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A
DESCRIPTIVE CATALOGUE

OF THE

NAIADES, OR PEARLY FRESH- Divion of Moti
WATER MUSSELS ——:

BY
CHARLES TORREY SIMPSON
iy 433 Gy,

PART III

UNIONIDA:,
HARMANDIA — DIPLODON
MUTELIDA:

BRYANT WALKER
DETROIT, MICHIGAN
1914

MAY 0 3 1988

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DESCRIPTIVE
CATALOGUE OF THE NAIADES

PART III.
Division of Mothuiz
Sectional Library

Genus HARMANDIA Rochebrune, 1882.

Harmandia RocHEBRUNE, Bull. Soc. Phil., VI, 1882, p. 45.

Shell subtrapezoidal, subalate, rather thin, posteriorly com-
pressed, with low beaks and irregularly radial sculpture, a few
of the ribs converging at the center of the disk, the rest be-
coming divaricate and covering the shell, those of the poste-
rior slope springing from the rib on the low, posterior ridge;
epidermis gray-green; left valve with two arcuate, compressed,
elongate pseudocardinals in front and a triangular cardinal
under the beak, the right with two pseudocardinals in front and
a pit under the beak; there are two nearly straight, lamellar
laterals in each valve, and a small, up-curved lamella above
them near their posterior end; anterior muscle scars deep;
nacre white, brilliant, showing the outside sculpture.

Animal unknown.

Type, Harmandia somboriensis Rochebrune.

HARMANDIA SOMBORIENSIS Rochebrune.

Shell subrhomboid or imperfectly triangular, considerably
narrower in front, subcompressed, rather thin, inequilateral ;
beaks moderately elevated, somewhat pointed, their sculpture
apparently subradial; anterior end narrowly rounded, almost
pointed ; base line lightly curved, somewhat fuller behind the
middle; dorsal outline almost angled at the beaks, nearly
straight in front of and behind them; posterior slope obliquely

1050 HARMANDIA

truncate; posterior ridge low, ending behind in a feeble bian-
culation; surface sculptured with strong, irregular, subradial
ridges, which are heaviest on the middle of the disk ; epidermis
grayish-green ; anterior pseudocardinal of the left valve elon-
gated, convex, double; posterior subtriangular and connected
with the long straight laterals; right valve with two oblique,
lamellar pseudocardinals; each valve -with two long laterals
and an additional lamella branching and curving upward from
near their posterior ends; nacre pearly, shining.

Length 40, height 28, diam. 16 mm.

Rapids of Sombor-Sombor, Mekong.

Harmandia somboriensis ROCHEBRUNE, Bull. Soc. Phil., VI,
1882, p. 46, pl. 1, figs. I-3.—SiMpson, Syn., 1900, p. 827.—
Haas, Conch. Cab., Unio, 1912, pl. 31; fies:

A remarkable shell with very strong, subradial sculpture,
the heavy ribs in front of and behind the beaks coalescing be-
low. The upper lateral in each valve bifurcates near its pos-
terior end, the small upper part curving away from the main
lateral.

HARMANDIA CASTELNEAUL Rochebrune.

“Shell compressed, subovate, solid, brownish-gray ; above
straight ; below obliquely convex; anterior end short, nearly
straight, pointed, point obtuse, conic; posterior end expanded
in a broad, thin, compressed wing; surface radiating costate,
anterior ribs eight, straight, oblique, granular above; posterior
ribs five, wide, curved, laminated, set at an angle with those
of the anterior region; the interval between the ribs circularly
striate with heavy, undulating striz; cardinal tooth in the
right valve oblique, jagged; in left valve subexcavated ; ante-
rior lateral very short, nearly straight; median the longest,
subconcave, angulated: posterior short, straight; umbones
very short, eroded; nacre of a bluish lead-color, very brilliant.

Long. 52, lat. 32, crass. 12 mm.” (Rochebrune).

Type locality, Cochin China.

Harmandia castelneaui RocH¥eRuNE, Bull. Mus. Hist. Nat.,

1904, p. 139.

GRANDIDIERIA IO5I

Harmandta castelnaui Haas, Conch. Cab., Unio, 1912, pl. 31,

figs. 11-12.

“The Harmandia castelneaw differs from the somboriensis
by its slightly larger size and thicker valves; by its anterior end
not concave and almost oval, but short, straight, and with an
obtuse, conical point ; by its dorsal margin expanded in a large
angulated wing, not short and obliquely rounded ; by the great
number of ribs, the anterior ones narrow, straight, granulated,
reaching the ventral margin, and not squamose and broken
in the central part by a deep groove: the posterior ones
oblique, large, projecting, with large, imbricated scales, not
finely granulated; by the inter-costal space ornamented with
heavy, not fine, strize; by the right cardinal tooth being oblique
and deeply sulcate. not pyramidal and sulcate on the inner
side; by the lateral teeth, of which the anterior is very short,
almost straight and not concave, and the lower straight and
not as long as the median; and finally by the color of the nacre,
which is a very brilliant, bluish lead-color, not pure white.”

Haas, (1. c.), considers this a synonym of H. somboriensis.

Genus GRANDIDIERIA Bourguignat, 1885.

Grandidieria BourcuIcNAT, Bull. Soc. Mal. Fr., II, 1885, p. 6.

Shell small, oval, rounded or rhomboid, solid, much inflated,
generally narrowly biangulate behind, often apparently of two
forms, one more inflated in the basal and post-basal parts than
the other ; beaks high, curved forward and inward and pointed,
very delicately and beautifully sculptured with zigzag lire,
which become finely nodulous and sulcate on the disk, especi-
ally in front and behind; posterior ridge well developed, often
slightly double; hinge line curved; two pseudocardinals in
the right valve separated by a parallel-sided socket, one or
two in the left, with often an irregular, triangular, ragged
tooth under the beak, which is frequently reftexed; one ob-
liquely striate lateral in the right valve and two in the left;
nacre of peculiarly soft, rich texture, white, coppery, or pur-
plish, delicately radiate; beak cavities moderate; muscle scars
distinct.

Type, Unio burtoni Woodward.

1052 GRANDIDIERIA

A group of small Uniones, which seems to be confined to
Lake Tanganyika in Tropical Africa. Most of the species
have well marked, concentric sculpture which shows a ten-
dency to become wavy or zigzagged, and it often becomes
granulous. Quite commonly the pseudocardinals are reflexed
and considerably ragged. The group from conchological char-
acters seems to be closely related to the African species, which
I have placed in Parreysia.

I would not be surprised if, when the anatomy of the
Grandidierias is known, it may be found that all four gills of
the female contain embryos when gravid as, apparently, is the
case in Parreysia. The beak sculpture of many of the Quad-
rulas closely approaches that of the Endobranchie, and there
may be a sort of connection between Quadrula, Physunio,
Parreysia, Grandidieria and the Endobranchs in general.

KryY TO SPECIES OF GRANDIDIERIA.

Sheil nearly smooth, rayed. G. tanganyicensis.
Shell sculptured, rayless or nearly so.
Short elliptical, strongly sculptured. G. burton.
Ovate.
Rather short, biangulate behind. G. gravida.
Pointed behind. G. smitli, rothschildi, thomsont.

With full beaks, much drawn out behind, G. rhynchonella.
Narrowed and drawn out in front and behind, G. callista.
Decidedly rhomboid. G. bourguignati.

GRANDIDIERIA BURTONI (Woodward).

Shell short, elliptical, subsolid, inequilateral, convex or sub-
inflated; beaks small, moderately elevated, turned forward,
pointed, their sculpture appearing to be very faint corruga-
tions: posterior ridge low, rounded, having two feeble, raised,
radial ridges above it, ending in a blunt point about on the
median line; surface with three patterns of sculpture consist-
ing of irregular, concentric ridges, faint, radial impressions
and fine, chevron-shaped bars, which break up more or less
into nodules or granules; epidermis thin, pale brownish or

GRANDIDIERIA 1053

whitish, not shining; pseudocardinals somewhat split up; an-

terior scars impressed ; nacre silvery white to purple.

Length 26, height 18, diam. 14 mm.

Lake Taganyika.

Unio burtont Woopwart, Proc. Zool. Soc. Lond., 1859, p. 349,
pl. xiv, fig. 2—SoweErsy, Conch. Icon., XVI, 1866, pl.
XLVU, fig. 251.—SMmituH, Proc. Zool. Soc. Lond., 1881, p.
207, Pl SMV) f1SS:.33, 220.

Margaron (Unio) burtont Lea, Syn., 1870, p. 31.

Grandidieria burtont BourcuicNat, Bull. Soc. Mal. Fr., II,
1885, p. 6.—Srmpson, Syn., 1900, p. 828.

Grandidieria cyrenopsis BourGUIGNAT, Bull. Soc. Mal. Fr., II,
1885, p. 9, pl. 1, figs. 7-9; Icon. Mal. Tan., 1888, pl. x1x, figs.
1-3.

Woodward’s figure, which agrees well with shells in the
National Museum collection, shows this a short shell, a little
full in the post-basal region and very bluntly pointed. ‘The
epidermis is sometimes almost silky. The sculpture is some-
times quite faint. According to Smith the nacre varies from
white to coppery-purple.

Var. servainiana Bourguignat.
D D>

More circular in outline than the type, almost as high as

long, with stronger sculpture.
Lake Tanganyika.

Grandidieria servainiana Bourcuticnat, Bull. Soc. Mal. Fr.,
fi 1885) p: 6:

Umio burtoni var. servainiana von Martens, Besch. Deuts.
Ost-Af., 1897, p. 238.

Grandidieria burtoni var. servainiana SIMPSON, Syn., 19Q0, p.
828.

Var. insignis Bourguignat.

Almost equilateral, triangular, reminding one of the form
of Spisula solidissima; lower edge moderately rounded.
Lake Tanganyika.
Grandidieria insignis BourcuicnaT, Esp. Ouk. Tan., 1885, p.
16.

1054 CRANDIDIERIA

Unio burtomi var. insignis VON Martens, Besch. Deuts. Ost-

Af., 1897, p. 238.
Grandidieria burtomi var. insignis SIMPSON, Syn., 1900, p. 828.

Var. sturanyi (von Martens).

Shell more depressed and more convex than the typical
form: nacre yellowish-gray or reddish-gray, iridescent.

Lake Tanganyika.

Grandidieria STuRANY, Baumann, Durch Massailand, 1894, p.

6) pl. XXiV, fig. 31; xxv, fe 35,

Unio burtom var. sturanyi von Marrens, Besch. Deuts. Ost-

Ad., 1807, p. 228:

Grandidieria burtoni var. sturanyi SIMPSON, Syn., 1900, p. 828.

The above forms have, with one exception, never been fig-
ured, but are placed by von Martens under burtoni as varieties.
I know nothing about them but give them on his excellent
authority.

GRANDIDIERIA ‘TANGANYICENS!S (Smith).

Shell small, irregularly oval, solid, somewhat inflated and
inequilateral ; beaks full and high, turned inward and forward,
sculptured with fine, zigzag-radial corrugations; lunule indis-
tinct: anterior end narrowed and rounded; base line well
curved, a little fuller just behind the middle; posterior ridge
close to the dorsal line, narrowly rounded, the whole curved
slightly to a point behind on the median line; surface finely
and unevenly concentrically sculptured and often having traces
of radial sculpture; it is also more or less overlaid with deli-
cate granules arranged as if engine-chased; pseudocardinals
rather solid, ragged; nacre whitish, liver-colored or purplish,
sometimes coppery, often lighter on the border; epidermis
ereenish or ashy-brown, often densely rayed.

Length 24, height 18, diam. 12 mm.

Lake Tanganyika.

Unio tenganyicensis SmrrH, Proc. Zool. Soc. Lond., 1880, p.

351, pl. xxx, figs. 9, 9a; 1881, p. 208, pl. xxx1v, fig. 35.
Grandidieria tanganyicensis SIMPSON, Syn., 1900, p. 828.
Grandidieria tanganikana Bourcuicnat, Bull. Soc. Mal. Fr.,

{1, 188s; p. 7

GRANDIDIERIA 1055,

A neat little species, which seems to show considerable
variation. The specimen first figured by Smith is decidedly
rayed; another figured later by him in the P. Z. S. 1881, pl.
XXXIV, fig. 35, is rayless or nearly so. Four valves forming
two matched pairs of what I believe to be this are in the col-
lection of the National Museum and are formed exactly like
the figures of Smith and show a transition from the almost
smooth, rayed form, which is somewhat shining, to that which
is dull-colored, rayless and corrugated throughout. Specimens
from Ancey said to be labeled Unio hauttecauri by Bourguig-
nat are without doubt the above, and quite different from
Bourguignat’s species.

GRANDIDIERIA SMITHI Bourguignat.

Shell suboval, rather solid, subinflated or convex, inequilat-
eral; beaks moderately elevated, turned forward, with fine,
subradial, somewhat zigzag sculpture ; posterior ridge rounded,
ending in a decided but blunt point behind; above it are two
dark, slightly raised, radiating ridges; surface with concen-
tric, finely radial and zigzag, sub-nodulous sculpture; epider-
mis dull, pale brownish; pseudocardinals ragged; anterior
scars impressed; nacre whitish to coppery-purple, and often
lighter colored at the edge of the sheil.

Length 32, height 24, diam. 14 mm.

Lake Tanganyika.

Umio burtoni Smiru (part), Proc. Zool. Soc., 1881, pl. xxxrv.
fig. 334. |

Grandidieria smithi Bourcvicnat, Bull. Soc. Mal: Fr., II,
1885, p. 7—Simpson, Syn., 1900, p. 820. ;

Umno burtoni var. smithi von Martens, Besch. Deuts. Ost-Af..
1897, p. 238.

Grandidierta anceyi Bourcuicnat, Esp. Ouk. et Tan., 188s,
Peto con. Moll Lan) 1888. p43. plaxix, hes, 4-6.—
Simpson, Syn., 1900, p. 820.

T am inclined to think with Bourguignat, who separated this
from burtoni, that it is a valid species. A specimen in the
National Museum agrees very accurately with Smith’s figure

1056 GRANDIDIERIA

33a in the P. Z. S. referred to above, save that its beaks are
not quite so large as there figured. It seems to be a larger
shell and the hinder end is more decidedly drawn into a point,
and it is apparently a little solider than burton. By an error
Grandidieria anceyi was allowed to stand as a separate species
in the Synopsis. I do not know whether it or G. smithi has
precedence, both having been published the same year, but I
believe that they are the same.

GRANDIDIERIA GRAVIDA Bourguignat. |

Shell short, irregularly oval, subsolid, inflated, inequilateral ;
beaks rather high and pointed, turned forward, with zigzag-
radial sculpture; anterior end rounded, subangulate above;
base very full, especially behind the middle, but incurved in
front of the posterior point; posterior ridge narrowly double,
ending behind just below the median line in a narrowly bi-
angulate snout or beak; surface with zigzag-radial and well-
marked concentric sculpture; pseudocardinals somewhat elon-
gated, compressed, reflexed and cut into strongly marked
teeth; laterals rather ragged; nacre whitish or purplish.

Length 23, height 26, diam. 20 mm.

Lake Tanganyika.

Grandidieria gravida Bourcuicnat, Bull. Soc. Mal. Fr., IT,
1885, p. 7, pl. 1, figs. 1-6; Icon. Moll. Tan., 1888, p. 41, pl.
XVul, figs. [11-16.—SIMPSON, Syn., 1900, p. 820.

Grandidieria rostrata Bourcuicnat, Bull. Soc. Mal. Fr., II,
1885, p. 10, pl. 3, figs. 10-12; Icon. Moll. Tan., 1888, p. 41,
pl. xvi, figs. 17-10.

Unio rostralis von Martens, Besch. Deuts. Ost-Af., 1897, p.
238.

Grandidieria locardiana Bourcuicnat, Esp. Ouk., 1885, p. 18.
—SIMPSON, Syn., 1900, p. 830.—GrERMAIN, Moll. Lac Tang.,
1908, p. 682, figs. 31-32.

Shorter in proportion to length than G. tanganyicensis and
having more compressed, reflexed pseudocardinals. These, as
figured by Bourguignat, are remarkable and resemble to some
extent those of Lampsilis parva of the United States.

GRANDIDTERIA 1057

GRANDIDIERIA ROTHSCHILDI Neuville and Anthony.

“Shell subrotund, slightly longer than high, rounded in
front, slightly carinated and scarcely pointed posteriorly ; con-
centrically striate along the margin, above, at the umbones,
in the centre of the disk and on the posterior slope strongly
plicate; cardinal teeth usually small; anterior lamella thick
and plicate ; posterior oblong.

enethy27) heicht. 20 mins 9 CN & A.)

Type locality, Lake Rodolphe.

Unio (Grandidieria) rothschildi Neuvitin and ANTHONY,
Bull. Mus. Hist. Nat., 1906, p. 409; Bull. Soc. Philom., (9),
MIE 19060; p= 409; pli 12.

“This species, which is distinguished by its very strony,
bilateral inflation, belongs to the group of Unios from Tan-
ganyika that Bourguignat, relying on characters of very little
value, incorrectly thought should be referred to the family
Spheriide and for which he established the genus Gran-
didieria. It is related, moreover, to certain types of Unios
from Lake Victoria, such as Unio acumimatus Adams and U.
grandidier: Bet. Jt is, however, more closely allied to Unio
(Pareyssia) bakeri Adams or to Unio (Grandidieria) gravida
Bet. Much resembling the former by its general form, it
is distinguished by its shorter contour. and the more marked
accentuation of the folds, which extend more generally over
the surface than in that species. It differs from the second
(U. gravida Bet.) by being more pointed posteriorly. less
height compared with the length and stronger plications.”

GRANDIDIERIA THOMSONI (Smith).

Shell small, irregularly ovate, subinflated, inequilateral ;
beaks only moderately full or high, zigzag-wrinkled, rather
pointed; anterior end narrowed and rounded; base quite full
at or just behind the middle; from there to the posterior point
the outline is straight; posterior ridge close to the dorsal out-
line, narrowly rounded, lightly curved, ending in a decided
point on the median line; surface more or less covered with

1058 GRANDIDIERIA

fine, corrugated sculpture; epidermis yellowish or pinkish,
faintly rayed with a dull pinkish hue; anterior teeth small,
irregularly cut into denticles; nacre variable, bluish-white
rayed with pinkish, or uniform purplish.
Length 21, height 15, diam. 10 mm.
Lake Tanganyika.
Unio thomsoni SmirH, Ann. and Mag., VI, 1880, p. 430; Proc.
Zool. Soc. Lond., 1881, p. 299, pl. xxx1Vv, fig. 36.
Grandidierta thomsoni Bourcurcnat, Bull. Soc. Mal. Fr., II,
1885, Pp. 7.— SIMPSON, Syn., 1900, p. 829.
Grandidieria corbicula Bourcuicnat, Not. Prod., 1885, p. 100;
Icon. Moll. Tan., 1888, p. 43, pl. x1x, figs. 10-12.
Grandidieria granulosa Bourcuicnat, Not. Prod., 1885, p.
102; Icon. Moll. Tan., 1888, p. 43, pl xix, fies: 1, 2.
Grandidieria singularis BourcuIGNA’, Icon. Moll. Tan., 1888,
p- 43, pl. xrx, figs. 18-20.
Close to tanganyicensis and | fear that it is only a mutation
of that variable species. The curved post-dorsal outline and
the straight outline of the hinder part of the base cause the
hinder point of the shell to appear as if it drooped, and this
peculiar configuration is different from that of tanganyicensis.

GRANDIDIERIA RHYNCHONELLA Bourguignat.

Shell somewhat elongated, irregularly ovate, inflated, rather
solid; beaks full and high; anterior ends rounded; base line
full and curved, a little fuller just behind the middle ; posterior
ridge double, ending in a long, biangulate beak on the median
line; surface with light, concentric sculpture, scarcely corru-
gated.

Length 24, height 12 mm.

Lake Tanganvika.

Grandidieria rhynchonella Bourcutcnat, Icon. Moll. Tan.,
1888, p. 43, pl. xrx, figs. 16, 17——S1mpson, Syn., 1900, p.
820.

A decidedly elongate form with very full, high beaks, hav-
ing the posterior end drawn out into a long beak or rostrum.

GRANDIDIERIA 1059

GRANDIDIERIA CALLISTA Bourguignat.

Shell somewhat elongated, irregularly ovate, scarcely inflat-
ed, slightly inequilateral; beaks very full and high; posterior
ridge strong, double, ending at or below the median line in a
slight biangulation; the anterior and posterior ends both
drawn out and much narrower than the middle of the shell;
anterior end rounded, subangular above and below; posterior
end slighty angled above and below; the base line is very full
and rounded just behind the middle; surface covered with zig-
zag-radial and subnodulous sculpture.

Length 22, height 14, diam. 9 mm.

Lake Tanganyika.

Grandidieria callista BourcuIcNAT, Icon. Moll. T'an., 1888, p.

43, pl. xix, figs. 13-15.—SIMPSON, Syn., 1900, p. 829.

A most singularly shaped shell, being high and full in the
middle and drawn out into a sort of beak at each end. It is
quite probable that the specimens figured are somewhat dis-
torted G. rhynchonella, though that species is apparently much
smoother. Unfortunately I do not have access to any original
material of this and two other species of this group, which are
figured in Bourguignat’s Iconographie.

GRANDIDIERIA GIRAUDI Bourguignat.

Shell decidedly and irregularly long rhomboid, scarcely in-
flated, inequilateral; beaks sharp, subcompressed and but little
elevated; anterior end broadly rounded, subangulate above ;
base line full below and just in front of the beaks, greatly in-
curved towards the posterior end; posterior ridge double,
rather wide, much curved, close to and parallel with the dor-
sal outline, ending at the base of the shell in a long, drawn
out, biangulate beak, which curves downward in a remarka-
ble manner; surface curved with fine, zigzag-radial, subgran-
ulous sculpture.

Length 28, height 18, diam. 11.5 mm.

Lake Tanganyika.

Grandidieria giraudi Bourcuicnat, Nat. Prod., 1885, p. 95.—

Simpson, Syn., 1900, p. 830.—Germatn, Moll. Soc. Tang.,

1908, p. 683, figs. 33-34.

1060 GRANDIDIERIA

Grandidieria bourguignati JOUBERT in Bourguignat, Icon. Moll.
Tan., 1888, p. 43, pl. x1x, figs. 7-9.—Si1mpson, Syn., 1900, p.
829.—GERMAIN, Moll. Lac. Tang., 1908, p. 683, figs. 35-36.
A remarkably formed shell, having a long, biangulate pos-

terior beak that curves downward in a striking manner. I

cannot feel sure as to the validity of several of these species,

as I have seen but a small amount of material belonging to
only a few of them. I cannot help suspicioning that in some
cases distorted or unhealthy shells have been selected and
made the types of so-called species.

Germain (1. c.), considers bourgutgnati as synonym of gir-
audi. He, however, also refers the form to gravida as “a var.
elongata of the rostrata type.”

GRANDIDIERIA TSADIANUS von Martens.

“Shell solid, oblong-elliptical, much inflated, concentrically
striate and marked with more distinct lines of growth; yellow-
ish or greenish-brown; shortly rounded in front; subrostrate
behind ; dorsal margin sloping in front, horizontal and straight
to the end of the laterals, thence oblique at an obtuse angle;
ventral margin strongly curved at both ends; beaks swollen,
incurved, eroded, sculptured with a few, scattered nodules and
posteriorly with a few, short, compressed folds straight or
slightly converging. Nacre bluish, somewhat shining, slight-
ly radiate striate. Pseudocardinals in the right valve two,
compressed, separated by a deep, longitudinal groove, the up-
per thin and longer, the lower a little thicker, shorter, less
prominent; in the left valve one, compressed, slightly concave
above, prominent and elongated, and one under the beak, com-
pressed, triangular, obtuse, with two small, auxiliary teeth
between them; laterals elongate, slightly curved, in the right
valve one, sculptured above with two, light, longitudinal lines ;
in the left valve two, subequal.

Length 31, greatest height 20, at the umbones 19, diam.
18 mm. Beaks situated at 1-4 of the length.” (von Martens).

Type locality, South shore of Lake Tsad.

GRANDIDIERIA 1061.

Unio (Grandidieria) tsadianus von. Martens, S. B. Ges.

INatiGh 10035. pS:

“At the first glance, this species reminds one of the species
of Tanganyika, especially Unio burtoni Woodw., by reason
of the greatly swollen upper portion of the shell, the general
outline and the brilliancy of the nacre, but the sculpture is a
little weaker, as are also the anterior teeth.

No similar species is known to me from the Nile. One
specimen in the Berlin Museum received in about 1841 from
Captain Mion from Senegal, resembling U. gabonensis Kust.,
has a certain likeness in size and inflation, but is decidedly
nearer Unio egypticus and niloticus Fer., (group Pharaonia
Bgt.), owing to the thin shell, the more central beaks, the very
thin cardinal teeth and the less brilliancy of the nacre, than our
species from Lake Tsad.”

GRANDIDIERIA CHEFNEUXI Neuville and Anthony.

“Shell elongated, much longer than high, rounded before,
slightly pointed behind, posterior ridge slightly angulated;
concentrically striate in the central part of the disk near the
margin and on the dorsal slope, slightly plicate above .and at
the umbones; cardinal teeth minute; anterior lamella rather
thick; posterior elongate.

Length 28, height 18 mm.” (Neuville and Anthony).

Type locality, Lake Rodolphe.

Unio (Grandidieria) chefneuxi Nevviti£e£ and ANTHONY, Bull.
Mus. Hist. Nat., 1906, p. 409; Bull. Soc. Philom. (9), VIII,
1906, p. 410, pl. 12.

“This species is specially distinguished by the restriction to
the beaks of the characteristic plications and its elongated
form. It resembles, perhaps, Unio acuminatus Ad.”

The following are unfigured species of Grandidiecria:
G. rotundata Bourguignat, Not. Prod., 1885, p. 098.
G. mira Bourguignat, Not. Prod., 1885, p. 96.
G. incarnaia Bourguignat, Moll. Gir., 1885, p. 1or.
G. elongata Bourguignat, Moll. Gir., 1885. p. 14.

1062 PHYSUNIO

Genus PHYSUNIO, Simpson, 1900.

Physunio SIMPSON, Syn., 1900, p. 830.

Shell thin, irregularly obovate, narrowed in front, decidedly
produced at post-base, pointed behind and posteriorly winged,
with a moderate posterior ridge and often a second or third
faint ridge above it; beak sculpture zigzag-radial, somewhat
disposed in two sets, the one down the posterior ridge slightly
nodulous; posterior slope having irregular, radial corruga-
tions, the rest of the shell smooth; epidermis often cloth-like,
with one or more green rays on the posterior slope; hinge line
curved; a single obliquely granularly striate. pseudocardinal
and generally three laterals in the left valve and two pseudo-
cardinals and two laterals in the right, all greatly compressed ;
beak cavities deep; muscle scars irregular; nacre bright, blu-
ish, and iridescent.

Animal unknown.

Type, Unio gravidus Lea.

At first sight the members of this group would seem to be
closely related to if not identical in some cases with Hyriopsis,
but so far as is known the beak sculpture is very different from
that of members of that group, being decidedly zigzag-radial,
while that of Hyriopsis is concentric. The inflated forms like
gravidus and superbus appear to be connected with the group
Lens through such species as semialatus and micropterus.

KrY TO SPECIES OF PHYSUNTO.

Shell much inflated.

Light greenish or greenish-yellow. gravidus.
Dark brownish. superbus.
Moderately inflated.
Decidedly inflated. mucropterus.
Obovate.
Shell rather large, 80 mm. semialatus.
Shell rather small, 35 mm. crossel.
Small, 25 mm., bronzy. cambodiensis.
Shell compressed, strongly winged.
Painted green and yellow. extmius:

Uniform yellowish-green. friersont.

PHYSUNIO 1063

Section PHYSUNIO s. s.
Shell inflated ; beak cavities deep and rounded.

PHYSUNIO GRAVIDUS (Lea).

Shell irregularly obovate, inflated, thin inequilateral; beaks
full and high, the sculpture apparently almost radial, with two
radiating ridges, the hinder one bearing pustules; posterior
ridge often scarcely marked, but faintly angulate, and ending
in a slight angle below the median line; sometimes there are
one or two feeble, dark ridges on the dorsal slope; hinge line
slightly sinuous, running up into a low wing, behind which
it is almost squarely truncated posteriorly ; anterior end nar-
rowed and rounded; base line almost angularly inflated be-
hind the middle; surface with fine, radial or chevron-shaped
wrinkles on the dorsal slope; epidermis ashy-yellowish, green-
tinted, sometimes having faint, dark ashy rays, smooth, dull
or shining; left valve with one elongated, compressed, ragged
pseudocardinal and two remote, curved laterals; right valve
with two compressed pseudocardinals, the upper small and one
lateral; muscle scars shallow; nacre brilliant, bluish, silvery
and iridescent.

Length tot, height 81, diam. 60 mm.

Siam; Cambodia; Cochin China.

Umo gravidus Lea, Pr. Ac. N. Sci. Phila., VIII, 1856, p. 93;
Ohseevleia57) p12, pls XXIV, fiers safle Ac <N- ocr. Phila.,
IIT, 1858, p. 292, pl. xxiv, fig. 5—Sowersy, Conch. Icon.,
XV le 1806,, pl. bi, figs 271:

Margaron (Unio) gravidus Les, Syn., 1870, p. 28.

Lampsilis gravidus RocHEBRUNE, Bull. Soc., Phil., VI, 1882,
Pp. 43-

Physunio gravidus SIMPSON, Syn., 1900, p. 830.—Haas, Conch.
Cabs UiiG, 1612)-ple35, fe. 1

Unio abnormis Moreret, Rev. et Mag., XIV, 1862, p. 480.

Unio superbus Sowrrpy, Conch. Icon., XVI, 1867, p. LIX,
fig. 295.

A magnificent shell of delicate structure and large propor-
tions, the nacre being of a remarkable shade of blue, silvery

1064 PHYSUNIO

and almost as rich as that of a Nawtilus. ‘The greatest diame-

ter is just behind the beaks; from this point there is a sudden

and regular decrease in diameter to either end. The species
is closely allied to P. superbus but is not quite so solid, is less
inflated, is lighter colored and has a more brilliant nacre.

PHYSUNIO SUPERBUS (Lea).

Shell large, irregularly obovate, somewhat inflated, inequi-
lateral, scarcely subsolid; beaks full and high, their sculpture
apparently zigzag-radial, and having a row of tubercles on
their posterior ridge; hinge line lightly curved, with a small
wing behind; anterior end narrowed and rounded, angled
above; base line almost straight but very full behind the mid-
dle; posterior end almost squarely subtruncate ; posterior ridge
moderate, lightly angled, ending in a rounded point below the
median line; surface with irregular, concentric growth lines;
epidermis smoky-brown or smoky-olive, scarcely shining;
pseudocardinals elongated, ragged, one in the left valve and
two in the right; laterals remote, curved, two in the left valve
and one in the right; muscle scars shallow ; nacre bluish-white,
smoky-tinted, iridescent behind.

Length 93, height 75, diam. 44 mm.

Sumatra; Cochin China.

Unio superbus Lea, Desc. 12 New Uniones, 1843 (no pagina-
tion) ; Tr. Am.. Phil. Soc. 1X,1845, p. 281, pl. xan, fic a1;
Obs. TVs 1848; Pp. 20" pin oct Ue die etal.

Margaron (Unio) superbus Lea, Syn., 1852, p. 19; 1870, p. 28.

Physunio superbus Simpson, Syn., 1900, p. 830.— Haas,
Conch. -Cab., Unio, ro12, pl. 35, fig-*2.

Unio velaris HANLEY, Biv. Shells, 1856, p. 385, pl. xxuut, fig.
42.

Umo massini Morevet, Jl. de Conch., XII, 1864, p. 288; Ser.
Conch. 1V, 1875. p. 348, pl aavghesen:

A fine species, close to grazidus but solider, having a darker
epidermis, less inflated, with a curved hinge line instead of a
sinuous one, and with smoky-bluish nacre, not nearly so bril-
liant as that of gravidus. There are one or two darker rays on
the posterior slope.

PHYSUNIO 1065

Puysunio crosser (Deshayes and Julien).

Shell irregularly obovate, thin, imequilateral, scarcely in-
flated; beaks moderately full, acute, sculptured with rather
regular, subradial ridges, which unite along a median line to
form a chevron-shaped pattern; anterior end rounded, nar-
rowed, angled above; base line straight, very full behind the
middle; hinge line a little sinuous, the hinder end produced
into a small wing; posterior end obliquely truncate above, bi-
angulate on the median line; surface delicately, concentrically
sculptured; dorsal slope with subradial plications ; epidermis
fuscous-yellowish; teeth delicate, much compressed; nacre
flesh-colored, iridescent.

Length 35, height 22, diam. 13 mm.

Cambodia; Cochin China.

Unio crossei Destaves and Jutien, N. Arch. Mus., X, 1874,

pe (24, ple va, hes. 5-7.

Physunio crossei SIMPSON, Syn., 1900, p. 831.
Contradens crossei Haas, Conch. Cab., Unio, 1912, pl. 20, figs.

1-3.

If the specimen described and figured by Deshayes is adult
the species is much smaller and much less inflated than either
gravidus or superbus. The beak sculpture is figured and con-
sists of beautifully regular, subradial bars, which meet on a
median line and form a sharply pointed chevron-shaped pat-
teri.

PHYSUNIO MICROPTERUS (Morelet).

Shell subrhomboid, subinflated, inequilateral, rather thin;
beaks full and high; anterior end narrowed and rounded,
scarcely angulate above; base line lightly curved, slightly fuller
behind the middle; dorsal outline curved, carried up behind
into a small wing; dorsal slope obliquely subtruncate behind ;
posterior ridge full, rounded, ending in a rounded point near
the base of the shell; surface with very fine, concentric sculp-
ture and a few wrinkles; epidermis greenish-olive, subshining ;

1066 PHYSUNIO

pseudocardinals and laterals compressed, lamellar, lightly
curved: muscle scars shallow; nacre pale bluish, iridescent.
Length 60-68, height 37-41, diam. 23-25 mm.
Siam ; Cambodia.
Unio micropterus Morrie, Jl. de Conch., XIV, 1866, p. 63;
Ser. Conch., IV, 1875, p. 349, pl. xv, fig. 6.
Physunio micropterus SIMPSON, Syn., 1900, p. 831.—HAaas,
Conch Cab., Unio, 1912, pl. 33, fig. 9.
I cannot be certain as to the relationships of this species as
I know nothing whatever of the beak sculpture, and the form
is more distinctly rhomboid than in any of the species I have
placed in the group.

PHYSUNIO SEMIALATUS (Deshayes and Julien).

Shell irregularly obovate, thin, scarcely inflated, inequilat-
eral; beaks full, and somewhat elevated, their sculpture not
known; posterior ridge rounded, nearly straight, ending be-
hind in a rounded point about on the median line; hinge line
straight, carried out into a small wing behind; anterior end
narrowed, rounded, angled above; base line lightly curved,
very full and widely rounded behind the middle; dorsal slope
obliquely truncate behind; surface with delicate growth lines
with a slight radial ridge on the posterior slope and a row of
minute wrinkles or folds along it with a few feeble plications
above it; epidermis greenish-olive, brilliant ; teeth greatly com-
pressed, lamellar; laterals curved, apparently triple in the left
valve; nacre yellowish, brilliant.

Length 83, height 53, diam. 24 mm.

Siam ; Cambodia.

Unio semialatus DeESHAYES and JULIEN, N. Arch. Mus., X,

[S745 ps 123) pleviz nest ce.

Physumio semialatus Simpson, Syn.,. 1900, p. 831.—HAas,

Conch. Cab., Unio, 1912, pl. 34, figs. 1-2.

This may be a Hyriopsis, but without knowing anything of
the beaks I cannot tell. Deshayes says it seems to be equally
related to Unio discoideus lea and U. superbus.. The row
of minute folds down the dorsal slope recalls a character of
Cristaria plicata and Hyriopsis cumingii, but they are a great
deal finer than in either of those species.

PHYSUNIO 1067

PHYSUNIO CAMBODIENSIS (Lea).

Shell small, scarcely subsolid, irregularly obovate, subinflat-
ed; beaks full and high, somewhat eroded in the only speci-
men seen but having zigzag-radial sculpture; posterior ridge
doubie, ending in a feeble biangulation below the median line;
anterior end narrowed and rounded, slightly angled above;
base line lightly curved, full behind the middle; hinge line
curved a little, carried out into a small wing behind; dorsal
slope obliquely truncate; surface with irregular growth lines,
somewhat wrinkled on the dorsal slope; epidermis bronzy-red-
dish, shining ; teeth compressed ; laterals curved ; muscle scars
shallow; nacre bluish-white, iridescent.

Length 25, height 15, diam. 11.5 mm.

Takrong River at Korat, Cambodia.

Unio cambodiensis Lea, Pr. Ac. N. Sci. Phila., VIII, 1856, p.
OP ele Acad. No SC hil Iie TS57, p. 313," pl. xxx, tie.
Ze Ns Wile TSS 750 Ds 335 pl. eM. Tet 28.

Margaron (Unio) cambodiensis Lea, Syn., 1870, p. 42.

Physunio cambodiensis Stimpson, Syn., 1900, p. 831.—Haas,
Conch. Cab., Unio, 1912, pl. 34, fig. 5.

