,
39
to the eastern states. I found it in great abundance
in the Potomac river, near Washington, where the
specimens are exceedingly elongated. The smaller
specimen figured is a female variety from James
river, Virginia, where they are generally ornamented
with rays; the other figure represents a rare purple
variety from Chester river, Maryland: it is in the
cabinet of Mr. Phillips. In old shells the teeth are
often thick and direct.
UNIO ICTERINUS.
Plate XVIIL— Fig. 2.
DESCRIPTION.
Shell elliptical, moderately thick; anterior margin
regularly rounded; posterior margin descending ob-
liquely, and subtruncated at the extremity; umbo not
prominent; summit decorticated; umbonial slope very
oblique, angulated; epidermis smooth and polished,
olive yellow; within salmon coloured; cardinal tooth
in the left valve trifid, in the right, single.
SYNONYME.
U. icterinus, Nob. New fresh water shells, p. 41. pi. vi. fig. 5.
Cab. A. N. S. No. 2106.
OBSERVATIONS.
I found the species in the Savannah river, at Au-
gusta. It resembles U. lanceolatus in epidermis and
colour. Its proper place, we think, is between nasu-
tus and declivis, Say.
40
UNIO CARIOSUS.
Plate XIX.
DESCRIPTION.
Shell subovate, ventricose, thick anteriorly; epider-
mis yellowish or straw coloured, very smooth and
polished, with a few narrow dark green rays poste-
riorly, more numerous on the posterior slope; umbo
prominent, decorticated; umbonial slope angulated;
ligament margin elevated; ligament prominent; basal
margin swelling posteriorly; within white; cardinal
teeth double in each valve, prominent, oblique.
SYNONYMES.
U. cariosus, Say. Nich. Enc. (Amer. ed.) art. Conch, pi. iii.
fig. 2. female.
U. luteola, Lam. An. sans vert. vol. vi. p. 79.
U. ovatus, Valenc.
Cab. A. N. S. No. 1022.
OBSERVATIONS.
This is one of the most abundant species in the
tide waters of the middle states, but I found it com-
paratively rare in the Potomac and James rivers. In
varieties of form it much resembles U. crassus, and
both male and female are represented, in order to
convey a clear idea of sexual differences, which are
so striking in a large proportion of the species. It
is very often destitute of rays, and I have seen only
one specimen in which the rays extended over the
disk to the anterior margin.
/?
..'•- s, i
'10
' m" miffiloides, HMfin-eMtu.
41
UNIO MYTILOIDES.
Plate XX.
DESCRIPTION.
Shell elevated, subtriangular; epidermis reddish-
brown, with crowded wrinkles; posterior side with a
broad furrow; anterior side gibbous; umbo tapering,
curved, narrowed at the summit, which is much ele-
vated; lunule obtusely cordate; within white, purple,
and iridescent towards the posterior extremity; car-
dinal teeth large, very thick, prominent, sulcated;
posterior muscular impressions impressed, the smaller
one profoundly.
SYNONYMES.
U. mytiloides, Raf. Ann. gen. des Sc Phys. vol. v. p. 47. pi. 82.
fig. 8. Poulson's trans, p. 53.
U. rubra, Raf.
U. pyramidatits, Lea. Trans. Amer. Philos. Soc, new series,
vol. iv. p. 109, pi. xvi. fig. 39.
U. caridiacea, Say of Guerin.
Cab. A. N. S. No. 2017.
OBSERVATIONS.
This common species, since its first discovery in
the western waters, has always been known by the
name we have adopted. It is nearly allied to U. cor,
Nob., and U. undatus, Barnes, but is very distinct,
although its varieties are intricate and perplexing.
Young specimens are very short and greatly elevated,
and frequently rayed; old shells are compressed, cu-
42
neiform, and produced posteriorly; the rays confined
to the umbo and obsolete. Inhabits the Alabama
and Black Warrior rivers.
<
UNIO DILATATUS.
Plate XXI.
DESCRIPTION.
Shell ovato-elliptical, thick and ponderous, slightly
sinuous; posterior side produced, compressed, cunei-
form; umbo broad, flattened, summit obtusely round-
ed; anterior lunule large, elliptical; umbonial slope
angulated, not very distant from the margin; basal
margin slightly contracted near the middle; within
obliquely sulcated from the umbo towards the poste-
rior basal margin; colour purple, with a bluish mar-
gin; cardinal teeth thick, direct; lateral teeth very
thick, and terminating rather abruptly.
SYNONYMES.
U. dilatatus, Ruf. Ann. gen. des Sc. Phys. vol. v. p. 31. Poul-
son's trans, p. 25. Say, Amer. Conch. No. 6. Ferr. Mag. de
Zool.
U. nasutus, Lam. An. sans vert. vol. vi. p. 75.
U. gibbosus, Barnes. Silliman's Journ. vol. vi. p. 262.
Cab. A. N. S. No. 1072.
OBSERVATIONS.
In outline this species approaches U. fasciolaris,
but "differs in the much less dilated cardinal plate, in
having the anterior [posterior] smaller muscular im-
Zi
I 'did (1 ilnl rtl u.s, Rn\~iiie,Y(H'<-
%%
Unit) tuherr-til ut us: ' KaJ.
■ ■
43
pression situated immediately beneath the tip of the
lamelliform teeth, in having the anterior [posterior]
lunule much more depressed, with slightly elevated
lines crossing the wrinkles."* It also differs in hav-
ing a purple interior, varying from an intense shade
of that colour, approaching an indigo blue, to a pale
reddish-purple. The great thickness of the superior
portion of the shell causes the cavity of the umbo to
be very shallow.
Common in the tributaries of the Ohio, Upper
Mississippi, and Missouri. In Alabama, I found it
only in the Tennessee and its tributaries. It is a
common species in the mountainous region of North
Carolina and Virginia, where, from a poverty of cal-
careous matter, it is always comparatively small.
U. cuprea and U. atroviolacea, Raf., appear from the
descriptions to be mere varieties of V. dilatatus.
UNIO TUBERCULATUS.
Plate XXII.
DESCRIPTION.
Shell subquadrangular, convex, thick; disk covered
with irregular tubercles, except towards the anterior
margin; tubercles largest near the centre of the disk;
anterior margin obtusely rounded; posterior margin
direct, emarginate; anterior lunule elliptical, profound;
umbo narrow, very prominent; beaks pointed, ap-
proximate, but generally eroded or worn in maturity;
* Say. Ainer. Conch, pi. 22.
44
umbonial slope angulated; basal margin arcuate; epi-
dermis green olive, with green capillary rays over
the umbo; within chocolate colour; cardinal teeth
very large, direct, prominent, trifid in the right valve;
cavity of the beak very profound.
SYNONYMES.
U. tuberculatus, Raf. Ann. gen. des Sc. Phys. vol. v. p. 42.
Say. Amer. Conch. No. 6. Ferr. Mag. de Zool.
U. verrucosus, Barnes. Silliman's Journ. vol. vi. p. 125, pi. 5,
fig. 6.
U. tuberculosa, Valenc.
Cab. A. N. S. No. 1430.
OBSERVATIONS.
Some varieties of this species closely resemble U.
bulletins exteriorly, but independent of other charac-
ters, the chocolate coloured interior, which, though
sometimes pale, never wholly disappears, will at once
distinguish the present species from all its congeners.
It is a very variable shell; some specimens from the
Harpeth river, Tennessee, being much dilated and
compressed, and the ligament margin so much ele-
vated as to give the posterior side an alated appear-
ance. Other specimens are far more elevated in
proportion to their length, and the posterior sulcus
and emargination profound. These great differences
may be sexual characters, but require an anatomical
investigation of the animal to settle that point.
Common in the western rivers, and inhabits Lake
Erie and the Ouisconsin, according to Mr. Barnes.
It is not found in Alabama south of the Tennessee
river and its tributaries.
•a
LUrtiii deelivtx, Say.X.TZBtandinaianug, Lea
Lthmnn L'Vitro] IMI'
45
UNIO DECLIVIS.
Plate XXIII.— Fig. 1.
DESCRIPTION.
Shell trapezoidal, moderately thick; anterior mar-
gin obtusely rounded; beaks slightly elevated, with
oblique undulations; hinge margin rather elevated
and compressed, angulated at tip; posterior margin
rectilinear, descending obliquely to a prominent ros-
trum of the posterior basal margin at the extremity of
the umbonial slope; umbonial slope abruptly rounded,
and bounded on its posterior side by two slightly im-
pressed lines; basal margin arcuate; surface deeply
wrinkled; within tinged with purplish; cardinal teeth
oblique; lateral teeth distant from the cardinal teeth.
SYNONYMES.
U. declivis, Say. Trans. Journ. vol. iv. p. 527, Amer. Conch.
pi. 35.
U. geometricus, Lea. Trans. Amer. Philos. Soc. new series,
vol. v. p. 38, pi. 4, fig. 10.
Cab. A. N. S. No. 1875.
OBSERVATIONS.
This species resembles a variety of the complanatus
in its general form, and its teeth and posterior angle
are somewhat similar to those ofnasutus. It is very
distinct from either. The figure is from a fine speci-
men which I found in a small creek in Greene county,
Alabama, where the species is abundant, but usually
more compressed than the one I have selected for
representation. I was unable to find a specimen in
46
any of the large rivers. It is common in Bayou
Teche, Louisiana, and has been found in the Ohio
canal near Louisville, whence Mr. Hyde has received
it.
UNIO BLANDINGIANUS.
Plate XXIII.— Fig. 2.
DESCRIPTION.
Shell subtrapezoidal, rather thin, ventricose; ante-
rior margin very obtusely rounded; ligament margin
much elevated, slightly arcuate, angulated at tip, pos-
terior margin long, oblique and rectilinear; extremity
subtruncated or obtusely rounded; beaks slightly ele-
vated, eroded; umbonial slope rounded, very distant
from the margin; epidermis finely wrinkled; within
purplish, with green stains; cardinal teeth small, single
in the right valve and compressed; widely bifid, and
rather obtuse in the left; lateral teeth distant from
the cardinal teeth, and arcuate; anterior muscular
impressions marginal.
SYNONYME.
U. blandingianus, Lea. Trans. Amer. Philos. Soc. new series,
vol. v. p. 101, pi. xv. fig. 44.
Cab. Ji. N. S. No. 1859.
OBSERVATIONS.
A species allied to complanatus and declivis, but
differing from both in the elevated ligament margin
and inflated disks. The anterior lunule resembles
%}
'-X.
I mo JieT.ronattt* <faif.
■ . yj> ...
47
that of the preceding species. It was obtained in
East Florida, from an Indian, by Dr. Blanding, and
to this worthy naturalist the species has been pro-
perly dedicated.
UNIO PERSONATUS.
Plate XXIV.
DESCRIPTION.
Shell sublenticular; length rather more than the
height; anterior margin forming with the basal mar-
gin a regular curve to the termination of the umbo-
nial slope; posterior side narrowed; posterior margin
subtruncated; umbo rounded, very prominent, subme-
dial; umbonial slope swelling near the base, gaping
and denticulate on the margin; epidermis with nu-
merous capillary rays, profound and undulated on
the posterior side; within pink; cardinal teeth direct,
thick, prominent; lateral teeth slightly recurved; cavity
of the beak not profound.
SYNONYMES.
U. personatus, Say. New Harmony Disseminator, p. 309, 1829.
U. capillaris, Lea. Trans. Amer. Philos. Soc. new series, vol.
v. p. 29, pi. 2, fig. 2, 1832.
Cab. A. N. S. No. 1382.
OBSERVATIONS.
It would seem from the observations of Dr. Kirt-
land, that all those Uniones which have the peculiar
denticulated and dilated base, are female shells; and
48
if so, we arc unacquainted with the male personatus.
The exterior somewhat resembles V. Icevigatus, and
the cardinal teeth are very like those of U. nexus;
Say's description applies only to the immature shell.
For the use of the splendid specimen here represented
and described, we are indebted to G. W. Feather-
stonhaugh, Esq., who procured it from Cumberland
river, Tennessee. Mr. Say's specimens were from
the Wabash.
UNIO CORDATUS.
Plate XXV.
DESCRIPTION.
Shell subtriangular, not oblique, length and height
nearly equal; beaks distant from the anterior margin,
prominent, incurved and pointed; anterior lunule very
broad and obtusely obovate, beneath which is a flat-
tened cordate space with the opposite margin recti-
linear; inferior portion of the anterior margin regu-
larly rounded to the middle of the basal margin,
which is emarginate and ascending posteriorly; sinus
of the posterior side not oblique, slightly arcuate;
posterior margin rounded above, angulated at its
junction with the basal margin; epidermis fuscous,
with green interrupted rays over the umbo; within
white.
SYNONYME.
U. cordatus, Raf. Ann. gen. ties Sc. Phys. vol. v. p. 46. Poul-
son's trans, p. 52.
Cab. A. N. & No. 2018.
Z5
i in,) r o rda l n.Y, A' f/ fin i' .vii uf .
Z6
I nio n irirr'' R nj
49
OBSERVATIONS.
I formerly supposed this shell a variety of myti-
loides, but the differences are so constant in a great
number of specimens, that it may be useful to intro-
duce it to conchologists by the name which Rafinesque
has bestowed upon it. It differs from mytiloides in
not being oblique, in being about as long as it is high,
in having the beaks distant from the anterior margin,
and never in any stage of growth having the poste-
rior side prolonged obliquely downwards.
Inhabits the Ohio and its tributaries. The speci-
men figured belongs to the cabinet of Mr. Feather-
stonhaugh, and is from Cumberland river, Tennessee.
It connects U. mytiloides with 77. imdatus.
UNIO NIGER.
Plate XXVI.
DESCRIPTION.
Shell elliptical; with age, subovate, or subtriangu-
lar; thick and ponderous; disks somewhat flattened;
posterior lunule with short, oblique, vermicular raised
lines; posterior side compressed, cuneiform; umbo
broad, flattened, summit obtusely rounded; umbonial
slope angulated; epidermis reddish-brown, frequently
rayed; within purple or salmon colour; cardinal teeth
direct, prominent; lateral teeth thick, distant from
the cardinal teeth; posterior muscular impression
slightly impressed; cavity of the beak shallow.
G
50
SYNONYMES.
U. niger, Raf. Ann. gen. des Sc. Phys. vol. v. p. 25. Poul-
son's trans, p. 15. Say. Amer. Conch. No. 6. Ferr. Mag. de
Zool.
U. crassidens, var. b. Lam.
U. cuneatus, Barnes. Silliman's Journ. vol. vi. p. 263.
Cab. A. N. S. No. 2400, 2401, 2402.
OBSERVATIONS.
In the observations on U. congarceus, I compared
that species with the niger, but however the young
of both may resemble each other exteriorly, the car-
dinal teeth of the latter are always more robust and
less oblique, and the interior very often dark purple,
which is never the case with the congarceus. It dif-
fers most obviously from U. dUatatas, in being com-
paratively much shorter, and in the raised lines on
the posterior lunule.
Common in the western streams, and very abun-
dant in the Black Warrior and Alabama rivers. In
Detroit river, Michigan, it has been obtained by Dr.
Sager.
UNIO GIBBOSUS.
Plate XXVII.— Fig. 1.
DESCRIPTION.
Shell subovate, oblique, with a submedial nodulous
ridge projecting at base; concentric sulci very dis-
tinct; posterior side with a wide furrow; umbonial
slope angulated; umbo prominent; posterior end and
%'l
'■-..:•:••■•
Cth-.
51
posterior basal margin emarginate; epidermis smooth,
shining, yellowish with numerous green rays; within
white, rarely rose coloured.
SYNONYMES.
U. gibbosus, JRaf. Ann. gen. des Sc. Phys. vol. v. p. 49. Poul-
son's trans, p. 56.
U. torulosus, Raf. lb. p. 48. Poulson's trans, p. 56.
U. perplexus, Lea. Trans. Amer. Philos. Soc. new series, vol.
iv. p. 122, pi. 17, fig. 42.
Cab. A. N. S. No. 1051.
OBSERVATIONS.
Besides its affinity with the preceding species, this
shell has a general resemblance to three others, with
none of which, however, can it be confounded by
those who are familiar with the subject; these are
V.Jtexuosus, U. Phillipsii, and U. refiexus.
Common in the Wabash and Scioto, and I have
found it in the Tennessee river, at Florence, Alabama,
but not farther south. The female may be readily
distinguished by the dilated margin, which is more
profound in this species than in any other.
UNIO GIBBOSUS.
VARIETY PEROBLIQ.UUS.
Plate XXVII.— Fig. 2.
OBSERVATIONS.
This is perhaps a mere variety of U. gibbosus, Raf.,
but it is much more oblique, the beaks nearer the
52
anterior extremity, the posterior basal emargination
much less profound, and the central tubercles are
obsolete; in outline it closely resembles U. obliquatus,
but that species is always of a purple colour within,
though the tint is sometimes pale.
Inhabits the Wabash river, Indiana, and Detroit
river, Michigan.
UNIO TERES.
Plate XXVIII.
DESCRIPTION.
Shell narrow — elliptical, subcylindrical, moderately
thick; umbo slightly prominent; summit obtusely
rounded; umbonial slope abruptly rounded, submar-
ginal; posterior side produced, cuneiform; epidermis
yellowish and polished, rarely rayed; within white or
pale salmon colour; cardinal teeth double in each
valve, subcompressed, very erect; lateral teeth distant
from the cardinal teeth.
SYNONYMES.
U. teres, JRof. Ann. gen. des Sc. Phys. vol. v. p. 55. Poulson's
trans, p. 68.
U. anodontoides, Lea. Trans. Amer. Philos. Soc, new series,
vol. iv. p. 91, pi. viii. fig. 11.
Cab. A. N. S. No. 1S83.
OBSERVATIONS.
A well characterized species, approaching the rec-
tus in outline, but is comparatively shorter and emi-
U/d
_\ I- fin' (errs, Accf.
53
nently distinguished by the peculiarity of its pale
epidermis. The sexes are well marked by difference
of outline.
Not uncommon in the Western rivers, and in Bayou
Teche, Louisiana, where it is ornamented with pale
green rays. In the Alabama river it is partial to a
muddy bed, and rare on the bars.
I have figured a specimen in Mr. Poulson's cabinet,
brought from the west and labelled by Rafinesque.
UNIO SAGERI.
Plate XXIX.— Fig. 1.