I am not at all sure that the type, the only shell of this spe-
cies I have seen, is adult. It is, however, somewhat strong,
and the epidermis is of a peculiar bronzy-reddish tint.

Section Lens Simpson, 1900.

Lens SIMPSON, Syn., 1900, p. 831.

Shell sublenticular ; three laterals of left valve distinct ; cav-
ity of the beaks compressed.

Type, Unio eximius Lea.

PHYSUNIO EXIMIUS (Lea).

Shell subtriangular, compressed, winged on the post-dorsal
border, rather thin, inequilateral; anterior end much narrow-
ed, rounded, slightly angled above; base line straight or a lit-
tle incurved, full behind the middle; dorsal outline lightly
curved ; dorsal slope almost squarely truncate behind, the line
of truncation sometimes a little incurved; beaks neither full

1068 PHYSUNIO

or high, their sculpture consisting of corrugated, zigzag-radial

bars; posterior ridge low, ending below the median line on

adult shells, in a feeble point; surface with fine, concentric
growth lines, plicately sculptured on the dorsal slope; epider-
mis greenish-yellow, marked with imperfect bands and rays of
blue-green, subshining; nacre bluish, somewhat iridescent ;
teeth delicate, lamellar, laterals two in the right valve and
three in the left.

Length 65, height to point of wing 50, diam. 17 mm.

Siam ; Cambodia.

Umo extmius Lea, Pr. Ac. N. Sci Phila., VII. 1856, p. 93;
Obs, Vil 9857, p14) pl. xan hese aac. Nes Serer ilar
TIT, 1858, p. 294, pl. xxv, fig. 8.—Sowersy, Conch. Icon.,
KV 11868; pl UxXxxix, fig. 4ST.

Margaron (Unio) eximius Lea, Syn., 1870, p. 28.

Physunio eximius SIMPSON, Syn., 1900, p. 831.—Haas, Conch.
Cab., Unio, 1912, pl. 34, figs. 6-8.

Unio semiquadrata Sowrersy, Conch. Icon., XVI, 1866, pl.
XLVIIL, fig. 258.

Unio semiquadratus Payrei, Conch. Sam., III, 1890, p. 167.
The old shells of this species are decidedly triangular, hav-

ing a high post-dorsal wing, and have almost exactly the ap-
pearance of a Hyriopsis. But the vounger shells are rather
more inflated in proportion and show relationships to P. grav-
idus and superbus. Their beak sculpture is decidedly zigzag-
radial and not concentric as it is, in all cases where I have been
able to examine it, in Hyriopsis.

PHYSUNIO FRIERSONI n. n.

Shell obovate or subtriangular, thin, rather compressed, pale
green, neither radiated or sculptured; beaks small, pointed ;
posterior ridge scarcely developed; anterior end much nar-
rowed, rounded, angled above; base line nearly straight, full
near the posterior end; dorsal line with a high posterior wing,
which is almost squarely truncate behind ; posterior end widely
and evenly rounded; lunule excavated; pseudocardinals large,
lamellar.

Assam,

SIMPSONELLA 1069

Unio velaris SowERsy, Conch. Icon., XVI, 1868, pl. Luxx, fig.

2068.

Physunio velaris Stmpson, Syn., 1900, p. 831.—Haas, Conch.

Cab-, Unio 19125 pl. 245 hes, 0:

I have never seen this species and as I know nothing regard-
ing its beak sculpture I cannot be certain whether it belongs
here or in Hyrtopsis. Sowerby does not say anything about
its nacre. Compared with P. eximius, to which it seems most
closely related, it is a shorter shell, more rounded behind and
lighter colored. I think it likely that the shell figured is young.

Genus SIMPSONELLA Cockerell, 1903.

Dalliella Simpson, Syn., 1900, p. 832; non Cossman, 1895.
Simpsonella CocKERELL, Naut., XVI, 1903, p. 118.

Shell subtrapezoidal, generally thin, inflated, with a low,
rounded posterior ridge and rather full beaks, which have
somewhat zigzag-radial sculpture, with a row of chevron-
shaped folds running some distance down the posterior ridge,
and with fine corrugations in front of the beaks; epidermis
somewhat cloth-like; substance of the shell of a peculiar pur-
plish-brown tint; hinge line narrow; teeth imperfectly de-
veloped, sometimes reduced to mere rudiments, when present
consisting of greatly compressed, feeble pseudocardinals and
laterals; beak cavities rather shallow; dorsal scars one to a
few, scattered; muscle scars faint; prismatic border wide.

Animal unknown.

So far as conchological characters go, and we know nothing

f the anatomy of the above group, it would seem that Simp-
sonella was closely related to Pseudodon. In the present
genus pseudocardinals and laterals are generally present,
though quite commonly in greatly reduced form, they are
compressed or lamellar, while in Psewdodon the laterals are
wanting and the pseudocardinals are smooth and usually more
or less tubercular. There is a peculiar purplish or coppery
tint present in all the members of this genus. The group of
S. msularis seems to partially connect it with Psewdodon.

Type, Anodonta purpurea Valenciennes.

1070 SIMPSONELLA

KEY TO SPECIES OF SIMPSONELLA

Shell rather thin, nacre purple or coppery.

Subrhomboid.
Short, subshining. purpurea.
Somewhat elongated, silky. subcrassa.
Wide behind. dark, tenuis.
Much elongated. gracilis.
Obovate. crepera.

Shell subsolid, nacre lurid, tinted purplish.

With feeble concentric sculpture, subshining, crassa.
With strong, concentric sculpture, dull, insularis.

Group of Simpsonella purpurea.

Shell not biangulate behind, rather smooth; nacre coppery-
purple; teeth very faint, compressed.

SIMPSONELIA PURPUREA (Valenciennes).

Shell subelliptical or subrhomboid, scarcely inflated, rather
thin, inequilateral ; beaks only moderately full and high, point-
ed and turned slightly forward, sculptured with zigzag bars;
anterior end rounded; base line nearly straight, often a little
full behind the middle; dorsal outline lightly curved; dorsal
slope obliquely subtruncate ; posterior ridge and the lower part
of the hinder end rounded; surface with delicate, irregular
growth lines; epidermis brownish-coppery, darker and with
an indistinct, green ray or two on the dorsal slope; teeth rudi-
mentary, there being delicate, vestigial, lamellar pseudocar-
dinals and laterals: muscle scars shallow; nacre coppery with
radial markings; prismatic layer wide, lurid coppery.

Length 57, height 32, diam. 19 mm.

Length 50, height 31, diam. 18 mm.

Length 66, height 38, diam. 25 mm.

Length 54, height 28, diam. 20 mm.

Philippines.

SIM PSONELLA LO7L

Anodonta furpurea VALENCIENNES, Rec. Obs. Zool., I, 1833,
p. 236, pl. xivir, bis, fig. 3, 3a, 3b—CLEssin, Conch. Cab.
ZANIO™, L705. De 775, Dei, Or Te

Margarita (Anodonta) purpurea Lua, Syn., 1836, p. 51; 1838,

p. 30.
Anodon purpurea CATLow and ReEEvE, Conch. Nom., 1845, p.
67. .
Margaron (Anodonta) purpurea Lea, Syn., 1852, p. 50; 1870,

Pp. 79.

Dalliella purpurea Simpson, Syn., 1900, p. 832.

Simpsonella purpurea Haas, Conch. Cab., Unio, 1912, pl. 24,
figs. 1-3.

Anodonta burroughiana, Lea, Tr. Am. Phil. Soc., V, 1834, p.
105, pl. xvi, fig. 49; Obs., I, 1834, p. 217, pl. xvi, fig. 49.—
Cressin, Conch. Cab. Ano., 1875, p. 164, pl. Liv, figs. 3, 4.

Margaron (Anodonta) burroughiana Lea, Syn., 1870, p. 81.

Anodon burroughianus, Sowrerpy, Conch. Icon., XVII, 1870,
pl. xxvil, fig. 103.

Margarita (Umio) bengalensis Lra, Syn., 1836, p. 26; 1838, p.
20.

Unio bengalensis Lea, Tr. Am. Phil. Soc., VI, 1838, p. 3, pl.
Dipti oe (Obs. JUL mSz8ip. 2) pl ihc: 3.—HaAniey, Biv:
Shells, 1843, p. 194, pl. xx1, fig. 50-—CueENu, III. Conch.,
1858, pl. xxi, figs. 2, 2a, 2b—-Kuster, Conch. Cab. Unio,
LeOhp1225, pl: LXXVIT, es. 2) 3:

Margaron (Um) bengalensis Lea, Syn., 1852, p. 30; 1870, p.
47.

Anodon bengalensis Sowerny, Conch. Icon., XVII, 1867, pl.
XIV, fig. 49.

Anodonta bengalensis Ciesstx, Conch. Cab. Ano., 1876, p.
Te epi VED. te. Ds

Unio verecundus Goutp, Pr. Bost. S. N. Hist., III, 1850, p.
205 Ure se xple Hh xp. WL Tse agi. fies. 54r, Sara,
5416, 541c.—ReEFVE, Conch. Icon., XVI, 1865, pl. xxv, fig.
125.

Unio mauritianus Lea, Pr. Ac. N. Sci. Phila., III, 1859, p. 152;
jieneeNe ses Philay iV. as6o: pu 257, pl. xk, fig. 138; Obs,
Wit, 186059p. 75, pl.xw; fie. 138:

Margaron (Unio) mauritianus Lea, Syn., 1870, p. 42.

1072 SIMPSONFLLA

?Anodonta heldu Kuster, Conch. Cab. Ano., 1873, p. 64, pl.

MOK his. iT.

Anodonta chinensis KusteER? Where?.

This seems to be an abundant form and quite a variable
one. I have no doubt but that Lea’s Unio bengalensis is the
same as the .dnodonta purpurea of Valenciennes, as is Lea’s
Unio mauritianus and that the localities, India and Mauritius,
given by him are wrong. ‘The shell is usually somewhat long
rhomboid, the anterior end being a little narrowed, the dorsal
and ventral outlines being nearly parallel. Sometimes, how-
ever, the outline is almost evenly elliptical or slightly obo-
vate. Specimens of Anodonta purpurea, so labeled by More-
let, and from his collection, belong to the National Museum
and do not in any essential character differ from [ea’s types
of U. bengalensis and mauritianus. Sometimes the texture of
the shell is coppery-tinted with green, and in other cases it is
decidedly violet.

SIMPSONELLA CREPERA (Lea).

Shell somewhat elongated, almost regularly obovate, rather
thin, convex, inequilateral; beaks not full or high, their sculp-
ture zigzag-radial; posterior ridge low, rounded, sometimes
feebly double and at such time ending in a very slight bian-
gulation behind; surface with irregular growth lines; epi-
dermis dull brownish, banded with greenish and feebly rayed,
subshining ; teeth reduced to mere lineal vestiges ; muscle scars
shallow; nacre dull, lurid, coppery-tinted, a little thickened in
front, slightly iridescent behind; prismatic layer wide, dull,
coppery-tinted.

Length 85, height 43, diam. 27 mm.

J_uzon Island, Philippines.

Anodonta crepera Lea, Pr. Zool. Soc. Lond., 1850, p. 198; Jl.
Ae: IN. Set, (Phila. LV, 1860; 9p: 4228.) plea xxactv, aie sate
Obs., VII, 1860, p. 56, pl. xxxtv, fig. 117,—C1LEssin, Conch.
Cab. Ang 1873, 1p..076 pli xxix, fies) "5. Gr

?Anodon creperus SowERBy, Conch. Icon., XVII, pl. vit, fig.
16.

SIMPSONELLA 1073

Margaren (Anodonta) crepera LEA, Syn., 1852, p. 50; 1870,

PuncO:

Dalliella crepera SiMPsoN, Syn., 1900; p. 833.
Simpsonella crepera Haas, Conch. Cab., Unio, 1912, pl. 25,
fig.

The dimensions given above are from the type, which is a
larger shell than any specimen | have ever seen of purpurea.
It is more evenly obovate and more elongate in proportion
to height as a rule than that species, and the color is rather
more dull. The teeth are, perhaps, more faintly developed.

SIMPSONELLA TENUIS (Lea).

Shell decidedly long rhomboid, narrowed somewhat in front,
inequilateral, thin, scarcely inflated; beaks neither full or high
but sharp pointed, sculptured with strong, zigzag ridges; pos-
terior ridge quite full, rounded or feebly biangulate, ending
below the median line; dorsal line nearly straight; anterior
end rounded, subangulate above; base line straight or very
slightly incurved in the middle: dorsal slope obliquely trun-
cated ; posterior end rounded below ; surface with rather strong
growth lines, dull greenish-brown, sometimes faintly rayed ;
teeth linear and almost obsolete; nacre bluish, flesh-colored or
purplish, dull, but iridescent behind.

Length 76, height 41, diam. 24 mm.

Luzon Island, Philippines.

Anodonta tenuis LA, Pr. Zoo. Soc. Lond., 1850, p. 198; Jl.
EXCH INES OCI aiiilal wal VNeT SOO py 237 pla xexTutio. TOK
Obs., VII, 1860, p. 55, pl. xxx, fig. 116.—Muscrave, Phot.
Conch. I., 1863, pl. 1, fig. 8.—CLesstn, Conch. Cab. Ano,.
1862" )5.00, plu xxx, figs: 3; 4.

Margaron (Anodonta) tenuis Lea, Syn., 1852, p. 53; 1870, p.
83.

Anodon tenuis SowrErBy, Conch. Icon., XVI, 1867, pl. xv, fig.
55:

Dalliella tenuis Simpson, Syn., 1900, p. 833.

Simpsonelia tenuis Haas, Conch. Cab., Unio, 1912, pl. 24,
figs. 4-5.

1074 SIMPSONELLA

Close to crepera, but more decidedly rhomboid, the anterior
base of some specimens being somewhat cut away. The
posterior ridge is quite high, so much so that there is a faint
radial depression in front of it, while that of crepera is rather
low. The point of greatest diameter is situated nearer the
posterior end than in crepera.

SIMPSONELLA SUBCRASSA (Lea).

Shell subrhomboid, subsolid, slightly inflated, inequilateral ;
beaks rather full and high, with zigzag-radial sculpture; an-
terior part of the shell scarcely narrowed; anterior end round-
ed, cut away a little below; base line straight or incurved ; dor-
sal outline lightly curved; dorsal slope obliquely truncate
above; posterior ridge full, feebly angled, ending in a blunt
point below the median line; surface with fine, irregular
growth lines on the disk, these become stronger at the ends
of the shell; epidermis pale greenish-brown with faint rays,
often having a grayish, silky surface when not worn; teeth al-
most wholly wanting, linear; nacre bluish, salmon-tinted or
purplish.

Length 75, height 40, diam. 29 mm.

Luzon Island.

Anodonta subcrassa LEA, Pr. Zool. Soc. Lond., 1850, p. 198:
il. AcON: Se. Phila, VV, 1859; p.- 236, ple xxxmr me sms.
Obs., VII, 1860, p. 54, pl. xxxit, fig. 115.—MuscRAvE,
Phot. Conch., 1863, pl. 1, fig. 3—Ciessin, Conch. Cab. Ano.,
16739 p. OS mpl xXkxt; Migsh, 2,

Margaron (Anodonta) subcrassa Lea, Syn., 1852, p. 51; 1870,
p. 81.

Anodon subcrassa Sowrerspy, Conch. Icon., XVII, 1867, pl.
XIII, fig. 42. ;

Dalliella subcrassa Stupson, Syn., 1900, p. 833.

Simpsonella subcrassa Haas, Conch. Cab., Unio, 1912, pl. 25.
fig, 2.

More solid than the allied species and somewhat more in-
flated. The epidermis in fresh specimens is wholly or partly
covered with a peculiar grayish, silky sort of bloom, which
wears off to some extent after they are handled.

SIMPSONELLA . 1075

SIMPSONELLA GRACILIS (Lea).

Shell rather elongated, the dorsal and ventral outlines being
nearly parallel, convex or subinflated, inequilateral, scarcely
subsolid; beaks only moderately full or elevated, with zig-
zag-radial sculpture; anterior end rounded and cut away a
little below ; posterior ridge rounded or feebly double, ending
in a slight biangulation at and below the median line; dorsal
slope obliquely subtruncate; surface with irregular growth
lines; epidermis pale brownish-green and feebly rayed in the
younger shells, coppery-brown in old ones, scarcely shining ;
teeth rudimentary, reduced to mere lines ; anterior scars broken
up; nacre varying from bluish to purple or coppery, dull and
lurid; prismatic layer wide.

Length 85, height 40, diam. 24 mm.

Dingle, Isle of Panay, Philippines.

Anodonta gracilis Lea, Pr. Zool. Soc. Lond., 1850, p. 197; JI.
we, Wace. Phila, 1V, 1860, p. 230, pl. xxxiv, fig’ 159 ; Obs:,
VII, 1860, p. 57, pl. xxxiv, fig. 119.—-CLEesstn, Conch. Cab.
Ano. 1873, p: OQ, pl. xxix, figs. 3, 4.

Margaron (Anodonta) gracilis Lea, Syn., 1852, p. 51; 1870,
p. 82.

Dalliella gracilis Stueson, Syn., 1900, p. 833.

Simpsonella gracilis Haas, Conch. Cab., Unio, 1912, pl. 25,
henna.

Close to the foregoing species. It is more elongated than
any of them, has nearly parallel dorsal and ventral outlines,
is very slightly rhomboid, and has dull, lurid nacre, scarcely
iridescent behind.

SIMPSONELLA SERRADELLI (Drouet ).

Shell ovate, inflated, thin, delicately striate with concentric
growth lines, shining, olivaceous; dorsal outline slightly as-
cending behind; ventral outline nearly straight; posterior end
obtusely produced into a beak; beaks rather prominent, with
zigzag-radial sculpture; teeth elongate, compressed, rudiment-
ary; muscle impressions shallow ; nacre violaceous.

Length 62, height 35, diam. 20 mm.

Philippines.

1076 SIMPSONELLA

Unio serradelli Drourt, Jl. de Conch., XL, 1892, p. 86.
Dalliella serradelli Stmpson, Syn., 1900, p. 834.

Evidently a Simpsonella and quite probably synonymous
with some of the species already described. So far as I know
it has never been figured. If the outline is really ovate as is
claimed in the description, it may be a valid species.

Group of Simpsonella insularis.

Shell subsolid, subrhomboidal, biangulate behind; pseudo-
cardinals and laterals blurred, not greatly compressed; nacre
lurid, tinged purplish.

SIMPSONELLA INSULARIS (Drouet).

Shell long rhomboid, inequilateral, slightly narrowed and
rounded in front, subcompressed, subsolid; beaks not promi-
nent; dorsal line lightly curved; basal line nearly straight;
dorsal slope obliquely truncate; posterior ridge moderate,
somewhat double, ending below the median line in a feeble
biangulation; surface with strong, sulcate, concentric sculp-
ture; epidermis brown, not shining; vestigial pseudocardinals
and laterals present ; nacre lurid.

Length 48, height 30, diam. 15 mm.

Borneo; Palawan Island, Philippines.

Pseudodon insularis Drover, Rev. Biol. Fr., VI, 1894, p. 217,

fig. 2.

Dalliella insularis Stimpson, Syn., 1900, p. 834.
Pressidens insularis Haas, Nachr. Deutsch. Mal. Ges., 1910, p-

103;;;ConchiCab:, Unie, 1912) pla23 fics. 1-2:

Close to S. crassa, but appears to be smaller, not quite so
much elongated, more compressed, more strongly, concen-
trically sculptured and duller-colored. I have seen one young
shell and an adult valve of what I take to be this species, from
Palawan Island, belonging to the collection of Mr. Berlin H.
Wright. ‘These have somewhat zigzag sculpture, perfect lat-
erals and moderately developed pseudocardinals.

According to Haas. (1. c.), this species belongs to his new
genus Pressidens.

PRESSIDENS 1077

SIMPSONELLA CRASSA (Drouet).

Shell long rhomboid, slightly narrower in front, subsolid,
convex or slightly inflated, inequilateral ; beaks not prominent,
their sculpture apparently zigzag-radial; posterior ridge full,
imperfectly double, ending in a wide, feeble biangulation be-
low the median line; dorsal line lightly curved; base line
straight or nearly so; anterior end rounded; dorsal slope
obliquely truncated; surface with irregular, concentric sculp-
ture; epidermis warm brown, subshining; teeth feeble or rudi-
mentary, lamellar, vestiges of both pseudocardinals and lat-
erals being present; muscle scars shallow ; nacre pale purplish,
coppery-tinted, slightly thickened in front.

Length 68, height 37, diam. 21 mm.

Borneo.

Pseudodon crassuts Drover, Jl. de Conch., XL, 1892, p. 93.—
Drourt and CHaper, Mem. Soc. Zool. de Fr., V, 1892, p.
151, pli Vi, figs. 1-3:

Dalliella crassa Stimpson, Syn., 1900, p. 834.

Two fine specimens of this species from Banguey Islands,
North Borneo, received under the name Pseudodon insularis,
are in the National Museum collection. It is a smoother, more
inflated, rather more elongate form than msularis, though
the two are closely related and, I believe, belong here instead
of with Pseudodon. In the latter group the vestigial pseudo-
cardinals are stumpy and there are no laterals; in Simpsonella
there are vestigial pseudocardinals and laterals, the whole he-
ing lamellar.

Genus PRESSIDENS Haas, 1910.

Pressidens Haas, Nachr. Deutsch. Mal. Ges., 1910, p. 102.
“Shell oval, thin. Beaks low, beak-cavities shallow; beak
sculpture consisting of concentric ridges, each ridge made
up of two curves, which meet in a sharp angle on the oldest
part of the beak and gently curve with each other on the
younger part; the anterior of these curves surrounds the front
of the beak in a semi-circle, the posterior curve is angularly

1078 PRESSIDENS

bent downwards towards the posterior margin so that the
vertex of the angle is on the posterior ridge, the upper part
of the rear curve is the most prominent part of the beak
sculpture and continues down on the posterior ridge for a
considerable distance from the beaks. Dorsal slope high, tri-
angular. Hinge with a long, compressed cardinal tooth and
a long, low lateral in each valve. The cardinal tooth of the
right valve and the lateral of the left valve, may have a weak,
lamelliform auxiliary tooth above them. Nacre bluish-white,
under the beaks salmon-colored.

To this group belong: P. moellendorffii n. sp., from Pala-
wan and /?. msularis Drouet from Palawan and Borneo.”
( Eiaas)):

Type, Pressidens moeliendor fi Haas.

PRESSIDENS MOELLENDORFFI Haas.

“Shell oval, thin, finely and evenly striate. Beaks low, with
the sculpture given for the genus, almost wholly eroded in
mature specimens, situated at 24/100 of the total length. Up-
per anterior margin straight, slightly sloping, with a distinct
angle where it passes into the semicircular anterior end, which
curves gradually into the horizontal ventral margin; posterior
end obliquely angled; posterior margin oblique, postero-dorsal
angle not strong; dorsal margin almost horizontal, which is
nearly as high as the beaks. Posterior slope high; posterior
ridge low; ligament long, thin. Hinge weak, one lamelliform
cardinal tooth and a slightly curved lateral in each valve; in
front of the cardinal of the right valve there may be a weak,
lamelliform auxiliary tooth and above the lateral of the left
valve there are noticable indications of another tooth. Angle
of the cardinal teeth 25°, of the lateral teeth o°. Muscular
impressions faint. Nacre bluish-white, under the beaks sal-
mon-colored. [pidermis chestnut-brown, in young shells light
yellowish-brown and also on the worn beaks.

Length 63, height 38, diam. 20 mm.”’ (Haas).

Type locality, Paragua, Palawan.

Pressidens moellendorfii Haas, Nachr. Deutsch. Mal. Ges.,

1910, p. 103; Conch. Cab., Unio, 1912, pl. 23, figs. 3-5.

PSEUDODON 1079

Genus PSEUDODON Gould, 1844.

Pseudodon Gout, Pr. Bost. Soc. Nat. His., 1844, p. 161.
Monodontina Conran, Pr. Ac. N. Sci. Phila., 1853, p. 269.
Trigonodon ConraApd, Am. Jl. Conch., I, 1865, p. 233.
Monocondylus Morretrr, Rev. et Mag., 1866, p. 167.
Pseudodus pk Morcan, Bull. Soc. Zool. Fr., X, 1885, p. 422.

Shell oval to elongate, having two posterior ridges and often
one or two slight, radiating elevations above on the posterior
slope, above which there is usually a small wing; beaks rather
low, sculpture unknown: epidermis dark, often having a few
faint wrinkles on the posterior slope, without rays when adult.
There is a single, smooth tooth in each valve, with occasional
vestiges of a second; laterals nearly or quite wanting; beak
cavities shallow; dorsal scars conspicuous, deep, distinct, 4
to 7 in a row under the hinge; anterior scars irregular; nacre
generally dull and lurid.

Animal having the branchize wide and rounded behind, be-
coming narrow in front; palpi enormously long, apparently
slender, pointed behind, where they project free for some dis-
tance; mantle thin, with a wide, slightly thickened border,
faintly papillose behind, there seeming to be but little dis-
tinction between anal and branchial openings; anal opening
apparently smooth.

Type, Anodon inoscularis Gould.

The genus Psewdodon of Gould, as I have defined it, con-
tains a limited number of species of Unionide belonging ex-
clusively to the Oriental Region. The shells vary a good deal
in form, from nearly orbicular to considerably elongated ; they
are generally brownish or blackish and without rays, and with-
out striking sculpture. They have usually but a single blunt
tooth in each valve, which is almost always smooth. In two or
three species there is a vestigial second tooth. The laterals
are nearly or quite wanting ; when present they are represented
merely by a low, longitudinal ridge. The ligamental patch
is mostly rather conspicuous and there is in a number of the
forms, a slight indication of a pallial sinus.

1080 PSEUDODON

All that is known of the animal is the figure, without descrip-
tion, of Deshayes and Jullien of P. moreleti. From the char-
acter of the shells I am inclined to believe that they are closely
related to those of Simpsonella. though I have been unable
to examine any specimens that gave any clue to the beak
sculpture. I am not certain that all the species I have placed in
Pseudodon should go there.

KrEY TO SPECIES OF PSEUDODON.

Shell somewhat elongated.

Inflated.
Rather thin. nankingensis.
Subsolid. secundus.
Not inflated.
Blackish, folded on dorsal slope. loomisi
Brownish. salwenianus.
Green-tinted, scarcely convex. mouhott.
Tawny, convex. exilis.
Compressed. solidus.
Shell not elongated.
Triangular or subtriangular. cambodjensis.
Subrhomboid.
Strongly, concentrically sulcate.
Inflated. chaperi.
Convex or subcompressed. crebristriatus.
With folds on the dorsal slope. harmandi.

Nearly smooth or merely concentrically striate.
Shell inflated; dorsal ridge high. awreus,
walpolet.
Compressed or merely convex. resupinatus, eneolus,
cumingu, vondembuschianus, zollingeri, ovalis.

Subinflated. imoscularis, peguensis.

Inflated, large. moreleti, ponderosus.
Obovate, subinflated. bicristatus, thomsont.
Oval.

Inflated. tumidus.

Subcompressed or convex. ellipticus,

Suborbicular. orbicularis.

PSEUDODON 1081

Section SuzorBIcULUS Simpson, 1900.

Suborbiculus SIMPSON, Syn., 1900, p. 835.

Shell compressed, nearly round in outline, feebly biangulate,
and having a posterior dorsal wing; beaks low; hinge with a
single, compressed, smooth, slightly curved, triangular tooth
in each valve.

Type, Monocondylus orbicularis Morelet.

PSEUDODON ORBICULARIS (Morelet).

Shell suborbicular, compressed, thin, inequilateral; beaks
small, acute, compressed, having in front of them a well-
marked, deep lunule; dorsal outline behind the beaks decid-
edly curved and rising to a wing; behind this the dorsal slope
is subtruncate; anterior end somewhat narrowed, rounded,
angled above at its junction with the lunule; base line well
curved; posterior ridge somewhat double and feebly biangu-
late behind, the longer point of the biangulation being below
the median line; surface with light, concentric sculpture, which
is more strongly developed at the border; epidermis brown-
ish, subshining’; each valve has a single, compressed, elevated
and triangular, smooth tooth; nacre bluish, pale salmon in the
cavities, iridescent.

Length 74, height 60, diam. 22 mm.

Siam ; Cambodia.

Monocondylus orbicularis Moretet, Rev. et Mag., XVIII,

1866, p. 167.

Pseudodon orbicularis Morretet, Ser. Conch., IV, 1875, p.

338, pl. xvt, fig. 5—Srmpson, Syn., 1900, p. 835.
Monocondylea orbicularis Pate, Conch. Sam., III, p. 174.

Evidently a fine species. The outline is suborbicular, the
length being slightly greater than the height. There is a deep
lunule, which cuts into the outline of the shell and below it the
anterior end is strongly angled. The species cannot be mis-
taken for any other.

Section TrRiconopon Conrad, 1865.

Trigonodon Conran, Am. Jl. Conch., I, 1865, p. 233.
Shell solid, compressed rhomboid, round in front, widely
and faintly biangulate and rough behind; surface irregularly,

1082 PSEUDODON

concentrically, wavy sulcate; hinge with a strong triangular
pseudocardinal in the right valve, having a decided excava-
tion behind it, and at the posterior side of the pit a faint tooth ;
there is one strong triangular tooth in the left valve and a
vestige of one in front of it at the upper edge of the shell;
anterior scars irregular; dorsal scars crowded close to the
hinge line.
Type, Monoccndylea crebristriata Anthony.

PSEUDODON CREBRISTRIATUS (Anthony).

Shell subrhomboid, rather solid, convex, inequilateral ; beaks
apparently but slightly prominent; posterior ridge inclined to
be double, ending in a wide, feeble biangulation near the base
of the shell; dorsal and basal outlines slightly curved ; anterior
end a trifle narrowed, rounded; dorsal slope obliquely trun-
cated ; surface with rather fine, irregular, concentric sculpture
and light radial sculpture on the dorsal slope; epidermis
brownish or yellowish-brown, rather dull; left valve with a
strong, triangular tooth, a triangular pit in front of it and a
feeble anterior tooth; right valve with a strong, triangular
anterior tooth, a triangular pit behind it and a feeble posterior
tooth ; muscle scars well marked: nacre dull, lurid, bluish, with
a flesh-colored tint in the cavities.

Length 60, height 38, diam. 22 mm.

Burma; Pegu; Cambodia?

Monecondylea crebristriata ANtHONY, Am. JI. Conch., I, 1865,

p. 205, pl. xvitt, fig. 1.

Trigonodon crebristriata Conrap, Am. Jl. Conch., I, 1865, p.

233-

Margaron (Monocondylea) crebristriata Lea, Syn., 1870, p.
2.

Unio crebristriatus SowERBY, Conch. Icon., XVI, 1868, pl. xcv,
fig. 517.

Trigonodon crebristriatum HAntey and THropap, Conch.
Ind.21876,p2)5..pl- 1x, fies

Pseudodon crebristriatus SIMPSON, Syn., 1900, p. 835.

Unio vondembuschii Sowrerevy, Conch, Icon., XVI, 1868, pl.
xcVv, fig. 518.

PSEUDODON 1083

From a study of material of what I believed was P. peguen-
sis and credristriatus in the National Museum I came to the
conclusion that both were of the same species. Further study
inclines me to doubt whether the P. peguensis is genuine. The
crebristriatus seems to be a smaller, more compressed form,
more strongly sculptured, and having less inflated beaks than
P. peguensis.

Var. curvatus Preston.

“Shell having the ventral margin more curved and generally
less ovate in shape than in the typical form.” (Preston).
Type locality, Pegu.
Pseudodon crebristriatus var. curvata Preston, Rec. Ind.
Mis. Vile Tore; pe205:

PskUDODON PEGUENSIS (Anthony).

Shell smooth except on the posterior slope, which has
broad, rugose folds, subrhomboid, somewhat narrower in
front, inequilateral, subinflated, solid; beaks full and high, the
umbonal region broad; posterior ridge more or less double,
ending in a wide, feeble biangulation; base line curved, a lit-
tle fuller behind the middle; anterior end rounded; dorsal
slope obliquely subtruncate; epidermis dark brown or nearly
black; pseudocardinals prominent and slightly bilobed, par-
ticularly in the right valve; anterior scars distinct, deep; pos-
terior scars confluent; dorsal scars deep; nacre light salmon,
iridescent.

Length 93, height 60, diam. 30 mm.

Burma; Pegu.

Monocondylea peguensis An'troNy, Am. J]. Conch., I, 1865,

p. 205, pl. xviii, fig. 2.

Margaron (Monocondylea) peguensis Lea, Syn., 1870, p. 73.
Trigonodon crebristriatum var. peguensis HANLEY and THEO-

BALD, Conch. Ind., 1876, p. 5; pl. 1x, fie: 5.

Pseudodon crebristriatus var. peguensis SIMPSON, Syn., 1900,

p. 835. ;

Specimens in the National Museum from Pegu labeled
Pseudodon peguensis are probably P. crebristriatus, but they

1084 PSEUDODON

show much variation and approach peguensis very closely.
Some of them are much larger than Anthony’s measurements,
as well as more inflated. The chief distinguishing character,
I take it, would be the full, high beaks of the latter, while those
of crebristriatus are not so large or high.

Section PSEUDODON s. s.

Characters given under generic name.

Group of Pseudodon harmandti.

Shell rather small, solid, rhomboid, short, inflated ; posterior
ridge high, only slightly biangulate, faintly corrugated on the
posterior slope.

PsEUDODON HARMANDI Crosse and Fischer.

Shell long rhomboid, inflated, solid, inequilateral; beaks ap-
parently somewhat elevated but not inflated; anterior end
rounded; base nearly straight ; dorsal and post-dorsal outlines
curved, being almost subangular behind the ligament; poste-
rior ridge somewhat double, ending in a biangulation at and
above the base of the shell; surface for the most part smooth,
having some irregular growth lines on the disk and a few,
subradial corrugations on the dorsal slope; epidermis dark
brown or blackish, shining; in each valve there is a subcom-
pressed smooth tooth; muscle scars well impressed; dorsal
scars few, deep, arranged in a row under the beaks; nacre
lurid purplish.

Length 62, height 40, diam. 29 mm.

Cambodia.

Pseudodon harmandi Crosse and FiscHer, Jl. de Conch.,
XXIV, 1876, p. 331. pl. x, fig. 2—Srmpson, Syn., 1900, p.
836.

Monocondylea harmandi Pare, Conch. Sam., III, 1890, p.
174.

A solid, rhomboid, much inflated species with shining, al-
most black epidermis. The posterior ridge is rather high, and
behind it the dorsal slope falls away abruptly.

PSEUDODON 1085

PSEUDODON AUREUS Heude.

Shell rather small, subsolid, rhomboid, inflated, inequilat-
eral; beaks somewhat elevated but not inflated, strongly undu-
late; anterior end rounded; base full at the middle; post-dor-
sal outline subangulate behind the ligament, below the angula-
tion obliquely truncate; posterior ridge elevated, apparently
somewhat double, ending near the base of the shell in a blunt
point; epidermis yellowish-green ; nacre fuscous-salmon.

Length 30, height 20, diam. 15 mm.

China,

Pseudodon aureus Heupr, Conch. Fluv. Nank., IX, 1885, pl.

LXXII, fig. 140.—SIMPSON, Syn., 1900, p. 836.

Margaritana aurea Patri, Conch. Sam., III, 1890, p. 172.

A small, inflated, decidedly rhomboid species, which would
seem to be most nearly related to P. harmandi. I have never
seen it.

Group of Pseudodon vondembuschianus.

Shell rather large, somewhat compressed, subsolid, elliptic-
rhomboid, wider behind, where it is widely biangulate; teeth
compressed.

PSEUDODON VONDEMBUSCHIANUS (Lea).

Shell irregularly subrhomboid, scarcely subsolid, subcom-
pressed or convex, inequilateral; beaks only moderately full
or high; posterior ridge sometimes faintly double, ending in a
blunt point below the median line; dorsal outline nearly
straight or lightly curved, raised into a low wing behind;
anterior end a little narrowed, rounded, angled above; base
line curved, fullest behind the middle; dorsal slope obliquely
truncated ; surface nearly smooth; epidermis pale olive-green,
smoky, darker and a little rougher on the dorsal slope; teeth
one in each valve, subcompressed, smooth; dorsal scars deep ;
muscle scars shallow; nacre dull, lurid purplish, often blotched
in the cavities,

Length 72, height 44, diam. 20 mm.

Java; Sumatra; Borneo; Malacca.

1086 PSEUDODON

Margaritana vondembuschiana Lea, Pr. Am. Phil. Soc. 1,
1840; p. 2005 Tr. Am: Phil. Soc: VIG 1642. sp. io22 al
XVvIll, fig. 39; Obs., III, 1842, p. 60, pl. xvi, fig. 39.—
KustER, Conch. Cab. Unio, 1862, p. 295, pl. xcvitl, fig. 3.

Margaron (Monocondylea) vondembuschiana Lea, Syn., 1852,
P. 45; 1870, p. 73.

Monocondylea vondembuschiana H. and A. ADAMs, Gen. Rec.
Moll., Il, 1858, p. 501.

Pseudodon vondembuschiana ConRaAp, Am. Jl. Conch., I, 1865,
pres.

Pseudodon vondembusclianus SIMPSON, Syn., 1900, p. 836.

Monedontina buschiana Conrap, Pr. Ac. N. Sci. Phila., VI,
1853, pp. 269, 449.