DESCRIPTION.
Shell narrow — elliptical, moderately thick on the
anterior and thin on the posterior side; disks slightly
contracted from beak to base, causing the basal mar-
gin to be slightly sinuous; anterior side short, margin
regularly rounded; posterior side produced, somewhat • ,
pointed, extrem||| obtuse; ligament margin elevated; XUf-
umbo not prominent, flattened; umbonial slope round-
ed; within bluish-white and iridescent; cardinal tooth
in the right valve thick, direct, divided at the summit
by a deep groove; in the left valve widely bifid, with
a submedial lamelliform elevation; lateral teeth com-
pressed.
OBSERVATIONS.
This interesting species was found in Detroit river,
Michigan, by Dr. Abraham Sager, of Detroit, to whom
t
54
I have a pleasure in dedicating it. The outline of
a young specimen is very similar to a variety of V,
dilatatus, but the thinness of the shell, colour of in-
terior, and particularly the form of the teeth, will
readily distinguish it. The old shell might perhaps
be mistaken for a variety of the U. rectus, but the
young has very little resemblance to that of the latter.
U. dilatatus is found in company with this species,
retaining all the peculiarity of habit which it pos-
sesses in the Ohio and other tributaries of the Missis-
sippi, which confirms our opinion that the shell we
described above is new and distinct.
UNIO LAPILLUS.
Plate XXIX.— Fig. 2.
DESCRIPTION.
Shell suboval, thick, yellowish, with very numerous
, dark green undulated rays; anterior jnargin not very
short, rounded; beaks but little elevated, simple; liga-
ment margin declining gradually in an arcuate line;
posterior extremity rounded; umbonial slope unde-
fined; basal margin straight or slightly contracted in
the middle; within pearly white; cardinal teeth direct,
thick; lateral teeth thick, oblique; cicatrices very deep
and rounded; cavity of the beaks almost obliterated.
SYNONYMES.
U. lapillus, Say. Trans. Journ. of Med. vol. iv. p. 528, Amer.
Conch, pi. 41.
?Q
y
•
iV'rvia iSaaerij C. &.u.l<LpLUii$,Sa.ii
m
-30
/
'.<-> -truijil is. i. ■! ,
55
U. fabalis, Lea. Trans. Amer. Philos. Soc. vol. iv. p. 96, pi. x.
fig. 16.
Cab. A. N. S. No. 2404.
OBSERVATIONS.
Mr. Say observes that "the robust teeth and the
thickness of the whole shell have induced many, and
myself amongst the number, to consider this shell as
the young of gibbosus, Barnes, [dilatatus, Raf.] but a
very slight examination serves to show that it is very
distinct. The young of that species is always much
more elongated transversely, not so thick, with the
beaks much undulated," &c.
It is usually smaller than the specimen represented,
and, except the aciitissimus, is the least of North
American Uniones yet described. Dr. Sager found
it in Detroit river, Michigan, and it is not uncommon
in the Ohio and its tributaries. The figure repre-
sents a fine specimen, of more than ordinary size,
which we owe to the politeness of Professor J. Green.
UNIO FRAGILIS.
Plate XXX.
DESCRIPTION.
Shell ovate, thin, fragile, somewhat inflated over
the umbonial slope; disks flattened towards the base;
hinge margin elevated into a large wing, connate;
within bluish and highly iridescent; cardinal teeth
very oblique, compressed, disposed to be single in
each valve; lateral teeth arcuate.
56
SYNONYMES.
U. fragilis, Raj. Ann. gen. ties Sc. Phys. vol. v. p. 29. Poul-
son's trans, p. 22. Say, Amer. Conch. No. 6.
U. gracilis, Barnes. Silliman's Journ. vol. vi. p. 174.
U. fragilis, Swains.
Symphynota gracilis, Lea. Trans. Amer. Philos. Soc. new se-
ries, vol. iii. p. 66.
Cab. A. N. S. No. 1657.
OBSERVATIONS.
Allied to U. alatas, but is longer in proportion,
thinner, and lighter coloured in the interior and epi-
dermis. In some localities the wing is small, but in
others generally elevated.
Found by Mr. Schoolcraft in Fox river; it inhabits
the Detroit river, Michigan, lakes, and the western
rivers generally, and I found it common in the Ala-
bama at Claiborne.
UNIO ALATUS.
Plate XXXI.
DESCRIPTION.
Shell triangular, ovate, moderately thick; disks
flattened anteriorly, and inflated over the umbonial
slope; anterior side narrow, margin obliquely recti-
linear above; posterior side profoundly dilated, and
rising into an elevated connate wing; umbo oblique,
inclined, not prominent; posterior lunule with two
subangulated lines; umbonial slope regularly rounded;
wing emarginate inferiorly; posterior end biangulated;
■v
X
Into a La- 1 us, tSau.
3Z
X;v,
. ^--.
( ,m, ijif lulus
57
epidermis dark green-olive, wrinkled; wrinkles lamel-
liform posteriorly; within reddish-purple, iridescent;
cardinal teeth direct, double in each valve; lateral
teeth arcuate.
SYNONYMES.
U. alatus, Say . Nich. Enc, Am. ed., art. Conch.
U. (metaptera) megaptera, Raf. Ann. gen. des Sc. Phys., vol.
v. p. 299.
Symphynota alata, Lea. Trans. Amer. Phil. Soc, (new series,)
vol. iii. p. 448.
Cab. A. N. S. No. 20409.
OBSERVATIONS.
This well known species approaches a variety of
U. purpuratus, Lam., but is less inflated and has a
more elevated wing. From the fragilis it can be
distinguished by its larger size, dark epidermis, purple
nacre, thicker cardinal teeth, &c.
Inhabits Fox and Ouisconsin rivers, North- West
Territory, Mr. Barnes; Detroit river, Michigan, Dr.
Sager; western streams generally, and the great lakes.
It is extremely rare in South Alabama.
UNIO INFLATUS.
Plate XXXII.
DESCRIPTION.
Shell triangular, ovate, thin; contracted obliquely
from beak to base; inflated over the umbonial slope;
valves elevated into a small wing anteriorly and into
H
58
a broad high wing posteriorly, and connate in both;
posterior margin of the wing arcuate, and slightly
emarginate or angulated at base; beaks slightly pro-
minent; cardinal teeth single in both valves, and
lamelliform; lateral teeth arcuate, prominent towards
the extremity; nacre purple.
SYNONYMES.
Symphynota inflata, Lea. Trans. Amer. Phil. Soc, new series,
vol. iv. p. 99, pi. xiv. fig. 28.
U. Alabamensis, Nob. New Fresh Water Shells, p. 67.
Cab. A. N. S. No. 20405.
OBSERVATIONS.
Differs from U. (Symphynota) Icevissimus in the
inflated umbonial slope and more elevated wing. It
was discovered near Claiborne, Alabama, by Judge
Tait, and sent to Mr. Lea. I have since found it
very abundantly a few miles south of Claiborne, but
it is rare in the upper part of the Alabama and in the
Black Warrior rivers, and has not hitherto been found
elsewhere.
UNIO LEPTODON.
Plate XXXIII.
DESCRIPTION.
Shell narrow-elliptical, very thin and fragile, com-
pressed anteriorly, and slightly inflated over the um-
bonial slope; beaks very small, approximate; posterior
0 •_>
O.)
J--
/
Unto Lefttodortj Jttcf.
59
side produced, pointed; hinge margin elevated; pos-
terior margin very oblique, extremity acutely angular,
and much above the line of the base; basal margin
regularly arcuate; epidermis olive-yellow, with very
oblique narrow rays; within bluish, tinged with violet
above, highly iridescent; cardinal teeth obtuse, smooth,
nearly obsolete; lateral teeth single in each valve.
SYNONYMES.
U. leptodox, Raf. Ann. gen. des Sc. Phys., vol. v. p. 295.
Poulson's trans., p. 21. Say, Amer. Conch. No. 6. Ferr.
Mag. de Zool.
U. plaxus, Barnes. Silliman's Journal, vol. vi. p. 272.
Axodoxta purpurascexs, Swainson.
Symphyxota texuissima, Lea. Trans. Amer. Philos. Soc, (new
series,) vol. iii. p. 453, pi. xi. fig. 21.
Cab. A. N. S. No. 20406.
OBSERVATIONS.
This shell has an exterior much resembling that of
an Anodonta, but the teeth are generally sufficiently
developed to constitute it a true Unio. It is allied
to V.fragilis, but differs widely in the teeth, in being
pointed posteriorly, and in not being alated. It is
connate when perfect.
Inhabits the Ouisconsin, Mr. Barnes. I found a
single specimen in Alabama. The specimen figured
is from the Scioto river, and was presented by Dr.
William Blanding.
60
UNIO ELLIPSIFORMIS.
Plate XXXIV. —Fig. 1.
DESCRIPTION.
Shell elliptical, slightly ventricose, produced pos-
teriorly, moderately thick; disks slightly contracted
anteriorly; umbonial slope rounded; beaks slightly
prominent, approximate, simple; basal margin dilated
posteriorly to the middle; within bluish; cardinal teeth
thick, direct.
OBSERVATIONS.
This species I have seen only in the cabinet of Mr.
John Phillips, who received it from Michigan. It is
very similar in outline to U. lienosus, but the short,
thick, direct teeth, simple beaks, and bluish nacre,
form a very distinctive character.
UNIO LIENOSUS.
Plate XXXIV.— Fig. 2.
DESCRIPTION.
Shell elliptical, inflated, slightly furrowed or con-
tracted from beak to base; substance of the shell
thickened towards the base; posterior dorsal and
posterior basal margin rounded, extremity subangu-
lated; beaks pointed, approximate, slightly prominent,
/
2.
Unto elUj>.?ifoTm.is,C Z. (f.li&no.iu*,(i.
61
with interrupted undulations; concentric lines promi-
nent; epidermis dark olive, obscurely rayed, wrinkled
on the margins; cardinal teeth double in both valves,
slightly compressed, oblique, striated; nacre varying
from bluish white to deep salmon or purple; cavity
most capacious under the umbonial slope.
SYNONYMES.
U. lienosus, Nob. Silliman's Journal, vol. xxv. p. 339, pi. 1,
fig. 4.
U. Nashvillianus, Lea. Trans. Amer. Phil. Soc, (new series,)
vol. v. p. 100, pi. xiv. fig. 43.
Cab. A. N. S. No. 20407.
OBSERVATIONS.
This shell is remarkable for inhabiting exclusively
the small streams, and is common in Greene county,
Alabama. It is a variable species, sometimes not
easily recognised, and the sexual distinctions are as
obvious as in U. siliquoideus. The colour of the in-
terior is remarkably inconstant, but a purple ap-
proaching to salmon is the most prevailing tint, and
the margin is bluish-white. The affinities are U.
parvus, Barnes, and V. glans, Lea, but it is much
larger than either, has very different beaks, and does
not inhabit the same waters with those species.
36
/. Unio stupfs. Leu Z. i. inter in edi'us; Conrad.
03
UNIO INTERMEDIUS.
Plate XXXV.— Fig. 2.
DESCRIPTION.
Shell suboval, compressed; disks flattened or slight-
ly furrowed from beaks to base, covered, except on
the posterior side, with small slightly elevated tuber-
cles, which are rib-shaped on the posterior slope;
umbonial slope not prominent, and rounded or sub-
angulated; posterior slope obtusely angulated; beaks
oblique, not prominent; ligament margin long, arcu-
ate; posterior margin direct, emarginate; within white;
cardinal teeth direct.
OBSERVATIONS.
Three specimens of this species were obtained by
Dr. S. Blanding, of Columbia, S. C, from Nolachucky
river, Tennessee, and were kindly submitted to my
inspection. They differ from the preceding in being
somewhat oblique, in having less prominent beaks, a
wider posterior slope, but particularly in being desti-
tute of tubercles anteriorly. From the metancvra it
is easily distinguished by the want of a swelled um-
bonial slope. It is so evident a link between these
two species, that I have given it the name of inter-
medins, suggested by my friend Mr. John Phillips.
In a young specimen which I have figured, the epi-
dermis is covered with small crowded angular green
spots, but in the old shell they disappear. The latter
becomes distinctly angulated or furrowed on the pos-
64
terior slope, and profoundly emarginate posteriorly,
as represented in the outline, fig. 3.
UNIO OCCIDENTALS.
Plate XXXVI.— Fig. 1.
DESCRIPTION.
Shell elliptical, convex, anterior margin very regu-
larly rounded; anterior dorsal margin elevated; basal
margin straight and parallel with the ligament mar-
gin; posterior margin oblique, extremity rounded;
umbonial slope undefined; beaks slightly prominent,
with undulated grooves; summit rounded; epidermis
yellowish, with narrow green rays, which are obso-
lete or wanting on the anterior side; within bluish;
cardinal teeth direct, prominent, acute; lateral teeth
lamelliform.
OBSERVATIONS.
This shell has an outline similar to that of U. com-
planatus. It differs from that species in its yellow
epidermis, the peculiarity of its rays, more elevated
anterior margin, lamelliform lateral teeth, &c.
Inhabits Currant river, Arkansas, whence it was
brought by Mr. Featherstonhaugh, to whose kindness
I owe the use of this and several rare and beautiful
species.
36
z
I. I'nin Occidentffli-i; C- &>. I'- Collittun, Con.
On sin.eiifT.AT..
65
UNIO COLLINUS.
Plate XXXVL— Fig. 2.
DESCRIPTION.
Shell elliptical, rather thin, with coarse concentric
lines; umbonial slope rounded; posterior side slightly
produced, and rapidly narrowed to the extremity,
which is rounded; basal margin straight near the
middle; beaks small, slightly prominent, approximate,
undulated; umbones with two or three small tubercles
posterior to the middle; epidermis yellowish-brown,
obscurely rayed; within white or pale rose colour;
cardinal teeth oblique, robust.
Cab. A. N. S. No. 20408.
OBSERVATIONS.
This species may readily be known by the small
tubercles on the umbones. The female, when young,
closely resembles U. heterodon in outline, but the usual
formation of the lateral teeth and the tubercles emi-
nently distinguish it. Inhabits North river, a branch
of James river, Virginia, where it was found by Mr.
Constant Newkirk, of Washington College, from
whom I received three specimens.
66
UNIO SOWERBIANUS.
Plate XXXVIL— Fig. 1.
DESCRIPTION.
Shell ovate, convex, with concentric furrows; disks
slightly gibbose in the middle; posterior side with a
furrow from beak to base; a slight groove on the pos-
terior submargin; raised radiating lines extend from
the angle of the larger furrow to the posterior extre-
mity, which is direct and slightly retuse; basal margin
retuse posteriorly; epidermis glabrous, with faint fili-
form brown rays; within purple or rose colour; car-
dinal teeth very large and prominent, double in each
valve.
SYNONYME.
U. sowerbianus, Lea. Trans. Amer. Phil. Soc, new series, vol.
v. p. 68, pi. x. fig. 28.
OBSERVATIONS.
The fine specimen of this beautiful and very distinct
species which I have figured, was kindly loaned for
the purpose by Mr. Featherstonhaugh, who procured
it from Cumberland river, Tennessee. I found one
in the summer of 1833 on the bank of Elk river,
Alabama, and judging from Mr. Lea's figure of the
pileus, I supposed it to be that species.* The speci-
men is in the cabinet of Mr. Poulson.
The Sovjerbianus is remarkable for its highly po-
lished epidermis and raised lines on the posterior side.
* New Fresh Water Shells, p. 69, note.
si
67
UNIO POLITUS.
Plate XXXVII.— Fig. 2.
DESCRIPTION.
Shell suborbicular, convex, with slight concentric
furrows; anterior margin obtusely rounded; posterior
margin nearly direct; ligament margin rectilinear,
slightly declining; umbonial slope rounded; disks flat-
tened or very indistinctly furrowed posteriorly; basal
margin rounded, or slightly gibbous in the middle;
epidermis glossy, with fine concentric wrinkles; umbo
prominent, smooth and polished, with dark green
interrupted rays; within white; cardinal teeth thick,
very direct.
SYNONYMES.
U. politus, Say. Amer. Conch., No. 6.
U. subrotundus, Lea. Trans. Amer. Phil. Soc, new series, vol.
iv. p. 117, pi. xviii. fig. 45.
Cab. A. N. S. No. 20409.
OBSERVATIONS.
Related to U. Kirtlandicus, Lea, from which it dif-
fers in being proportionally more elevated and much
less compressed. It is also a smaller species. The
name of subrotundus has necessarily been abandoned,
as it is preoccupied for a different species.
08
UNIO NEXUS.
Plate XXXVIII.— Fig. 1.
DESCRIPTION.
Shell triangular, sub-rhomboidal, much inflated,
thick; umbo prominent; posterior slope much de-
pressed, with a broad, shallow groove, which extends
from the beak to the posterior margin; posterior
margin forming nearly a right angle with the base,
obtusely emarginate in the middle by the termination
of the groove; umbonial slope carinated, in conse-
quence of the depression of the posterior side; lunule
very short; epidermis yellowish-brown, obsoletely ra-
diated; within white; cardinal teeth direct; lateral
teeth short, with but little obliquity.
SYNONYMES.
U. nexus, Say. Trans. Journ., vol. iv. p. 527, 1831. Amer.
Conch., pi. li.
U. arceformis, Lea. Trans. Amer. Phil. Soc, new series, vol.
iv. p, 116, pi. xvii. fig. 44.
Cab. A.N. S. No. 20410.
OBSERVATIONS.
Mr. Say remarks that this species is "related to
triqueter, Raf., but differs in the greater prominence
of the superior portion of the anterior [posterior]
margin." There is also a great difference in the
teeth and in the markings of the epidermis, which in
the nexus are filiform rays, but in the triqueter gene-
rally sagittate spots. Not uncommon in the Cumber-
■VI
'..-
1. Vnio nein.r, li'ay. Z. V. Grecnci. (fonrad
C9
land river, and it seems chiefly confined to the waters
of Tennessee — I saw none in Alabama. The figure
is from a specimen in the cabinet of Mr. Feather-
stonhaugh.
UNIO GREENII.
Plate XXXVIII.— Fig. 2.
DESCRIPTION.