Unio von buschea Sowersy, Conch. Icon., XVI, 1866, pl. 11.
fig. 260.

Alasmodonta crispata Mousson, L. and W. Moll. Java, 1849,
Pp. -O7, DL XVI mes. 12)

Margaritana crispata P&tEL, Conch. Sam., II], 1890, p. 173.

Monocondylea planulata Lea, Pr. Ac. N. Sci. Phila., XI, 1859,
pae7 4a). Ac. NG Scie Phila. TVG 1850. p. 202 sl me:
142; Obs., VII, 1860, p. 80, pl. xi, fig. 142—?PKUSTER,
Conch. Cab. Unio, 1862, p. 305, pl. c, fig. 8.

Pseudodon planulata Conrap, Am. Jl. Conch., I, 1865, p. 233.

Margaron (Monocondylea) planulata Lea, Syn., 1870, p. 73.

Microcondylea planulata Pavrer, Conch. Sam., III, 1890, p.
Te Se

Margaritana fragilis KustER, Conch. Cab. Unio, 1862, p. 295,
pls XGvinn she: 2.

Microcondylea fragilis Pret, Conch. Sam., III, 1890, p. 175.

Morocondylea rhomboidea Kuster, Conch. Cab. Unio, 1862, p.
204,01. Cc, fir..7.

This species grows larger than the measurements given,
which are from the type. All the specimens I have seen have

a smoky epidermis.

PsEUDODON ELLIPTICUS Conrad.

Shell almost elliptical, inclining a little towards being rhom-
boid, scarcely subsolid, convex, inequilateral; beaks not prom-
inent: posterior ridge inclined to be double, ending at and

PSEUDODON 1087

below the median line in a faint biangulation; anterior end
a little narrowed, rounded ; basal and dorsal lines curved ; post-
dorsal slope subtruncated ; surface nearly smooth, sometimes
having a few feeble wrinkles on the dorsal slope; epidermis
pale tawny or horn colored, with dark rest marks, greenish
and having one or two faint rays on the dorsal slope, shining ;
teeth one in each valve, subcompressed, rounded, smooth; dor-
sal scars deep, forming a row under the beaks; muscle scars
shallow; nacre dull, lurid purplish, slightly iridescent behind.

Length 70, height 48, diam. 24 mm.

Cambodia.

Pseudodon ellipticum Conran, Am. Jl. Conch., I, 1865, p. 352,

pl. xxv, fig. 1.—Simpson, Syn., 1900, p. 836.

Two fine shells of this species from the Laos Mountains,
Cambodia, are in the Lea collection with other specimens, all
bearing the name of Monocondylea cumingii. As Conrad
has pointed out, it is more elliptical, is smoother, is regularly
rounded below and lighter colored than cwmingit. One of
these has slight posterior plications. The color is peculiar.

PSEUDODON ZOLLINGERI (Mousson).

Shell long rhomboid, convex, subsolid, inequilateral; beaks
apparently not prominent; posterior ridge double, curved, end-
ing in a wide biangulation from the median line to the base;
dorsal and post-dorsal outlines curved, the elevation being
most prominent at the end of the ligament; base line straight,
sometimes a little incurved; anterior end rounded; surface
rather rough, the epidermis being brown and somewhat con-
centrically wrinkled or lamellose ; teeth one in each valve, rath-
er stout, elevated and rounded, subcompressed; nacre brown-
ish.

Length 77, height 45, diam. 26 mm.

Java.

Alasmodonta zollingeri Mousson, L. and Suss. Moll. Java.

1849, p. 96, pl. xvitt, fig. 2.

Margaritana sollingeri Kustrr, Conch. Cab. Unio, 1862, p.

294. pl. xcvitr, fig. I.

Pseudodon zollingeri Stimpson, Syn., 1900, p. 837.

1088 PSEUDODON

Monocondylea sollingeri Pairr., Conch. Sam., III, 1890, p.

174.

There is no reference to any plate or figures in the descrip-
tion of this species given by Mousson, but the three figures
on plate XVIII, are probably intended to represent it. Num-
ber I is probably some other species, while 2 represents an
elongated rhomboid shell with a double posterior ridge, which
is quite strongly developed, and ends in a wide, decided bian-
gulation behind. I have before me an author’s specimen of
Alasmodonta zollingeri, from the Morelet collection, which
exactly agrees with Mousson’s figure 2 on the plate XVIII of
the “Mollusken von Java.”

PSEUDODON INOSCULARIS (Gould).

Shell irregularly rhomboid, rather solid, slightly inflated,
the greatest inflation being just behind the middle of the shell,
inequilateral; beaks not prominent; posterior ridge high, dou-
ble, ending in a wide, distinct biangulation at’ and below the
median line; anterior end somewhat narrowed, rounded; base
line almost evenly curved; post-dorsal outline high and almost
angled behind the ligament, subtruncate behind; surface with
. irregular growth lines and sometimes with a few, faint, subrad-
ial plications on the dorsal slope; epidermis tawny-brown,
subshining; teeth single in each valve, blunt and rounded;
dorsal scars few, forming a row under the beaks, deep ; muscle
scars shallow; nacre lurid brownish. .

Length 74, height 48, diam. 25 mm.

River Salwen, British Burma.

Anodon moscularis Goutp, Pr. Bost. Soc. N. H., I, 1844, p.
160.—HaAnLry and THEoBALD, Conch. Ind., 1876, p. 5, pl.
DXi g02;

Margaron (Monocondylea) inoscularis Lua, Syn., 1870, p. 73.

Margaritana moscularis Paver, Conch. Sam., III, 1890, p. 173.

Pseudodon inoscularis Stmeson, Syn., 1900, p. 837.

Close to P. cumingti, but shorter, solider and a little fuller.
I have before me a single specimen and a valve belonging to
the Lea collection bearing the name An. inoscularis, from the
author of the species. It is considerably more solid and in-
flated than P. vondembuschianus.

PSEUDODON 1089

PsgUDODON CUMINGII (Lea).

Shell irregularly subrhomboid, convex, scarcely subsolid, in-
equilateral; beaks not prominent; posterior ridge rather full,
rounded or imperfectly double, ending in a blunt point or a
feeble biangulation near the base; anterior end somewhat nar-
rowed, rounded; dorsal line curved; dorsal slope obliquely
subtruncate ; base curved, fullest about at the middle; surface
with irregular growth lines; epidermis brownish to blackish,
smooth and shining, though slightly smoky; teeth single in
each valve, subcompressed, smooth; dorsal scars deep; muscle
scars well marked; nacre bluish or purplish, sometimes brown
tinted.

Length 85, height 53, diam. 26 mm.

Malacca; Perak ; Siam ; Cambodia.

Anodonta cunungi Lea, Pr. Zool. Soc. Lond., 1850, p. 199.—
Muscrove, Phot. Conch., 1863, pl. 1, fig. 6.

Magaron {Monocondylea) cumingu Lea, Syn., 1852, p. 50,
1O7O; ps 273-

Monocondylea cumingu Lea, Jl. Ac. N. Sci. Phila., [V, 1860,
pyess pl xx hie 14's Obs, Vil =1860, p. 53) pli xxxi15,
fig. 114.

Anodon cumingiti Reeve, Conch. Icon.,X VII, 1870, pl. xxxt1,
Het 22.

Micrecondylea cumingti Cursstx, Conch. Cab. Ano., 1876, p.
Z5OW Digi OxTT eiloSs ay Al

Pseudodus cumingti pe Morcan, Bull. Soc. Zool. de Fr., X,
1885, p. 422.

Pseudodon cumingu SIMPSON, Syn., 1900, p. 837.

Very close to P. vondembuschianus, but darker colored,
rather more solid and inflated and having a higher posterior
ridge. It is quite probable that a large series from different
localities would show that the two intergraded.

PSEUDODON ASNEOLUS Drouet.

SE

Shell elliptic rhomboid, subcompressed, subsolid, inequilat-
eral; beaks low and subcompressed; dorsal outline lightly
curved, ending in a low wing behind; dorsal slope subtrun-

1090 PSEUDODON

cate; base line arcuate, fullest behind the middle; anterior end

rounded, narrowed; posterior ridge widely double, ending in

a biangulation at and below the median line ; surface often hav-

ing subvertical folds, also radial plications on the dorsal slope

but these are sometimes nearly or quite obsolete in adult
shells; epidermis brownish or coppery, with metallic tints on
the disk, subshining ; teeth single in each valve, small, smooth;
dorsal scars deep; muscle scars shallow but distinct; nacre

livid, coppery, purplish or salmon-tinted, slightly iridescent.

Length 65-70, height 38-40, diam. 18-20 mm.
Borneo.

Pseudodon eneolus Drourr, Jl. de Conch., XL, 1892, p. 94.—
Drove? and CHAPER, Mem. Soc. Zool. de Fr., V, 1892, p.
152, pl. v1, figs. 4-7——Simpson, Syn., 1900, p. 837.

Very close to P. vondembuschianus, but more solid and more
coppery-colored. The plications do not seem to be constant.

PSEUDODON RESUPINATUS von Martens.

“Shell oblong, moderately thick, quite compressed, sculp-
tured on the posterior and upper parts with radiating folds,
curved and ascending towards the margin and more or less
subdivided, elsewhere smooth; epidermis black, somewhat
shining; anterior margin rounded; posterior dorsal margin
curved as far as the sinulus, thence oblique and straight;
posterior end sub-biangulate, quite short, perpendicular; ven-
tral margin straight, in old shells slightly sinuate; cardinal
teeth single in both valves, thick, obtuse; posterior cardinal
somewhat thick, obtuse; sinulus inequilateral, low, obtuse-
angled; nacre bluish-pearly; anterior muscular impressions
deep, posterior superficial, anterior accessory impression quite
deep.

Length 73, height, vertical 32, ala 38, diam. 22 mm. Beaks
situated at 1/5 of the length.” (von Martens).

Type locality, Than-Hoi, Tonkin.

Pseudodon resupinatus voN Martens, Nachr. Deutsch. Mal.

Ges. 1902; p." 131.

PSEULODON ; IOQI

“Nearest to Ps. aeneolus Drouet from Borneo, but propor-
tionately longer and with more strongly impressed sculpture.
These two Pseudodons are, to my knowledge, the only ones
with the folds bent upwards on the posterior surface and al-
most deserve to be put in a small group, resembling the genus
Ptychorhyncus Simp., in which Unio apicellatus Heude in-
vites comparison, but they have no indications of lateral teeth,
only a stout, somewhat swollen hinge margin as in M. mar-
garitifera I,.; whereas both in Simpson’s generic diagnosis
and in Heude’s figures the usual lateral teeth of Unio clearly
appear ; to be sure, Heude says of many of his species that they
properly belong to Alasmodonta, but this is in contradiction of
his figures.

The intensity of the sculpture seems to be variable; on one
mature example, in addition to the upward curved folds on
the hinder part, there are in the middle a few almost vertical
wrinkles, slightly curved forwards, that are wholly wanting
in others; on two somewhat smaller specimens which, how-
ever, can not be considered as young, the characteristic up-
ward curved folds are as feeble as in Heude’s figure of
apicellatus, but they are decidedly stronger on the example
on which I base my description. On one specimen I count
but two, on another four small, rounded muscular impres-
sions.”

PsgkuUDODON TuMIDUS ( Morelet).

Shell nearly elliptical, inflated, rather thin, inequilateral ;
beaks full and elevated ; dorsal outline generally rounded, hav-
ing a deeply impressed lunule in front and a slight prominence
just at the end of the ligament; anterior end somewhat nar-
rowed, rounded: base line eventy curved, not quite so full as
the dorsal outline; posterior ridge high, narrowly rounded,
ending in a blunt point just below the median line; epidermis
yellowish-brown in young shells, chestnut in adults; teeth sin-
gle in each valve, rather strong, smooth; nacre bluish-white,
fulvous under the beaks.

Length 70, height 46, diam. 34 mm.

Siam; Cambodia.

TOQg2 ; PSEUDODON

Monocondylus tumidus Morevet, Jl. de Conch., XIV, 1866,
p- 62.—Mabi.e, Rev. Zool., XXIII, 1872, p. 51, pl. v, figs.
Goo

Pseudodon tumidus Morevet, Ser. Conch., IV, 1875, p. 337,
pl. xv1, fig. 1—Simpson, Syn., 1900, p. 837.

There is an old, somewhat eroded, dead shell in the Lea
collection from Haines labeiled Monocondylea inoscularis,
Siam, which is not Gould’s species I am sure, but may be the
above. It is 110 millimeters in length, 70 in height and 45 in
diameter. The earlier growth lines conform to those of More-
let’s she!l, but in the later ones the posterior point is somewhat
drawn down, as is often the case with old shells. The species
may be distinguished from allied forms by its inflation, its
nearly elliptical form and the high, narrow posterior ridges.

PSEUDODON OVALIS Morlet.

Shell elliptic rhomboid, rather short, subcompressed, thin,
inequilateral ; beaks low: posterior ridge full, widely rounded,
ending bluntly behind, a little above the base ; anterior end very
slightly narrowed, rounded; base line evenly curved; dorsal
outline curved, produced into a low wing behind; dorsal slope
obliquely subtruncate; epidermis with decided, concentric,
strie, brown, slightly shining; teeth rather small, smooth;
muscle scars rather deep; nacre bluish with blotches of pale
orange, iridescent.

Length 75, height 53, diam. 19 mm.

Srakeo River, Siam.

Pseudodon ovalis Moret, Jl. de Conch., XXXVII, 1880, p-

197; pl. vil, fig. 3—StmPson, Syn., 1900, p. 837.

I have never seen this species, but it seems to be well dis-
tinguished from all the others by its short, elliptical, rhomboid
form, small teeth and biue nacre blotched with pale orange.

PSEUDODON THOMSONI Morlet.

Shell irregularly long obovate, scarcely inflated, thin, in-
equilateral; beaks moderately inflated; dorsal outline slightly
and irregularly curved; anterior end narrowed and rounded;
base line almost straight throughout its anterior half, full and

PSEUCUNDODON 1093

rounded at and behind the middle; posterior ridge very faintly,
widely double, ending at and below the median line in a wide,
faint biangulation; dorsal slope rather abruptly subtruncate ;
surface pale chestnut, the epidermis subject to exfoliation ;
teeth small; nacre pale orange under the beaks, becoming rosy
white in the disk, iridescent and ornamented with feeble, trans-
verse striz.

Length 53, height 32, diam. 19 mm.

Cambodia.
Pseudodon thomsont Mor.urt, Jl. de Conch., XXXII, 1884, p.

401, pl. xu, figs. 2, 2a.— Simpson, Syn., 1900, p. 838.
Margaritana thomsoni Pare, Conch. Sam., III, 1890, p. 174.

Morlet states that this shell has feeble laterals. [I cannot
be certain that it is a Pseudodon. It is possibly a species of
Hyriopsis.

PSEUDODON SALWENIANUS (Gould).

Shell rhomboid ellipticai, compressed or convex, subsolid,
inequilateral ; beaks only moderately elevated; dorsal outline
lightly arcuate ; anterior end rounded; base line lightly curved ;
posterior end obliquely truncate, joining the dorsal end with
an angle; posterior ridge strongly and angularly developed;
ending in a blunt point near the base; dorsal slope radiately
plicate ; epidermis blackish; muscle scars shallow; nacre sub-
livid.

Length t4o, height 64, diam 31.5 mm.

River Salwen, British Burma.

Anodon salweniana Goutp, Pr. Bost. Soc. N. Hist., I, 1844...

5160!

Anodonta salwveniana GouLp, Otia Conch., 1862, p. 193.
Pseudodon salweniana Conrap, Am. Jl. Conch., I, 1865, p.

223)

Monocond\lea salweniana Pare, Conch. Sam., III, 1890, p.

174.

Unio salwenianus Sowrrsy, Conch. Icon., XVI, 1868, pl.

RCH S151:

Margaron (Monocondylea) salweniana LEA, Syn., 1870, p. 72.

1094 PSEUDODON

Pseudodon salwenianum HANtEy and THropaLp, Conch. Ind.,
E376; pe 5, pl. EX, fie. 4.
Pseudodon salwenianus SIMPSON, Syn., 1900, p. 838.
Sowerby and Hanley and Theobald figure what they believe
is the above species, but the measurements given by Gould are
for a shell much longer in proportion to its height than theirs.
The species would seem to be easily distinguishable by its
considerable length, and the strong posterior plication. I am
doubtful whether the figures in the Conchologia Indica and
the Conchologia Iconica really are taken from Gould’s shell.

PSEUDODON MORELETI Crosse and Fischer.

Shell large, subrhomboid, subinflated, rather solid, inequi-
lateral; beaks full, wide, moderately prominent; posterior
ridge full, widely rounded, with one or two small, distinct
ridges above; anterior end a little narrowed, rounded; base
lightly curved or straight; posterior end obliquely subtruncate
above, rounded below; surface with irregular growth lines;
epidermis dark brown, somewhat shining, roughened on the
border of the shell and behind; teeth single in each valve, not
large, smooth and subcompressed ; dorsal scars forming a row
under the beaks; anterior scars impressed; posterior scars
large, semicircular, shallow; nacre pale purplish, iridescent
behind.

Length 124, height 80, diam. 48 mm.

Cambodia.

Monocondylea tumida DrsSHAYES and JuriiEeN, Nouv. Arch.

de Mus., 1874, p. 117, pl. v, figs. 1-3.

Pseudodon moreleti Crosse and Fiscuer, Jl. de Conch., XXV,

1876, p. 330.—SIMPsoN, Syn., 1g00, p. 838.

A magnificant specimen of this species with the above
measurements is in the National Museum Collection from
Cambodia. It is the largest Psewdodon I have seen. The form
is slightly obovate, inclining to rhomboid; the nacre is pale
purple and differs in color from that of any species I am ac-
quainted with. Deshayes and Jullien figured both shell and
animal of this species beautifully in the Nouvelles Archives du

PSEUDODON 1095

Museum under the name Monocondylea tumida of Morelet,
which is: quite a different species, and Fischer and Crosse
gave it a new name.

PsEUDODON CAMBODJENSIS ( Petit).

Shell subtriangular, subsolid, convex, inequilateral; beaks
low, compressed ; posterior ridge full, rounded, ending bluntly
at the base of the shell; anterior end narrowed, rounded; dor-
sal outline curved, carried into a low wing behind; dorsal slope
strongly and obliquely truncated; base line nearly straight ;
surface with irregular, concentric growth lines, ashy-brown or
greenish-brown, subshining ; teeth single in each valve, large,
elevated, subtriangular; dorsal scars forming a row under the
beaks; muscle scars irregular, impressed ; nacre flesh-colored,
somewhat silvery; ligamental patch large, dark, triangular.
Behind the teeth of old shells the epidermal matter covers the
hinge plate.

Length 107, height 72, diam. 31 mm.

Cambodia ; ‘Tonkin.

Monocondylea cambodjensis Prrir, Jl. de Conch., XIII, 1865,

p. 16, pl. 1v, fig. 4.

Margaron (Monocondylea) cambodjensis Lea, Syn., 1870,

De 72:

Pseudodon cambodjensis SIMPSON, Syn., 1900, p. 838.

The National Museum possesses a fine series of shells of
this species, young and old. The young shells are rather
thin, but they become quite strong with age. The young shells
are more obovate and less distinctly triangular than those of
the adults. The peculiar form will distinguish this species.

Psrupopon cuAPERI (de Morgan).

Shell subrhomboid, somewhat inflated, solid, inequilateral ;
beaks only moderately full or high; posterior ridge widely and
decidedly double, ending at the median line and near the base ;
anterior end narrowed and rounded; base line lightly curved ;
dorsal line curved from the anterior end to the median line be-
hind, fullest just behind the ligament; surface covered with
strong, concentric ridges; epidermis thick, brownish. There

1096 PSEKUDODON

is a low, radial ridge on the posterior slope midway between
the upper part of the posterior ridge and the dorsal line, that
ends in a slight angle behind; hinge with a strong, very prom-
inent, triangular tooth in each valve; anterior muscle scars
well marked; posterior scars shallow; dorsal scars six in each
valve, forming a row under each beak, deep; nacre grayish-
white.

Length 84, height 48, diam. 38 mm.

Cambodia; Siam.
Pseudodus chaperi pe Morcan, Bull. Soc. Zool. de Fr., X,

1885, Pa 422, pilex, fos, Tee
Pseudodon chaperi Stmpson, Syn., 1900, p. 838.

de Morgan places this species and the Anodonta cumingii
Lea in the genus Pseudodus and credits the genus to Gould,
who bestowed the name Pseudodon on the group of oriental
Naiades having a single large tooth in each valve and practi-
cally wanting laterals. The author of this species describes it
as having very long laterals, but they probably are rudiment-
ary, as the shell seems to be a Pseudodon. Its distinguishing
characters are its strong, concentric sculpture and the decided-
ly wide, double posterior ridge.

PsEUDODON WAI,POLEI (Hanley).

Shell irregularly rhomboid, considerably narrowed in front,
convex, rather solid, inequilateral; beaks moderately elevated,
not inflated; posterior ridge full, rounded, ending in a blunt
point at the base of the shell; above it there are two or more
faint, radial ridges, the middle part of the dorsal slope is ir-
regularly and strongly plicate; anterior end narrowed and
rounded, subangulate above; base line straight or lightly ar-
cuate: hinge line curved a little; outline of dorsal slope ob-
liquely rounded, angled behind the ligament; teeth single in
each valve, small and but .little elevated; dorsal scars few.
placed in a row under the beaks; muscle scars shallow; nacre
lurid purplish ; ligamental sinus well marked.

Length 55, height 32. diam. 19 mm.

Borneo.

Monocondylea walpolei HANtEY, Proc. Zool. Soc. Lond., 1871,

p. 587.—Stmpson, Syn., 1900, p. 840.

PSEUDODON 1097

Since the Synopsis was written the National Museum has
received three fine specimens of what are undoubtedly this
species from Sarawak, Borneo. The epidermis is reddish-
brown and shining, and there are traces of radial sculpture
on the anterior end of the shell. Above the corrugated area
on the dorsal slope there is a narrow, smooth zone reaching
to the ligament. The incremental striz are not very strong in
these shells. Walpole states that the basal margin is incurved
in the middle. The type is a little larger than the measure-
ments given above.

Section BrnkURUS Simpson, 1900.

Bineurus SIMPSON, Syn., 1900, p. 830.

Shell elongate rhomboid, thin, rounded in front, widely and
feebly biangulate behind, having two or more raised, radiating
lines on the posterior slope, which is slightly, obliquely wrin-
kled; beaks low; surface finely, irregularly, concentrically
grooved: epidermis olive; teeth smooth, compressed; nacre
bluish. Animal unknown.

Type. Monocondylea mouhoti Lea.

PsEUDODON MOUHOTI (I,ea).

Shell elongated, subrhomboid, slightly narrowed in front,
subcompressed, rather thin, inequilateral ; beaks subcompress-
ed, not prominent; posterior ridge wide, rounded; dorsal out-
line lightly curved; anterior end rounded; base nearly or quite
straight ; dorsal slope obliquely truncated ; posterior end round-
ed below; growth lines somewhat strong and irregular; epi-
dermis greenish-brown often marked or shaded green on the
dorsal slope; teeth small, rounded, subcompressed, single in
each valve; nacre bluish, lurid purplish in the cavities, irides-
cent behind; muscle scars shallow.

Length 67, height 34, diam. 18 mm.

Cambodia ; Siam.

Mon >condylea mouhoti Lea, Pr. Ac. N. Sci. Phila., VII, 1863,

Pp. 190.

Pseudodon manhoti Conran, Am. Jl. Conch., T, 1865, p. 233.

1098 PSEUDODON

Monocondylea mouhotiana Lea, Jl. Ac. N. Sei. Phila., VI,
1866;-p; 65; pl. xxi; fig. 62; Obs, XI, 1867, p;.60; pla axa,
fig. 62.—C1«ssin, Conch. Cab. Ano., 1876, p. 261, pl. Lxxxu,
eset 2:

Margaron (Monocondylea) mouhotiana Lea, Syn., 1870, p.
73:

Unio mouhotianus Sowrersy, Conch. Icon., XVI, 1868, pl. xctt,
fig. 503.

Pseudodon mouhotianus Moree, Ser. Conch., IV, 1875, p.
330. |

Pseudodon mouhott SIMPSON, Syn., 1900, p. 839.

Elongated, rather thin and subcompressed. It does not
seem to be as much inflated as P. evilis.

Psrubopon EXILIs (Morelet).

Shell elongate, subrhomboid, inequilateral, thin, convex or
subinflated; beaks not prominent; anterior end narrowed and
rounded; dorsal outline lightly curved; dorsal slope obliquely
tuncated; base line almost straight, full behind the middle;
posterior ridge widely rounded; posterior end rounded below ;
surface with strong growth lines; epidermis tawny-brown ;
teeth single in each valve, small, compressed ; nacre bluish, ful-
vous in the cavities.

Length 57, height 30, diam. 18 mm.

Perak.

Monocondylus exilis MoRELET, Jl. de Conch., XIV, 1866, p. 63.
Pseudodon exilis Moreiet, Ser. Conch., IV, 1875, p. 340, pl.

XVII, fig. 1.—SIMpsoN, Syn., 1900, p. 839.

I suspect that this is merely a variety of P. mouhoti. The
beaks are not quite so near the anterior end as they are in
that species, the shell is more tawny, more strongly, obliquely
truncate on the dorsal slope, and more inflated.

Psgupopon Ava (Theobald).

Mandelay, Burma.
Monocondylea ava THroBALD, Jl. As. Soc. Beng., XLII, Pt.
21 a72. pe 200, ‘pl-gX Ville Hes 15:
Pseudodon ava SIMPSON, Syn., 1900, p. 839.
The description of this species is not accessible to me. I
am not certain that it belongs in this group.

PSEUDODON 1099

PsSEUDODON BICRISTATUS (Strubell).

“Shell almost regularly ovate, rather thin, small, scarcely
inflated, lightly striate, not very shining, olivaceous-brown.
Anterior end short; posterior end moderately elongated, di-
lated, the greatest height being at the postero-dorsal angle.
Dorsal margin short, almost straight, ascending, forming a
distinct angle posteriorly, an indistinct one in front; anterior
end very shortly rounded; basal margin scarcely curved,
slightly ascending posteriorly, forming with the posterior mar-
gin a short, biangulated, truncated beak. Umbones anterior,
depressed, widely, but superficially, eroded; areola none; area
elongate, compressed, distinctly bicarinate, carine prominent
at the posterior margin; ligament narrow, almost covered.
Hinge very narrow, teeth almost obsolete, lateral narrow;
muscular impressions superficial; nacre bluish, livid towards
the umbones.

Iength 42, height 25, diam. 12 mm.” (Strubell).

Type locality, South Sumatra.

Microcondylea bicristata StRUBELL,, Nachr. D. Mal. Ges., 1897,
pe:

I am indebted to the courtesy of Dr. F. Haas for the correct
generic position of this species.

Section Nasus Simpson, 1900.

Nasus SIMPSON, Syn., 1900, p. 830.

Shell somewhat solid, rather inflated, much elongated, with
a well-developed posterior ridge, with a low, faint one above
it, bluntly pointed at post-basal part ; beaks not high, eroded in
the specimens seen; epidermis dark; teeth compressed, high.

Animal unknown.

Type, Pseudodon nankingensis Heude.

PSEUDODON NANKINGENSIS (Heude).

Shell rather thin, long elliptical, inflated, inequilateral ; beaks
not elevated; posterior ridge high, subangulate; anterior end
rounded ; dorsal and ventral outlines lightly curved; posterior
end bluntly pointed or rounded, somewhat drawn out; surface

IITOO PSEUDODON

with strong, irregular, concentric growth lines; epidermis
dark brown or blackish, subshining ; teeth single in each valve,
small but elevated, rounded, compressed; muscle scars shal-
low ; nacre whitish; pallial line sinused behind.

Length 62, height 26, diam. 20 mm.

Rivers of Nankin.

Monocondyilca nankingensis HEupE, Ji. de Conch., XXII, 1874,

p. 116; Conch. Fluv. Nank., I, 1875, pl. 1v, fig. 9.
Pseudodon nankingensis SIMPSON, Syn., 1900, p. 8390.
Monocondylea nanquinensis Pate, Conch. Sam., III, 1890,

Pp. 174.

A single, badly worn author’s specimen of this species is in
the National Museum collection, which is more pointed behind
than the figure. It 1s much inflated and the umbonal region is
scarcely elevated above the general outline.

PSEUDODON SECUNDUS Heude.

Shell subsolid, elongated, subrhomboid, inflated, inequilat-
eral; umbonal region slightly elevated ; posterior ridge strong,
subangled, ending in a point near the base line; anterior end
rounded; dorsal outline lightly curved; base line nearly
straight; posterior slope obliquely subtruncate; epidermis
brownish, somewhat shining; teeth single in each valve, sub-
compressed, triangular, elevated; muscle scars well marked;
nacre bluish-tinted, dirty flesh-color in the cavities ; pallial line
having a distinct sinus behind.

Length 82, height 30, diam. 30 mm.

Length 73, height 33, diam. 25 mm.

River Hoz, China.

Pseudodon secundus Hrupr, Conch. Fluv. Nank., III, 1877,

pl. xvin, fig. 38.—Srmpson, Syn., 1900, p. 840.

Unio secundus Pasret,, Conch. Sam., III, 1890, p. 167.

The first of the above measurements is that given by Heude
and I am inclined to think that the diameter is too large in
proportion to the rest of the shell. ‘The second measurement
is from an author’s shell in the National Museum. ‘The spe-
cies is close to nankingensis, but is more solid, less elongated in
proportion, and has lighter colored, smoother epidermis.

PSEUDODON IIOL

Section Oxvovatis Simpson, 1900.

Obovalis SIMPSON, Syn., 1900, p. 840.

Shell obovate. subinflated, with a low, rounded posterior
ridge and with radiating wrinkles on the posterior slope; disk
nearly free from wrinkles; epidermis blackish; there is a high,
triangular tooth in each valve; laterals very faint, rounded;
nacre coppery.

Type, Pseudodon loomisi Simpson.

PSEUDODON LOOMISI Simpson.

Shell slightly rhomboid, obovate, convex, scarcely subsolid,
inequilateral; beaks moderately full, but little elevated; pos-
terior ridge rounded, ending below the median line in a blunt
point; dorsal border lightly arcuate; basal line curved; anter-
ior end rounded, subangular above ; dorsal slope obliquely sub-
truncate; surface with irregular growth lines, which become
rather strong ridges in front, radiately plicate on the dorsal
slope; epidermis nearly black, somewhat sericeous where not
worn; left valve with one tooth and a vestigial one in front
of it; right valve with a single tooth; teeth elevated; laterals
reduced to a rounded ridge ; anterior scars impressed ; posterior
scars shallow; dorsal scars on the under side of the hinge
plate; nacre bluish, becoming dull purplish in the cavities,
somewhat iridescent ; pallial line with a posterior sinus.

Length 67, height 36, diam. 22 mm.

Japan.

Pseudodon loomisi Simpson, Pr. Ac. N. Sci. Phila., 1900, p.

84, pl. Iv, fig. 7; Syn., 1900, p. 840.

There is a single shell, the type, in the National Museum
collection. It differs from all other species of Pseudodon in
its obovate, elongated outline and radial plications on the dor-
sal slope.

SPECIES INCERT.® SEDIS.

PsrEvupopoN sorimus Haas.

“Shell long-elliptical, solid, heavy, quite compressed, ante-
rior upper margin curved, uniting without an angle the short,
steep anterior end, which curves gently into the slightly

I102 PSEUDODON

curved, almost horizontal ventral margin. Posterior end
nearly perpendicular; posterior slope curved; posterior dorsal
margin at first straight, then rather sharply curved where it
joins the posterior margin. Beaks situated at 21-100 of the
total length, quite swollen, extending slightly above the pos-
terior dorsal margin and very much above the anterior dorsal!
margin, eroded, showing, however, remnants of a sculpture
consisting of close, concentric ridges. Posterior slope quite
high, somewhat compressed, posterior ridge indistinct. Areola
small, ligament long, strong, half-covered. Simulus broad
lanceolate, cutting deep into the beaks. Sinus not recogniza-
ble. Epidermis brownish-black, lighter towards the beaks.
Outline from above narrow lanceolate, decreasing quite regu-
larly in thickness from front to rear. Hinge with two, blunt,
tooth-like projections, that in the right valve obtusely trian-
gular, quite high and stands in front of the beak, while that of
the left valve is longer and is situated under the beak. An-
terior muscular impressions deep, confluent, (that of the lower
retractor is very large almost separated), the posterior im-
pressions are shallow and confluent. The dorsal muscular
impressions, 4-6, lie in a groove in the beak cavity. Nacre
porcellaneous, bluish-white, slightly iridescent.

Length 92, greatest height 54, at beaks 45, diam. 31.5 mm.”
(Haas).

Type locality, Hunan, Centrai China.
Pseudodon solidus Haas, Nachr. Deutsch. Mal. Ges., 1911, p.

46.

PSEUDODON PONDEROSUS Preston.

“Shell solid, moderately convex, sub-trapezoidal, covered
with a coarse, black, scaly periostracum, which becomes lamin-
iferous towards the posterior side; anterior side bluntly round-
ed; posterior side rounded above, somewhat rostrate below;
dorsal margin slightly arched; ventral margin almost straight ;
umbones large, prominent; interior of shell nacreous, irides-
cent, tinged with pinkish mauve, deepening posteriorly.

Length 117, height 66 mm.” (Preston).

Type locality, Nan-ko, Siam.

PARREYSIA LLOs,

Pseudodon ponderosa Preston, Pr. Mal. Soc. London, VIII,.
1EOOs ps 202, pk WEN heer

The following are unfigured or indeterminate species.

Spatha compressa VON Marrens, Proc. Zool. Soc. Lond., 1860,
p. 66. Siam.

Pseudodon sulcatum RocHEBRUNE, Bull. Soc. Phil., 7th ser.,
VI, 1882, p. 41. Mekong River, Cochin China.

Pseudodon pierrei Rocurerunr, Bull. Soc. Phil., VI, 1882, p.
41. Cochin China.

Pseudodon mabilli RocuEBRUNE, Bull. Soc. Phil., VI, 1882,
p. 41. Cochin China, Cambodia.

Pseudodon anodontinum RocuEpruNne, Bull. Soc. Phil., VI,
1882, p. 41. Cambodia.

Genus PARREYSIJA Conrad, 1853.

Parreysia Conrap, Pr. Ac. N. Sci. Phila., VI, 1853, p. 267.—

OrtMANN, Ann. Car. Mus., VIII, 1912, p. 276.

Shell solid, inflated, oval to subrhomboid, with full, high,
zigzag, radially sculptured beaks, the sculpture often extend-
ing over the disk; epidermis smooth and bright, sometimes a
little rayed: with two irregular pseudocardinals in the left
valve which are more or less broken into ragged denticles, or
are strongly, vertically striate, and two laterals, the lower the
larger: right valve with one, sometimes two pseudocardinals,
the upper small, compressed, and a few tubercles behind them,
with two laterals, the upper the larger; cavity of the beaks
rather deep, not compressed ; dorsal scars under the hinge, not
visible; the two upper anterior muscle scars very deep, con-
fluent, the lower linear; nacre white to salmon, iridescent be-
hind.

Length 65, height 27.5, diam. 15.5 mm.

Type, Unio multidentatus Philippi.

In the above reference Conrad gives the name Parreysia and
refers to Unio multidentatus Parreyss, which may be taken
as the type. I do not know that he ever described the group.

The species, which I have placed in the above named assem-
blage, seem, so far as conchological characters show, to be

1104 PARREYSIA

closely related to Nodularia. Both groups, as I have constitut-
ed them, have numerous representatives in Tropical Africa
and southeast Asia. The shells of this group are generally
more solid, more inflated and shorter than those of Nodularia.
The beaks and earlier growth, as a rule are rather more strong-
ly sculptured with zigzag-radial ridges than are those of that
genus and the pseudocardinals are heavier and more split up.
In a great many species there are small tubercles on the hinge
plate, behind the pseudocardinals. The beak cavities are, as a
rule, deeper than those of the species of Nodularia.

Ortmann, (1. c.), from an examination of P. wynegungen-
sis Lea, remarks: “Soft parts partly primitive, partly more
advanced. Super-anal separated from the anal by a well-de-
veloped mantle-connection, which is rather long. Inner lam-
ina of inner gills entirely connected with the abdominal sac.
All four gills are marsupial in the female, with well-developed
septa and water-tubes, which latter are somewhat narrower in
the outer gill than in the inner. In the male, the septa are dis-
tinctly more distant than in the female. During pregnancy,
the gills swell but little, and the edges remain sharp, and the
ovisacs remain simple. Placentz subcylindrical, only slightly
compressed, and not very solid. Glochidia not observed.”

K&Y TO THE GROUPS OF PARREYSIA.

Shell with imperfect laterals. Group of P. biesiana.
Shell generally having perfect laterals.
Ovate. obovate or elliptical.
Small, ovate with strong, concentric outer ridges.
Group of P. aurora.
Medium sized; beaks high, strongly sculptured ;
pseudocardinals strong and ragged.
Group of P. corrugata.
With a high, pinched-up posterior ridge.
Group of P. chinensis.
Beak sculpture very strong, extending part way over
the disk, abruptly changing to concentric sculpture.
Group of P. bakert.

PARREYSIA T105

Elliptic rhomboid.
Sculpture extending only part way over the disk.
Group of P. rugosa.
Nearly smooth or very finely sculptured.
Group of P. corbis.
Strongly sculptured. Group of P. leopoldvillensis.
Triangular.
Posterior ridge high; surface sculptured.
Group of P. nyassensis.
Beaks high; posterior ridge low. Group of P. corrugata.
Shell subquadrate, concentrically sculptured.
Group of P. molleurt.
Shell rhomboid, very small, solid, inflated.
Group of P. fabagina.

Subgenus PARREYSIA Ss. s.

Characters the same as the genus.

Group of Parreysia corrugata.

Shell having the middle of the basal region swollen, beak
sculpture strong, the central ridges generally united at their
lower points to form chevron-shaped markings.

PARREYSIA CORRUGATA (Muller).

Shell variable in outline, generally somewhat elliptical, sub-
inflated or inflated, rather solid, more or less inequilateral ;
beaks full, quite elevated, sculptured with radial ridges, which
are more or less zigzagged, and sometimes extend well out over
the disk; anterior end more or less narrowed, rounded; base
rounded, usually fullest behind the middle; dorsal outline ar-
cuate; outline of dorsal slope obliquely subtruncate, some-
times obliquely rounded, with an angle where it meets the
dorsal outline; posterior ridge usually full and subangulate,
surface with irregular growth lines, which are developed into
ridges in front; the upper anterior region and the dorsal slope
often have irregular, radial plications; epidermis generally
smooth and shining, yellowish, tawny, straw-colored or brown-

1106 PARREYSIA

ish with green, concentric bands, sometimes it 1s almost a uni-

form green; on the posterior slope there are generally two or

three dark rays and there are rarely faint rays on the disk.

Left valve with two ragged pseudocardinals and two laterals;

right valve with two pseudocardinals and one lateral; there

are usually a few tubercles behind the pseudocardinals; beak
cavities rather deep; anterior scars impressed; nacre white,
sometimes salmon-tinted in the cavity, iridescent behind; pal-
lial line often with a trace of a posterior sinus.

Length 42, height 30, diam. 18 mm.

Length 43, height 30, diam. 21 mm.

Length 52, height 35, diam. 22 mm.

India.

Mya corrugata MuLieR, Verm. Terr. et Fluv., 1774, Pt. 2, p.
2t4 >. BeschGes.Nat. Ber ,.1779)-p5 5O,cplsniby fies o7.n0.
—ScuHroTer, Fluss, Conch., 1779, p. 181, pl. 1x, fig. 3.—
Woop, Gen. Conch., 1, 1815, p. 108, pl. xxiv, figs. 1-3.—
Mawe, Linn. Conch., 1823, pl. 1v, fig. 3—Woop, Ind. Test.,
1625, p. 12, pl. 11, fie. 2g 1356. rev. .ed.,. p..16,- pl ai sae aaite

Unio cerrugata LAMARCK, An. sans Vert., VI, 1819, p.°78.—
DESHAYES, Enc. Meth., II, 1827, p. 584, pl. cexivitl, fig. 8..

Unio (Potamida) corrugata Swainson, Tr. on Mal., 1840, p.
268, fig. 51; p. 281, fig. 57.

Unio corrugatus Rerztus, Diss. Hist. Nat., 1778, p. 18—Kus-
YER, Conch. Cab. Unio, 1862, p. 289, pl. xcvur, figs. 3, 4.—
Sowerpy, Conch. Icon., XVI, 1868, pl. Lxxt, fig. 360.—HAN-
LEY and THEOBALD, Conch. Ind., 1876, p. 21, pl. xLv, figs.
2-5.

Margarita (Unio) corrugatus Lea, Syn., 1836, p. 29; 1838,
py2k-

Margaron (Unio) corrugatus LEA, Syn., 1852, p. 20; 1870, p..
30.

Parreysia corrugata Stmpson, Syn., 1900, p. 84T.

Mya spuria GMELIN, Syst. Nat., 13th ed., 1788, p. 3222.

Mya gaditana Scuretpers, Verstch., 1793, p.

Unio multidentatus Prtisept, Conch. ITT, 1847, p. 46, pl. 11,
fig. 4—Kuster, Conch. Cab. Unio., 1856, p. 136, pl. xxxvt,
fig. 5

Margaron (Unio) multidentatus Lea, Syn., 1870, p. 50.

PARREYSIA 1107

Unio fulmineus Pitre, Conch., III, 1847, p. 46, pl. 1, figs.
5, 6.—Kusrer, Conch. Cab. Unio., 1862, p. 286, pl. xcvI,
fiSSe32)) 3s

Unio lutens Lwa, Pr. Ac. Nat. Sci. Phila., VIII, 1856, p. 93.

Unio luteus Lea, Jl. Ac. N. Sci. Phila., III, 1857, p. 291, pl.
XXIV, foes) Obs., VIE 1857, p. 11, pla xxiv, fig. 4.

Margaron (Unio) iuteus La, Syn., 1870, p. 46.

? Unio semirugatus CHENU, Ill. Conch., 1858, pl. x11, figs. 2, 2a.

Unio merodabensis KustEr, Conch. Cab. Unio, 1861, p. 233,
pl. Lxxvill, fig. 4.

Unio wynegungensis Haniry and Turosarp, Conch. Ind.,
iSO pein pl CLV 112.00:

Unio tennenti HANniKy and ‘THEOBALD, Conch. Ind., 1876, p.
22) ple Xv, fos. 7-0:

Unio phayresi THEOBALD, manuscript.

The shells of this group are very variable and, it seems to
me, have received far too many names at the hands of conch-
ologists. I have given as varieties some of these and others
have not seeined to me to be worthy even of that rank.

Miiller’s description of Mya corrugata is inadequate, but in
the Beschaftigungen it is further discussed and characteristic
figures are given of the species we know as Unio corrugatus
of India.

The form that I take to be typical, and my views in this
matter agree with those of Hanley and Theobald, is of mod-
erate size, narrowed a little in front, rather full behind the
middle of the base, rather smooth and shining. The beak
sculpture consists of strong, radial ribs, which extend out on
to the disk and are zigzagged below. Sometimes the beak
sculpture is but slightly developed or absent in specimens,
which seem to be typical in other respects.

Var. levirostris (Benson).

According to the figures of Hanley and Theobald, this form
is more elongated than the type, has quite full beaks, which
may be strongly sculptured, and is not inflated behind the mid-
dle of the base. It appears to merge into the typical forin.
Unio levirostris Benson, Ann. and Mag., 1862, p. 192.

1108 PARREYSIA

Unio corrugatus var. levirostris HANEY and THEOBALD,
Conch: Inds; 1876; p:-21, pl: xEry, figs 516:

Parreysia corrugata var. levirostris Stmpson, Syn., Igoo, p.
842.

Var. nagpoorensis (Lea).

A rather thin, somewhat elongated, subrhomboid form with
reddish-brown, striate, rayless, epidermis. The type is in the
Wheatley collection, and there are no examples in the Lea
collection. It may be a valid species, but I am inclined to agree
with Hanley and Theobald in considering it a variety of cor-
rugata.

Nagpoor, Bengal; Burma?

Unio nagpoorensis Lea, Pr. Ac. N. Sci. Phila:, IJ], 1859, p.
331; Jl. Ac. N. ‘Sci.’Phila., 1V,-1860, p..270, pl. xv hie. 150;
Obs., VII, 1860, p. 88, pl. xiv, fig. 150.

Margaron (Unio) nagpoorensis Lea, Syn., 1870, p. 38.

Unio corrugatus Mull. var. nagpoorensis HANLEY and THEO-
BALD, Concheind:. 1876. p..2i

Parreysia corrugata var. nagpoorensis SIMPSON, Syn., 1900, p.
842.

PARREYSIA WYNEGUNGANSIS (Lea).

Shell oblong, subrhomboid or subelliptical, slightly inflated,
solid, inequilateral: beaks high, moderately full, sculptured
strongly with zigzag-radial bars that extend well out on to the
disk ; posterior ridge rounded; anterior end rounded or often
slopingly truncate above; base line curved, sometimes a little
fuller behind the middle; dorsal outline arcuate; outline of
dorsal slope obliquely rounded or subtruncate: surface with
rather strong, concentric growth lines, the dorsal slope and
sometimes the upper part of the anterior end having wrinkled
sculpture; epidermis generally olive, often dark, occasionally
banded faintly, subshining; pseudocardinals much torn and
ragged; laterals two in the left valve, the lower the stronger,
semidouble in the right valve; anterior scars deep; posterior

+

PARREYSIA I10Q:

scars shallow; beak cavities deep; nacre whitish, flesh-colored

or salmon-tinted, thickened in front, iridescent behind.

Length 62, height 38, diam. 25 mm.

Length 61, height 40, diam. 22 mm.

Wynegunga River, Bengal.

Unio wynegungensis Lea, Pr. Ac. N. Sci. Phila., III, 1850, p.
Sor plac. No SeisPhilas IVos6o, p. 271, pls xiv, hig. 1ST:
Obs., VII, 1860, p. 89, pl. xiv, fig. 151—Sowersy, Conch.
Teon.,-X VI, 1868, pl. Lxvil, p- 330:

Margaron (Umo) wynegungensis LEA, Syn., 1870, p. 50.

Parrensia wynegungensis SIMPSON, Syn., 1900, p. 842.

More elongated, generally a little less inflated and darker
colored than corrugata. The form is quite variable, subrhom-
boid to almost evenly elliptical. The variety levirostris of
corrugata approaches it, but is differently colored.

PARREYSIA FAVIDENS (Benson).

Shell rather large, heavy, somewhat inflated, irregularly ellip-
tical or ovate, inequilateral ; beaks high, full and large, sculp-
tured with strong, zigzag-radial ridges, which usually do not
extend on to the disk; posterior ridge well marked; narrowly
rounded or subangulate, ending about on the median line in a
blunt point; there is often a low, radial central elevation ex-
tending to the base of the shell, which is slightly produced
where it ends; surface with strong, irregular growth lines,
sometimes concentrically sculptured; epidermis tawny or
brownish, sometimes banded with green, covered when fresh
with a grayish bloom, occasionally feebly rayed; pseudocardi-
nals strong and very much split up; there are often small tu-
bercles behind them; laterals two in the left valve, with often
a vestigial third one, dcuble in the right valve, club-shaped ;
beak cavities deep; muscle scars impressed; nacre yellow-sal-
mon, or white.

Length 70, height 50, diam. 33 mm.

India.

? Mya spuria Woon, Ind. Test., 1825, p. 12, pl. 11, fig. 35a.

ILLO PARREYSIA

Unio favidens Benson, Ann. and Mag., X, 1862, p. 188.—
Hanixy and THropatp, Conch. Ind., 1876, p. 6, pl. x1, fig. 1.
—Reeve, Conch. Icon., XVI, 1865, pl. xxv1, fig. 131.

Margaron (Unio) favidens Lea, Syn., 1870, p. 38.

Parreysia favidens SIMPSON, Syn., 1900, p. 842.

Unio favidens var. marcens BENSON, Ann. and Mag., X, 1862.
p. 188.

Unio marcens Hantey and THrosatp, Conch. Ind., 1876, p.
10, pl. xu, figs. 4-6.

Unio smaragdites Benson, Ann. and Mag., X, 1862, p. 190.—
Han ry and Turorap, Conch. Ind., 1876, p. 5, pl. x, fig. 5.

Parreysia smaragdites Preston, Rec. Mus., VII, 1912, p. 290.
Several varieties, marcens, trigona, delte, viridula and densa

are given by Benson, which hardly seem to me to be worth

mentioning.

Var. tripartita (Lea).

Possibly worthy of a varietal name. I,ea has two shells, one
of them the type, in his collection. They are a very little more
produced behind the middle than most of the shells of favidens
and the epidermis is lighter colored. The nacre is more sil-
very and iridescent than in that species. ‘he tripartite lateral
of the left valve is a character often found in favidens.

Unto tripartitus Lea, Pr. Ac. N. Sci. Phila., VII, 1863, p. 190;
jl. AcN~ Sci. Phila, Vil, 1866, p..57,.Dl. XIX, me, -55- Obs
Xi, 1867, p: 61, pl. xaxehie ss

Margaron (Unio) tripartitus Lea, Syn., 1870, p. 35.

Parreysia favidens (part), Stmpson, Syn., 1900, p. 843.

Var. trirostris (Musgrave).

Shell considerably produced at the anterior end, the central
base and the posterior end. The epidermis is brown. Doubt-
fully worthy of varietal rank.

U'mto trirostris MuscrAve, Hanley Phot. Conch., 1863, pl. 11,
fig. 9.—Haniry and THrosaip, Conch. Ind., 1876, p. 6, pl.
xa fie: @:

Parreysia favidens, (part), Simpson, Syn., 1900, p. 842.

PARREYSIA IIIl

Var. par (Benson).

Shell smaller than the type, somewhat elongated. I quite
agree with Hanley and Theobald in considering this a small
variety of favidens.

Length 49, height 30 mm.

Unio pinax Benson, Ann. and Mag., 1862, p. 192.
Umio favidens var. pinax HAN LEY and THEosBALpD, Conch. Ind.,

ie ZOe ps6, pls Xi, fey 2.

Parreysia favidens var. pinax SIMPSON, Syn., 1900, p. 843.

Var. plagiosoma (Benson).

Another small form with rather narrow elevated beaks, the
general form being much like that of favidens.
Length 40, height 28 mm.
Unio plagiosoma Benson, Ann. and Mag., X, 1862, p. I9T.
Unio favidens var. plagiosoma HANLeY and THEOBALD, Conch.
lndsn1576-p..0; pl, XI, fig. 3:
Parreysia favidens var. plagiosoma Simpson, Syn., 1900, p.
843.
Var. assamensis Preston.

“Shell more convex than the typical form, the dorsal margin
is rather less posteriorly angled, the anterior side more rounded
and the posterior slightly more nasute.” (Preston).

Type locality, Digong; also Assam and Arrah.

Parreysia favidens var. assamensis Preston, Rec. Ind. Mus.,

VIEL, 1902; ps 209.

PARREYSIA BHAMOENSIS (Theobald).

Shell subtriangular, subinflated, solid, inequilateral; beaks
high and full, with zigzag-radial sculpture, which does not
extend over the disk; posterior ridge narrowly rounded, end-
ing in a point below the median line; anterior end and base
evenly rounded: outline of dorsal slope arcuate but higher
just behind the ligament; surface with irregular growth lines,
usually corrugated on the upper anterior part and the dorsal
slope. green-brownish and yellowish-banded, shining; hinge

Telere?, PARREIEYSTA

solid; pseudocardinals ragged; laterals split, sometimes into

three divisions in each valve; beak cavities very deep, com-

pressed; muscle scars deep; nacre silvery.

Length 50, height 38, diam. 22 mm.

Burma.

Unio bhamoensis THEOBALD, Jl. As. Soc. Beng., XLII, 1874,
Pt. 2, p. 207, pl. xvi, fig. 1—?PHANLEyY and THEOBALD,
Conch. Ind., 1876, p. 62, pl. civ, fig. 2—von Martens,
Arch. fiir Naturf., 1899, p. 38, pl. v, figs. 2-4.

Parreysia bhamoensis SIMPSON, Syn., 1900, p. 843.

A solid, triangular species. JI have before me a right valve
of a shell, which agrees almost absolutely with the figure in
the Conchologia Indica, but is not quite so strongly corrugated
behind. The beak cavity is very deep and compressed, the
muscle scars are small and deep and the nacre is brilliant.

PARREYSIA MANDELAYENSIS (Theobald).

’ Shell decidedly triangular, rather solid, subinflated, beaks
and umbonal region much elevated, strongly sculptured with
zigzag-radial bars, sometimes with one or two radial rows of
tubercles, the sculpture being continued over the whole shell;
posterior ridge narrowly rounded, placed close to the lightly
curved post-dorsal outline: anterior end obliquely subtruncate
above, rounded below; base line rounded; surface having
strong, uneven, concentric sculpture; epidermis tawny to
greenish, subshining; pseudocardinals subtriangular, not very
ragged; anterior muscle scars deep; beak cavities deep; nacre
bluish-white.

Length 40, height 31, diam. 21 mm.

Mandelay.

Unio mandelayensis Turopatp, Jl. As. Soc. Beng., XLII,
1874, p. 208, pl. xvi, fig. 2—Hantey and Turonap, Conch.
Ind., 1876, p. 62, pl. cLiv, fig. 4.

Parrevsia bhamoensis, (part), Stmpson, Syn., 1900, p. 843.
In the Synopsis I placed this in the Synonymy of P. bhamo-

ensis, but T am satisfied that this was an error. Since writing

that I have seen several shells, which agree fairly well with

PARREYSIA BEDS

figures and description of mandelayensis and T believe now
that it is a good species. The beaks and umbonal region are
very high and placed well forward, they are strongly and
sometimes tubercularly sculptured ; the whole shell is decidedly
triangular.

PARREYSIA PERNODULOSA Preston.

“Shell small, ovate, dark brown; both valves sculptured an-
teriorly with coarse, corrugate ridges, which become more nod-
ulous and irregular in the median and posterior regions; um-
bones rather large; dorsal margin rapidly sloping anteriorly,
slightly sloping posteriorly ; ventral margin somewhat round-
ed: anterior side rather contracted, sharply rounded; poste-
rior side broad, very gently rounded; cardinal teeth very ante-
riorly situate, in the right valve squarish, bearing two elongate
grooves; in the left valve large, jagged, split into three por-
tions, between each of which occur two deep notches, the mid-
dle portion, or that between the two notches being by far the
smallest ; at the base of the anterior portion is situated a small-
er, jagged tooth, which is obliquely grooved in the centre; lat-
teral teeth in both valves posteriorly, elongately arched, groov-
ed down the whole length; anterior scars very deep; posterior
scars elongate, but not well marked; interior of shell pale blu-
ish, nacreous.

Long. 15.5, lat. 20.5 mm.” . (Preston): eA

Type locality, Zayleyman, Upper Burma. :
Parreysia pernodulosa Preston, Rec. Ind. Mus., VII, 1912,

Pp. 300.

PARREYSIA FEDDENI (Theobald).

Shell obovate, subsolid, subinflated, nearly equilateral ; beaks
ful! and high: anterior end considerably narrowed and round-
ed; posterior end wide, almost evenly rounded, produced a
little behind the ligament and at the median line; posterior
ridge well developed, narrowly rounded; surface irregularly
marked with growth lines; epidermis yellowish-green, with
indications of being banded, feebly rayed, shining; teeth rather
delicate: pseudocardinals subcompressed, ragged; laterals

Trr4 PARREYSTIA

curved, wide, two in the left valve, the lower wider, and one
in the right; muscle scars rather shallow ; nacre bluish-white,
not shining.

Length 26, height 17, diam. 11 mm.

Penugunga River, Central India.

Umo feddeni Turonatp, Jl. As. Soc. Beng., XLII, 1874, p.

20S 7p) xvi, fis 3.

Parreysia feddeni SIMPSON, Syn., 1900, p. 843.

The original figure and description of this species are not
accessible as I write this description, but a specimen is before
me from the Morelet collection bearing the name Unio feddeni
Theobald, from Yunnan. It has the appearance of being
young. It is remarkable for its obovate form, being almost
evenly rounded behind, and for having very wide laterals and
subcompressed pseudocardinals. It was compared with the
figure and description of feddeni and agrees fairly well with
them.

PARREYSIA DACCAENSIS Preston.

“Shell differing from P. feddeni Theobald, in its much
larger size, more ponderous form, and more elongately ovate
shape, it is much darker in color, being of a dark, blackish-
brown instead of the greenish-yellow shade of that species, the
shell is much more coarsely, concentrically striate and is also
considerably malleated, while P. feddeni is almost smooth in
texture ; the umbones in the present species are, though larger,
far less prominent, but the system of hinge teeth is the same.

Long. 47, lat. 76.5, diam. 29 mm.” (Preston).

Type locality, Dacca.

Parreysia daccaensis Preston, Rec. Ind. Mus., VII, 1912, p.

300.

PARREYSIA TAVOYENSIS (Gould).

Shell subtriangular, sometimes sub-obovate, subinflated, sub-
solid to moderately solid, slightly inequilateral ; beaks high and
full, strongly sculptured with zigzag-radial bars, this sculpture
often extending over the whole disk of the shell; sometimes
it is almost wanting and the surface is concentrically furrowed ;

PARREYSIA Per

posterior ridge well developed, narrowly rounded or suban-
gular; dorsal slope often obliquely truncate, usually covered
with strong, subradial folds; epidermis usually dirty bottle-
green, sometimes slightly variegated and faintly rayed, at other
times it is a lurid, greenish-brown, scarcely shining ; hinge line
arched; teeth only moderately strong; pseudocardinals some-
what divided, but much less so than in most related species ;
beak cavities only moderately deep; nacre dull, bluish to flesh-
colored, often lurid in the cavities.

Length 52, height 39, diam. 24 mm.

Length 44, height 35, diam. 21 mm.

Burma, India.

Unio tavoyensis GouLp, Pr. Bost. Soc. N. Hist., I, 1843, p. 140.
—Kusrtrr, Conch. Cab. Unio, 1856, p. 166, pl. xLvilil, fig. 2.
—Retve, Conch. Icon., XVI, 1864, pl. x11, fig. 49—Han-
LEY and THroBaLD, Conch. Ind., 1876, p. 62, pl. cLiv, figs.
(Bie

Margaron (Unio) tavovensis Lea, Syn., 1870, p. 31.

Parrevsia tavoyensis SIMPSON, Syn.., 1900, p. 843.

Unio savoyensis PxtEL, Conch. Sam., IIT, 1890, p. 166.

Unio parma Benson, Sowerby, Conch. Icon., XVI, 1868, pl.
xcv, fig. 514—Hantry and THrosaip, Conch. Ind., 1876,
PuGl PlCEiv. fig. o1
Close to corrugata, but usually more covered with sculpture

and having a dirty greenish or brownish epidermis. The
specimen represented by figure 7 on plate cliv in the Conch-
ologia Indica is brighter colored than any I have seen. The
pseudocardinals are less ragged than in corrugata and allied
forms.

I am inclined to believe that Unio parma Benson is a some-
what elongated form of this, as there is a specimen of tavoy-
ensis from Gould in the J.ea collection that is much like the
figure in the Conchologia Indica.

Var. triembolus (Benson).

This seems to me to be a short, pale colored variety of
tavovensis, in which the disk is almost free of sculpture. Unio
houngdaranicus Tapperone-Canefri, of which specimens from

aE 1KS) PARRLYSIA

Ifea are before me, is much like it, but is a little brighter col-
ored. One ot them has considerable zigzag sculpture scattered
over the disk.

Burma ; India.

Unio triembolus BENSON, Jl. As. Soc. Beng., XXXV, 1855, p.
144.—Han.ey and THEonatp, Conch. Ind., 1876, p. 43, pl.
evil; hg. 3;

Parreysia tavoyensis var. triembolus. SIMPSON, Syn., 1900, Pp.
844.

Unio houngdaranicus ‘TAPPERONE-CANEFRI, Ann. Mus. Civ.,
VII, 1889, p. 341.

PARREYSIA VULCANUS (Hanley).

Shell subtriangular, solid, inequilateral, green throughout
except the anterior extremity ; strongly plicate or tuberculately
corrugated; anterior end somewhat narrowed, rounded; pos-
terior end wider, rounded below, subtruncated obliquely above ;
base line lightly arcuate; beaks high; hinge strong; pseudo-
cardinals solid, lacerated; anterior muscle scars deep; nacre
white, slightly iridescent.

Length 33, height 25 mm.

3urma; Pegu.

Unio vulcanus Haniry, Pr. Zool. Soc. Lond., 1875, p. 606.—
Haney and THeopatp, Conch. Ind., 1876, p. 62, pl. cLv,
He. 38

Parreysia vulcana SIMPSON, Syn., 1900, p. 844.

A very distinct species apparently, having a moderately near
relationship to P. mandelayensis. It is, however, not so trian-
gular as that species, being somewhat obovate, and its sculp-
ture is more decidedly tuberculate. It is more nearly equilat-
eral than that species.

PARREYSIA FE% (Tapperone-Canefri).

Shell subtriangular or subrhomboid, rather inflated, sub-
solid or solid, somewhat inequilateral; beaks high and full,
with irregular zigzag-radial sculpture; posterior ridge well
developed, narrowly rounded, curved, sometimes partly double,
ending in a blunt point or biangulation below the median line ;

PARREYSIA HEL

surface somewhat concentrically sculptured, sometimes having
faint zigzag sculpture; epidermis dirty yellowish-green in
young shells, brown on old specimens, scarcely shining ; pseu-
docardinals subtriangular, low, but little ragged; laterals re-
mote, curved, not strongly developed, granular; muscle scars
well marked; beak cavities only moderately deep; nacre flesh-
colored, often luridly blotched in old shells.

Length 54, height 45, dia. 27 mm.

Length 60, height 41, diam. 28 mm.

Burma.

Unio fee TAPPERONE-CANEFRI, Ann. Mus. Civ. Gen., 2d ser.,

VII, 1889, p. 340.

Parreysia fe@ SIMPSON, Syn., 1900, p. 844.

‘This species has never been figured, so far as I know. Three
shells bearing the name Unio fee Tapperone-Canefri, from
Fea himself, taken from the Houngdaran River, Burma, are
before me and they show it to be a variable species. One of
them is quite rhomboid; the other two are subtriangular. The
laterals are not strongly developed and are granular some-
thing like those of P. biesiana.

PARREYSIA RAJAHENSIS (Lea).

Shell inflated, solid, triangular, slightly inequilateral; beaks
full and high, their sculpture not seen; lunule well marked ;
posterior ridge high, subangular; above this there is a radial
furrow ending in a sinus, and the dorsal slope is subtruncated ;
anterior end angled at its junction with the depressed lunule,
obliquely truncate below this, rounded below; base rounded,
fullest just behind the middle; surface with decided, concen-
tric growth lines; epidermis brownish-green, slightly banded,
shining; hinge line arched; pseudocardinals ragged; anterior
scars deep; nacre bluish, silvery and iridescent.

Length 36, height 29, diam. 21 mm.

Calcutta.

Unio rajahensis Lea, Pr. Am. Phil. Soc., II, 1841, p. 30; Tr.
Ante nik ‘Soceev Ill 1842, p230. pl. xxiir, fig. 53/3Obs:,
III, 1842, p. 77, pl. xxin, fig. 53.—CHENU, Ill. Conch., 1858,
pl. xxvi, figs. 3, 3a, 3b.

T1118 PARREYSIA

Margaron (Unio) rajahensis Lea, Syn., 1852, p. 25; 1870, p.
38.

Parreysia rajahensis SIMPSON, Syn., 1900, p. 844.

Unio indicus SowrErey, Conch. Icon., XVI, 1866, pl. x1, fig.
222. Han ery and THerosatp, Conch. Ind., 1876, p. 43, pl.
CUy fe, 1...

Margaron (Unio) mdicus Les, Syn., 1870, p. 31.

I have only seen the type, but it seems to me that the species.
is very distinct. The almost angular posterior ridge with the
rather deep radial groove above it are excellent distinguishing
characters.

Group of Parreysia rugosa.

Shell rather solid, elliptical to subtrapezoidal; beaks full,
with zigzag-radial sculpture and fine corrugations and gran-
ules over the surface of the shell.

PARREYSIA RUGOSA (Gmelin).

Shell long elliptical or long rhomboid, subinflated, rather
solid, inequilateral; beaks full and high, with strong, zigzag-
radial sculpture ; posterior ridge rounded; anterior end round-
ed, sometimes angled above; base line nearly straight; pos-
terior end rounded or obliquely subtruncate above; dorsal out-
line arcuate; surface with irregular growth lines; epidermis
greenish in young shells, brownish in old ones; pseudocardi-
nals solid, much split; laterals straight, two in the left valve
and a partly double one in the right; anterior scars deep; pos-
terior scars shallow; nacre salmon, iridescent, thicker in front.

Jength of type 42, height 24 mm.

Length of shell in Lea collection 57, height 34, diam. 22 mm.

Coromandel.

Mya rugosa GMELIN, Syst. Nat., 13th ed., 1788, p. 3222.—
Woon, Ind. Test., 1825, p. 12, pl, fg? 33@; rev. ed. 1856,.
ps 16, plo ihe. 33.

Umo rugosus Kuster, Conch. Cab. Unio, 1862, p. 290, pl.
XCVII, fig.’ 5.

Parreysia rugosa SIMPSON, Syn., 1900, p. 844.

Gmelin refers to the Mya corrugata magna, etc., of Chemnitz
in the tenth volume of the Conchylien Cabinet, p. 346, pl CLXx,.

PARREYSIA IIIGQ

fig. 1649. This appears to be a young shell with well-pre-
served beaks, which have strong, zigzag-radial sculpture and
a yellowish-green epidermis. There is a shell in the Lea Col-
lection from the Vellaur River in the Coromandel region. of
India, which is evidently adult and seems to me to be this.
The beaks are so eroded that no sculpture is visible and the
epidermis is brown, the posterior basal part is slightly pro-
duced, but the pseudocardinals are characteristic of Parreysia
and I have no doubt that it is Gmelin’s shell.

PARREYSIA CORBIS (Hanley).

Shell somewhat obovate, subinflated, moderately solid, in-
equilateral ; beaks full and high, with zigzag-radial sculpture ;
posterior ridge rounded; anterior end narrowed and rounded ;
base line arcuate, fullest behind the middle; dorsal outline
curved; outline of dorsal slope rounded, the posterior end be-
ing bluntly pointed a little below the median line; surface
nearly smooth, having only faint, concentric sculpture; epider-
mis greenish or brownish-green, shaded with yellowish, in
some specimens having indications of rays; pseudocardinals
ragged; laterals curved, remote ; beak cavities well impressed ;
anterior scars deep; nacre rather dull, whitish, yellowish or
pale, lurid purplish, thinner behind.

Length 44, height 29, diam. 20 mm.

Length 38, height 25, diam. 16 mm.

Assam.

Unio corbis HANLEY, Biv. Shells, 1856, p. 386, pl. xxii, fig-
43.—Hantey and THEopaLp, Conch. Ind., 1876, p. 22, pl.
AL fis. LO!

Margaron (Unio) corbits eA, Syn., 1870, p. 50.

Parreysia corbis SIMPSON, Syn., 1900, p. 845.

Three shells are before me, belonging to the National Mu-
seum collection from Assam, India, which agree fairly well
with Hanley’s description and figure and with the figure in the
Conchologia Indica. JI am not certain that the species belongs
to the same group with P. rugosa, though they: are probably
rather nearly related.

I120 PARREYSIA

PARREYSIA BURMANA (Blanford).

Shell subelliptical, solid, convex, decidedly inequilateral,
blackish or fuscous-olive, concentrically plicate striate; disks
with oblique, angular, subgranulose sculpture in the middle
and behind; umbonal region full and wide; beaks with zigzag-
radial sculpture; posterior ridge full, narrowly rounded; an-
terior end rounded; dorsal outline well arched ; basal line near-
ly straight; posterior end rounded, very slightly produced at
or below the median line; pseudocardinals short, somewhat
ragged; laterals remote, elevated; nacre salmon to bluish
white.

Length 52, height 35, diam. 22 mm.

Length 45, height 32, diam. 20 mm.

Burma.

Unio burmanus BLAN¥ForD, Pr. Zool. Soc. Lond., 1869, p. 449.

—von Martens, Arch. fur Naturf., 1899, p. 38, pl.-v, fig. 5.
Unio birmanus HANLEY and VHrKosaLp, Conch. Ind., 1876, p.

LQsspleper ale doe, Abe
Parreysia burmanus SIMPSON, Syn., 1900, p. 845.

Two young shells from Fea, collected in the Upper Irrawady
River, are in the National Museum. Their color is yellowish-
green, with darker bands. This seems to differ from P. corbis
in having the dorsal outline much rounded and that of the base

nearly straight, and in having a considerable part of the sur-
face sculptured, while corbis is smooth.

PARREYSIA SIKKIMENSIS (Lea).

Shell rather short, subrhomboid, subsolid, subinflated, in-
equilateral; beaks apparently moderately full and elevated,
with zigzag-radial sculpture that sometimes extends well on
to the disk; posterior ridge double, though sometimes scarcely
so, ending in a biangulation near the base of the shell; surface
finely, concentrically sculptured; epidermis greenish-brown,
scarcely shining; pseudocardinals much split up, with denti-
cles behind them; laterals short, high, remote; anterior scars
impressed; nacre white, or bluish, somewhat iridescent.

Length 32, height 21, diam. 14 mm.

Length 30, height 21, diam. 13 mm.

Sikkim ; Tulpigorie, India.

IPE IRIE SHEN lez

Unio sikkimensis Lea, Pr. Ac. N. Sci. Phila., III, 1859, p. 151;
(ipAcoN sch. ehila IVi tesQnp.<251,.pl; xXxX1x; fig. 131;
Obs., VII, 1860, p. 69, pl. XxxIXx, fig. 131.—SoweErsy, Conch.
Icon., XVI, 1868, pl. LXxv1, fig. 400—HaANntry and THEo-
BALM Conch,. Ind 1876;.p-.0, plixt fret 45 p..44,. pl. cv,
figs. 6, 7. .

Margaron (Unio) sikkimensis Lea, Syn., 1870, p. 64.

Parreysia sikkimensis SIMPSON, Syn., 1900, p. 845.

A small species, of which the type is not in the Lea collec-
tion. Four shells, however, are before me, two of them from
Sikkim, the other two from Tulpigorie, India, which agree
well with Lea’s figures and description. The species seems to
be smaller than P. burmana, the posterior ridge is double, the
surface has less zigzag sculpture and the form is rather more
rhomboid.

PARREYSIA GOWHATTENSIS (Theobald).

Shell small, short rhomboid, convex, inequilateral, scarcely
subsolid; beaks only moderately full and elevated, with very
fine, zigzag-radial sculpture, which extends all over the sur-
face and is subangular in places; besides this, the shell is deli-
cately but decidedly, concentrically sculptured ; posterior ridge
inclined to be double, ending in a feeble biangulation near the
base of the shell; epidermis pale yellowish-green back to the
posterior ridge, over this and the hinder end of the shell it is
green, sometimes faintly rayed; pseudocardinals ragged; an-
terior scars impressed; nacre bluish, sometimes yellowish in
the cavities, iridescent..

Length 24, height 15.5, diam. 10 mm.

Gowhatti, in Assam.

Unio gowhattensis Turopatp, Jl. As. Soc. Beng., XLII,

1973. p: 200, ple xvit, fig. 4.

Parreysia gowhattensis SIMPSON, Syn., 1g00, p. 845.
Unio gowlattensis Patter, Conch. Sam., III, 1890, p. 154.

Distinguished from the other members of the group by its
small size and wonderfully subgranulous sculpture that covers
the entire shell, the light anterior and dark posterior portions.

pr22 PARREYSIA

PARREYSIA ANNANDALEL Preston.

“Shell oval, convex, moderately solid, coarsely, concentrical-
ly ribbed, covered with a thin, smooth, brownish-olivaceous
periostracum; umbones rather small, not prominent; dorsal
margin arched; ventral margin considerably rounded ; anterior
side slightly produced and rather sharply rounded; posterior
side very bluntly subrostrate ; cardinal teeth two in each valve,
somewhat anteriorly situate, rather coarse, corrugated ; lateral
teeth strong, curved; anterior scars rather small, very deeply
excavated ; posterior scars also small, ovate, deeply impressed ;
interior of shell whitish, iridescent.

Long. 20, lat. 41, diam. 20 mm.” (Preston).

Type locality, Gowhatty.

Parreysia annandalei Preston, Rec. Ind. Mus., VII, 1912, p.

302.

PARREYSIA PERCONVEXA Preston.

“Shell ovate, slightly curved, very convex, solid, but much
eroded, where intact covered with a dark, blackish brown
periostracum ; umbones moderately large; dorsal margin slop-
ing in an anterior direction; ventral margin slightly curved
posteriorly ; anterior side gently rounded; posterior side slight-
ly and very bluntly produced, rounded; cardinal teeth very
anteriorly situate, with upper surface multi-ridged and sup-
ported in each valve by an enormous column-like callus thick-
ening of the shell; lateral teeth coarse, rather short, curved ;
anterior muscular scars of great depth; posterior scars sub-
circular, well impressed; interior of shell very pale, greenish-
white.

Long: 27; lat. 55; diam. 23°mim. “(exeston)):

Type locality. Nangvong Lake.

Parreysia perconvera Preston, Rec. Ind. Mus., VII, 1912,

p..302:

PARREYSIA MODESTA (Heude).

Shell solid, subinflated. somewhat elongated and irregularly
ohovate or subrhomboid, inequilateral; beaks apparently not
elevated; posterior ridge feebly developed, slightly double;

PARREYSIA TED

anterior end narrowed, rounded: dorsal outline arched ; dorsal
slope obliquely rounded; base line straight, sometimes very
slightly incurved medially ; surface olivaceous-fuscous, shining ;
pseudocardinals conical, simple; laterals short, obsolete.

Length 60, height 30, diam. 25 mm.

Province of Ngan-Hoei, China.

Unico modestus Hrupr, Conch. Fluv. Nank., II, 1877, pl. xiv,

fig. 29.

Unio simpularis Heupe, Jl. de Conch., XXXII, 1884, p. 20.
Parreysia simpularis SIMPSON, Syn., 1900, p. 845.