Shell sub-triangular; disks slightly flattened; ante-
rior side not very short, margin rounded, not very
obtuse; umbo flattened, not elevated; beaks eroded;
umbonial slope straight, subangulated; ligament short,
ligament margin forming with the posterior margin a
nearly regular arcuate line; extremity obtusely round-
ed or subtruncated; basal margin slightly arcuate;
epidermis wrinkled on the margins, with narrow
green rays on the posterior slope and interrupted
rays on the umbo; within white; cardinal teeth slightly
oblique; lateral teeth oblique and very slightly curved.
SYNONYME.
U. greenii, Nob. New Fresh Water Shells, p. 32, pi. iv. fig. 1.
Cub. A. N. S. No. 20413.
OBSERVATIONS.
Dedicated to my friend Jacob Green, M. D., Pro-
fessor of Chemistry in Jefferson College, a gentleman
well known as a contributor to Conchology. Inhabits
the head waters of Black Warrior river, Alabama;
not uncommon.
70
UNIO SHEPARDIANUS.
Plate XXXIX.
DESCRIPTION.
Shell profoundly elongated, sinuous, compressed,
tapering to the posterior extremity, which is trun-
cated; valves rather thin, with concentric lines, pro-
found over the umbonial slope, which is slightly ele-
vated; a carinated line passes between the umbonial
slope and posterior dorsal margin; beaks very small,
hardly raised above the dorsal line; within purple;
lateral teeth long and rectilinear, somewhat dilated
or thickened near the anterior termination.
SYNONYME.
U. shepardianus, Lea. Trans. Amer. Phil. Soc, new series, vol.
v. p. 95, pi. xiii. fig. 38.
Cab. .&. N. S. No. 20411.
OBSERVATIONS.
This is perhaps the most elongated, proportionally,
of any known Unio, except the Grayanus, and differs
chiefly in this respect from U. angustatus, which is
the species most nearly related to it.
Inhabits Alatamaha river, near Hopeton and Da-
rien, Georgia.
QC
39
Unio jShebardicmua, l.rtf .
71
UNIO COMPRESSUS.
Plate XL.— Fig. 1.
DESCRIPTION.
Shell oblong or elliptical; disks flattened; anterior
margin regularly rounded; umbonial slope slightly
elevated, rounded; beaks undulated, not prominent,
distant from the anterior extremity; ligament margin
elevated, connate; posterior margin oblique, recti-
linear, extremity truncated and slightly projecting
beyond the line of the base; epidermis ochraceous,
with numerous unequal green rays, some of which
are very broad; within white, tinged with pale salmon
under the beaks; cardinal tooth scarcely double in
the right valve, very oblique, elongated, rather thick;
in the left valve widely trifid, compressed, posterior
lobe rather behind the apex.
SYNONYMES.
U. compressus, Deshayes.
Symphynota compressa, Lea. Trans. Ainer. Phil. Soc, (new
series,) vol. iii. p. 450, pi. xii. fig. 22.
Cab. A. N. S. No. 1098.
OBSERVATIONS.
This species can at once be distinguished from all
others by the peculiarity of its hinge. It inhabits
the Ohio, Scioto, and Wabash rivers; also Oak Orch-
ard creek, in the State of New York, and Norman's
Kill, near Albany. The figure is from a specimen
which I found in a mill pond at the village of Adams,
72
Jefferson county, New York, where the species is
extremely abundant.
UNIO CAPS^EFORMIS.
Plate XL. — Fig. 2.
DESCRIPTION.
Shell sub-oval, slightly ventricose, moderately
thick; posterior side flattened or very slightly grooved;
umbonial slope obtusely angulated; basal margin
rounded medially, straight or slightly emarginate
posteriorly; posterior extremity direct, truncated,
narrowed, slightly produced; summits obtusely round-
ed, not prominent; epidermis yellowish, with nume-
rous narrow unequal green rays; within white; cardi-
nal teeth very erect and prominent.
SYNONYME.
U. capsjEformis, Lea. Trans. Amer. Philos. Soc, new series,
vol. iv. p. 143, pi. ii. fig. 4.
Cab. A. N. S. No. 20414.
OBSERVATIONS.
Inhabits Cumberland river near Nashville, Tennes-
see. I have found it in the Tennessee river at Flo-
rence, Alabama. It bears a slight resemblance to
the young of U.flexuosus, and is a very distinct spe-
cies. The female is represented in figure 3. Be-
tween the sexes the difference in outline is greater
than in any species with which we are acquainted,
except U. gibbosus, Raf.
40
I I nio c om hrcssuv. Z. V.c'ap#cefoTmi.<i,Lea. 3. female.
41
•
/ Unio xubhlanu* C. J . V-flavus, Kaf.X
73
The two fine specimens figured belong to the
splendid collection of Mr. Poulson. They were sent
from Nashville, Tennessee.
UNIO SUBPLANUS.
Plate XLI. — Fig. 1.
DESCRIPTION.
Shell sub-oval; disks flattened; anterior margin
regularly rounded, obliquely descending; umbonial
slope rounded; posterior slope dilated; beaks not pro-
minent, distant from the anterior extremity; ligament
margin elevated, slightly oblique; posterior extremity
truncated; epidermis yellowish-brown, with numerous
fine concentric wrinkled lines; within pale rose colour;
cardinal teeth oblique; lateral teeth rectilinear.
Cab. A. N. S. No. 20412.
OBSERVATIONS.
I have recently received several specimens of this
shell from Lexington, Rockbridge county, Virginia,
where they were found by Mr. Newkirk in a branch
of the James river. Approaches U. Masoni, but is
more compressed and elongated, and cannot be con-
founded with it.
K
74
UNIO FLAVUS.
Plate XLL— Fig. 2.
DESCRIPTION.
Shell sub-triangular, moderately thick; disks flat-
tened on the posterior side; anterior margin obtusely
rounded; ligament margin oblique, rectilinear; poste-
rior margin wide, straight, nearly direct; extremity
obtuse; basal margin straight from the posterior ex-
tremity to beyond the middle; umbonial slope cari-
nated; umbo rather prominent; beaks flattened, with
a few obtuse oblique undulations; within salmon
colour; cardinal and lateral teeth large and very pro-
minent.
SYNONYMES.
U. flava, Ttf. Ann. gen. des Sc, vol. v. p. 59. Poulson's
trans., p. 38.
U. rubiginosits, Lea. Trans. Amer. Phil. Soc, new series, vol.
iii. p. 41, pi. viii. fig. 10.
Cab. A. N. A'. No. 1126.
OBSERVATIONS.
This shell is so distinctly described and even figured
by Rafinesque, that no honest inquirer can refuse
him credit for the species. He remarks that he found
"it only in the small rivers falling into the Kentucky,
Salt or Green rivers." This peculiarity of habitat
is remarkable, and I was unable to find a specimen
in either the Alabama, Tombeckbe, or Black Warrior
rivers, although several were found in a small mill
stream in Greene county, Alabama. Rafinesque re-
4x
capaic, Green.,
75
marks that the "young shells are almost yellow, and
the animal of a deep or orange-yellow colour," which
accords with my own observation. I do not, how-
ever, consider the colour of the animal any safe guide
in specific distinction, as I have found the same spe-
cies, particularly V. decisas, to contain in some spe-
cimens an orange coloured, and in others a perfectly
white animal.
UNIO CAPAX.
Plate XLIL
DESCRIPTION.
Shell very globose; valves rather thin, translucent,
connate; umbones tumid, summit obtusely rounded,
prominent, distant from the anterior margin; epider-
mis straw colour, polished, with two faint green rays
on the posterior slope; within white and iridescent;
cardinal teeth lamellar, prominent, double in the right
valve, crenate and single in the left; lateral teeth
arcuate.
SYNONYMES.
U. capax, Green. Cab. of Nat. Hist, vol. ii. p. 290. 1832.
Symphynota globosa, Lea. Trans. Amer. Phil. Soc, new series,
vol. iv. p. 153, pi. iv. fig. 12. 1834.
Cab. A. N. S. No. 1227.
OBSERVATIONS.
The most ventricose of all the Unios known, and,
when young, one of the most delicate and beautiful.
76 ,
It most nearly resembles U. cardium, Raf., but the
tumid umbones will always prove a di$tf/)btf(fi cha-
racter. Dr. Green was the first to recognise this as
an undescribed species, and his name, having priority,
must necessarily be adopted. He observes, "I now
describe a fine large shell, which seems to have
escaped the notice of our conchologists. The first
specimens of this shell which I observed were from
the Falls of St. Anthony. I afterwards received it
from the Bayou Teche, but I never discovered or
ascertained that it exists in the Ohio." Mr. Lea, on
the authority of Col. Long, informs us that it inhabits
the Ohio, 150 miles below Louisville, Ky.
UNIO RUDIS.
Plate XLIII.— Fig. 1.
DESCRIPTION.
Shell ovate-acute, thick anteriorly; diameter great-
est at the umbones; beaks eroded; posterior side
cuneiform; ligament and posterior margins arcuate,
extremity subangulated; epidermis brown, wrinkled
inferiorly; within white; cardinal teeth small, direct;
lateral teeth slightly arcuate.
SYNONYME.
U. ravenelianus, Lea. Trans. Amer. Phil. Soc, new series, vol.
iv. p. 144, pi. iii. fig. 5.
Cub. A. N. S. No. 20415.
OBSERVATIONS.
Inhabits French Broad river, North Carolina, Dr.