I can only guess at the relationship of this form, of which
Heude gives only an outline figure and a very meagre Latin
description. He states that the shell is compressed but his
dimensions (given above) show it to be much inflated. He
also states that the beaks are corrugated. It may possibly be
a Pseudodon, though the general form would indicate that it
was related to P. corbis.

The name modestus having been used previously for a Bra-
zilian Unico, Heude afterwards changed his name to simpular-
is. But I can not find that this Brazilian. form, which is gen-
erally credited to Ferussac, was ever described, hence Heude’s
first name must stand. It is quite probable that this should
form a separate group.

PARREYSIA TRISULCATA (Heude).

Shell small, subtriangular, solid, subinflated, inequilateral ;
beaks and umbonal region full, having three strong, low, sub-
concentric sulcations; posterior ridge full, feebly double or
rounded; terminating in a faint biangulation; dorsal outline
strongly arcuate ; base line much more nearly straight, so that
the shell is somewhat triangular ; epidermis yellowish-fuscous,
transversely, minutely striate; pseudocardinals conical, obtuse ;
laterals short, obsolete ; nacre flesh-colored.

Length 30, height 17, diam. 11 mm.

China.

Unio trisulcatus Hsupr, Conch. Fluv. Nank., VIII, 1883, pl.

LVI, fig. 108.

Parreysia trisulcata StIMPSON, Syn., 1900, p. 845.

1124 PARREYSIA

Acuticosta trisulcata Haas, Conch. Cab., Unio, 1912, pl. 30,

fie, <i

I know nothing whatever of this species and am very doubt-
ful whether it is related to P. corbis at all. The three sub-
concentric ridges on the umbonal region are characters not
found in any other species I have placed in Parreysia and if
they are a part of the beak sculpture they would indicate that
this shell belonged in the Fxobranchizw. Heude states, however,
that the beaks are eroded. The general form of the shell as
indicated by his figure would seem to ally it with the forms
I have first described.

Group of Parreysia leopoldvillensis.

Shell rounded rhomboid, somewhat inflated, subsolid, with
a rounded post-ridge; beaks full, the sculpture strongly and
regularly zigzag-radial and extending well over the body of
the shell; pseudocardinals heavy, subcompressed, crenate ; an-
terior scars deep.

PARREYSIA LEOPOLDVILLENSIS ( Putzeys).

Shell irregularly obovate or subtriangular, subsolid, subin-
flated, somewhat inequilateral; beaks small but decidedly ele-
vated, sculptured with radiating ridges on the posterior slope
and with chevron-shaped markings below them, this sculpture
extending over a considerable part of the surface; posterior
ridge scarcely developed; dorsal line curved from the upper
part of the narrow, rounded anterior end to the hinder end of
the small wing; the posterior end is obliquely and somewhat
roundly truncated, the truncation ending in a rounded point
near the base of the shell; pseudocardinals rather strong, sub-
compressed, crenulate ; laterals lamellar, curved; anterior scars
impressed ; nacre pearly, bluish, salmon-tinted in the cavaties.

Length 45, height 28-30, diam. 15-19 mm.

Stanley Pool, Leopoldville, Congo.

Umo leopoldullensis Purzeys, Proc. Verb. Soc. Mal. Belg.,

XX VG rakes; ple xxvir, fiessr2, hrs:

Parreysia leopoldvillensis Stupson, Syn., 1900, p. 846.

PARREY STA TU 5

I have never seen this shell, which seems from the descrip-
tion and figures to be rather closely related to the species of the
group of P. bakeri. It is less inflated and does not have a
strong posterior ridge, but the zigzag sculpture, ending con-
siderably above the base of the shell, is like that of the species
I have placed in that group.

Group of Parreysia bakeri.

Shell small, inflated, oval, rounded in front, bluntly pointed
behind, inflated at or behind the central base; beaks full, high,
sculptured with very strong, zigzag bars, which extend part
way over the disk and end rather suddenly, below which the
shell is smooth; posterior ridge well developed, rounded: two
compressed pseudocardinals and one lateral in the right valve,
two pseudocardinals and two laterals in the left valve.

PARREYSIA BAKERI (H. Adams).

Shell transverse ovate, thin, subinflated, inequilateral; an-
terior end rounded; posterior end dilated, subangulate, strong-
ly, undulately plicate; epidermis olivaceous; beaks subpromi-
nent, nodulous at the apices; pseudocardinals small, sulcate ;
laterals nearly straight, double in the left valve; nacre pearly
or silvery, tridescent.

Length 30, height 21, diam. 14 mm.

Lake Albert Nyanza, Central Africa.

Unio bakeri H. Apams, Pr. Zool. Soc. Lond., 1866, p. 376.—
SMITH, Ann. and Mag., X, 1892, p. 126, pl. x11, fig. 11.—
von Marrens, Besch. Deuts. Ost-Af., 1897, p. 231, pl. vit,
fig. 6.

Parreysia bakeri SIMPSON, Syn., 1900, p. 846.

Adams does not figure his species, but Smith and von Mar-
tens do. ‘The figure given by the former is of a young shell
in the first or strongly zizzag radial stage of growth and shows
an obovate specimen. ‘That of von Martens is taken from
an adult specimen and shows both the earlier zigzag-radial
and later the nearly smooth, concentric sculpture character-
istic of this group. His figure shows a somewhat rhomboid

1126 PARREYSIA

shell and he gives as its greatest lengtii 43 millimeters. The
early sculpture of this form is excessively strong. Adams’
type was probably a young specimen.

PARREYSIA STUHLMANNI (von Martens).

Shell irregularly elliptical, somewhat inflated, shining,
brown, inequilateral; beaks very high, with strong zigzag-
radial sculpture, which extends to some distance out on the
disk, the outer part of the shell being nearly smooth; anterior
end rounded; base line curved; hinge line lightly curved, ang-
led at the hinder end of the ligament; dorsal slope obliquely
truncate; posterior ridge rather high, ending in a rounded
point below the median line; nacre silvery white.

Length 43, height 26, diam. 14 mm.

Albert Edward Lake, Central Africa.

Unio stuhlmanni von Martens, Besch. Deuts. Ost-Af., 1897,

p. 230; pl vir, fies 63:

Parreysia stuilmannt SIMPSON, Syn., 1900, p. 846.

In outline this shell resembles certain specimens of Plagiola
donaciformis. The characteristic beak and earlier sculpture
does not appear to come very far out over the surface.

PARREYSIA HAUTTECGURI (Bourguignat ).

Shell irregularly oval, subinflated, rather solid, inequilateral ;
feeaks moderately full and high, with strong, zigzag sculpture,
which extends over the shell nearly to its border; beyond this
the border is concentrically striate ; anterior end rounded ; base
line curved, with a tendency to be slightly produced in the
middle; outline of dorsal slope arcuate; posterior ridge full,
narrowly rounded, placed near to the upper edge of the shell,
ending in a rounded point a little below the median line;
epidermis uniform brown-olive; nacre bluish; pseudocardinals
compressed, triangular, elevated ; laterals thin.

Length 36, height 22, diam. 16 mm.

Lake Victoria Nyanza, Central Africa.

Unio hautteceuri Bourcuicnat, Moll. Ny. Ouk., 1883, p. 5,
figs. 1-3.—von Marrens, Besch. Deuts. Ost-Af., 1897, p.
2227 Mime hoes) pl sVil, aes 2

Nodularia hautteceuri Stmpson, Syn., 1900, p. 846.

Unio grantianus Bourcurcnat, Moll. Ny. Ouk., 1883, p. 14.

PARREYSIA 1127

Differs from P. stwhlmani in having less elevated beaks, in
being nearly covered with strong zigzagged sculpture and hav-
ing the dorsal slope rounded instead of angled.

Var. edwardsiana Bourguignat.

This may be a form of the above. The surface is sculptured
almost out to the edge of the shell. It is a little more inflated
in proportion to its height than typical shells are.

Length 25, height 14, diam. 12 mm.

Lake Victoria Nyanza.

Umo edwardsianus Bourcutcnat, Moll. Ny. Ouk., 1883, p.

hs hies.97; 9:

Nodularia hautteceurt var. edwardsiana SIMPSON, Syn., 1900,

p. 846.

PaREYSSIA POSTUMA (Rochebrune).

Shell subelliptical or subrhomboid, convex or moderately in-
flated, inequilateral, subsolid; beaks moderately elevated, cov-
ered with strong zigzag-radial sculpture that extends almost
to the border of the shell, the border being concentrically
sculptured; anterior end rounded, slightly cut away below;
base almost evenly rounded; dorsal outline lightly arcu-
ate; posterior slope obliquely subtruncate; posterior ridge
faintly double, ending in a feeble biangulation at and below the
median line; epidermis yellowish-olive or chestnut-olive ; nacre
white or salmon-tinted ; teeth subcompressed.

Length 23, height 15.5, diam. 11.5 mm.

Length 21, height 15, diam. 8 mm.

Lake Victoria Nyanza.

Unio duponti Bourcuicnat, Moll. Ny. Ouk., 1883, p. 8, figs.

10-12.

Parreysia duwponti SIMPSON, Syn., 1900, p. 846.
Unio bakeri voN Martens, Sitzber. Ges. Nat. Fr., 1879, p.

104. .

Unio grandidieri Bourcurtcnat, Moll. Ny. Ouk., 1883, p. 7,

figs. 4-6.

Unio postumus ROoCHEPRUNE, Bull. Mus. Hist. Nat., 1904, p.

258.

1128 PARREYSIA

‘The only difference I can see, that amounts to anything, be-
tween this and the Unio grandidieri of Bourguignat is that
the latter is a little more inflated in proportion to its height.
The outlines of both are alike, rhomboid elliptical and the
sculpture does not seem to differ.

In the Synopsis this species was referred to U. duponti
Roche. But that author claims that the two species are quite
distinct and (1. c.) has proposed a new name for the duponti
Bet.

PARREYSIA RUELLANI (Bourguignat).

Shell subsolid, elliptic rhomboid, inflated, inequilateral ;
beaks slightly elevated, with strong, zigzag sculpture, which
does not extend far out on the disk, the rest of the surface
is concentrically sculptured and shows traces of radial sculp-
ture; epidermis yellowish-green ; anterior end rounded, slight-
ly cut away below; dorsal and basal outlines lightly arcuate;
outline of dorsal slope obliquely rounded, subangulate just
behind the ligament ; teeth somewhat compressed ; nacre white.

Length 35, height 23, diam. 16.5 mm.

Lake Victoria Nyanza.

Unio ruellani Bourcuicnat, Moll. Ny. Ouk., 1883, p. 10, figs.

16-18.

Parreysia ruellani SIMPSON, Syn., 1900, p. 846.

In form this is much like P. hawttecwuri, but it is rather
more inflated, the strong, umbonal, zigzag sculpture does not
extend far out on the disk and the remainder of the shell
shows traces of radial sculpture.

Var. bayont (Germain).

“Shell more elongated-oval, proportionally less globose ; an-
terior end more developed on account of the less anterior
position of the beaks; epidermis differently colored. The
hinge is the same as in typical rivellani, except that the cardinal
teeth are slightly more elongated, owing to the greater develop-
ment of the anterior part of the shell. Shell not very thick,
solid, beaks much eroded; epidermis of a clear yellow-chest-
nut and quite brilliant ; lines of growth irregular. Nacre bluish
and iridescent.

PARREYSIA 1129

Length 33-35, height 21-24, diam. 15-14 mm.” (Germain).
Type locality, Bugala Island, Sesse Archipelago, Victoria-
Nvanza.
Unio ruellani var. bayont GERMAIN, Bull. Mus. Hist. Nat.,
1909, p. 275, pl. im, fig. 36.

PARREYSIA MULTICOLOR (von Martens).

Shell oval rhomboid, moderately solid, inflated, inequilater-
al; beaks rather full and high, with zigzag sculpture, which
does not extend far out over the disk; anterior end rounded,
cut away somewhat below; dorsal and basal outlines arcuate ;
dorsal slope obliquely subtruncate; posterior ridge full, round-
ed, ending in a rounded point at the base; epidermis shining,
dirty greenish-yellow or brownish-green with many narrow,
grass-green rays; pseudocardinals thick, lamelliform with a
few strong furrows and notches; laterals arched; nacre rose
or purplish-red.

Lake Victoria Nyanza.

Unio multicolor von Martens, Besch. Deuts. Ost-Af., 1897,

p- 236, pl. vit, fig. 4.

Parreysia multicolor SIMPSON, Syn., 1900, p. 847.

This species may be distinguished by the fine, bright rays
on the smoother part of the shell and the rich, purplish rose-
colored nacre.

PARREYSIA NGESIANA (von Martens).

Shell subsolid, subinflated, rhomboid oval, inequilateral ;
beaks full and high, with strong, zigzag sculpture, which ex-
tends about half way over the disk with two radial rows of
tubercles, the rest of the surface nearly smooth; anterior
end narrowly rounded; base arcuate, fuil at the middle; hinge
line curved; dorsal slope obliquely truncate; posterior ridge
rather high, narrowly rounded, ending just below the median
line in a blunt point; epidermis light brown; nacre silvery with
bluish or rose-red tints; pseudocardinals lamelliform, notched ;
laterals moderately arched.

Length 33-35.5, height 24-24.5, diam. 16-17 mm.

Lake Albert Edward Nyanza.

II30 PARREYS!

Unio ngesianus VON Marvens, Besch. Deuts. Ost-Af., 1897, p.
234, pl. wit, fig. 7.
Parreysia ngesianus SIMPSON, Syn., 1900, p. 847.
This species has two radial rows of tubercles, which some-
times become somewhat \-shaped, that radiate from the beaks.
The base is slightly produced in the center.

The following unfigured species are placed in this group by

von Martens:

Unio billotianus CHARMES, Bull. Soc. Mal. Fr., II, 1885, p.
170, Bbagamoyo, Central Africa.

Unio euphymus CHarmeEs, Bull. Soc. Mal. Fr., II, 1885, p. 171,
Bagamoyo.

Unio dumesleanus CnarMes, Bull. Soc. Mal. Fr., II, 1885, p.
108, Bagamoyo.

Group of Parreysia fabagina,

Shell very small and solid, inflated, compressed on the sides,
rhomboid, with a high, sharp posterior ridge and high beaks,
having zigzag-radial sculpture sometimes extended over the
disk, the posterior slope furnished with upcurved plications ;
pseudocardinals heavy, torn, one in the right valve, two in the
left; muscular impressions circular, the anterior very deep.
PARREYSIA FABAGINA (Deshayes).

Shell very solid, small, inflated, rhomboid, inequilateral ;
beaks full and elevated, with irregular zigzag-radial sculpture ;
posterior ridge high, angled, rather close to the edge of the
shell, curved, ending in a sharp point near the base of the
shell; anterior end rounded; base line lightly arcuate; dorsal
outline arched; dorsal slope obliquely subtruncate, there being
a low angle where it joins the dorsal part of the shell; epider-
mis fuscous-green; pseudocardinals thick; laterals strong
greatly curved; muscle scars small, the anterior ones deep,
the posterior ones semilunar; nacre silvery.

Length 17, height 12, diam. 1t mm.

Mekong River, Cambodia.

PARREYSIA _ I131

Umio fabagma Drsuayrs, Nouv. Arch. de Mus., X, 1874, p.
128, pl. vit, figs. 4-6.

Parreysia fabagina SIMPSON, Syn., 1900, p. 847.

Unionelia fabagina Haas, Conch. Cab., Unio, 1912, pl. 31, fig. 8.
An exceedingly solid, small species with strongly arched

dorsal outline, high, sharp posterior ridge and curved laterals.
Haas has recently, (Nachr. Deutsch. Mal. Ges., 1913, p.

37), made this species the type of a new genus, Unionella.

PARREYSIA BROTI (Deshayes).

Shell small, solid, inflated, rhomboid, inequilateral; beaks
full and high; below them there are three strong, low V-shaped
ridges, and on the dorsal slope there are oblique wrinkles;
posterior ridge high and decidedly angled, slightly arched;
anterior end narrow, rounded; dorsal outline strongly arched
from the anterior end to the point at the posterior base; base
line nearly straight ; epidermis yellowish-green, darker on the
ridges and border; pseudocardinals solid; laterals heavy, but
slightly curved; muscle scars small, deep; nacre silvery.

Length 15, height 11, diam. 9 mm.

Mekong River, Cambodia.

Unio broti DesHayes, Nouv. Arch. de Mus., X, 1874, p. 129,

pl. vit, figs. 1-3.

Parreysia broti Simpson, Syn., 1900, p. 847.

Unionella broti Haas, Conch. Cab., Unio, 1912, pl. 31, fig. 9.
If the specimen, which Deshayes has described, is adult

this is probably the smallest Naiad known. It is characterized

by the three very strong V-shaped bars across the disk; it has

shorter, heavier, less curved laterals than fabagina.

Group of Parreysia nyassaensis.

Shell small, solid, inflated, triangular to rhomboid, the base
straight or even a little arcuate, but sometimes having a slight
fullness behind the central part, a high, well-defined posterior
ridge ends at the post-base and is sometimes slightly double ;
posterior slope abrupt; beaks high, with zigzag-radial sculp-
ture, the bars approaching and often coalescing behind the cen-

1132 ' PARREYSTA

ter of the disk, the whole shell frequently corrugate sculp-

tured; epidermis greenish, often slightly rayed; teeth solid,

much like those of typical Parreysia; nacre white or bluish,

sometimes microscopically, granularly radiate outside the pal-

lial line; beak cavaties not deep; anterior scars distinct.
Animal unknown.

PARREYSIA NYASSAENSIS (Lea).

Shell rhomboid, solid, subinflated, inequilateral; beaks high,
full, with strong, zigzag sculpture, which extends over the disk
nearly or quite to its outer edge, becoming subnodulous in
places, plicate on the dorsal slope; there being also a pattern
of irregular, concentric ridges and sometimes feeble radiat-
ing furrows; anterior end rounded; base straight or lightly
curved; hinge line lightly arched, angled where. it joins the
obliquely subtruncate dorsal slope; posterior ridge high, sub-
angular; epidermis ashy to greenish, sometimes feebly banded
and rayed, subshining; hinge solid; pseudocardinals much
split up: laterals more or less double in each valve; anterior
scars impressed; nacre whitish or flesh-colored.

Length 33, height 23, diam. 15 mm.

I,ength 30, height 22.5, diam. 15 mm.

Lake Nyassa, Central Africa.

Unio nyassaensis Lea, Pr. Ac. N. Sci. Phila., VIII, 1864, p.
10S¢ [lcAcs NeiScinPhilagev il, 1866, piss eplo xin ho: sae"
Obs., XI, 1867, p. 37, pl. xu, fig. 32—SmirH, Pr. Zool. Soc.
Lond., 1881, p. 298, pl. xxx1v, fig. 34.

Margaron (Unio) nyassaensis Lea, Syn., 1870, p. 30.

Parreysia nyassaensis SIMPSON, Syn., 1900, p. 848.

Unio nyasse Sowr;rpy, Conch. Icon., XVI, 1868, pl. x11, figs.
224, 224a, 224b.

Unio nyassanus Bourcuicnat, Bull. Soc. Mal. Fr., VI, 1880,
p. 38.

Unio hermosus Bourcutenat, Bull. Soc. Mal. Fr., VI, 1880,
p. 38.

The above measurements are first from the type and the
second from a shell belonging to the Morelet .collection.

PARREYSIA GS

PARREYSIA KIRKII (Lea).

Shell short, subtriangular, subinflated, solid; beaks very
high, full, their sculpture consisting of zigzag, swbnodulous
ridges; this sculpture reappears feebly in various parts of the
disk, the posterior slope and upper anterior end being plicate ;
beside this there are irregular, concentric ridges and feeble
radial grooves on the anterior end; posterior ridge high, sub-
angular, with one or two faint ridges above it; lunule distinct,
narrow ; anterior end narrowly rounded below, obliquely trun-
cate above; base line nearly straight; outline of dorsal slope
obliquely rounded from the beaks to the rather sharp basal
point; epidermis greenish, feebly rayed, with two or more
dark rays on the dorsal slope; hinge strong, arched; pseudo-
cardinals very ragged; laterals heavy, short, treble in the left
valve. double in the right; muscle scars impressed; nacre
bluish-white, thicker in front.

Length 32.5, height 28, diam. 16 mm.

Lake Nyassa.

Unio kirkii Lea, Pr. Ac. N. Sci. Phila., 1864, p. 108; Jl. Ac. N.
Sci. Phila. Vip 18660" p. 32, pl. xa, fig. 30% Obs.,. Xi, 1867,
Peso ple sain. tgs 20.

Margaron (Unio) kirkti Lea, Syn., 1870, p. 30.

Parreysia kirkii Stimpson, Syn., 1900, p. 848.

Close to nyassaensis but higher in proportion to length,
more triangular, smoother and having a greener epidermis.
I have only seen the type.

PARREYSIA UJIJIENSIS (Bourguignat).

Shell ovate rhomboid or ovate triangular, subinflated, in-
equilateral; beaks high and full, rather sharp; anterior end
rounded and very slightly truncated in the middle; base line
evenly curved; dorsal outline high at the beaks, arched; pos-
terior end slopingly truncate, subangulate where it joins the
dorsal part; posterior ridge full, subangulate, ending in a point
a little above the basal line; surface with slight, concentric
sculpture with zigzag or wrinkled sculpture above on the
anterior end and on the dorsal slope.

Length 20, height 20 mm.

Lake Tanganyika.

1134 PARREYSIA

Unto nyassaensis var. Smiru, Pr. Zool. Soc. Lond., 1881, p.

298, pl. xxxIVv, fig. 34.

Grandidieria wjijiensis BouRGUIGNAT, Bull. Soc. Mal. Fr., I,

1885, p. 7.

Parreysia wjijiensis SIMPSON, Syn., 1900, p. 848.

Mr. Smith does not give a description of this form, whicli
he figured in the Proceeding of the Zoological Society and
referred to Umio nyassaensis Lea, as a variety. There is some
little confusion about it, as he refers to fig. 34) on pl. xxxiv,
and there is no such number. His 34a seems to be
typical myassaensis and the 34 a different species, being tri-
angular ovate and smoother than myassaensis. Bourguignat
suggested the name wjijiensis for this species, but his account
of the shell is not accessible as I write. I can not therefore
give any account of the beak sculpture, nacre, solidity or diam-
eter of this form.

PARREYSIA AFERULA (Lea).

Shell rhomboid, solid, convex, inequilateral; beaks neither
very full nor high, with strong, zigzag sculpture and corru-
gations, which extend over the entire surface of the disks;
posterior ridge full, feebly double, ending in a faint biangula-
tion at the base of the shell; anterior end rounded; base line
almost straight; hinge line lightly arched, ending in an angle
where it joins the obliquely truncate dorsal slope; epidermis
dirty ash colored, not shining; hinge solid; pseudocardinals
much split ; laterals double in each valve ; muscle scars impress-
ed: nacre bluish-white.

Length 29, height 20, diam. 12.5 mm.

Lake Nyassa.-

Unio aferula Lea, Pr. Ac. N. Sci. Phila., VIII, 1864, p. 109.
Unio aferulus Lea, Jl. Ac. N. Sci. Phila., VI, 1886, p. 34, pl.

Mitihe. 24.4 @bs.; X1, A867, pase, pla kU Mee BA.

Margaron (Unio) aferulus Lea, Syn., 1870, p. 30.
Parreysia aferula Simpson, Syn., 1900, p. 848.

It is quite likely that this is the same as Lea’s Unio nyassaen-

sis, but I have only seen a single shell, the type, and do not feel

PARREYSIA 1135,

like uniting it without more evidence. This may be a young
or not fully developed shell. It is less inflated, more strongly.
and completely sculptured and duller colored than nyassaensis.
In the right valve there is a sort of triangular pit in the hinge
plate behind the pseudocardinals, which is not present in the
shells of nyassaensis | have seen.

PAREYSSIA MUTELA‘FORMIS (Germain).

“Shell smali, very elongate rectilinear in shape; rather solid,
slightly inflated; dorsal and ventral margins nearly parallel ;
dorsal margin straight ; ventral margin nearly straight, slightly
subsinuous in the center and curved upwards towards the pos-
terior end; anterior end rather short, well rounded; posterior
part elongated horizontally, almost three times as long as the
anterior, keeping the same height as far as the postero-dorsal
angle, then narrowing, especially above, to a sharp posterior
end ;~beaks rather anterior, (but very noticeably less than in
Unio monceti Bourguignat), somewhat inflated, compressed
laterally ; dorsal crest well marked; in the right valve a double
cardinal and two, very long, rather low laterals; in the left
valve, one, very high, subquadrangular, distinctly crenulate
cardinal and one very long, rather low lateral; anterior muscu-
lar impressions deep, posterior superficial. Epidermis yellow-
ish-chestnut or ochreous, sometimes very dark, somewhat worn
towards the beaks; lines of growth quite delicate, regular,
stronger posteriorly ; nacre clear Prussian blue, quite iridescent.

Length 24-26, height 9-10, diam. 5 mm.” (Germain).

Type locality, Lake Tchad.

Unio muteleformis GERMAIN, Mem. Soc. Zool. Fr., XIX,
1906, p. 336; l Afrique Cent. Fr., 1907, p. 540, pl. lith. figs.
3, 4-

“This species can be compared only with Unio monceti
Bourguignat, but is distinguished by its smooth surface; its
much more elongated form, though the posterior part is not.
as in typical monceti, three times as long as the anterior, as
the anterior end of monceti is remarkably short, very round,
with the beaks placed very anteriorly ; by the much less prom-
inent beaks and much more compressed form.”

1136 PARREYSIA

Var. chariensis (Germain).

“This shell differs from the type by its much shorter form,
being elliptic-oval; by its dorsal margin slightly ascending
and a little subconvex ; by its ventral margin, not straight, but
very notably and regularly convex; by the higher posterior
region by reason of the greater divergence of the dorsal and
ventral margins, so that the greatest height is not uniform with
that through the beaks, as in the type, but is in the posterior
region; by the two quite pronounced dorsal angles; etc.”
(Germain).

Type locality, La Mamoun, Senoussi country.

Unio muteleformis var. chariensis GERMAIN, |’Afrique Cent.

Bry £007; (p. ‘SAT.

“Tn this little shell, the beaks are much less prominent, the
ligament is less strong, and very short ; the epidermis of a pale
vellowish-red, with fine, close and regular lines of growth:
the nacre is of a very iridescent, brilliant rose-salmon color.”

PARREYSIA HYPSIPRIMNUS (von Martens).

Shell trapezoid or subrhomboid, solid, inflated, somewhat in-
equilateral; beaks moderately full and high; posterior ridge
full, rounded, ending in a blunt point near the base; anterior
end somewhat narrowed, rounded ; base nearly straight ; dorsal
outline slightly sinuous, arched from the beaks to the end
of the ligament; posterior end obliquely truncate; surface cov-
ered with peculiar, strong, wavy, concentric sculpture; epi-
dermis dirty brown; teeth rather strong; laterals curved ; nacre
whitish.

Length 33, height 23, diam. 16.5 mm.

Lake Nyassa.

Unio hypsiprimnus von Marvrens, Besch. Deuts. Ost-Af.,
1897, p. 230, pl. vit, fig. 1—Grrmain, Bull. Mus. Hist. Nat.,
1906, p. 302, figs. 8-16.

Parreysia hypsiprimnus Stmpson, Syn., 1900, p. 849.

A peculiar species, of which the type is very badly eroded.
The sculpture consists of wavy or somewhat ragged, concen-
tric ridges, differing from that of any allied form that I am
acquainted with.

PARREYSIA WI y7/

Group of Parreysia molleuri.

Shell subquadrate, solid, inflated, rounded in front, trun-
cated behind, with high beaks, the sculpture of which was not
observed, and a strong, sharp, curved posterior ridge; surface
concentrically grooved; pseudocardinals thick, short, cut up
with vertical grooves; laterals curved; nacre white.

PARREYSIA MOLLEURI ( Morlet).

Shell subquadrate, solid, scarcely inflated, inequilateral ; dor-
sal outline very strongly arched throwing the rugose beaks
well up; anterior end a little narrowed, rounded; base iine
nearly straight; posterior end almost squarely truncated ; pos-
terior ridge high, curved, angulate, ending in a blunt point at
the base of the shell; surface covered with strong, concentric
strie; epidermis brown-green; pseudocardinals small, thick,
short, ragged; laterals much curved; nacre white.

Length 25, height 21, diam. 14 mm.

Valley of the Mekong River.

Unio molleuri Moret, Jl. de Conch., XXXIX, 1891, p. 242,

pl. vir, fig. 4.—Haas, Conch. Cab., Unio, 1912, pl. 31, fig. 7.
Parreysia molleuri SIMPSON, Syn., 1900, p. 849.

A peculiar form, somewhat quadrate in outline, strongly
arched on the entire dorsal region and almost squarely trun-
cate behind.

Haas, (I. c.), considers this a synonym of P. fabagina.

Subgenus Diaurora Cockerell, 1903.

Aurora SIMPSON, Syn., 1900, p. 840.
Diaurora CocKERELL, Naut., XVI, 1903, p. 118.

Shell small, ovate, subinflated, pointed behind, rather solid,
with high, small beaks and strong, corrugated sculpture, which
extends over half the disk in somewhat lachrymous, zigzag
ridges and nodules, the outer part of the disk apparently hav-
ing one or more strong, concentric ridges, the posterior slope
being radiately ridged and nodulous; epidermis fulvous, beau-
tifully and delicately green radiated; pseudocardinals conical,
truncate, striate; laterals lamellar; nacre orange.

Type, Unio auroreus Heude.

1138 PARREYSIA

x

PARREYSIA AUROREA (Heude).

Shell almost evenly elliptical or very slightly rhomboid, solid,
scarcely inflated, inequilateral; beaks only moderately high,
small, deeply corrugated, apparently by zigzag ridges; poste-
rior ridge full, narrowly rounded, ending in a blunt point below
the median line; anterior end rounded; dorsal and basal out-
lines almost evenly curved; dorsal slope obliquely subtruncate ;
surface with strong, subradial, tear-like nodules on its earlier
growth and, apparently, about three strong, concentric ridges
on the later growth; posterior slope with radial, nodular sculp-
ture; epidermis fuscous, rayed with green; pseudocardinals
short, much cut up; muscle scars impressed ; nacre orange.

Length 34, height 21, diam. 12 mm.

China.

Unio auroreus HeupE, Conch. Fluv. Nank., VIII, 1883, pl.

LVII, fig. 106.

Parreysia aurorea SIMPSON, Syn., 1900, p. 849.

Heude’s description is very brief and of little value, and as
in several other cases the measurements given are manifestly
wrong. This must be an attractive species having an almost
evenly elliptical form, decided radial, lachrymose sculpture and
orange nacre.

Subgenus PSEUDOBAPHIA Simpson, 1900.

Pseudobaphia SIMPSON, Syn., 1900, p. 840.

Shell large, oval, inflated, gaping in front and behind, rather
solid, with full beaks, the beak sculpture not seen, posterior
part distinctly biangular; ligament large; epidermis smooth,
brownish, somewhat rayed, right valve with a large, irregu-
lar pseudocardinal in front of the beak, with a pit in front of
it; behind it on the hinge are numerous denticles, and at some
distance behind two very faint laterals; left valve with two
large pseudocardinals, one behind the other, and two remote,
blurred laterals; two upper, anterior muscle scars united, very
deep; posterior scars united, the lower long and oblique ; beak
cavities very large, deep; nacre flesh-colored, scarcely nacreous.

Animal unknown.

Type, Unio biesianus Heude.

PARREVOTA I139

PARREYSIA BIESIANA (Heude).

Shell large, rather solid, inflated, subrhomboid, somewhat
equilateral; beaks very full and high, corrugated; ligament
large, brown; posterior ridge more or less double, ending in a
biangulation at and below the median line, the region above it
obliquely truncate; epidermis fuscous-olivaceous, slightly ray-
ed when young; surface with irregular, concentric sculpture
anteriorly and posteriorly nearly smooth and shining medially ;
pseudocardinals strong, stumpy, slightly roughened, showing
behind them numerous nodules; laterals feeble, in old shells
almost wanting; anterior scars deep in their hinder portion;
posterior scars large; beak cavities deep, compressed; nacre
dirty white or flesh-colored.

Length 106, height 76, diam. 52 mm.

China.

Unio biesianus Hrupe, Conch. Fluv. Nank., II, 1877, pl. xiv,

fig’. 30.

Parreysia biesiana StMPsON, Syn., 1900, p. 850.
Pseudobaphia biestana Haas, Con. Cab., Unio, 1910, pl. xt,
16Sgvetle

A large inflated, strong species with a rhomboid form being
slightly cut away at the lower part of the anterior end. The
anterior and posterior ends. gape slightly. The laterals are
feeble, but between them and the pseudocardinals there are a
number of small tubercles.

Subgenus Acuttcos'ra Simpson, 1900.

Acuticosta SIMPSON, Syn., 1900, p. 850.

Shell pointed behind, produced at the center of the base, in-.
flated, solid, with a sharp, pinched-up, but vanishing posterior
ridge, beaks full, the sculpture strong, zigzag-radial ; epidermis
smooth, rayed; pseudocardinals somewhat compressed, verti-
cally ridged, ragged; laterals well developed, strongly oblique-
ly ridged and granular.

Type, Unio chinensis Lea.

PARREYSIA CHINENSIS (Iea).

Shell irregularly elliptical or ovate, somewhat inflated, rather
solid, inequilateral ; beaks full and high, sculptured with very
strong, often subnodulous, zigzag sculpture, which extends

II140 PARREYSIA

well out over the umbonal region; posterior ridge not greatly
elevated, but usually sharply angled above, ending in a point
at or a little below the median line; there is also a low, ill-de-
fined, radial ridge about on the middle of the disk, the base
of the shell being quite full where it ends; lunule large; an-
terior end rounded; dorsal slope obliquely subtruncate; sur-
face nearly smooth or with irregular, concentric sulcations;
epidermis ashy-green or yellowish-green with olive-green rays ;
pseudocardinals subcompressed, somewhat ragged; laterals re-
mote, elevated; beak cavaties moderately deep; anterior scars
impressed ; posterior scars shallow ; nacre bluish-white, thicker
in front.

Length 47, height 31, diam. 22 mm.

Length 40, height 29, diam. 21 mm.

China.

Unio chinensis Lea, Pr. Ac. Nat. Sci. Phila., XII, 1868, p.
150; fl Acs Nat.oct. Phila Vib 1868 sp. .325-.ply ii she.
138 5 Obs.,, XtL, 1860, p: 85; pk. Lim, fig. -138.

Margaron (Unio) chinensis Lea, Syn., 1870, p. 30.

Parreysia chinensis StMPSON, Syn., 1900, p. 850.

Acuticosta chinensis Haas, Conch. Cab., Unio, 1912, pl. 30,
figs. 1-3, 6-7.

The type of this is in the collection of Yale College, accord-
ing to Dr. Lea, but I have before me three shells of what is
undoubtedly this species. They vary a little in form, coloring
and the degree of umbonal sculpture. One of them is not
very strongly sculptured on the beaks.

Var. sguammosa (Heude).

Most of the anterior part of this shell is covered with squa-
mose ridges. Heude merely figures the form and gives no de-
tails.

China.

Unio sinensis var. squammosus Heupr, Conch. Fluv. Nank.,

Vit “183, ple iviii, fie 13.

Parrevsia chinensis var. squammosus SIMPSON, Syn., 1900, p.

850.

Acuticosta chinensis var. squammosa Haas, Conch. Cab., Unio,

1O12, pl. 30; tise. 5.

PARREYSIA II4I

Var. lewis (Heude).

Shell large, nearly or quite destitute of sculpture, with broad,
dark rays.
China.
Unio smensis var. levis Hrupr, Conch. Fluv. Nank., VIII,
LSOse pla LIX, te. T1G:
Parreysia chinensis var. levis SIMPSON, Syn., 1900, p. 850.
Acuticosta chinensis var. levis Haas, Conch. Cab., Unio, 1912,
Diz 20; fis.

PARREYSIA RETIARIA (Heude).

Shell rather small, inflated, solid, somewhat inequilateral ;
beaks full and high, turned forward; anterior end rounded;
base line nearly straight; outline of dorsal slope obliquely
rounded ; posterior ridge full, narrowly rounded, ending in a
feeble biangulation almost at the base of the shell; in front
of the posterior ridge there is a wide, radial, somewhat de-
pressed space; epidermis fuscous horn-color, slightly rayed;
pseudocardinals solid, split up; nacre amethyst-rose.

Length 22, height 15, diam. 10 mm.

Streams of Ning-kouo fou and of Tche-tcheou fou, China.
‘Umo retiarius Heupr, Conch. Fluv. Nank., VIII, 1883, p.

LVII, fig. 107.

Parreysia retiaria St1MPSON, Syn., 1900, p. 850.
Acuticosta retiaria Haas, Conch. Cab., Unio, pl. 30, fig. 12.

A fine, small species, which probably is related to P. chin-
ensis. Its most conspicuous character is the wide, radial, de-
pressed area in front of the posterior ridge.

SPECIES INCERTA SEDIS
PARREYSSIA ALLUAUDI Dautzenberg.

“Shell very thin, shining, elongate-oval, rounded in front,
truncate and rostrate behind. Ventral margin convex and pro-
jecting in the middle. Beaks inflated, quite prominent. Sur-
face .sculptured in the umbonal region with oblique, zigzag
folds, which extend more or less over the whole of the disk.

I1l42 PARREYSIA

Nacre very shining. Anterior muscular impressions round,
posterior elongated, rather faint. Hinge very weak. In the
right valve, two, weak, elongated cardinals and a single lat-
eral equally weak and elongated. In the left valve one cardinal
and two laterals.

Epidermis bluish-green with metallic reflections, ornament-
ed with concentric zones and rays of yellow. Nacre very iri-
descent.

Length 27, height 16, diam. 11 mm.” (Dautzenberg).

Type locality, Bay of Kavirondo, Victoria-Nyanza.

Unio (Parreyssia) alluaudi DAutTzeEnBeErG, Jl. de Conch., LVI,

1908, p26, pliid, figs. 135.04, 15,/16.

“Although a certain number of species of Unio are known
from Lake Victoria, we have not been able to refer to any one
of them, the one here described. It is characterized by its thin,
very brilliant shell with metallic reflections, weak hinge, elon-
gate form, attenuate and rostrate at the posterior end and by
the convex, ventral margin, projecting in the middle.

The sculpture is very variable in Unio alluaudi: sometimes
the zigzag folds appear only in the umbonal region; but they
frequently extend over the whole surface. ‘The coloration is
equally variable, for we have seen examples without rays and
of a uniform yellow.”

PAREYSSIA MWERUENSIS (EK. A. Smith).

“Shell small, inequilateral, moderately thin, narrowly gap-
ing at both ends, rounded in front, narrower and produced
posteriorly, covered with a brownish-olive periostracum, some-
times painted posteriorly with radiating green lines, smooth
but sculptured with lines of growth and more or less corru-
gated towards the umbones; umbones eroded, placed well for-
ward; nacre white, pearly, iridescent; cardinal teeth rugose,
laterals thin, elongated; anterior cicatrix moderately deep,
posterior light, not impressed.

Length 26, height 15, diam. 10.5 mm.” (Smith).

Type locality, Lake Mweru.

Unio mweruensis %. A. Smrtru, Pr. Mal. Soc. London, .VIII,

1908, p. 13, text-figs.

PARREYSIA I143

“This species varies considerably in form and _ sculpture.
Some specimens are much longer than others, and the amount
of corrugation towards the umbones varies considerably. Some
examples are almost entirely smooth, whereas occasionally the
wrinkling may extend over two-thirds of the surface. The
valves are white beneath an olive-brown periostracum, which
almost invariably exhibits one or more green rays down the
hinder slope. ‘There is in most specimens a kind of lunule in
front of the umbones, which varies much in shape, being quite
broad and diamond-shaped in some shells and quite narrow
and linear in others. An elongate example is 29 mm. in length
and 14 in height. A shorter is 20.5 long and 12.75 high.”

PAREYSSIA HUNANENSIS Haas.

“Shell very inequilateral, solid, thick. Anterior end very
short, semi-circular; ventral margin slightly convex or angu-
lated, posterior end long, biangulate. Beaks situated at 31-100
of the total length, much swollen, incurved ; beak sculpture con-
sisting of two, radial, strong ribs, which unite at the apex.
The anterior extends in the direction of the deepest point of
the ventral margin, but does not reach it; it is tuberculate and
may be broken up into a series of distinct tubercles; the pos-
terior extends to the lower angle of the posterior end, where
it becomes almost flat and is tuberculate only towards the
beaks. ‘The anterior part of the beaks shows weak, slightly
raised, radial, somewhat undulating striz. Ligament short.
Dorsal slope low, oblique, with a faint line that extends from
the beak to the upper angle of the posterior point. Hinge
strong, cardinal tooth of the left valve divided by a rectangu-
lar, deep groove, jagged, striate, compressed, between the car-
dinal and !aterals, which meet at a decided angle, there is a
long interval; laterals short, strong; the cardinal teeth make
an angle of about 30° and the laterals one of 15° with the
axis of the shell. The anterior muscular impression deep,
funnel-shaped, the posterior not. Nacre of a magnificent blu-
ish-white. Epidermis chestnut-brown with yellowish-brown
rays, mostly worn off on the umbones.

T144 PTYCHORHYNCHUS

Length 36, height 26, diam. 19 mm.” (Haas).
Type locality, Hubei, Hunan, Central China.

Pareyssia hunanensis Haas, Nachr. Deutsch. Mal. Ges., 1910,
p..G7>-Conch. Cab: Unio; 1912) ply.a0) igo:

Genus PTYCHORHYNCHUS Simpson, 1900.

Ptychorhynchus SIMPSON, Syn., 1900, p. 850.

Shell elongate, elliptical, round in front, pointed behind, the
point being midway of the height of the shell, solid, slightly
inflated, with a faint posterior ridge; beaks rather low, sculp-
ture not seen; the posterior slope sculptured with strong, up-
curved ridges, which sometimes extend slightly on to the disk,
which is otherwise smooth and shining; left valve with two
rather stumpy, roughened pseudocardinals and 1-2 somewhat
blurred, granulous laterals; right valve with a single blunt
pseudocardinal, the hinge line in front of which is excavated,
and a curious blurred lateral, which is sometimes slightly split
up; beak cavities shallow; dorsal- scars few; nacre whitish.
Animal unknown.

Type, Unio pfisteri Heude.

I have placed in this group a number of forms which seem
to be rather closely related and have given the group generic
rank, because I could not refer the species to any known genus.
All are oblong forms with dark epidermis, with more or less
plicate sculpture on the dorsal slope. The pseudocardinals
are solid and generally triangular, the laterals usually remote
and not strongly developed.

KEY TO SPECIES OF PTYCHORHYNCHUS.

Shell regularly long ovate or nearly so.
Posterior ridge well developed, epidermis olive-green.
P. pfistert.
Posterior ridge low, epidermis blackish-brown. P. levis.
Shell more or less long rhomboid.
Posterior ridge double, shell biangulate behind,
P. nieuwenhuisi, apicellatum.
Posterior ridge not double.
Shell rather short. P. schomburgianum.
Shell somewhat elongated, P. murinum.

PTYCHORHYNCHUS T1145

Group of Ptychorhynchus pfisteri.
Characters as in the genus.

PTYCHORHYNCHUS PFISTERI (Heude).

Shell almost evenly long elliptical or long ovate, convex or
subinflated, rather solid, inequilateral; beaks but slightly ele-
vated; posterior ridge well-developed, subangular or narrow-
ly rounded, ending behind in a blunt point on the median line ;
surface of the disk nearly smooth, exhibiting a few feeble,
low, concentric ridges; posterior slope everywhere covered
with strong, corrugated plications; epidermis shining, olive-
green; pseudocardinals two in the left valve and one in the
right, stumpy, nearly smooth and even in size; laterals remote,
rather feeble, two in the left valve and a partially double one
in the right; beak cavities shallow with a few, faint dorsal
scars: muscle scars but slightly impressed; nacre whitish, iri-
descent behind; pallial line with indications of a posterior
sinus.

Length 77, height 34, diam. 20 mm.

Nankin River, China.

Unio pfisteri Heung, Jl. de Conch., XXII, 1874, p. 112; Conch.

BitveeNank., 11875, plo 1, tie. 1.

Ptychorhynchus pfisteri Stueson, Syn., 1900, p. 851.

This species bears some external resemblance to the North
American Ptychobranchus subtentus, but lacks the square blot-
ches.

Var. imspiratum (Heude).

Seems to differ from the type in having less sculpture on
the dorsal slope and the posterior point more drawn down. I
am doubtful whether it is worthy of varietal rank.

Unio pfisteri var. inspiratus Heupr, Conch. Fluv. Nank., I,

1877, pl. xiv, fig. 28.

Ptychorhynchus pfisteri var. inspiratus, SIMPSON, Syn., 1900, p.

S51.

I 146 PTYCHORHYNCHUS

Var. mediastinum (Heude).

Heude separates this from his Unio pfisteri on account of
its having more elevated beaks than that species. The type of
U. phsteri, according to the figure, is so badly eroded in the
umbonal region that nothing of the beaks can be made out.
That of U. mediastinus is also somewhat eroded and its beaks
are not at all full. The posterior end of the type is a little
more blunt than the National Museum specimens or Heude’s
figures of U. pfisteri.

China.

Unio mediastinus Hreupr, Conch. Fluv. Nank., VIII, 1883, pl.

LST Mi oor.

Ptychorhynchus mediastinus SIMPSON, Syn., 1900, p. 851.

PTYCHORHYNCHUS La&viS Haas.

“Shell elongate-elliptical, subsolid, rather compressed,
rounded in front, bluntly. pointed behind about the middle of
the height; posterior ridge low, rounded; angulate, basal
margin regularly curved. Beaks somewhat prominent,
situated at 29-100 of the total length; their sculpture
is invisible on account of erosion. Epidermis smooth,
shining, of a blackish-brown, with darker lines’ of
growth. Hinge consisting of two cardinals and vestiges of
two laterals in the left, one cardinal and vestiges of one lateral
in the right valve. Cardinals high, the one of the right valve
pyramidal, the anterior one of the left valve smaller and lower
than the posterior one, almost triangular. Laterals very short,
low, only indicated; interval long, narrow and smooth. An-
terior cicatrices deep, rough, that of the anterior adductor and
that of the anterior retractor confluent. Posterior cicatrices
distinct, faint. Dorsal cicatrices united to a narrow groove
situated at the inner side of the interval. Beak-cavities shal-
low. Nacre reddish, bluish at the margin, not brilliant.

Length 59, height 31, diam. 16 mm.” (Haas).

Type locality, Saghalin Island.

Ptychorhynchus. lewws Haas, Ann. Mag. Nat. Hist., (8), VI,

1910, p.. 498.

PTYCHORHYNCHUS 1147

Group of Ptychorhynchus apicellatun.
Shell subrhomboid, more or less biangulate behind

PTyCHORHYNCHUS APICELLATUM (Heude).

Shell somewhat elongated, subrhomboid, being a little higher
behind than in front, rather solid, convex, inequilateral; an-
terior end rounded; base line nearly straight; dorsal outline
lightly curved; dorsal slope obliquely truncate ; posterior ridge
widely, feebly double, ending in a biangulation at and below
the median line; beaks apparently low, plicate sculptured ; sur-
face with faint, concentric sculpture and with numerous deli-
cate plications on the dorsal slope; epidermis yellowish-black ;
pseudocardinals rather solid, striate; laterals remote, not
strongly developed ; nacre brownish-rose.

Length 6o, height 33, diam. 16 mm.

Torrents of Tche-tcheou fou, province of Ngan-houe, China.
Unio apicellatus Hrupr, Conch. Fluv. Nank., VIII, 1883, pl.

XII, fig. 126:

Ptychorhynchus apicellatus SIMPSON, Syn., 1900, p. 85.

Heude states that the beaks of this in a young state are deli-
cately plicate sculptured, but whether the plications are zigzag,
radial or concentric he does not inform us.

PTYCHORHYNCHUS SCHOMBURGIANUM (Heude).

Shell elliptic rhomboid, moderately solid, subinflated, in-
equilateral ; beaks but slightly elevated; anterior end narrowed
a little, rounded; base line lightly curved; posterior ridge
rounded; dorsal outline somewhat arched; dorsal slope ob-
liquely subtruncate, below the truncation the shell is rather nar-
rowly rounded ; surface brownish-black ; dorsal slope having a
few faint plications ; pseudocardinals pyramidal, solid, oblique,
serrulated ; lateral double in the right valve, obsolete in the left ;
muscle scars well marked; nacre salmon, fuscous, shining,
radiately striate, concentrically iridescent.

Length 52, height 25, diam. 17 mm.

Isle of Hainan, China.

1148 PTYCHORHYNCHUS

Unio schomburgianus Heupr, Conch. Fluy. Nank., 1X, 1885,
pl. LXxu, fig. 139.—FiscHeEr, Jl. de-Conch., XL, 1892, p. 314.
Ptychorhynchus schiomburgianus SIMPSON, Syn., 1900, p. 851.
Close to P. apicellatum, but less decidedly rhomboid and not
distinctly biangulate behind. It seems to stand between that
species and the varieties of pfisteri. Meude states that the epi-
dermis is radiate, but the figure does not show it.

PryCHORHYNCHUS NIEUWENHUISI (Schepman).

Shell long, subrhomboid, convex or almost compressed, in-
equilateral; beaks apparently low and subcompressed; pos-
terior ridge low, widely double, ending behind in a wide bian-
gulation from a point below the median line to the base; an-
terior end very slightly narrowed, rounded; base line nearly
straight; dorsal line lightly curved; dorsal slope obliquely
truncate above, the truncation meeting the dorsal line at a
low angle and the biangulation below at a sharper angle;
surface apparently concentrically striate, the stridtion coarser
below ; posterior end of the shell covered with rather fine,
curved, radiating folds which are slightly divaricate on the
upper part of the posterior ridge; epidermis dark brown,
fibrous; hinge strong; one thick pseudocardinal in the right
valve and two in the left; one lateral in the right valve
and two in the left, lightly curved and crenate posteriorly ;
anterior scars deep, irregular; posterior scars shallow ; pallial
line distinct ; nacre iridescent, olive-yellow in the cavities, blu-
ish-white on the border. A flat callosity runs from the beaks
within obliquely towards the ventral margin.

Length 69, height 40, diam. 19 mm.

Bloe-oe, East Borneo.

Unio meuwenhuisi ScHEPMAN, Notes Leyd. Mus., XX, 1808,
p- 92, pl. 1, figs. 1, 2—Drouet, Jl. de Conch., xivi1, 1899,
p. 406.

Unio newenhuisi Stmeson, Syn., 1900, p. 803.

Schepmania nieuwenhuisi HAas, Con. Cab., Unio, 1910, pl.
Kit; Ss as

PTYCHORHYNCHUS IIl49

Although the origina! description of this species is very
full I am unable to feel any certainty as to where it belongs.
Nothing is known of the anatomy and the entire umbonal re-
gion is so badly eroded in the specimen figured that no idea
can be formed of the beak sculpture. The form is almost
exactly that of Unio complanatus save that it is more widely
and distinctly biangulate behind. I place it with some doubt
near the Unio apicellatus of Heude. The solid pseudocardi-
nals, the posterior plications and its form and color are some-
thing like that shell.

Haas has recently, (Nachr. Deutsch. Mal. Ges., 1913, p. 33),
made this species the type of a new genus, Schepmania.

Var. parcesculptum (von Martens).

“Shell oblong, compressed, thick, closely, concentrically stri-
ate and sculptured on the posterior slope near the umbones
with upward curved folds, often slightly divided; very short
and rounded in front, elongate and subtruncate behind; um-
bones quite compressed, eroded; posterior dorsal margin sub-
horizontal as far as the sinulus, thence with a very obtuse an-
gle sloping gradually to one-half of the height of the shell ;
posterior margin straight, slightly oblique, separated from the
ventral margin by a more or less distinct angle ; ventral margin
posteriorly and in the centre subhorizontal, very slightly
curved, in the anterior third at first a little, then sharply as-
cending. Nacre milky-white, slightly pearly; cardinal tooth
of the right valve strong, conic-triangular, crenulate; poste-
rior cardinal tooth of the left valve not quite so strong, conic,
anterior weak, compressed triangular; laterals straight.

Length 70, height 43, diam. 20 mm.” (von Martens).

Type locality, Guleh River, East Borneo.

Unio (OQuadrula) nieuwenhousi var. parcesculptus von Mar-

TENS, S. B. Ges. Naturf. Fr., 1903, p. 425.

Schepmamia parcesculpta Haas, Con. Cab., Unio, 1gto, pl. xi,
fig. 4. ;

“Differs from the species described by Schepman as well as
from the typical form from East Borneo by the weaker sculp-

1150 VIRGUS

ture; the curved folds reach the dorsal margin only very near
the beaks, but do not near the postero-dorsal angle nor along
the posterior slope, but stop 6-12 mm. from it; the post-basal
point is also less distinctly angulated.”

PryCHORHYNCHUS MURINUM (Heude).

Shell almost evenly oblong elliptical, very slightly rhom-
boid, subsolid, inequilateral, beaks low; posterior ridge widely
rounded; anterior end rounded; dorsal and basal outlines
nearly straight and parallel; posterior end obliquely subtrun-
cate above, rounded below; surface concentrically striate, very
feebly plicate on the dorsal slope, blackish-iridescent ; pseudo-
cardinals subtriangular, conoid, striate; laterals remote; nacre
flesh-colored. .

Length 50, height 23, diam. 20 mm.

Nanking, China.

Unio compressus Heupr, Conch. Fluv. Nank., III, 1877, pl.

XXIV, fig. 52.

Unio murinus Hrupr, Conch. Fluv. Nank., VIII, 188,, pl.

LMI, fig. 121;

Unio merinus Pavret, Conch. Sam., III, 1890, p. 160.
Ptychorhynchus mncertus SIMPSON, Syn., 1900, p. 851.

In this case again Heude contradicts his measurements. He
states that the shell is compressed, and gives the height as 23
millimeters and the diameter 20, which would make a much:
inflated shell. The species is apparently close to schomburg-
ianum, but is more elongated in proportion to height, and is
not quite so rhomboid. The name compressus given by Heude
to this species was long before preoccupied by Lea in Unio.
That the epidermis should be blackish-iridescent (“sub-nigra
iridescente”) seems peculiar, but that is the statement made in
the original description.

Genus VIRGUS, Simpson, 19goo.

Virgus SIMPSON, Syn., 1900, p. 851.
Shell rather solid, elongated, inequilateral, compressed,
rounded in front, nearly straight below. the dorsal line as far

VIRGUS II51

back as the hinder end of the hgament parallel with the base,
behind the ligament the shell is obliquely truncate, the trun-
cation somewhat upcurved, the shell ending in a rounded
point at the posterior base; posterior ridge elevated, rounded,
with sculpture radiating from it above and below; beaks rather
low, radially ridged ; pseudocardinals small, two in each valve ;
laterals rather short, club-shaped, one in the right and two in
the left valve.

Animal unknown.

Under this generic name | have placed three species from
New Guinea and Borneo, which agree quite well in general
conchological characters. The shells are quite elongated, the
dorsal and ventral outlines nearly parallel to the hinder part
of the ligament. The ventral line is nearly straight through-
out; the dorsal slope is cut away above in a long oblique trun-
cation or subtruncation to a blunt point near the base of the
shell. The beaks are low and, no doubt, subradially sculp-
tured: the pseudocardinals are short and rather strong; the
laterals club-shaped. The group differs from Rectidens in
having solider shells, and strong, short pseudocardinals as well
as heavier laterals.

KryY TO SPECIES OF VIRGUS.

Posterior ridge rounded, separated from the rest of the
shell by sulci, V. beccarianus.
Posterior ridge with strong devaricate ridges,
V. mattirols.
Posterior ridge widely rounded, V. misoolensis.

Group of Virgus beccarianus.

Shell having the posterior ridge high and rounded, out-
lined on each side by a sulcus, the radiations from this ridge
rather fine; surface concentrically sculptured.

VIRGUS BECCARIANUS (Tapperone-Canefri).

Shell elongated, subinflated, inequilateral, the base line near-
ly straight; dorsal line almost parallel with the base line as
far back as the hinder end of the ligament, behind which point

1152 VIRGUS

it is carried out with a slight curve to the extreme hind end of
the shell; anterior end rounded; posterior ridge high, nar-
rowly rounded, separated above and below from the rest of the
shell by a sulcus, the ridge ending behind at the base of the
shell; surface with dense, concentric striz, which are crossed
below the posterior ridge with strong, nearly vertical folds;
dorsal slope sculptured with folds; epidermis olivaceous-fus-
cous; pseudocardinals small, sulcate above, unequally dentate
on the margin; laterals elongated; nacre silvery or bluish
white. The beaks are tumid and plicate.

Length go, height 29, diam. 16 mm.

Fly River, New Guinea.
Unio beccarianus ‘TAPPERONE-CANEFRI, Ann. Mus. Genov.,

XTX, 1682,/p. 201, pl. xipfig. 2:
Virgus beccarianus SIMPSON, Syn., 1900, p. 852.—Haas, Con.

Cab.7 Unio; 1910, p--120, pr xii, fie at

A greatly elongated shell which is drawn out to a point be-
hind at the base. It is remarkable for its high, rounded pos-
terior ridge, which is separated from the rest of the surface
by distinct sulci and for the vertical plications below it.

Group of Virgus mattiroh.

Posterior ridge full, rounded, not outlined by sulci, covered
with very strong corrugated ridges, which curve outward each
way from the center, the remainder of the shell smooth.

Vircus MATTIROLI (Tapperone-Canefri).

Shell somewhat elongated, solid, inequilateral, subinflated ;
base line nearly straight; dorsal line parallel with it as far
back as the hinder end of the ligament, from that to the pos-
terior point it is slopingly truncate; anterior end rounded;
posterior ridge full, ending in a rounded point at the base of
the shell, sculptured throughout its length with very strong,
divaricate ridges ; beaks only moderately full; pseudocardinals
two in each valve subcompressed, laterals club-shaped, one in
the right valve and two in the left; nacre bluish-white.

Length 52, height 26, diam. 15 mm.

Fly River, New Guinea.

VIRGUS WIG)

Unio mattiroli TAPPERONE CANEFRI, Ann. Mus. Genov., XIX,

TSSsipe 202, pli xa ise We
Virgus mattiroli Simpson, Syn., 1900, p. 852.

Virgus mattirolii Haas, Con. Cab., Unio, 1910, p. 131, pl. X1n,

fig’. 2.

Apparently more solid than U. beccarianus. It is not so
greatly elongated as that species and may be at once distin-
guished by the very strong, divaricate sculpture along the
entire length of the posterior ridge. :

Group of Virgus misoolensis.

Posterior ridge merely rounded, with radiating folds scat-
tered over the sheli, pseudocardinals two in the left valve and
one in the right.

VIRGUS MISOOLENSIS (Schepman).

Shell elongated, rather compressed, very inequilateral, near-
ly smooth, with numerous, fine, concentric striz; beaks but
slightly prominent, with conspicuous, radiating folds, extend-
ing more or less over the disk of the shell; there are a few
radiating grooves on the anterior end, and microscopic, radi-
ating wrinkles of the epidermis on the posterior slope; epi-
dermis reddish-brown in the adult, yellowish-olive-green in
the young state; dorsal outline lightly arcuate from the beaks
to the extreme posterior end near the base; base line almost
straight; anterior end rounded; posterior ridge full, simply,
widely rounded, ending near the base in a rounded point;
nacre bluish-white, iridescent behind; thicker in front; scarce-
ly more than one short, thick, crenated pseudocardinal in each
valve; a small knob in the left valve may perhaps be consid-
ered a second one; laterals club-shaped, elongated, two in the
left valve and one in the right; anterior scars deep.

Length 65, height 24, diam. 16 mm.

Misool, Borneo.

Unio misoolensis SCHEPMAN. Notes from Leyd. Mus., XVIII,

1806, p. 250, fig.

1154 CRISTADENS

Virgus misoolensis SiMPSON, Syn., 1900, p. 852.—Haas, Con.

Cabs) Unio; agro; p. 133) pl. xi ghee:

I have given Schepman’s very excellent description almost
entire. He states that the nacre is much thickened near the
anterior ventral part, forming a callus connecting with an-
other running from the umbones to it. He believes it to be
most nearly allied to the Unio beccarianus of Tapperone-Cane-
fri. It differs from that in having a wider posterior ridge,
which is not marked off from the-rest of the shell.

For this species, Haas, (1. c., p. 132), has proposed a new
section, Leiovirgus.

Genus CHRISTADENS Simpson. n. n.

Ctenodesma SIMPSON, Syn., 1900, p. 852.

Shell subtrapezoid to long elliptical, rather thin, compressed,
with a scarcely developed posterior ridge and low beaks, whose
sculpture is densely zigzag-radial, becoming finely corrugated
or nodulous on the disk and extending over most of the shell;
the disk is concentrically striate or sulcate at its outer edge;
pseudocardinals one to two in each valve, very diverse in form,
but showing a tendency to break up into denticles; one lateral
and sometimes a faint secondary one in the left valve and two
in the right ; dorsal scars few, diversified in form, and various-
ly disposed in the shallow beak cavities; anterior muscle scars
united ; nacre whitish.

Animal unknown.

Type, Unio borneensis Issel.

In the Synopsis I placed under the generic name Ctenodesma
two species of Uniones, which ] am unable to refer to any
other generic combination. ‘This name having been preoccu-
pied by Cook in Myriopoda, J change it to Cristadens.

The species placed here are elongated, somewhat compressed
forms, covered with a peculiar, fine pattern of broken, zigzag
sculpture. The pseudocardinals are much lacerated, being in
some cases Cut into numerous teeth.

CRISTADENS 1155

CRISTADENS BORNEENSIS (Issel).

Shell long rhomboid, rather thin, subcompressed, inequilat-
eral; dorsal and ventral outlines nearly straight and parallel ;
anterior end rounded; dorsal slope obliquely truncate or sub-
truncate ; posterior ridge low, rounded, ending near the base
in a blunt point: beaks but little elevated, the sculpture con-
sisting of numerous, close-set zigzag-radial, subnodulous
ridges. This sculpture extends well out over the disk and
gradually changes to fine, irregular, concentric sculpture;
sculpture on the dorsal slope subplicate ; epidermis yellowish-
green or brownishzgreen, often with several wide or narrow
green rays on the dorsal slope; pseudocardinals compressed,
ridged, often cut up into dentilations ; laterals delicate, straight,
remote; nacre bluish-white, iridescent.

Length 48, height 23, diam. 13 mm.

Borneo; Siam; Malacca.

Unio plicatulus Lea, Pr. Ac. Nat. Sci. Phila., III, 1859, p. 152;
jl. Ac. Nat. Sci. Phila., [V, 1860, p. 247, pl. xxxvul, fig. 126;
Obs., VII, 1860, p. 65, pl. xxxvu, fig. 126.—ReEEveE, Conch.
Teon., XVI, 1865, pl. xxi, fig. 102.

Margaron (Unico) plicatulus Lea, Syn., 1870, p. 31.

Unio borneensis Issrt., Moll. Borneo, 1874, p. 113.

Ctenodesma borneensis StmPpson, Syn., 1900, p. 853.—Haas,
Conch: Cabs, Wai; 1912;/p: 135.

Virgus borneensis Haas, Con. Cab., Unio, 1910, pl. x11, figs.
4-5.

Unio penisatus FiscHER and Crosse, Miss. Sci., Pt. 7, II, 1894,
Pp. 599.

Three specimens of the above are before me, none of which
are quite so large as the type, which is not in the Lea collec-
tion. Two of these shells are more rounded behind than the
type; in all of them the epidermis is somewhat wrinkled. Two
have bright green posterior rays; the other is rayless.

Lea’s name was preoccupied by Kuster, or Charpentier, for
a Mexican species in 1856. The name proposed by Issel in
1874 will have to be used.

The name fpenisatus was proposed by Fischer and Crosse,
because [.ea’s name flicatulus was preoccupied by Kuster.

1156 CRISTADENS

CRISTADENS GUPPY!f (Smith).

Shell oblong elliptical, very inequilateral, a little higher be-
hind, subsolid, subcompressed or convex: beaks not promi-
nent, sculptured with a great number of zigzag-radial, wavy,
fine ridges, the sculpture extending well on to the disk; sur-
face with irregular, rather strong, concentric sculpture and
faint vestiges of radial grooves; posterior ridge low, rounded;
anterior end narrowed and rounded; outlines of dorsum and
base nearly straight; posterior end irregularly rounded, the
upper part slightly and obliquely truncate; epidermis thick,
reddish-brown, peeling off behind showing the iridescent shell ;
pseudocardinals small, often split into numerous denticles;
laterals small, remote, straight; anterior scars impressed;
nacre bluish-white, bronzy iridescent behind, thicker in front.

Length 69, height 32, diam. 19 mm.

Length 67, height 33, diam. 15 mm.

Shortland Island; Solomon Islands.

Unio guppyi Smiru, Pr. Zool. Soc. Lond., 1885, p. 608, pl.

XXXVIT, figs. 88a, 88d.

Ctenodesma guppyi Stmpson, Syn., 1900, p. 853.—Haas, Con.

Cab., Unio, 1910, pl. x11; figs. 6-7.

The above measurements are from two fine specimens in the
National Museum collection from the Solomon Islands. The
whole surface shows a tendency to feeble granulation.

CRISTADENS BEAUFORTI (Bavay).

“Shell irregularly elliptical, slightly inflated, not very thick,
beaks placed quite anteriorly ; anterior end short, truncate and
rounded, posterior end elongated, rounded and compressed
above, angulate below, ventral margin almost straight, slightly
curved in the middle; a very large ridge extends from the
beaks to the lower posterior angle; epidermis heavily striate
in front and behind, smoother in the centre of the disk. Car-
dinal teeth weak, short, that of the right valve bifid; laterals
long and thin, not extending beyond the ligament, the right
slightly prominent, the left bifid. Epidermis bronzy, greenish-
black; nacre bluish-white.

Length 70, height 37, diam. 20 mm.” (Bavay).

Type locality, Lake Sentani, New Guinea.

RECTIDENS TTS 7

Unio beauforti Bavay, Nova Guinea, 1908, p. 291, pl. xiv,
fig. 16.
“This species is very near to U. guppyi E. Smith of Short-
land Island, Solomon Group, which itself resembles many
forms from Australia and New Zealand.”

Genus RECTIDENS Simpson, 1900.

Rectidens Stmpson, Syn., 1900, p. 853.

Shell elongated, with an angle at the anterior dorsal part,
pointed and slightly biangulate behind, moderately solid, with
two or three posterior ridges, the lower the higher; beaks full,
sculpture not observed, but probably zigzag-radial; the pos-
terior slope, and often part of the disk, covered with faint,
granular, radiating sculpture; epidermis smooth, olive; one
compressed, short, recurved pseudocardinal in the left valve
under the beak, and a very long one in front of it, and two
laterals; two compressed pseudocardinals in the right valve,
and a single lateral; all the teeth straight or nearly so; anterior
muscle scars separate; beak cavities rather shallow; only one
or two dorsal scars in each valve; nacre white or reddish.

Animal unknown.

Type, Unio prolongatus Drouet.

The species placed in this group seems to be closely allied
and are characterized by much elongated shells with rather
low beaks and delicate, lamellar pseudocardinals and laterals,
which are granular or more or less vertically striate. There is
generally a feebly double posterior ridge, each part being
pinched up in the upper part. All the species seem to have
traces of radical sculpture.

KEY ’T0 SPECIES OF RECTIDENS.

Shell inflated, strongly concentrically sculptured,
R. perakensis.
Shell compressed to convex, not strongly concentrically
sculptured.

1158 RECTIDENS

Small to medium sized.

Uniform brownish, subcompressed, R. lingulatus.
Greenish, rayed behind, R. orientalis.
Medium sized, convex. R. presstrostris ; prestoni;
sumatrensis.
Large.

Truncate before and behind,
R. gracilis; palembangensis; pahangensis.
Not truncate in front or behind, R. prolongatus.

RECTIDENS SUMATRENSIS (Dunker).

Shell elongate ovate, inequilateral, subsolid, convex, or sub-
inflated; beaks rather low, not much inflated; anterior end
rounded, a little fuller above; base line nearly straight, full
towards the posterior end; dorsal outline curved to the pos-
terior point, which is placed just below the median line; pos-
terior ridge rounded ; surface somewhat strongly, concentrically
striate, subgranose; epidermis dark olive-brown or blackish;
hinge line lightly curved; teeth delicate, compressed, pseudo-
cardinals subcrenate ; nacre reddish or violet-tinted, beautifully
iridescent.

Length 74, height 30, diam. 20 mm.

Lake Dana Luar, Sumatra.

Unio sumatrensis DUNKER, Zeits. fir Mal., IX, 1852, p. 52.—
PFFIFFER, Nov. Conch., II, 1866, p. 152, pl. xxxix,. figs.
10-12.

Rectidens sumatrensis SIMPSON, Syn., 1900, p. 853. — Haas,
Conch., Cab. Unio, 1912, pl. 28, figs. 3-6.

This species, which is quite evenly long ovate, has delicate
granulations on a part of its surface, according to Dunker.
I have seen a shell, which is probably this species, which is
richer-colored within and without, and is more nearly ovate in
outline than the other members of the group.

RECTIDENS PRESSIROSTRIS (von Martens).

“Shell elongate, concentrically striate and distantly lirate,
dirty brown, anterior end inflated, rounded, posterior com-
pressed, obtusely rostrate, posterior ridge well marked, but

RECTIDENS 1159

not reaching the margin, central parts of the dorsal and ventral
margins nearly straight ; beaks situated at 1/7 of the length;
nacre bluish, pale yellowish in the centre; cardinal teeth com-
pressed, elongate, parallel to the margin, slightly rugose, later-
als long, straight.
Length 87, vertical height 31, ale 27, diam. 25 mm.” (von
Martens).
Type locality, Lake Danau Baru, Indragiri, Sumatra.
Unio pressirostris von Martens, Nachr. Deutsch. Mal. Ges.,
LQOO, PLA.
Rectidens pressirostris Haas, Conch. Cab., Unio, 1912, pl. 27,
figs. 1-3.
“Stands in the same relation to U. sumatrensis Dunk. as
the European U. platyrhynchus F. Schmidt does to pictorum.”

RECTIDENS PRESTONI n. n.

“Shell closely allied to Unio pressirostris von Martens, of
which it may ultimately prove to be a variety, but differing
from that species in its less cuneate form and larger size, in its
less contracted anterior side and more obtuse and _ sloping
posterior side.

Long. 31, lat. 85.5, diam. 21 mm.” ( Preston.)

Type locality, Perak.

Umno perakensis Preston, Rec. Ind. Mus., VII, 1912, p. 287,

pl. viii, figs. 5-6.

“Perakensis”’ having already been used by de Morgan for a
species of Unio, I have changed the name as above.

RECTIDENS LINGULATUS (Drouet and Chaper).

Shell elongated, scarcely subsolid, subrhomboid, convex or
subcompressed, inequilateral; dorsal and ventral outlines
nearly straight and parallel; anterior end angled above, slop-
ingly rounded below; dorsal slope having a long, oblique trun-
cation; posterior ridge not greatly elevated but angled, usually
with a smaller ridge above it, ending in a blunt point near the
base of the shell; surface with irregular growth lines, the
middle of the disk often granular and occasionally having verti-
cal plications; dorsal slope usually having fine, radial folds;

I160 RECTIDENS

epidermis greenish-brown; teeth delicate, lamellar, the pseudo-
cardinals somewhat strongly vertically striate; muscle scars
shallow ; nacre bluish.

Length 65, height 27.5, diam. 15.5 mm.

Borneo.

Unio lingulatus Drourr and CHAPER, Mem. Soc. Zool. Fr., V,

1892, p. 148, pl. v, figs. 7-9.

Rectidens lingulatus Simpson, Syn., 1900, p. 854.—HAas,.

Conch. Cab., Unio, 1912, pl. 27, figs. 4-5.

A rather delicate species, of which a number of examples
are before me. In all of them the beaks are deeply eroded,
but they are probably not prominent. It is a smaller, less
inflated and rougher species than prolongatus.

RECTIDENS PROLONGATUS (Drouet).

Shell elongated, subsolid, subinflated, inequilateral; beaks
moderately full and high; dorsal and ventral outlines nearly
straight and parallel; anterior end rounded, angled above;
posterior ridge narrowly double above, each part pinched up
into a ridge, fading out behind, ending in a feeble biangulation
at and below the median line; dorsal slope obliquely truncate ;
surface with scattered, low, concentric ridges, with faint traces
of radical sculpture; dorsal slope with feeble plications; epi-
dermis dark greenish-brown, subshining; teeth lamellar, the
pseudocardinals much elongated; muscle scars shallow; nacre
blue. sometimes flesh-color in the cavities.

Length 110, height 42, diam. 30 mm.

Borneo.

Unio prolongatus Drourt, Rev. Biol. Nord. Fr., VI, 1894, p.
216.—KosEit, Abh. Senck. Nat. Ges., XXIV, 1897, p. 87,
ple aay gsc 4s 2:

Rectidens prolongatus Simpson, Syn. 1900, p. 854.—Haas,
Conch. Cab., Unio, 1912, pl. 26, figs. 1-5.

Much larger than lingulatus, more inflated, more shining and
having more elongated pseudocardinals. The nacre is some-
what granularly radiate striate.

RECTIDENS 1161

RECTIDENS PERAKENSIS (de Morgan).

Shell elongated, solid, inflated, inequilateral, nearly ovate;
anterior end slightly angled above; posterior ridge rather high,
subangulate or very narrowly rounded, ending in a point a
little’ below the median line; beaks only slightly elevated;
surface with strong, concentric ridges and very delicate radiat-
ing threads; epidermis thick, brilliant, olivaceous ; pseudocard-
inals lamellar, double in the right valve and single in the left;
laterals single in the right valve, double in the left; nacre
whitish-tinted lead-color, somewhat reddish in the beak cavi-
ties.

Length 80, height 30, diam. 22 mm.

Perak.

Unio perakensis DE Morcan, Bull. Soc. Zool. Fr., X, 1885, p.

424, pl 1x, figs. 35 4.

Rectidens perakensis SIMPSON, Syn., 1900, p. 854.—HAAs,

Conch. Cab., Unio, 1912, pl. 29, figs. 2-8.

More inflated and solid than the preceeding species and
having stronger concentric sculpture.

RECTIDENS PAHANGENSIS (Smith).