, f /■■!• : an. ''. V. ail :'«"■>: !■"■»
77
Ravenel. I found it in the upper part of the Black
Warrior river, Alabama, where it is rare.
Resembles U. pcrovatus in outline, but the shell is
far greater in diameter through the umbones, and the
beaks nearer the anterior extremity. The most
striking character, perhaps, is the accurate wedge-
shaped form of the posterior side. Mr. Lea first
published this species under the name of Ravenclianus,
but as I had previously published a different species
with the same name, I am compelled to substitute
another.
UNIO OBLIQUUS.
Plate XLIII.— Fig. 2.
DESCRIPTION.
Shell ovate-rotundate, oblique; disks with a slight
narrow furrow on the posterior side; umbonial slope
carinated; posterior slope with an obtuse carinated
line; ligament and posterior margins arcuate; posterior
extremity obliquely truncated; beaks very prominent,
curving forward; lunule sagittate; within white; car-
dinal teeth directed obliquely backwards; lateral teeth
arcuate; cardinal plate much thickened under the
cardinal teeth, contracting the cavity of the umbo.
SYNONYMES.
U. OBLiquA, Lam. An. sans Vert, vol. vi. p. 72. Ferus. Mag.
de Zool.
U. ebenus, Lea. Trans. Amer. Phil. Soc, new series, vol. iii.
p. 94, pi. ix. fig. 14.
Cab. Ji. N. S. No. 1259.
78
OBSERVATIONS.
Inhabits the Black Warrior and Alabama rivers,
where I found it in abundance; also the Ohio and its
tributaries.
The ovate form of this species and its obliquity
will distinguish it at a glance from undatus, Barnes.
The young is remarkable for being of yellow colour
behind the umbonial slope, which soon disappears in
general as the shell increases in size.
Mr. Lea appears to be ignorant of the true distinc-
tive character of this species, since he affirms that I
have published it under the name of mytiloides; the
latter is destitute of the callosity of the cardinal plate
which characterizes the obiiauus, has a very different
lunule, and is dissimilar in outline to that species.
Those who are conversant with the two shells will
not confound them.
Mr. Lea considers the obliqua of Lamarck to be
identical with undatus of Barnes, but Lamarck's de-
scription is wholly inapplicable to the latter, whilst
it agrees with the ebenus of Lea, with which it is
identical, according to Ferussac.
UNIO APICULATUS.
Plate XLIV.— Fig. 1.
DESCRIPTION.
Shell subquadrate, compressed; summits not very
prominent; hinge margin declining; disks with a dilat-
ed not deeply impressed furrow; umbonial slope
//
Mi v¥ -v <M
I [/mo afuriil at u .$•, l?cm %>.[/, bras inujtj > on.
>y
79
arcuate, carinated; posterior margin dilated, direct,
produced, and rounded or subtmncated at base; disks
covered with small subequal tubercles, arranged more
or less in symmetrical lines; within white.
SYNONYMES.
U. apiculatus, Say. Disseminator, 1829. American Conch.
pi. 52.
U. asper, Lea. Trans. Amer. Phil. Soc, new series, vol. iii. p.
95, pi. ix. fig. 15, 1832.
Cab. A. N. S. No. 1877.
OBSERVATIONS.
Inhabits the Alabama river, near Claiborne, where
I found specimens, but they were not numerous nor
comparable in beauty to those which inhabit Bayou
Teche in Louisiana.
Mr. Say thinks this may prove to be a variety of
U. quadrulus, but although it is nearly related to that
species we believe it to be very distinct. Old shells
become proportionally more elongated and produced
at the posterior extremity of the basal margin, and
the tubercles nearly disappear on the inferior half of
the disks. The figure is from a specimen from Bayou
Teche.
UNIO PRASINUS.
Plate XLIV.— Fig. 2.
DESCRIPTION.
Shell suborbicular, compressed, with distant con-
centric impressed lines; anterior margin obtusely
80
rounded; posterior margin wide, direct; basal margin
straight, parallel with the ligament margin; summits
rather prominent; disks smooth, with a few very
small tubercles on the posterior side; epidermis olive-
yellow, very broadly rayed with green; within white.
SYNONYMES.
U. prasinus, Nob. New Fresh Water Shells, p. 44. May, 1834.
U. schoolcraftensis, Lea. Trans. Amer. Phil. Soc, new series,
vol. iv. p. 149, pi. iii. fig. 9. Sept. 1834.
Cab. Jl.N. S.No. 1128.
OBSERVATIONS.
Inhabits the Scioto river, Indiana.
The specimen of this shell in the cabinet of the
Academy of Natural Sciences was brought by Mr.
Schoolcraft from Fox river, of Green Bay — others
are in the collection of Mr. Hyde. The species differs
from II. bulletins, Raf., in being of a suborbicular out-
line, more compressed, with much less prominent
beaks and fewer tubercles. Some specimens have a
few rather large tubercles near the base.
UNIO NODULATUS.
Plate XLV.— Fig. 1.
DESCRIPTION.
Shell suborbicular, slightly ventricose, moderately
thick; posterior margin direct, retuse in the middle;
ligament margin straight, elevated, scarcely declining;
disks with two scries of distant prominent tubercles;
ti
mzz>
■
Y r.vnio , iiaj z i iullai us, a af
81
posterior slope dilated, with nodules towards the
margin; beaks slightly elevated, granulate at tip;
epidermis olive-brown and rather smooth; within
white; cardinal teeth large and prominent; lateral
teeth subrectilinear.
SYNONYMES.
U. nodulata, Ruf. Ann. gen. des Sc. Phys. , vol. v. p. 41, pi.
lxxxi. figs. 17, 18. Poulson's translation, p. 42. Say. Amer.
Conch., No. 6. Ferrus. Mag. de Zool.
U. pustulatus, Lea. Trans. Amer. Phil. Soc, new series, vol.
iv. p. 79, pi. vii. fig. 9.
Cab. Ji. N. S., No. 1755.
OBSERVATIONS.
Inhabits the Ohio river and its tributaries. It is
related to U. bidlatus and U. Mortoni. From the for-
mer it differs in the regularity of its tubercles, in the
dilatation of the posterior slope, and in the absence
of the broad green ray on the umbo. From the latter
it may be distinguished by the same characters, and,
in addition, by the want of a broad depression or
furrow, which characterizes U. Mortoni. Rafinesque's
outlines of this shell, though rude, are characteristic
enough; and his description, though short, perfectly
clear and applicable to this species only.
82
UNIO BULLATUS.
Plate XLV.— Fig. 2.
DESCRIPTION.
Shell elevated, equilateral, inflated, irregularly tu-
berculated on the middle and posterior slope; medial
tubercles generally large; substance of the shell thick;
beaks elevated and granulated at tip; ligament slope
descending, short; posterior margin direct, nearly
straight; epidermis bright brown, a single broad in-
terrupted green ray passes from the apex to the middle
of the disk; within white; lateral teeth very short,
straight, thick and oblique.
SYNONYMES.
U. bullata, Raf. Ann. gen. des Sc. Phys., vol. v. p. 41. Poul-
son's trans., p. 43.
U. verrucosus albus, Hild. Silliman's Journ., vol. xiv. p. 289.
U. pustulosus, Lea. Trans. Amer. Phil. Soc, new series, vol.
iv. p. 76, pi. vii. fig. 7.
Cab. A. N. 3., No. 1175.
OBSERVATIONS.
Inhabits the Ohio and its tributaries, Alabama and
Black Warrior rivers. This common species is
easily recognised, and will be found to differ con-
stantly from U. prasinus by its more elevated and
ventricose form and more numerous tubercles. It
wants the furrow of the Mortoni, and is besides dis-
tinguished by its green ray and larger tubercles.
The white colour of the nacre is remarkably constant,
83
as I have never found it to vary in a great number
of specimens, which is seldom the case in most other
species. A variety is remarkably abundant in the
Black Warrior river, at Erie, Alabama.
Mr. Say has referred this species to V. ?iodiilosus,
Wood, but the figure of that shell in Wood's Con-
chology appears to me to represent a very different
species.
UNIO STEGARIUS.
Plate XL VI.— Fig. 1.
DESCRIPTION.
Shell elevated, ovate; valves thick, with concentric
furrows and ridges; disk with a narrow, not deeply
impressed furrow from beak to base; umbo and beaks
inclining forward; lunule large, ovate-acute, very dis-
tinct; beaks pointed and incurved; umbonial slope
carinated over the umbo; epidermis yellowish-brown,
with crowded, fine, green dotted rays, and broad
rays, composed of large dots; posterior margin direct;
within white; cardinal plate greatly dilated; cardinal
teeth direct, deeply sulcated; muscular impressions
small.
SYNONYMES.
U. stegaria, Raf. Ann. gen. des Sc. Phys., vol. v. p. 46.
Poulson's translation, p. 51. Say, Amer. Conch., No. 6.
Ferr., Mag. de Zool.
U. irroratus, Lea. Trans. Amer. Phil. Soc. , new series, vol.
iii. p. 269, pi. v. fig. 5.
Cab. A. N. S., No. 1122.
84
OBSERVATIONS.
Inhabits the Ohio, Scioto, Wabash, and more
rarely the rivers of Tennessee. I have not observed
it so far south as the Tennessee river, in Alabama.
It is a very beautiful species, remarkable for its very
numerous dotted rays and its regular and graceful
outline, which approaches that of U. retusus.