Shell elongated, convex, subsolid, inequilateral; beaks very
low; posterior ridge apparently double and ending in a wide
biangulation ; anterior end squarely truncate, subangular above ;
base line curved; dorsal slope with a long, oblique truncation ;
posterior end almost squarely truncate; surface concentrically
striate; epidermis fuscous; teeth lamellar, rather delicate,
pseudocardinals roughened; muscle scars well marked; nacre
pale yellowish-salmon.

Length 131, height 50, diam. 24 mm.

Pahang River, Malay Peninsula.

Unio pahangensis E. A. Smitu, Pr. Mal. Soc. Lond., III, 1899,

p. 315, fig.

Rectidens pahangensis SIMPSON, Syn., 1900, p. 854.—Haas,

Conch: Cabs Unio; 1912, pl. 20; figs1:

The distinctive characters of this species seem to be the trun-
cation of the anterior and posterior ends and the unusually
low beaks. In the specimen figured they are slightly eroded,
but they do not rise above the outline of the shell.

I162 RECTIDENS

RECTIDENS ORIENTALIS (1,ea).

Shell somewhat elongated, subelliptical or subrhomboid, con-
vex, inequilateral. scarcely subsolid ; dorsal line nearly straight ;
anterior end rounded, full and almost subangulate above; base
line curved, full behind the middle; dorsal slope obliquely sub-
truncate; beaks scarcely raised; posterior ridge subangulate,
pinched-up above, ending below the median line in a rounded
point ; above the posterior ridge there is a low, radial pinched-
up ridge; epidermis nearly smooth, showing feeble corrugations
at the anterior end and traces of nodules on the disk, yellowish-
green with green bands and two green rays on the posterior
end, shining ; teeth compressed ; the pseudocardinals showing a
tendency to break up into dentilations; nacre bluish, yellow-
tinted in the cavities of the shell.

Length 38, height 16.5, diam. 9 mm.

Java.

Unio orientalis Lea, Pr. Am. Phil. Soc., I, 1840, p. 285; Tr.
Am. Phil. Sec. VIM, 1842, p. 221, pl xvii dicen 2S-2 Ouse
III, 1842, p. 59, pl. xvirt, fig. 38.—CueEnu, Ill. Conch, 1858,
pl. xxx, figs. 6, 6a, 6b.—KusteEr, Conch. Cab. Unio, 1861,
p. 241, pl. LXxx, fig. 16—Sowersy, Conch. Icon., XVI, pl.
xcI, fig. 491. ;

Margaron (Unio) orientalis L&A, Syn., 1852, p. 38; 1870, p. 61.

Nodularia orientalis SIMPSON, Syn., 1900, p. 819. |

Elongaria orientalis Haas, Con, Cab., Unio, 1910, pl. xvit.,
figs. 3-5.

Unio productus Mousson, L. and $. W. Moll., Java, 1849, p.
93, pl. xvi, figs. 3-5.

Unio productior Lea, Syn. 1852, p. 29.

I,ea’s shell, the type of Unio orientalis, is, no doubt, young
and it seems to be identical with fig. 5, plate xvi, in Mousson’s
Iand and Susswasser-Mollusken von Java, which he refers to
his Unio productus. I am not at all sure that his figure 3 on
the same plate represents this species, as it has more the appear-
ance of some of the Furopean forms of the group of Unio
pictorum.

Haas has recently (Nachr. Deutsch. Mal. Ges., 1913, p. 34),
made this species the type of a new genus, Elongaria.

RECTIDENS 1163

RECTIDENS GRACILIS (Strubell).

“Shell much elongated, subcompressed, rather thin, delicate-
ly, costulate striate, not at all shining, brownish-olivaceous,
very inequilateral, squarely truncate in front, much elongated
posteriorly. Dorsal margin forming an angle with the very
short anterior margin; posteriorly it runs into the posterior
slope with a rounded angle; ventral margin horizontal, not at
all ascending posteriorly, forming with the posterior margin
a depressed, subvertically truncated rostrum. Umbones an-
terior, deeply eroded; areola subobsolete; area elongate, com-
pressed, with two obsolete carinae extending from the beaks;
ligament thin, quite long. Hinge thin; with two, elongate,
oblique, compressed, low teeth in the right valve, almost reach-
ing the margin; cardinal tooth elongate, with obsolete lamellz ;
muscular impressions indistinct. Nacre bluish-white, iridescent

posteriorly.
Length 55, height 23, diam. 12.5 mm.” (Strubell.)

Type locality, South Sumatra.

Microndylea gracilis StruprLL, Nachr. Deutsch. Mal. Ges.,

1897, p. 8.

Rectidens gracilis Haas, Conch. Cab., Unio, 1912, pl. 27, fig. 6.

“Tt differs from M. hageni not only by its much more striate
surface, but also by its heavy, stronger development of the
hinge-teeth.” (Strubell).

Haas, (1. c.), figures U. palembangensis Strubell and
U. pahwmbaénsis von Martens as synonyms of this species.

RECTIDENS PALEMBANGENSIS (Strubell).

“Shell very long ovate, very inequilateral, delicately and
closely striate, here and there roughly costate-sulcate, posterior
end distinctly biangulate, scarcely shining, rather thin, oliva-
ceous, overlaid with a thin gray deposit. Anterior end very
short, posterior elongate. Dorsal margin very slightly oblique,
forming with the very short, rounded, subtruncate anterior
margin a distinct angle and with the sloping posterior margin
an indistinct one; ventral margin almost straight, slightly
ascending posteriorly to the roundly-acuminate, depressed

1164 RECTIDENS

rostrum. Beaks situated at 14 of the length, low, deeply

eroded, not approaching; areola narrow, almost lanceolate;

posterior slope compressed, margined by the distinct posterior

ridge; ligament narrow, quite long. Hinge with a thin, nar-
row lateral and two, elongate, curved, lamelliform, equal
cardinal teeth in the right valve, one cardinal and an obsolete
posterior accessory tooth in the left, the long laterals forming
an angle with the cardinals; muscular and pallial impressions
not very strong; nacre bluish-white, somewhat livid under the
umbones.

Length 43, height 17.5, diam. 11 mm. (Strubell).

‘Type locality, South Sumatra.

Umio palembangensis StTRUBELL, Nachr. Deutsch. Mal. Ges.,
1897, p. 10.—SIMPSON, Syn., 1900, p. 862.—Haas, Conch.
Cab., Unio, 1912, pl. 27, fig. 7.

Haas, (1. c.), considers this a synonym of Rectidens gracilis.

Var. pahumbaénsis (von Martens).

“Differs by the shorter and posteriorly more elevated form,
as well as that the posterior ridge very soon disappears, so that
it is distinctly seen only in the umbonal.region. The rostrum
of this form is like that of the typical form, somewhat declined,
owing to the fact that the dorsal margin is oblique, while the
basal margin is almost straight, while in the closely related.
U. sumatrensis Dunk., the posterior margin descends almost
as much as the basal ascends, so that the rostrum points back-
ward.

Length 53, height at beaks 19, at wing 23, diam. 13 mm.

Beaks situated at 14 of the length.” (von Martens).

Type locality not given.

Unio palembangensis var. pahumbaénsis VON Martens, Nachr.

Deutsch.: Mal. Ges., 1900, p. 14.

Unio pahoembaensis Haas, Conch. Cab., Unio, 1912, pl. 28,

figs. 1-2.

Haas, (1. c.), considers this a synonym of Rectidens gracilis.

LAMELLIDENS 1165

Genus LAMELLIDENS Simpson, 1900.

Lamellidens SIMPSON, Syn., 1900, p. 854.—ORTMANN, Ann.

Camsvius.: Vili To12 pp) 277.

Shell elongate, elliptical, pointed behind, with a slight post-
dorsal wing, a low, often biangulate, posterior ridge and gen-
erally two sharp, radiating liree above it; beaks with curved,
radiating ridges, which sometimes are slightly zigzag, and
often become almost concentric, but which fade out as they
approach each other at the center of the disk ; epidermis smooth,
generally shining, brownish, often with concentric bands of
lighter color, rayless or nearly so; left valve with two com-
pressed pseudocardinals, the front one roughened, and two
laterals; right valve with two parallel, lamellar pseudocardinals
and one lateral; cavity of the beaks rather shallow; dorsal
scars few, deep, distinct, scattered; anterior scars separate;
nacre bluish-white to straw.

Animal unknown.

Type, Unio marginalis Lamarck.

The genus Lamellidens contains a number of closely allied
species, which seem quite distinct from other Naiades of the
Oriental Region. The group appears to be closely allied to the
subgenus Hyridella of Diplodon so far as shell characters have
been observed. The beak sculpture consists of subradial
curved bars much like that of the Australian species, but they
sometimes are slightly zigzagged. The general texture and
color of the shells are something like those of the Australian
species, the epidermis being usually dark and always rayless.

If I am correct in placing the Anodonta guillaini of Riecluz
in this group it will be seen that Lamellidens has a distribution
somewhat similar to that of Nodularia and Parreysia.

KEY TO SPECIES OF LAMELLIDENS.

Shell with imperfect hinge teeth, L,. guillaint.
Shell with well developed hinge teeth.
With a moderately developed post-dorsal wing.
Trapezoid, base slightly rounded, L. pulcher.
Elliptical or obovate, base rounded. [,. generosus-

1166 LAMELLIDENS

Post-dorsal wing low or wanting.

Shell oval, rather solid, L. jenkinsianus.
Elliptical or subrhomboid.
Solid smoky brown, L,. consobrinus.
Subsolid, shining, often banded. L,. marginalis ;
canefrianus ; thwaitesii; corrianus.
Thin, dark, L.. lamellatus.
Long rhomboid, black, L,. scutum.,
Cuneate, LL. narainporensts.

Flongate ovate, L. nongvangensis; phenchooganjensis.

Subgenus LAMELLIDENS Ss. Ss.
Shell dark colored; teeth well developed.

IAMELLIDENS MARGINALIS (Lamarck).

Shell subrhomboid or subelliptical, thin or subsolid, convex,
inequilateral; beaks but slightly inflated, not greatly elevated,
their sculpture consisting of subradial curved bars, the inner
of which coalesce below ; sometimes the bars are slightly zig-
zag; surface nearly smooth; posterior ridge rounded, ending
in a blunt point on or below the median line; epidermis usually
polished, sometimes showing faint wrinkles arranged in radial
series, brownish or yellowish-brown, marked with one or more
yellowish-tawny or straw-colored concentric bands; on the
dorsal slope there are two elevated, radial threads and often
faint, greenish rays: teeth delicate and lamellar, pseudocardi-
nals two in each valve, placed opposite each other in the right ;
anterior and posterior muscle scars shallow, nacre bluish to
salmon, generally soft and brilliant.

Length 85, height 45, diam. 26 mm.

Length 110, height 56, diam. 35 mm.

India; Burma; Pegu; Ceylon; Canton River, China? I
believe that Mousson’s U. ewanescens is L. marginalis, but can
it be from Java?

Die breite Mahler-Muschel aus Grénland, ScuroteEr, Flussc.,

1779; p: Ten, ph. 1x, ie. 4.

? Unio grenlandica Mércu, Am. Jl. Conch., [V, 1868, p. 38.

IL.AMELLIDENS GEOG:

?Unio testudinarius SPENGLER, Skriv. Selsk. Nat., III, 1793, 65.
?Unio truncatus SPENGLER, Skriv. Selsk. Nat., III, 1793, p. 65.
Unio marginalis LAMARcK, An. sans Vert., VI, 1819, p. 79.—

DesHayes, Enc. Meth. IT, 1827, p. 151, pl. ccxivu, fig. 1.—

HANLEy, Biv. Shells, 1843, p. 206, pl. xx, fig. 53.—KUSTER,

Conch. Cab. Unio, 1861, p. 239, pl. LXxx, fig. 4.—SOWERBY,

Conch. Icon., XVI, 1867, pl. 11x, fig. 297—HANLEy and

THEOBALD, Conch. Ind., 1876, p. 20, pl. xu, fig. 2.
Marganta (Umno) marginalis. Lea, Syn., 1836, p. 37; 1838,

p: 24.

Margaron (Unio) marginalis L&a, Syn., 1852, p. 38; 1870,

p. 60.

Lamellidens marginalis SIMPSON, Syn., 1900, p. 854.
Unio anodontina l,AMARCK, An. sans Yert., VI, 1819, p. 80.
Unio anodontinus Kuster, Conch. Cab. Unio, 1861, p. 240, pl.

Las Ky igen!

Symphynota bilineata Lua, Tr. Am. Phil. Soc., IV, 1831, p. 98,

pl. x1, fig. 19; Obs., I, 1834, p. 108, pl. x1, fig. 109.

Margarita (Unio) bilineatus Lea, Syn., 1836, p. 38; 1838, p. 25.
Unio bilineatus HANLEY, Biv. Shells, 1843, p. 207, pl. xx1, fig.

30.—SowERbY, Conch. Ieon., XVI, 1868, pl. Lxx1, fig. 365.
Margaron (Unio) bilmeatius Lea, Syn., 1852, p. 38; 1870, p. 61.
?Unio evanescens Mousson, Moll. Java, 1849, p. 91, pl. xvu,

fig. 2.

Unio dolichorhynchus 'TAPPERONE, CANEFRI, Am. Mus. Civ.

Gen., 1889, p. 348.

Unio gianelli TAPPERONE CANEFRI, Am. Mus. Civ. Gen., 1880,

P. 353-

I use Lamarck’s name for this species because the U. test-
udinarius and truncatus were only briefly and imperfectly
described, and never figured, their habitats being given as
Greenland. Jamarck refers to the figures in Enc. Meth., pl.
247, figs. 1, 1a, 1b, Ic, which very accurately represent the shell
we know as Unio marginalis.

An exceedingly variable species and I have only attempted
to give a description of fairly typical forms as understood by
Hanley and Theobald and Lea. The form is usually nearly

1168 LAMELLIDENS

elliptical, though sometimes slightly rhomboid as described by
Lamarck, the younger shells are smooth and polished, while
older ones are often somewhat rough.

Var. obesus (Hanley and Theobald).

A giant form, which does not exhibit any banding and is

much swollen. The surface is dark brown or blackish.
Length 127, height 69, diam. 45 mm.

Unio marginalis var. obesa HANLEY and THEOBALD, Conch.
Ind... 1876,,pu20, pl. SEIT, dap:

Lamellidens marginalis var. obesus SIMPSON, Syn., 1900, p.
855.

?Unio corrianus SOWERRBY, Conch. Icon., XVI, 1868, pl. Lxxvit,
fig. 401.

Var. tricolor (Kuster).
Shell fulvous with a broad outer yellowish band, the dorsal

slope greenish with darker rays.

Unio tricolor KusrER, Conch. Cab. Unio, 1856, p. 156, pl. xiv,
fig ae

Unio marginalis var. tricolor HANtEY and THEOBALD, Conch.
Ind., 1876, p. 20, plxiil, fig. 5.

Lamellidens marginalis var. tricolor SIMPSON, Syn., 1900,

p. 855.

It is doubtful whether this is worthy of a varietal name.

Var. candaharicus (Hanley and Theobald).

Shell rhomboid, the dorsal and ventral outlines nearly
straight and parallel; ashy brown, green on the dorsal slope.
Unio marginalis var. candaharica HANtEY and ‘THEOBALD,

Conch. Ind., 1870, p. 20, pl. x11, fig. 4.

Lamellidens marginalis var. candaharicus SIMPSON, Syn., 900,

p. 855.

Var. cylindricus (Hanley and Theobald).

Very much elongated, dorsal and ventral outlines nearly
straight and parallel; posterior end pointed about on the median
line; color brownish.

Length 108, height 48, diam. 30 mm.

LAMELLIDENS 1169

Unio marginalis var. cylindrica HANLEY and THEOBALD, Conch.

Ind., 1876, p. 20, pl. xiv, fig. I.

Lamellidens marginalis var. cylindricus SIMPSON, Syn., 1900,

p. 855.

Var. hanleyi Simpson.

Shell long rhomboidal; beaks elevated ; posterior ridge ele-
vated, rounded; epidermis brownish with a yellowish border.
This may possibly be a distinct species. The beaks appear to
be more elevated than they are in any other of the forms.
Hanley and Theobald believed it to be the Umo corrianus of
Lea, but it is not that species at all.

Unio marginalis var. corriana HANLEY and THEOBALD, Conch.

Ind“-1876; p: 20, ple xxiv, fig. 4:

Lamellidens marginalis var. hanleyi Simpson, Syn., 1900, Pp.

855.

Var. exanthematicus (Kuster).

This seems to be a small form with a bright yellow epidermis
and may be merely a young specimen.
Unio exanthematicus Kuster, Conch. Cab. Unio, 1861, p. 243,
Pip E KXKOCIs hie
Lamellidens exanthematicus StMPsON, Syn., 1900, p. 856.
Pressidens exanthematicus Haas. Conch. Cab., Unio, 1912, pl.
23, figs. 6-8.

Var. sublamellatus Preston.

“An elongate, somewhat rostrate form, having the hinge
teeth rather less developed.” (Preston).
Type locality, Burma.
Lamellidens marginalis var. sublamellatus PRESTON, Rec. Ind.
Mus.,, VIL, 1912, p.. 305-
Var. sawaddyensis Preston.
“Shell much more ovate and convex than the typical form,
having the dorsal margin more arched and posteriorly ascend-

ing, the ventral margin and anterior side more rounded, and
the posterior side produced and roundedly rosrate.” (Preston).

1170 LAMELLIDENS

Type locality, Sawaddy River; also Bhamo; Sawaddy, Teng-
ling Stream; Shuaygoomya, Upper Burma; Mandalay, Upper
Burma.

Lamellidens marginalis var. sawaddyensis Preston, Rec. Ind.

Mus., VII, 1912, p. 305.

LAMELLIDENS BURMANUS DN. n.

Shell trapezoid, rhomboid, narrowed in front, scarcely sub-
solid, convex, inequilateral; beaks low; posterior ridge semi-
double, faintly biangulate, ending near the base in a biangula-
tion; dorsal and basal outlines curved; anterior end rounded;
dorsal slope obliquely truncate, joining the dorsal line with a
blunt angle; surface irregularly, concentrically striate; epider-
mis brown, shaded with green and yellowish; teeth com-
pressed ; laterals and often the pseudocardinals curved, the two
sets widely separated; nacre bluish, orange-tinted in the cavi-
ties.

Length 72, height 44, diam. 21 mm.

Houngdaran, Burma. ;

Umo pulcher TAPPERONE-CANEFRI, Ann. Mus. Civ., VII, 1889,

p. 350.—Haas, Conch. Cab., Unio, pl. 33, figs. 7-8.
Lamellidens pulcher Simpson, Syn., 1900, p. 856.

More decidedly rhomboid than any specimens of marginalis
I have seen, more narrowed in front and shorter in proportion
to height. The National Museum possesses two specimens
from Fea that I believe are authentic.

Haas, (1. c.), considers this a svnonym of Physunio microp-
terus.

LAMEILIIDENS BURMANUS Nn. n.

Shell slightly obovate, or elliptical, subinflated, inequilateral,
rather thin; beaks moderately full; posterior ridge narrowly
rounded, ending in a point about on the median line; anterior
end rounded; dorsal slope slightly, obliquely truncate; surface
nearly smooth ; epidermis rich chestnut-brown, with narrow or
wide zones of yellowish, shining; pseudocardinals compressed ;

LAMELLIDENS LEA

laterals remote; muscle scars rounded and shallow; nacre

salmon-tinted, iridescent.

Length 70, height 39, diam. 22 mm.

Ceylon.

Unio thwaitesii Lua, Pr. Ac. N. Sci. Phila., III, 1859, p. 152;
jl. Ac. N, Sci. Phila., IV, 1860, p. 246, pl. xxxvu, fig. 125;
Obs., VII, 1860, p. 64, pl. xxxvu, fig. 125.—REEvE, Conch.
Icon., XVI, 1865, pl. xx111, fig. 105.

Margaron (Unio) thwaitesti Lma, Syn., 1870, p. 41.

Lamellidens thwaitesii SIMPSON, Syn., 1900, p. 8506.

Lamellidens merginalis var. thwaitesi Preston, Rec. Ind.
MusVil ik 1012; Dp. 303.

Unio consobrinus HANLEY and THrosaLp, Conch. Ind., 1876,
BeebO, pla xia, high 7.

Very close to consobrinus and it is quite probable that the
two run together. It seems to be rather less solid than that
species, is more conspicuously banded, more brilliant, and has
a salmon-tinted nacre.

LAMELLIDENS CONSOBRINUS (Lea).

Shell irregularly long elliptical or subrhomboid, rather solid,
inequilateral; beaks somewhat full and elevated; posterior
ridge high, narrowly rounded, ending in a blunt point below the
median line; anterior end rounded below, angled above; dorsal
slope obliquely subtruncate; surface nearly smooth, covered
with a dull chestnut epidermis having a faint, broad, greenish
border; teeth strong, compressed; laterals remote; muscle
scars impressed; nacre bluish-white, tinted flesh-color in the
cavities.

Length 60, height 33, diam. 21 mm.

Length 65, height 38, diam. 25 mm.

China; India; Ceylon.

Unio consobrinus Lea, Pr. Ac. N. Sci. Phila., III, 1859, p. 331;
J Ac. oN. Set. Phila, 18600; p. 272, pl. xiv, fig. 152; Obs.,
Vil, 1860; p..9o, pl. xiv, fig. 152.

Margaron (Unio) consobrinus Lea, Syn., 1870, p. 46.

Lamellidens marginalis var. consobrinus PRESTON, Rec. Ind.
Mus., VII, 1912, p. 304.

Lr72 LAMELLIDENS

Unio corbeti DEscHAMPs, Bull. Soc. Zool. Fr., XVII, 1892,

p. 68, fig.

Unio mainzwaringi Simpson, Syn., 1900, p. 856.
Lamellidens mainwaringi PRESTON, Rec. Ind. Mus., VII, 1912,

p. 300.

More solid, less brilliant and more rhomboid than L.
thwaitesii to which it is dangerously close. The type, whose
measurements I have given first, has been slightly injured on
the dorsal slope.

Shells have several times been received bearing the name
Unio mainwaringt Nevill, which seem to be the same as conso-
brinus or merely a small form of it. I cannot find that Nevill
ever described the species credited to him.

Since the publication of the Synopsis, Preston, (1. c.), has
published a description of Nevill’s species as follows:

“Shell rather small, cuneate, covered with a finely lamini-
ferous periostracum; both valves marked with rather fine,
concentric and finer, transverse, radiate, scratch-like striz;
dorsal margin anteriorly gradually sloping, posteriorly arched
and more rapidly descending; ventral margin somewhat
straight; anterior side rounded; posterior side angled above
and below, somewhat obliquely and obtusely rostrate; hinge-
teeth well developed, moderately short; anterior adductor scar
deeply impressed, posterior scar somewhat roughly triangular,
well impressed ; interior of shell bluish, iridescent, rather gran-
ulate.

Long. 25.5, lat. 50 mm.” (Preston).

Type locality, Siliguri; also Namtsik Dihang.

LAMELLIDENS LAMELLATUS (Lea).

Shell irregularly elleptical or subrhomboid, subinflated,
rather thin, inequilateral ; beaks moderately full and elevated,
their sculpture being the characteristic, curved, subradial bars;
posterior ridge elevated, narrowly rounded, there sometimes
being one or two faint, radial ridges above it; dorsal slope
obliquely subtruncate; dorsal outline nearly straight; surface
almost smooth; epidermis olive to olive-chestnut ; usually with
a smoky tint, more or less shining; teeth much compressed ;

LAMELLIDENS 1173

laterals nearly or quite straight; muscle scars shallow; nacre

bluish, sometimes deep blue.

Length 77, height 45, diam. 23 mm.
Length 70, height 36, diam. 25 mm.
India; Ceylon.

Unio lamellatus Lea, Tr. Am. Phil. Soc., VI, 1838, p. 19, pl. v1,
fig. 16; Obs., I], 1838, p. 19, pl. vi, fig. 16—HANLEy, Biv.
Shells, 1843, p. 194, pl. xx1, fig. 49—CueENu, III. Conch.,
1858, pl. xxil, figs. 3, 3a, 3b.—Sowersy, Conch. Icon., XVI,
1866, pl. uu, fig. 272—HaANLrEy and THrosaLp, Conch. Ind.,
1370s Pe epi ME lve. 7,

Margarita (Unio) lamellatus Lea, Syn., 1836, p. 26; 1838,
Pp. 20.

Margaron (Unio) lamellatus Lea, Syn., 1852, p. 29; 1870,
p. 46.

Lamellidens lamellatus SIMPSON, Syn., 1900, p. 856.

Lamellidens marginalis var. lamellatus Preston, Rec. Ind.
Mase Vili 1912s p. 304:

Unio layardu Lea, Pr. Ac. N. Sci. Phila., III, 1859, p. 153; Jl.
Ae N- Sci: Phila:, IV, 1860, p. 243, pl. xxxvi, fig. 122; Obs.,
VII, 1860, p. 61, pl. xxxvi, fig. 122——Rerve, Conch. Icon.,
XVI, 1856, pl. xxur, fig. 111—HaAntry and THEOBALD,
Conch. Ind., 1876, p. 19, pl. xu1, fig. 1.

Margaron (Unio) layardii Lea, Syn., 1870, p. 46.

The shell is generally rather thin, the epidermis is almost
always smoky, and is occasionally bordered by a lighter band.

The type is not in the Lea collection.

LAMELLIDENS SCUTUM (Sowerby).

Shell elongated, rhomboid, subinflated, inequilateral, with
dorsal and basal lines straight and parallel; dorsal slope ob-
liquely subtruncate; posterior ridge widely double, ending in
a wide biangulation below the median line; beaks apparently
not much elevated; surface smooth, of a uniform pitch color ;
teeth compressed; pseudocardinals slanting; laterals remote ;
nacre livid whitish.

Length too, height 50 mm.

Tenasserim.

1174 LAMELLIDENS

Unio scutum Sowersy, Conch. Icon., XVI, 1868, pl. xcrv, fig.
510.—HANLEyY and THEOBALD, Conch. Ind., 1876, p. 22, pl.
MEVi hg. 1.

Lamellidens scutum SIMPSON, Syn., 1900, p. 857.

T.amellidens marginalis var. scutum Preston, Rec. Ind. Mus.,
VIL 1012; p304-

A much elongated rhomboid species, the dorsal and basal
outlines being nearly straight and parallel. According to

Sowerby the epidermis is pitch color.

Var. humilior (von Martens).

“Somewhat lower, but on the whole agreeing well with the
typical form; young shells of a lively brownish-green, older
ones blackish. Basal margin nearly straight in young shells,
slightly incurved in mature ones. Posterior ridge well marked
near the umbones. Teeth tubercular, but proportionally small.

Length 124, height at beaks 49, at postero-dorsal angle 56,
diam. 26 mm. Beaks situated at 2/9 of the length, postero-
dorsal angle at 2/3 of the length.” (von Martens).

Type locality, Chindwin River near Kalewa, Upper Burmah
and its tributary, the Yu River.

Unio scutum var. humor von Martens, Arch. fir Naturg.,

[\1890; p: 45; pk v, fig. a:

“The younger specimens of this form have a great likeness
in their outer appearance to U. marginalis var. anodontinus of
the Conch. Ind., pl. 42, fig. 7, but they should have thinner
teeth to belong to marginalis.”

LAMELLIDENS CORRIANUS (Lea).

Shell irregularly long elliptical, thin, convex, inequilateral ;
beaks low; posterior ridge but slightly elevated, rounded, end-
ing in a blunt point about on the median line; dorsal outline
straight or nearly so; dorsal slope obliquely truncated ; anterior
end a little narrowed, rounded, slightly cut away below; sur-
face nearly smooth; epidermis ashy-olive, with radial rows of
very delicate wrinkles on the anter‘or end, brilliantly polished

LAMELLIDENS 1175

and having a somewhat metallic luster; teeth very delicate,

compressed ; laterals straight; nacre bluish, iridescent.
Length 54, height 26, diam. 14 mm.

India; Burma; Pegu.

Unio corrianus Lea, Tr. Am. Phil. Soc., VI, 1834, p. 65, pl.
ix 25; Obs, 1, 1834) p77, pl. 1x, hg. 25:—HANtey,
Biv. Shells, 1843, p. 207, pl. xx, fig. 60.

Margarita (Unio) corrianus L&A, Syn., 1836, p. 38; 1838, p. 25.

Margaron (Unio) corrianus Lama, Syn., 1852, p. 38; 1870, p. OF.

Lamellidens corrianus SIMPSON, Syn., 1900, p. 857.

Lamellidens marginalis var. corrianus PRESTON, Rec. Ind. Mus.,
Vil, 19r2, p. 304.

A very delicate, highly polished species, the epidermis hay-
ing a somewhat metallic or bronzy luster.

LAMELLIDENS GENEROSUS (Gould).

Shell irregularly elliptical or somewhat obovate, rather thin,
convex or subcompressed, inequilateral ; narrowed and rounded
in front; posterior ridge rounded, ending in a rounded point
at or below the median line; dorsal outline slightly arched;
dorsal slope obliquely truncate, its outline straight or incurved,
meeting the dorsal line at an angle ; base line rounded, especially
full behind the middle; surface more or less concentrically
sculptured ; epidermis dark chestnut or blackish, reddish in the
umbonal region, shining; teeth lamellar; laterals remote and
elevated ; nacre bluish, sometimes salmon in the cavities.

Length 91, height 58, diam. 27 mm.

Burma; Pegu.

Unio generosus Gout, Pr. Bost. S. N. Hist., Il, 1847, p. 220.
—HAan.ety and THEOBALD, Conch. Ind., 1876, p. 22, pl. XLVI,
fig. 4.

Margaron {Unio) generosus LEA, Syn., 1870, p. 29.

Lamellidens generosus SIMPSON, Syn., 1900, p. 857.

Lamellidens marginalis var. generosus Preston, Rec. Ind.
Must Wiis r912,. ps 304.

?Unio lamellatus SowERsy, Conch. Icon., XVI, 1868, pl. xcrv,
fig. 511.

Unio thwaitesti HANLEY and THropaLp, Conch. Ind., 1876,
Pp: 20) pli XEN He. 1.

1176 LAMELLIDENS

A fine matched pair with the label U. generosus Gould, is in
the Lea collection, presented by Dr. Gould from Newville,
British Burma. It has a rather well-developed post-dorsal
wing and shows decided, concentric sculpture.

LAMELLIDENS CANEFRIANUS Simpson.

Shell somewhat obovate, convex, rather thin, inequilateral ;
beaks compressed, their sculpture consisting of delicate, curved,
radial ridges, which are subnodulous and inclined to break up
into zigzags; posterior ridge low. rounded; there are two
delicate, pinched-up ridges above on the dorsal slope, which
fade out below, anterior end somewhat narrowed, rounded;
posterior end bluntly pointed above the median line; dorsal
slope obliquely truncate; dorsal and basal outlines lightly
curved, the latter quite full behind the middle; surface with
fine, concentric striz with excessively fine, radial, microscopic
lines in front, very faintly granular on the disk; epidermis
brilliant yvellowish-green, smoky-tinted green on the dorsal
slope; teeth delicate, compressed ; nacre whitish.

Length 89, height 44, diam. 27 mm.

Prome, Lower Burma.

Unio protensus TAPPERONE-CANEFRI, Am. Mus. Civ. Gen.,

VII, 1889, p. 349.

Lamellidens canefrianus StMPson, Syn., 1900, p. 857.

I am very doubtful whether this is anything but a variety of
marginalis. Several specimens from Fea, of the type lot, are
before me, none of them quite grown, but they are all in
beautiful condition, and show the character of the beaks and
surface perfectly. The shell is shorter in proportion than most
marginalis, and is much produced on the post-basal region.
The name protensus was used by Lea in 1865 for a North
Carolina Unio, hence I have changed it as above.

LAMELLIDENS JENKINSIANUS (Benson).

Shell somewhat solid, subinflated, irregularly long oval;
inequilateral; beaks full and high; anterior end subangulate
above, rounded below; base line nearly straight; dorsal, out-

LAMELLIDENS 1177

line arched: post-dorsal slope slopingly subtruncate; surface

with strong concentric striz; epidermis brownish; pseudo-

cardinals and laterals rather solid; muscle scars impressed;
nacre bluish-white.

Length 94, height 51 mm.

Assam.

Unio jenkinsianus Benson, Ann. and Mag., X, 1862, p. 185.
—Han ry and THEopatp, Conch. Ind., 1876, p. 19, pl. x1,
fig. 4.

Lamellidens jenkinsianus SIMPSON, Syn., 1900, p. 857.

Lamellidens marginalis var. jenkinsianus Preston, Rec. Ind.
Mists VI non2:. 9: 305;

I am at a loss to know what this is. Hanley and Theobald
think it may probably be considered an abnormal form of
U. marginalis or corrianus. It certainly cannot be the latter
but may possibly be the former. The figure bears some re-
semblance to that of an old Unio buckleyi. ‘There is a shell in
the National Museum collection, which I refer to this with
considerable doubt, but it is not so solid as the figure given by
Hanley and Theobald show jenkinsianus to be.

LAMELLIDENS NARAINPORENSIS Preston.

“Shell cuneate, moderately convex, posteriorly rostrate, dark
reddish-brown, covered, towards the margins, with a finely -
laminiferous periostracum, marked with concentric lines of
growth, bearing two carinz on each valve running from the
umbones in a dorsally posterior direction; umbones small, not
prominent, somewhat coarsely corrugated; dorsal margin very
gently arched ; ventral margin scarcely rounded in the anterior
and median regions, slightly curved posteriorly; anterior side
abruptly rounded; posterior side sloping above, then angled
and very abruptly descending; cardinal tooth in left valve
obtrusely triangular, erect, absent in the right valve; lateral
teeth anteriorly short, deeply grooved and projecting in the
right valve, erect and jagged in the left, posteriorly moderately
elongate and bifurcated in both valves; anterior scars rather
circular, deep; posterior scars lightly impressed; interior of

1178 LAMELLIDENS

shell pale flesh-color shading to iridescent bluish-white, very
minutely granulate.
Long. 35, lat. 84 mm.” (Preston).
Type locality, Narainpore Bhil, Murshidabad District,
Bengal.
Lamellidens narainporensis PRESTON, Rec. Ind. Mus., VII,
TO12; p. 300:

LAMELLIDENS NONGYANGENSIS Preston.

“Shell very elongately ovate, inflated, covered with a black-
ish-brown, finely laminiferous periostracum, concentrically
marked with rather coarse lines of growth; dorsal margin
anteriorly somewhat straight, posteriorly arched above, sloping
and slightly excavated below ; ventral margin scarcely rounded;
anterior side abruptly descending; posterior side rostrate,
obtusely rounded; cardinal teeth very anteriorly situate, trian-
gular, erect; lateral teeth elongate, also erect, terminating pos-
teriorly in an abrupt slope; anterior scars deeply marked;
posterior scars lightly impressed; interior of shell flesh-colored
shading to bluish, iridescent, minutely pitted and granulate.

Long. 45, lat. 94 mm.” (Preston).

Type locality, Nongyang Lake, South of Patkai.
Lameliidens nongyangensis PRESTON, Rec. Ind. Mus., VII,

IQ12, p. 300.

LAMELLIDENS PHENCHOOGANJENSIS Preston.

“Shell very elongately ovate, posteriorly obtusely rostrate,
dark blackish-brown, sculptured with fine, concentric striz,
crossed, especially in the anterior median region, by fine,
slightly distant, transverse, radiate striz, thus presenting a
minutely wrinkled appeatance; umbones flattened, much
eroded; dorsal margin anteriorly gently sloping, posteriorly
more rapidly sloping in a slight curve; ventral margin scarcely
rounded; anterior side angled above, gently rounded below;
posterior side produced, angularly rounded; hinge teeth very
elongate, somewhat fine; anterior scars ovate, moderately im-
pressed ; posterior scars roughly triangular, not well impressed ;
interior of shell shading from pale brown to bluish, nacreous,

LAMELLIDENS I179

marked, especially towards the anterior ventral region, with
very shallow, radiate furrows.
Long. 42, lat. 86 mm.’ (Preston).
Type locality, Phenchooganj, Central Sylhet.
Lamellidens phenchooganjensis Preston, Rec. Ind. Mus., VII,
IQI2, p. 300.

Subgenus SpAatuopsis Simpson. 1900.

Spathopsis SIMPSON, Syn., 1900, p. 857.

Sheil long, elliptical, compressed, beaks rather low, said to
bear concentrically roughened ridges, with slight plications in
front and behind them; posterior ridge not developed; surface
shining, smooth: hinge line narrow, with faint, greatly elon-
gated pseudocardinals and laterals; escutcheon deep, triangu-
lar; beak cavities shallow; anterior muscle scars elongated ;
posterior faint; iridescent behind.

Type, Anodonta guillaini Recluz.

LAMELLIDENS GUILLAINI (Recluz).

Shell elongated, almost evenly elliptical, convex, subsolid;
beaks not greatly elevated, sharp, turned forward; rugosely
concentrically grooved; posterior ridge low and widely round-
ed; surface with delicate, concentric sculpture; epidermis pale
reddish-brown, lighter at the umbonal region; muscle scars
complicated; nacre flesh-colored, slightly iridescent.

Length 120, height 56, diam. 27 mm.

Denog River, Brava, Northeast Africa.