UNIO DROMAS.
Plate XLVL— Fig. 2.
DESCRIPTION.
Shell obliquely ovate; disks flattened above, and
with a very prominent concentric angular ridge in
the middle; a slight furrow from beak to base on the
posterior side; beaks prominent, summit rather wide,
flattened; lunule angular; epidermis yellowish-brown,
with very numerous green interrupted capillary rays,
and a few broad rays; within white; cavity shallow.
SYNONYME.
U. dromas, Lea. Trans. Amer. Phil. Soc, new series, vol. v.
p. 182, pi. x. fig. 29.
Cab. A.N S., No. 20416.
OBSERVATIONS.
Inhabits Harpeth and Cumberland rivers, Tennes-
see; Elk river, near the muscle shoals, Alabama. I
have not found it further south.
My father, many years since, received this elegant
46
3 r>, •' o <£rom as, Lea
85
species from Harpeth river, Tennessee. It cannot
be confounded with U. stegarius, in consequence of
its remarkable gibbose disk. The rays are more
strongly marked than those of the latter species; the
disk is never tuberculated, whilst the stegarius is
sometimes covered with tubercles, as Mr. Lea has
stated in his remarks upon the dromas. A single
valve in my cabinet measures about four inches from
beak to base.
UNIO SUBTENTUS.
Plate XLVIL— Fig. 1.
DESCRIPTION.
Shell oblong-suboval, very widely and slightly con-
tracted at base; summits hardly elevated, decorti-
cated, obtusely rounded; posterior basal angle a little
prominent, rounded; posterior dorsal slope with nu-
merous subramose, slightly arcuate, oblique, parallel
costs; epidermis with broad interrupted green rays,
sometimes obsolete; within reddish-fulvous; cavity of
the umbo not deep; cardinal teeth somewhat direct,
not transverse; lateral teeth slightly arcuate.
SYNONYME.
U. subtentus, Say. Jour. Acad. Nat. Sc, vol. v. p. 130.
Amer. Conch., pi. xv.
Cab. Ji. N. S., flo. 20417.
OBSERVATIONS.
Mr. Say observes, " in general outline, this shell
86
has some resemblance to U. purpureus, Nob.; but it
is distinguished by many characters, and more ob-
viously by the character of the anterior costated
margin. It is a native of South Carolina,* and was
sent to me by Professor Vanuxem, who obtained it
from the North Fork of the Holston river."
Dr. William Blanding presented me with specimens
from Nollichucky river, Tennessee, the largest of
which is nearly destitute of the posterior ribs. I
found a few dead shells on the bank of Elk river,
near the muscle shoals, Alabama.
UNIO ACUTISSIMUS.
Plate XLVIL— Fig. 2.
DESCRIPTION.
Shell narrow-elliptical; posterior side produced,
gradually narrowed to a point; valves thin; posterior
side with parallel furrows extending from the umbo-
nial slope to base; posterior slope with slightly arcuate
ribs and furrows; umbonial slope carinated; beaks
not elevated above the dorsal line; epidermis yellow-
ish, with green dotted rays; within yellowish, highly
polished, exhibiting the ribs of the exterior.
SYNONYME.
U. acutissimus, Lea. Trans. Amer. Phil. Soc. , new series, vol.
iv. p. 89, pi. x. fig. 18.
Cab. A.N. S.,No. 20418.
* Mr. Vanuxem informs me that he found it in Virginia.
47
-■■ \
)
,^y
.-■■'
t.ZTnio auJttentws, iSav. Z.l aeutixsimite.JLeu 3.1 com a dins. Lea,.
87
OBSERVATIONS.
Inhabits the Alabama and Black Warrior rivers:
rare.
This is one of the smallest species of Unio, and
resembles the young of the conradius, but is much
more elongated. Mr. Lea observes that the lateral
teeth are single in each valve; but the specimens be-
fore me have the usual form of a divided tooth in the
left valve. The epidermis is marked with pale green
zig-zag lines, and the furrows on the disk are some-
times obsolete or wanting. I found two fine indi-
viduals at the village of Erie, Greene county, Ala-
bama, on a bar in the Black Warrior river.
UNIO CONRADIUS.
Plate XLVIL— Fig. 3.
DESCRIPTION.
Shell elliptical, basal margin straight or slightly
emarginate; ligament margin slightly declining; valves
rather thin, with undulations on the posterior side,
sometimes obsolete; posterior slope with arcuate
ribs; beaks very slightly prominent and undulated,
decorticated; epidermis finely wrinkled, yellowish-
brown, with numerous green rays; within inclining
to salmon colour; very iridescent and furrowed pos-
teriorly.
SYNONYME.
U. conradius, Lea. Trans. Amer. Phil. Soc, new series, vol. v.
p. 63, pi. ix. fig. 23.
Cab. JL N. S., No. 20419.
88
OBSERVATIONS.
Inhabits Flint river, Alabama, near its junction
with the Tennessee river, and is common in the
vicinity of Nashville, Tennessee. This small species
is related to U. sabtentus, but is very obviously dis-
tinct. It is proportionally shorter than the acutissimus,
and has more obvious beaks, but young individuals
much resemble the latter species, as may be observed
in fig. 4. In some specimens the posterior undula-
tions are large and profound, in others more nume-
rous and not so distinct.
UNIO INTERRUPTUS.
Plate XLVIII.
DESCRIPTION.
Shell subtriangular, disks flattened; umbones broad,
flattened, summits obtusely rounded; posterior slope
much depressed; umbonial slope abruptly rounded,
nearly terminal; epidermis brownish-yellow, wrinkled,
except on the umbo; rays numerous, narrow, inter-
rupted, of a dark olive colour; on the umbonial and
posterior slopes consisting of series of small quad-
rangular spots; within white; cardinal and lateral
teeth very robust; anterior and posterior muscular
impressions deeply impressed.
SYNONYMES.
U. interrupta, Jiaf. Ann. gen. des Sc. Phys., vol. v. p. 36.
Say. Amer. Conch., No. 6. Ferr. Mag. de Zool.
U. brevidens, Lea. Trans. Amer. Phil. Soc, new series, vol.
iv. p. 75, pi. vi. fig. 6.
Cab. A. N. S., No. 1114.
48
V inttrTu,btu. 8, Rfffivt-sifUe .
49
LU.hlixiis.i'. Z. (fhete.ro t£tm, !.»<£■ 3.V.aanstriotus} Conrtl<£.
89
OBSERVATIONS.
Inhabits Cumberland river near Nashville, Ten-
nessee, and Elk river, near the muscle shoals, Ala-
bama.
In outline it somewhat resembles Unio lineolatus,
but more nearly approaches the penitus. The rays,
very wide umbo, and the proportionally shorter out-
line distinguish it from the latter species. The lower
figure represents the female.
UNIO PLEXUS.
Plate XLIX.— Figs. 1, 2.
DESCRIPTION.
Shell suboval, ventricose; posterior margin trun-
cated or obtusely rounded; posterior slope with nar-
row ribs; umbo flattened, with longitudinal undula-
tions; umbonial slope subangulated; beaks eroded,
not prominent; epidermis nearly black, wrinkled;
within purple; cardinal teeth direct; anterior muscular
impression very rough.
Cab. A. N. &, No. 20421.
OBSERVATIONS.
This species was sent from Vera Cruz by the
American consul, Dr. Marmaduke Burrough. I am
unacquainted with its habitat. The larger speci-
men, of which an outline is given on the plate, much
resembles U. niger, but the undulations on the urn-
bones, the proportional length in the smaller speci-
M
90
men, and other characters, render it sufficiently
distinct. It has, perhaps, more general resemblance
to Unio trapezoides than to any other species.
UNIO HETERODON.
Plate XLIX.— Fig. 3.
DESCRIPTION.
Shell rhomboidal-ovate, ventricose, valves thin;
ligament margin short, elevated, parallel with the
basal margin; umbonial slope rounded; beaks decor-
ticated; basal margin straight in the middle; posterior
extremity rounded or very obtusely angulated, a little
above the line of the base; within bluish; cardinal
tooth in the left valve trilobed; in the right valve,
single, elongated, oblique, compressed; lateral teeth
slightly curved, double in the right valve.
SYNONYME.
U. heterodon, Lea. Trans. Amer. Phil. Soc, new series, vol.
iii. p. 428, pi. viii. fig. 11.
Cab. A. N. St., No. 20425.
OBSERVATIONS.
Inhabits the Schuylkill and other rivers in Penn-
sylvania. This interesting little species was first
found by Messrs. Mason and Hyde, and my father
suggested the name of heterodon, which Mr. Lea has
adopted. It is related to V. viridis and compressus,
but the double cardinal teeth being in the right valve
will distinguish it from every other species.
91
UNIO LIENOSUS.
VARIETY CONSTRICTUS.
Plate XLIX.— Fig. 4.
DESCRIPTION.
Shell elliptical, ventricose; beaks rather prominent,
undulated, distant from the anterior margin; posterior
side furrowed, contracted at base; posterior angle
much above the line of the base; epidermis obscurely
rayed; within white; cardinal teeth robust.
Cab. A. N. S., No. 20423.
OBSERVATIONS.
Inhabits North river, Rockbridge county, Virginia.
Several specimens of this variety exhibit the peculiar
groove on the posterior side, which has suggested the
name. . In other respects it agrees with U. lineosus
of the south-western streams, except that the cardi-
nal teeth are more robust.
UNIO STRAMINEUS.
Plate L. — Fig. 1.
DESCRIPTION.
Shell ovate, ventricose; disk with coarse prominent
lines of growth; umbo with numerous undulated plicae;
umbonial slope undefined; ligament margin elevated;
92
anterior side slightly contracted or furrowed from
beak to base; basal margin slightly emarginate; epi-
dermis straw-coloured, polished; within white; car-
dinal teeth double in each valve; lateral teeth slightly
arcuate.
SYNONYME.
U. stramineus, Nob. New Fresh Water Shells, pi. vii. fig. 3.
Cab. A. N. S.t No. 20420.
OBSERVATIONS.
Inhabits brooks or mill streams in Greene county,
Alabama.
This species may be compared to some varieties
of siliguoideus, but is sufficiently distinct, being desti-
tute of rays on the disk, and having remarkably
prominent lines of growth. The siliqaoideus has not
been found in Alabama.
UNIO PATULUS.
Plate L. — Fig. 2.
DESCRIPTION.
Shell ovate; convex anteriorly, and compressed
and cuneiform posteriorly; substance of the shell thick
on the anterior and thin on the posterior side; beaks
not terminal, prominent, undulated, almost contigu-
ous; umbonial slope undefined or obtusely rounded;
epidermis brownish-yellow, with broad interrupted
green rays composed of fasciculi of hair like lines;
within white; cardinal teeth, in the left valve pro-
so
X
y
>
j.U. straminevs, 6-. Z.l ' patnlu-s;Lca.
0 J
/"
-=sszr ; .•■ —
f/7w'w Hemieii, ('onrctfC.
93
foundly diverging; in the right valve single, robust,
sulcated; lateral teeth rectilinear.
SYNONYME.
U. patulus, Lea. Trans. Amer. Phil. Soc, new series, vol.iii.
p. 441, pi. xii. fig. 20.
Cab. A. N. S., No. 20424.
OBSERVATIONS.
Inhabits the rivers of Tennessee and Kentucky,
and appears to be comparatively rare. It may be
distinguished from U. clava by its less oblique and
more compressed form; and the beaks are less pro-
minent and not terminal. The beaks are acutely
pointed at the apex, and nearly touch each other;
and they are somewhat flattened on the summit and
have tubercular undulations. It is probable that U.
oviformis is but a variety of this species.
UNIO HEMBELI.
Plate LI. — Fig. 1.
DESCRIPTION.
Shell elliptical, convex, posterior extremity angular,
much above the line of the base; posterior slope with
obtuse undulations; beaks eroded, scarcely elevated
above the dorsal line; umbonial slope undefined; epi-
dermis dark brown, becoming black with age, much
wrinkled; within white; cardinal teeth robust, double
in each valve, direct, profoundly striated.
Cab. A. N. S., No. 20422.
94
OBSERVATIONS.
Many specimens of this shell was sent from New-
Orleans in company with the declivis, Mortoni, pur-
puratus, &c, but the locality was not given. It has
some affinity with the subtentas, but is thinner in sub-
stance, and differs widely in the posterior angle.
It is never rayed, whilst that species has well marked
interrupted rays. Some specimens which are desti-
tute of the undulations on the posterior slope might
be confounded with U. complanatus.
It is named in compliment to my friend William
Hembel, Esq., Vice-President of the Academy of
Natural Sciences of Philadelphia.
END OF VOL. I.
INDEX
Unio fasciatus,
OVATUS,
— CLAVA,
DECISUS,
— REFLEXUS,
FLEXUOSUS,
PHILLIPSII,
METANEVRUS,
MORTONI,
FRAGOSUS,
— COSTATUS,
• RETUSUS,
- PARVUS, -
GLANS,
SILIQUOIDEUS,
~ RADIATUS,
PECTOROSUS,
FASCIOLUS,
CONGARjEUS,
MASONI,
— COCCINEUS,
- CATILLUS,
PRODUCTUS,
LANCEOLATUS,
"-RECTUS, -
- CRASSUS,
- VIRIDIS,
~ OCHRACEUS,
-NASUTUS,
ICTERINUS,
- CARIOSUS,
- MYTILOIDES, -
» DILATATUS,
-TUBERCULATUS,
DECL1VIS,
*, BLANDINGIANUS,
PERSONATUS,
- CORDATUS,
PAGE.
PL.
FIG.
3
1
1
4
2
5
3
1
6
3
2
7
4
1
8
4
2
9
5
1
10
5
2
11
6
1
12
6
2
17
7
19
8
20
9
1
21
9
2
22
10
1
24
10
2
25
11
1
26
11
2
27
12
1
28
12
2
29
13
1
30
13
2
31
14
1
32
14
2
33
15
34
16
35
17
1
37
17
2
38
18
1
39
18
2
40
19
41
20
42
21
43
22
45
23
1
46
23
3
47
24
48
25
IV
PAGE. PL. FIG.
I-NIO NIGER, - - - - - - 49 26
r GIBBOSUS, - - - - - 50 27 1
PEROBLIQUUS, - - - - - 51 27 2
-teres, - - - - 52 28
SAGERI, - - - - - -53 29 1
LAPILLUS, - - - - 54 29 2
~ FRAGILIS, - - - - - 55 30
- ALATUS, - - - - - 56 31
inflatus, - - - - - 57 32
leptodon, - - - - - 58 33
ellipsiformis, - - - - - 60 34 1
lienosus, - - - - 60 34 2
stapes, - - - - - - 62 35 1
intermedius, - - - - 63 35 1
occidentals, - - - - - 64 36 1
collinus, - - - - 65 36 2
sowerbyanus, - - - - - 66 37 1
politus, - - - - 67 37 2
- nexus, - - - - - - 68 38 1
GREEN1I, - - - - - 69 38 2
shepardianus, - - - - - 70 39
compressus, - - - - 71 40 1
caps.eformis, - - - - - 72 40 2
subplanus, - - - - -73 411
- plavus, - - - - - -74 41 2
apax, - - - - - 75 42
RUDis, - - - - - - 76 43 1
obliquus, - - - - 77 43 2
apiculatus, - - - - - 78 44 1
- prasinus, - - - - - 79 44 2
"s nodulatus, - - - - - 80 45 1
- bullatus, - - - - - 82 45 2
- stegarius, - - - - - 83 46 1
*■ liROMAS, - - - - 84 46 2
subtentus, - - - - - 85 47 1
acutissimus, - - - - 86 47 2
conradius, - - - - - 87 47 3
— interruptus, - - - - 88 48
plexus, - - - - - - 89 49 1
heterodon, - - - - - 90 49 3
lienosus, - - - - - 91 49 4
stramineus, - - - - - 91 50 1
patulus, - - - - - 92 50 2
HEMBELI, - - - - 93 51 1
DESCRIPTION OF A NEW ANODONTA.
ANODONTA V1RGATA.
Description.
Shell subovate, thin and fragile, inflated; umbo prominent, distant
from the anterior extremity; beaks pointed, incurved, undulated; um-
bonial slope angulated; posterior margin arcuate, extremity angulat-
ed; basal margin dilated posteriorly; within bluish and iridescent;
cavity very capacious.
Observations.
This pretty Anodonta is related to A. undulata, Say, but can be
known by the posterior dilatation of the basal margin, which inclines
the outline to an ovate form, and by the rays, which are very numerous
and unequal, of a beautiful dark green, or the epidermis is green with
narrow pale rays, and much resembles Anodonta radiata, nob.; it is
comparatively shorter than that species.
This species was afforded me for description by Dr. Jacob Green,
Professor of Chemistry in Jefferson College. Mr. William Mason has
specimens from Buck Creek, Clarke county, Ohio.
Vr » v. DESCRIPTION OF A NEW ANADONTA.
^^ -\TTOtMrW.*] ANADONTA CARINIFERA.
Shell narrow, elliptical, compressed, thin and fragile; anterior side
narrow, rounded at the extremity; posterior side produced, subcunei-
form, truncated at the extremity; hinge margin long, straight, elevated
or slightly ascending, from anterior to the posterior extremity; beaks
not elevated above the dorsal line; basal margin straight in the middle;
colour of epidermis olive-green inferiorly, darker above; hinge margin
without a callous. Length, 2| inches; height, 1£ inch. Inhabits rivers
in Kentucky.
This species is in the fine collection of my friend Mr. John Phillips,
who informs me that it is from the Ohio or one of its tributaries below
Louisville. It has much the outline of Unio carinifera of Lam. (the
common variety of U. complanatus,) but is proportionally more elon-
gated, and the posterior extremity resembles that of Unio declivis,
except that it is truncated at the tip.
Unio gibbosus, var. perobliquus, pi. xxvii. fig. 2, 1 have ascertained
tQ be a species; it will therefore take the name of Unio perobliquus.
6%
U/i.f.o car-mv.x, Coiu*cc(£.
61
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S:-
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: \ v ~*-^
Into LattrarfUrtim, (l.
H
\ \ \\ 'r
, /
f. Unto #uM inflrftus, c. &.IT. atiffiisi <dus} Lea.
■> :J
55
lUnm e/rK.cullu,s,6on Z..U. pullus, (on,,.;
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