Anodonta guillaini Reciuz, Jl. de Conch., I, 1850, p. 55.—

Crosse, Jde Conch; XX XI 1883) p..222. pl. 1x, fie. 4:
Lamellidens guillaini SiMPsoN, Syn., 1900, p. 858.

Spatha guillaim GerRMain, Arch. Zool. Exp. et Gen., (5), I,

1909, p. 56.

The description given of this species is not at all full. The
excellent figure cited shows delicate lamellar pseudocardinals
and laterals and if it is correct this species belongs to the Un-
ionidae and it is not related to the Spatha rubens with which the
author compares it.

1180 TRAPEZOIDEUS

Genus TRAPEZOIDEUS Simpson. 1900.

Trapezoideus StMPson, Syn., 1900, p. 858.

Shell trapezoid, much compressed, with a low posterior ridge,
and but slightly raised, though pointed, beaks, which seem to be
sculptured with irregularly radial ridges arranged in two im-
perfect chevron-shaped loops; surface concentrically sculp-
tured, often having irregular radial ridges on the posterior
slope; epidermis yellowish-green or brownish, with two or
more green rays above the posterior ridge; teeth compressed ;
two pseudocardinals in the left valve, one under the beak, the
other in front, often not well separated, and two laterals;
right valve with two pseudocardinals and one lateral; pseudo-
cardinals all irregular, often pitted and peculiarly dentilate ;
laterals granular, showing traces of vertical striation; cavity
of the beaks rather deep, compressed; muscle scars shallow,
anterior scars separate; nacre soft, creamy, yellowish in the
beak cavities.

Animal unknown.

Type, Unio foliacea Gould.

The species which I have placed in this group have generally
elongated, rhomboid or trapezoid, rather thin, subcompressed
shells. The beaks are but slightly elevated and nothing is
known of their sculpture so far as I know. The surface has
well-marked, concentric sculpture, which is sometimes cor-
rugated, the teeth are compressed and roughened, the pseudo-

cardinals being usually rather feeble. The group does not
seem to be very close to any other.

KEY ‘TO SPECIES OF TRAPEZOIDEUS.

Shell with dark epidermis and nacre.

Long rhomboid. T. exolescens.
Ovate elliptical. T. ludovicianus.
Shell with light epidermis and nacre.
Trapezoid. T. pallegoixt.
Obovate rhomboid. T. theca; peninsularis.
Rhomboid.
Not arcuate, T. foliaceus.

Subarcuate, T. miscellus.

TRAPEZOIDEUS 1181

TRAPEZOIDEUS FOLIACEUS (Gould).

Shell long rhomboid, a little narrower in front, subsolid,
subcompressed or convex, inequilateral; posterior ridge feebly
double, there being often a third, faint ridge on the posterior
slope; dorsal outline lightly arched; posterior end obliquely
truncate above, somewhat biangulate below ; base line straight
or a little incurved; anterior end rounded; surface densely,
finely, concentrically sculptured; beaks apparently low ; epider-
mis yellowish-green or yellowish-olive, in old shells usually
faintly clouded or widely rayed with green behind; there are
two irregular, compressed, much-striated pseudocardinals in
each valve and two remote laterals in the left valve and one
in the right; beak cavities compressed but not deep; muscle
scars irregular; nacre bluish-white, salmon-tinted in the cavi-
ties, of a soft, iridescent tint.

Length 62, height 34, diam. 18 mm.

Burma ; Cambodia.

Unio foliacea Goutp, Pr. Bost. Soc. N. Hist., I, 1843, p. 141.

Unio foliaceus HANLEY and THEoBaLp, Conch. Ind., 1876, p.
19, pl. xuq, fig. 3—ANbDERSON, Yunnan Exp., 1877, p. 900,
pl. Lxxx, figs. 8-12.

Margaron (Umo) foliaceus Lea, Syn., 1852, p. 39; 1870, p. 62.

Trapezoideus foliaceus SIMPSON, Syn., 1900, p. 858.—HAas,
Conch. Cab., Unio, 1912, pl. 32, figs. 3-4.

Unio peguensis ANTHONY, Am. Jl. Conch., I, 1865, p. 351, pl.
XXv, fig. 2—Sowersy, Conch. Icon., XVI, 1868, pl. xcv, fig.
510.

Margaron (Unio) peguensis LEA, Syn., 1870, p. 51.

I am not positive that Gould’s Umio foliaceus is the young
of Anthony’s U. peguensis as Hanley and Theobald are, but
I am very strongly inclined to believe it. I have before me
two specimens from the Lea collection labeled Unio foliaceus
by Gould and presented by him to Dr. Lea.

They are rather thinner than any specimens I have seen of
U. peguensis Anthony, and are not quite so strongly sculptured,
but they are smaller than any peguensis in the National

1182 TRAPEZOIDEUS

Museum. Gould's shells are slightly plicate on the dorsal slope,
but this character is occasionally. present even in adult

peguensis.

Var. comptus (Deshayes and Julien).

Shell small, more inflated than the type, rather thin.
Length 32, height 18, diam. 10 mm.

Unio comptus DEsHAvEs and JULIEN, Arch. de Mus., X, 1874,
p. 126,.pl. vi, figs. 3, 4——Haas, Conch. Cab., Unio, 1912, pl.
22, ho.

Trapezoideus foliaceus var. comptus Simpson. Syn., 1900,
p. 858.

Unio fragilis NEviiu, Jl. As. Soc. Beng., XLVI, 1877, p. 39.—
ANDERSON, Yunnan Exp., 1877, p. 400, pl. Lxxx, figs. 8-12.
The figure by Deshayes and Julien shows quite a little plica-

tion on the dorsal slope. I have before me a specimen of Unio

fragilis Nevill, an author’s specimen, which is a little smoother
on the dorsal slope, but does not appear to differ otherwise.
Haas, (1. c.), considers this a synonym of misellus.

Var. sayleymanensis Preston.

“Shell thinner and smaller than the typical form, more pro-
duced anteriorly and much more obtuse posteriorly ; the slight
curve in the ventral margin is also absent.” (Preston).

Type locality Bhamo; also Zayleyman.

Trapezoideus foliaceus var. sayleymanensis, Preston, Rec.

Ind! Mus: VEL, Tor2) pH3o7:

Trapezoideus foliaceus var. zayleiwanensis Haas, Conch. Cab.,

Unio, 1912s pli33. figs

Haas, (1. c.), considers this a synonym of TJ. misellus.

TRAPEZOIDEUS MISELLUS (Morelet).

Shell elongated, subarcuately rhomboid, thin, compressed,
inequilateral; umbonal region somewhat elevated ; beaks rather
sharp; posterior ridge full, feebly biangulate, ending behind in
a faint biangulation at and below the median line; anterior end
narrowly rounded above, cut away below; base line incurved
in the middle; dorsal outline lightly arched; dorsal slope ob-

TRAPEZOIDEUS 1183

liquely truncate; surface rudely and unevenly concentrically

sculptured ; dorsal slope feebly plicate ; epidermis dirty green-

ish: teeth delicate, lamellar; laterals remote; nacre bluish, sal-
mon-tinted in the cavities.

length 60, height 27, diam. 12 mm.

Length 61, height 28, diam. 16 mm.

Siam.

Unio misellus Moret, Jl. de Conch., XIII, 1865, p. 21; Ser.
Conch., IV, 1875, p. 341, pl. xiv,-fig. 2—von MAaRrTENs,
Arch. fiir Naturg, I, 1899, p. 43, pl. v1, figs. 4-8.

Trapezoideus misellus Stmpson, Syn., 1900, p. 859.—Haas,
Conch. Cab., Unio, 1912, pl. 32, figs. 6-9.

Unio siamensis Lea, Pr. Ac. N. Sci. Phila., X, 1866, p. 133;
Jl. Ac. N. Sci. Phila., VI, 1868, p. 279, pl. xxxviu, fig. 93;
Obs., XII, 1869, p. 39, pl. xxxvui11, fig. 93.

Margaron (Unio) siamensis LEA, Syn., 1870, p. 57.

I have before me the type of Lea’s Unio siamensis, which
does not seem to differ in any particular from Unio misellus
as described and figured by Morelet, unless it may be a little
more compressed. Morelet’s measurements, given in the
“Series Conchyliologiques,”” make his species somewhat in-
flated and may be incorrect. ‘These are: length 66, height 31,
diam. 21 mm. The second measurements I have given are
those of his type.

Var. subclathratus (von Martens).

‘Differs mainly from the typical form by the folds, which
descend from the umbones, but do not reach the basal margin
in the centre of the disk; they are nearly vertical and more or
less regularly interrupted by the growth-lines and therefore
have a granulated appearance, sometimes, particularly near the
beaks, they also meet at acute angles pointed downwards, but
this is the exception rather than the rule. At both extremities
they radiate obliquely, without a noticeable curve and without
granulations; posteriorly they frequently fork and anteriorly
often meet at irregular acute angles. The general form and
coloring, as a whole, is like typical miscllus, but on the average
the shell is less thin, somewhat more inflated, the basal margin

1184 TRAPEZOIDEUS

straight or even somewhat convex, frequently there is a beauti-
full dark green ray on the forward part of the posterior slope.

Length 45, height at beaks 23, at postero-dorsal angle 24,
diam. 15 mm. Beaks situated at 1-3 of the length.” (von
Martens).

Type locality, Chindwin River near Kalewa and Matu and
in the Irriwadi near Yenangyoung, Burmah.

Unio miscellus var. subclathratus von Martens, Arch. fur

Naturg., I, 1899, p. 44, pl. v1, fig. 3.

Trapezoideus subclathratus Haas, Conch. Cab., Unio, 1912, pl.

B38) tie<6:

TRAPEZOIDEUS PALLEGOIXI (Sowerby).

Shell decidedly rhomboid or trapezoid, much wider behind
than in front, compressed inequilateral; beaks rather full;
posterior ridge prominent, narrowly rounded, ending near the
base of the shell in a rounded point; dorsal line nearly straight ;
posterior and almost squarely truncate; anterior end narrowed,
rounded above, cut away below; base line incurved in the
middle; surface with well marked, concentric wrinkles, with
a few nearly vertical, curved folds in front of the posterior
ridge ; epidermis greenish-yellow.

Length 70, height at beaks 28, at hinder end of ligament 33
mn.

Siam ; Cambodia.

Anodon pallegoixt Sowerby, Conch. Icon., XVII, 1867, pl.

vill, fig. 17.—Haas, Conch. Cab. Unio, 1912, pl. 33, figs. 3-5.
Anodonta pallegoixi Cirssin, Conch. Cab. Ano., 1876, p. 210,

Oui Ghiawarer (C%

Trapezoideus pallegoixi SIMPSON, Syn., 1900, p. 859.

Sowerby tells nothing of the teeth or nacre of this shell. It
is probable that the teeth are lamellar and rather feebly devel-
oped. It is plainly a number of the Trapezoideus group of
Uniones and differs from foliaceus and miscellus in the de-
cidedly trapezoid form and in having nearly vertical curved
plications in front of the posterior ridge.

Haas, (1. c.), considers this a synonym of T. mtsellus.

TRAPEZOIDEUS 1185

TRAPEZOIDEUS EXOLESCENS (Gould).

Shell long rhomboid, inequilateral, rather thin, subcom-
pressed ; anterior end rounded, narrowed; dorsal outline lightly
arched; dorsal slope obliquely truncate; base line nearly
straight; posterior ridge double, ending in a feeble biangula-
tion near the base; surface with irregular, concentric sculpture,
and in some cases faint plications on the dorsal slope; epider-
mis smoky-brown ; pseudocardinals rather shorter than in most
of the species, feebly developed; laterals remote, well devel-
oped; nacre bluish, lurid purplish in the cavities.

Length 69, height 32, diam. 17 mm.

Tavoy, Burma.

Unio exolescens Gout, Pr. Bost. S$. N. Hist., J, 1843, p. 141.—
AHANLEY and THEosaLp, Conch. Ind., 1876, p. 43, pl. cv,
fig. 5.

Margaron (Umo) exolescens LEA, Syn., 1852, p. 32; 1870,
DOSE,

Trapezoideus exolescens SIMPSON, Syn., 1900, p. 859.

Four odd valves are in the Lea collection, presented by Dr.
Gould under the name Unio exolescens. It is quite a distinct
species, differing from others of the group in its dark epider-
mis, the color of its nacre and the shorter pseudocardinals.

TRAPEZOIDEUS THECA (Benson).

Shell rather small, scarcely subsolid, somewhat elongated,
subrhomboid, quite inequilateral, beaks. small but somewhat
sharply elevated ; anterior end narrowed, a little, rounded ; base
line a little inflated just behind the middle; dorsal outline nearly
straight; outline of dorsal slope obliquely rounded; posterior
ridge rounded; surface with rather strong concentric sculpture
and slightly corrugated; dorsal slope plicate ; epidermis yellow-
ish; teeth delicate ; pseudocardinals oblique ; nacre bluish, red-
dish in the cavities, iridescent.

Length 40, height 2t mm.

Cane River, Bundelkhund, India.

Unio theca BENSON, Ann. and Mag., X, 1862, p. 186—Han-

LEY and THEOBALD, Conch. Ind., 1876, p. 6, pl. xu, fig. 5.
Trapezoideus theca StMPson, Syn., 1900, p. 859.

1186 TRAPEZOIDEUS

I am not certain as to the systematic position of this species,
which may belong here. It is a rather small, oblong, sub-
rhomboid form with concentric sculpture, apparently some-
what corrugated and having a yellowish epidermis.

TRAPEZOIDEUS PENINSULARIS Simpson.
I

Shell subrhomboid, rather thin, inequilateral; beaks but
slightly elevated; posterior ridge double, ending in a faint
biangulation at and below the median line; dorsal slope
obliquely truncate; anterior end narrowed and rounded, cut
away a little below; base line curved; surface finely wrinkled
and apparently concentrically sculptured; epidermis fulvous-
yellow or fulvous-olive. .

Length 39, height 23 mm.

Sumatra.

Unio sumatrensis SowrrsBy, Conch. Icon., XVI, 1865, pl.

XXVIII, fig. 142.

Trapezoideus peninsularis SIMPSON, Syn., 1900, p. 859.

I am not at all certain where this species should be placed, as
Sowerby’s description is very inadequate. It is shorter in pro-
portion to height than the other species, and the base line is
more rounded. This is not Lea’s sumatrensis, nor that of
Dunker. The name being preoccupied, I have changed it to
peninsularis. I do not think it is the same as the Umio comptus,
as Fischer believes.

TRAPEZOIDEUS LUDOVICIANUS (Rochebrune).

“Shell ovate elliptical, thick, moderately convex, brown;
anterior region rounded; dorsal margin arcuate behind, ab-
ruptly truncated below; ventral margin subsinuous; surface
deeply, concentrically sulcate, with minute, straight, interrupted
grooves, which toward the dorsal margin and especially at the
umbonal region develop into conspicuous, intricate waves;
umbones obtuse, greatly eroded, coppery; cardinal tooth
quadrate, thick, crenulate ; lateral teeth elongate, distant in the
right valve; interior nacreous, bluish, salmon under the beaks.

Length 50, height 32, diam. 22 mm.” (Rochebrune).

Type locality, Preck-Scholl, Upper Mekong.

ARCONAIA 1187

Diplodon ludovicianum RocHEBRUNE, Bull. Soc. Phil., 1882,
Pp. 43.—SIMPSON, Syn., 1900, p. 862.
Trapezoideus ludovicianus Haas, Conch. Cab. Unio, 1912, pl.
22, fies 5
This species, which was placed among the indeterminate
species in the Synopsis, has recently been figured as a Trap-
esoideus by Haas, (1. ¢.), but the accompanying text has not
yet been published.

Genus ARCONAITA Conrad, 1865.

Arconaia Conrap, Am. Jl. Conch., I, 1865, p. 234.

Shell greatly elongated, inflated, solid, twisted on its axis,
sometimes straight, but generally having the posterior end
curved strongly to the right or left, with a decided posterior
ridge on both sides of the shell, ending in a blunt point, with
generally a smail ridge above on the post-slope; beaks rather
low, sculpture not seen, but probably zigzag-radial; often a
few nodulous or wavy ridges cross the body of the shell,
which is irregularly sulcate; epidermis rayless; two pseudo-
cardinals in the right valve, the upper compressed, separated
from the split-up lower one by a parallel-sided pit, two in the
left, and two heavy laterals; one lateral in the right and a
vestige of one below it, laterals granulated and_ vertically
striate; muscle scars deep, anterior small, the front and upper
united, the hinder separate; posterior muscle scars long,
oblique; beak cavities very shallow; dorsal scars numerous,
placed just on the inner edge of the hinge; nacre white. The
lobes of the mantle are not united into siphons, but separated
throughout, with only a feeble commissure separating the anal
and branchial openings.

Type, Triquetra lanceolata Lea.

In 1865 Conrad established the genus Arconata for the Tri-
quetra lanceolata of Lea. I have placed in it, besides the
original form, two others which Heude doubtfully believes to
be varieties of lanceolata, but which seem to me to be valid
species. The systematic position of the group is a little uncer-
tain, but I am inclined to believe that it is one of the Endo-
branchs and should be placed in the supergeneric group
Rosanorhamphus.

1188 ARCONATA

Group of Arconaia lanceolata.
Shell with an anterior wing.

ARCONAIA LANCEOLATA (Lea).

Shell elongated, solid, subinflated, twisted on its axis,
curved to the right or left from the middle to the extreme
posterior end, with a strong anterior wing, which is carried
forward to a point; posterior ridge well developed, subangular
or narrowly rounded, fullest on the convex side of the shell,
ending in a blunt point below an oblique posterior truncation ;
beaks but little elevated; surface with irregular growth lines,
often with a few nodules or subvertical corrugations at the
anterior of the disk; epidermis ashy brown, somewhat silky;
pseudocardinals strong, double in each valve, usually much
split up; laterals very long, more or less vertically striate, two
in the left valve and one in the right; muscle scars well im-
pressed, the posterior ones long and oblique; dorsal scars
numerous; nacre whitish.

Length 130, height 34, diam. 22 mm.

China.

Triquetra lanceolata Lea, Pr. Ac. N. Sci. Phila., VIII, 1856,
Pp. 79.

Hynia lanceolata Lea, Pr. Ac. N. Sci. Phila., 1856, p. 300.

Arconaia lanceolata Conrap, Am. Jl. Conch., I, 1856, p. 234.—
SIMPSON, Syn., 1900, p. 860.

Inquetra contorta’ Lua, Pr. Ac) N. Sci. Phila., VIL, 1856,
p.. 400; Obs WAL1857, p. 20" pl seca hen a lh eAtewINE
set, Philay TN 1858, p: 310, pl xx xian fen.

Hyria contorta Sowrerpy, Conch. Icon., XVIT, 1869, pl. 1, figs.
2a, 2b.

Margaron (Triquetra) contorta L&A, Syn., 1870, p. 26.

Unio contortus HEupE, Conch. Fluv. Nank., II, 1877, pl. xv.,
fig. 31.

Several examples of this remarkable shell are before me,
most of which turn to the right behind; one, however, curves
strongly to the left. One of the shells curves but little and
there is quite a little variation in this matter, as well as in the

ARCONATA 1189

amount of the twist. A young, or perhaps not fully adult
shell, shows long anterior wings, 20 millimeters in length,
drawn out to a point, but these are generally more or less
broken away. ‘The type is not in the Lea collection, but a
smaller shell presented by Cunning.

ARCONAIA MUTICA (Heude).

Shell solid, inflated, elongated, twisted on its axis and having
the hinder part bent to one side; beaks apparently low ; anterior
end with a short wing above; posterior ridge elevated, double
and angled in the inner valve, the two ridges widely separated ;
posterior end widely, obliquely truncate; surface rather more
roughened than in lanceolata; epidermis reddish-brown or
blackish-brown, scarcely if at all sericeous; pseudocardinals
strong, triangular, ragged but not split into denticles in the
specimens seen; laterals vertically striate; muscle scars im-
pressed, the posterior ones long and oblique; nacre flesh-col-
ored.

Length 108, height 30, diam. 25 mm.

China.

Umo contortus var. muticus HeupeE, Conch. Fluv. Nank., II,
1S 77 spleen, Ness
Arconaia mutica SIMPSON, Syn., 1900, p. 860.

Heude makes this a variety of lanceolata, but, although I
have seen some intermediate material, I am inclined to believe
it worthy of a specific rank. It is solider, more inflated and
rougher than Janceolata, it is not so silky, the color is more
reddish, the posterior ridge of what may be called the inner
valve is widely and angularly double, the posterior end is
obliquely truncate instead of being pointed as in Janccolata.
The pseudocardinals are more solid and triangular, and not so
much split.

Group of Arconaia conjungens.

Shell moderately solid, slightly twisted and bent, rounded
in front; pseudocardinals not so much torn as in the lanceolata
group; not winged in front.

IIgo PSEUDAVICULA

ARCONAIA CONJUNGENS (Heude).

Shell somewhat delicate, elongated not very solid, but
slightly curved or twisted; posterior ridge rather high and
pinched up on the outer valve, ending in a point on the median
line; anterior end almost regularly rounded, slightly angled,
but wholely wanting a wing above; surface smooth; pseudo-
cardinals subcompressed, rather short; laterals long and nearly
straight; muscle scars impressed, the posterior ones long and
oblique.

Length 80, height 21 mm.

China.

Unio contortus var. conjungens Hrupr, Conch. Fluv. Nank.,

U1 1877, qples ie. 33°
Arconaia conjungens SIMPSON, Syn., 1900, p. 860.

Heude also makes this a variety of A. lanceolata, but states
that both his varieties are probably species. This is much more
delicate than lanceolata, is smaller, smoother, less solid, less
twisted and curved and has different pseudocardinals. His
description is very meagre.

Genus PSEUDAVICULA Simpson, 1900.

Pseudavicula SIMPSON, Syn., 1900, p. 860.

Shell with a well-developed anterior and posterior dorsal
wing; dorsal line strongly incurved; beaks full, not high; a
high, down-curved posterior ridge runs to the posterior basal
point, and between this point and the posterior point of the
wing the outline is deeply incurved; base and lower part of
anterior end rounded; surface slightly sculptured with con-
centric ridges; beak sculpture probably zigzag rayed; anterior
tooth of left valve elongate, slightly corrugated, that of the
right double; laterals in left valve double, single in the right,
straight, elongated, thin, and prominent ; nacre rose-tinted.

Animal unknown.

Type, Unio johnstoni Smith.

PSEUDAVICULA JOHNSTONI (Smith).

Shell irregularly rhomboid, compressed, rather thin, inequi-
lateral; dorsal margin an inverted arch, the anterior and pos-
terior ends of which extend into wings; beaks slightly elevated ;

ARCIDOPSIS LIQI

posterior ridge prominent, narrowly rounded, curved down-
ward in the middle, ending in a produced point near the base
of the shell; posterior end sharply incurved between the wing
and the base; base rounded; anterior end rounded and cut
away below; surface strongly, concentrically striate, highly
corrugated at the umbones; epidermis pale green, obscurely
radiate behind; nacre beautifully pearly, iridescent, pale rose
color; pseudocardinals elongated, corrugated, single in the
left valve, double in the right; laterals single in the right valve,
double in the left.

Length 53, height 30, diam. 9.5 mm.

Lake Mweru, British Central Africa.

Unio (Metaptera) johnstom Smiru, Pr. Zool. Soc. Lond.,

1893, p. 640, pl. LIx, figs. 18-20.

Pseudavicula johnstoni SIMPSON, Syn., 1900, p. 861.

This remarkable species bears a striking resemblance to a
Prisodon and is possibly closely related to that group. Smith
states that the region above the umbones is lightly corrugated,
but does not say whether this sculpture is zigzag-radial or
otherwise. He states that the shell gapes slightly at both ends.

Genus ARCIDOPSIS Simpson, 1900.

Arcidopsis SIMPSON, Syn., 1900, p. 861.

Shell inequilateral, elongated, with dorsal and ventral lines
nearly straight and parallel; anterior end strongly and obliquely
truncated from the beaks to the anterior base, and ending in a
rather sharp but rounded point below; posterior end obliquely
truncated above, rounded below; posterior ridge full, rounded ;
the shell in front and below rather compressed; surface con-
centrically and radially ridged; pseudocardinals strong, two in
the right valve, one in the left, and supported by a strong,
cardinal rib; muscle scars well impressed; pallial line distinct.

Animal unknown.

Type, Unio footer Theobald.
ARcrIbopsts FOOTEL (Theobald).

Shell trapezoid, elongated, compressed, inequilateral; beaks
prominent ; dorsal line straight, posterior end obliquely truncate
above, rather widely rounded below ; base line straight ; anterior

11g2 ORIENTAI, UNIONIDA

end slightly narrowed, obliquely cut away from the beaks to
near the base, narrowly rounded below; surface radially and
concentrically sculptured so that it is retriculated throughout ;
within there is a strong rib, which supports the cardinal teeth.

Length 95, height at the beaks 36, at hinder end of ligament
39 mm.

Kistna River, India.

Unio footei THEOBALD, Jl. As. Soc. Beng., XLV, 1876, p. 187,
pl. xiv, figs. 9, 9a.
Arcidopsis footer SIMPSON, Syn., 1900, p. 861.—HAas, Con.

Cab., Unio, 1gi0, pl. x1, figs. 2-4.

A remarkable form, which may not belong to the Unionide
at all. The beaks form an angle between the anterior end and
dorsum, the narrowly rounded anterior point below projecting
forward in an unusual manner.

Unfortunately Theobald’s Latin description of Unio footet
is not at all complete. No laterals are mentioned, and he says
nothing of the color of the epidermis or of the nacre. The
beaks were too much worn in his specimens to give any char-
acters. The shell resembles some of the Arcas of the Barbatia
group.

The following are indeterminate Oriental Unionide:

Unio alfierianus BourGuIGNAT, Voy. Choa, 1885, p. 43. Choa,

Central Africa.

Unio antiniloticus BourcuicNat, Bull. Soc. Zool. Fr., XI.

1880, 482, pl. x1, fig. 5. Senegal.

Unio ascia HANLEY, Biv. Shells, 1856, p. 385, pl. xxu11, fig. 20.

Penang.

Unio bridouxi Bourcuicnat, Un. & Ir. Tan., 1886, p. 13. Lake

Tanganyika.

Unio ferscali Parreyss. Where described? Egypt.
Umo gibbus SPENGLER, Skriv. Selsk. Nat., III, 1793, p. 64.

Tranquebar.

Unio guillemeti Bourcuicnat, Un. & Ir. Tan., 1886, p. 15.

Lake Tanganyika.

Umo hamyanus BourcutGcnat, Voy. Choa., 1885, p. 42. Cen-
tral Ethiopia.

ORIENTAI, UNIONIDA T193

Unio idgi BourcurGnat, Moll. Terr. et Fluv. Choa, 1885, p. 39.
Choa, Africa.

Unio ilgut SoLEULET, Voy. Choa, 1885, p. 40. Central Ethiopia.

Unio jossett Bourcuicnat, Un. & Ir. Tan., 1886, p. 19. L.
Tanganyika.

Unio jouberts BourcuicnaTt, Un. & Ir. Tan., 1886, p. 8. L.
Tanganyika.

Unio lavigerinus Bourcuicnat, Un. & Ir. Tan., 1886, p. 14.
1. Tanganyika.

Unio ligula Mousson, L. & S, W., Moll. Java, 1849, p. 94.
Java.

Unio longitudinatus AN'toN, Verz der Conch.

Unio madagascariensis SGANZIN, Mem. Soc. Hist. Strab., 1846,
p. 8. Mahoupa River, Madagascar. No figure.

Unio menardi Bourcutcnat, Un. & Ir. Tan.,. 1886, p. 20. L.

Tanganyika.

Unio meneliki, SOLEILLET, Voy. Choa, 1885, p. 41. Central
Ethiopia.

Unio moineti Bourcuicnat, Un. & Ir. Tan., 1886, p. 11. L.
Tanganyika.

Dysnomia pavonina ROCHEBRUNE, Bull. Soc. Phil., 1882, p 43.
Cochin, China.

Umio schweinfurtht voN MArRtENS, S. B. Nat. Fr., 1886, p. 127.
Egypt.

Unio sitifensis MoreLer, J. de Conch., 1853, p. 208.

Umo soleilleti Bourcuicnat, Voy. Choa, 1885, p. 39. Central
Ethiopia.

Loncosilla solenoides RA¥FINESQUE, Cont. Mon., 1831, p. 7.
Jellinghy River, Bengal.

Unio subamygdalinus Drover, J. de Conch., 1895, p. 33. West
Africa.

Unio truncatus SPENGLER, Skiv. Selsk. Nat., III, 1793, p. 66.
Tranquabar.

Unio vinckei Bourcuicnat, Un. & Ir. Tan., 1886, p. 18. L.
Tanganyika.

Unio vissert BoURGUIGNAT, Un. & Ir. Tan., 1886, p. 21. L.
Tanganyika.

T1194 TETRAPLODON

LAMPHORHAMPHUS.

Male and female shells alike; dull-colored; beak sculpture
nearly or quite radial, marsupium occupying the entire inner
branchiz, forming a pad-like mass.

Genus TETRAPLODON Spix, 1827.

Castalia LAMARCK, An. sans Vert., VI, 1819, p. 66.
Tetraplodon Srix, Test. Fluv. Bras., 1827, p. 32.
Prisodon L&A, Synopsis, 1852, p. 18.

Shell triangular, solid, inflated, with a high, sharp posterior
ridge, behind which it is decidedly truncated; beaks very full
and high, sculpture strictly radial, or with one or two pairs of
the central bars coalescing below, the whole extending more or
less over the disk as strong ridges ; epidermis thick, dark, dull-
colored; hinge line arched; there is a very strong, compressed:
pseudocardinal in the left valve, and there are two in the right,
all in front of the beaks; behind them are several denticles;
one lateral in the right valve and two in the left; all the teeth
strongly vertically ridged; beak cavities deep, not compressed ;
anterior muscle scars small, deep; nacre whitish.

Animal having the labial palpi wider than long; margins of
mantle inferiorly open, but united posteriorly to form two
siphons, branchial and anal; branchial opening surrounded with
papillz; anal opening smooth; outer branchiz united to the
mantle to their posterior ends; inner united to the abdominal
sac; foot tongue-shaped, thick, produced anteriorly. (Tro-
schel. )

Type, 7etraplodon pectinatum Spix.

A very natural, small group of South American Unionide.
The shells are generally triangular with high beaks having
radical sculpture, which extends well on to the disk and in
some cases all over it. The teeth are usually strongly vertical-
ly sculptured, the pseudocardinals are often somewhat split up.

TETRAPI,ODON 1195

KEY TO SPECIES OF TETRAPLODON.

Shell with very sharp, high posterior ridge, 7. quadrilatcrus.
Posterior ridge rounded or subangular.

Shell rhomboid. T. crosseanus.
Shell trapezoid.
With many zigzag-radial ridges. T. multisulcatus.
Ridges few, wide and short. T. retusus.

Ridges strong extending half way over the disk,
- T. ovatus.
Ridges fine, shell concentrically sculptured,
T. schombergianus ; cordatus.

Shell quadrate, nearly smooth, yellow. T. quadratus.
Shell more or less triangular.
Beaks nearly central. T. ecarinatus.
Beaks anterior.
Radial ribs strong. T. baro; ambiguus.
Radial ribs low. T. juruanus ; pectinatus.

Group of Tetraplodon ambiguus.
Characters as in the genus.

TETRAPLODON AMBIGUUS (Sowerby).

Shell subtriangular, greatly inflated, solid, quite inequilateral ;
beaks very full and high, their sculpture consisting of strong,
radial bars, which extend well over the disk, in some cases
to the base of the shell; anterior end narrowed and rounded;
base almost straight or curved; dorsal slope suddenly and
obliquely truncate, often somewhat angular behind the liga-
ment; posterior ridge very full and high, narrowly rounded,
ending in a blunt point at or near the base of the shell; epider-
mis thick, brownish, dull, showing concentric growth lines;
teeth vertically striate; pseudocardinals split up, usually there
are two or three more prominent than the rest in each valve;
laterals single or double in the right valve, double in the left;
beak cavities deep and rounded; anterior scars small, deep;
nacre whitish.

1196 TETRAPLODON

Length 60, height 42, diam. 42 mm.

Length 48, height 40, diam. 38 mm.

Amazon and Rio de la Plata River systems.

? Prisodon truncatus SCHUMACKER, Ess. Nouv. Syst., 1817,
Pp. 139.

? Castalia ambigua Lamarck, An. sans Vert., VI, 1819, p. 67.
—GUERIN, Icon. Regne. An., 1829, pl. xxvi11.—WYyaAtTt,
Man. Conch., 1838, p. 65, pl. x1, fig. 5 —-CHENUu, Man., 1859,
TEP: 407 tig735-

Unio ambigua DrsHayes, Tr. Elem. Conch., 1839, p. 18, pl.
XXIX, figs. 7-9.

Unio ambiguus SowrErsby, Rec. and Fos. Shells, XVI, 1823,
fig. d —REEVE, Conch. Syst., 1841, p. 117, pl. Lxxvu, fig. 2—
DrsuayEs, Tr. Elem., II, 1853, p. 210, pl. xxrx, figs. 7-9.

Tetraplodon ambiguus Simpson, Syn., 1900, p. 863.—von
InERING, Abhandl. Senckenb. Naturf. Ges., 32, 1910, p. 125,
pl. 12, figs. 4a-d.

Tetraplodon pectinatum Spx, Test. Fluv. Bras., 1827, p. 32, pl.
KV oy

Castalia inflata d’OrxicNy, Guer. Mag., 1835, p. 43.—HANLEY,
Biv. Shells, 1843, p. 173, pl. xx1v, fig. 12—d’Orsreny, Voy.
Am. Mer. 1843, p. 508, pl. 1x xtt, figs. 4-10.

Castalia turgida Hurr, Moll. Nouv., III, 1857, p. 76, pl. xt1v,
fig. 1—Sowergy, Conch. Icon., XVII, 1869, pl. ru, fig. 11.

Castalia hanleyana Sowrersy, Conch. Icon., XVII, 1860, pl. 1,
fig. 5.

Castalia carolinensis SoweRBY, Conch. Icon., XVII, 1860, pl. 11,
fig. 6.

Castalia cordata StropeL, Mat. Mal., Pt. I, 1874, p. 75.

An exceedingly variable form, some specimens being quite
elongated and straight on the base line; others are much
slighter, are rounded below, and almost rhomboid.

Schumacher gave only a brief description of his Prisodon
truncatus, and referred to no figure, and the same can be said
of Lamarck regarding his Castalia ambigua, both of which are
supposed by authors to be the above species. But either of
these descriptions apply equally well to several species, there-
fore they can not be considered authentic.

TETRAPLODON 1197

TETRAPLODON PECTINATUS Spix.

Shell subtriangular, inflated, subsolid, inequilateral, with
moderately full, high beaks; anterior end narrowed and
rounded; base lightly curved; dorsal slope arched; posterior
ridge elevated, rounded, ending in a point above the base; sur-
face with low, radiating ridges, which become rather feeble
below, the dorsal slope, ridged only near the beaks. Epidermis
fuscous or brownish; teeth rather delicate, elegantly vertically
striate; beak cavities deep; anterior scars impressed; nacre
silvery, thinner behind.

Length 43, height 27, diam. 22 mm.

Type locality, Rio Sao Francisco, Brazil.

Tetraplodon pectinatum Spix, Test. Fluv. Bras., 1827, p. 32,

pliecxvs fie. 4:

Tetraplodon ambiguus, (part), Simpson, Syn., 1900, p. 863.

Spix gives two figures, 3 and 4. I believe that fig. 3 is
T. ambiguus. Fig. 4 shows only the interior of two valves,
but they agree exactly with an old broken shell in my collection.
It is probably a valid species. There are other forms between
it and ambiguus.

TETRAPLODON JURUANUS von lhering.

“The form of the only specimen is similar to that of 7.
pectinatus, but the anterior end is smaller and the dorsal
margin slopes quite sharply to the hinder end; a double pos-
terior ridge separates the side of the shell from the smooth
posterior slope, which is not the case in pectinatus. The epi-
dermis is blackish, whereas it is brown in pectinatus. The scar
of the anterior adductors lies in front of the cardinal tooth and
in front of it the anterior part of the shell protrudes as far as
the adductor is wide, whereas this part of the shell in pectinatus
is only half the width of the adductor. The lateral teeth are
short, whereas in pectinatus they are very long. In my speci-
men the laterals of the left valve are 13 mm. long and the
distance of the anterior edge of the cardinal tooth from the
beginning of the lateral teeth measures the same.

1198 TETRAPLODON

It is clear, therefore, that we are dealing with two related
species, which, however, differ in the characters of the hinge,
the position of the beaks, ete.

The free border of the lunula on the Jurua specimen is
slightly convex, which is similar in T. ambiguus.

Length 46, height 30, diam. 21 mm. The beaks are situated
at 37-100 of the length.” (von Ihering).

Type locality, Rio Jurua, Brazil.

Tetraplodon ambiguus von Tarrinc, Rev. Mus. Paul., VI,

1904, p. 460.

Tetraplodon juruanus voN HERING, Abhandl. Senckenb.

Naturf.Ges:, 32. I910; p. 126;

TETRAPLODON BARO von Ihering.

“This rather thick-shelled species with high, inflated beaks,
straight basal margin and long oval form has absolutely no
near relationship to the genuine Castalia ambigua of Lamarck.
The beaks are placed far forward, situated at 16-100 of the
length. I have it from the Amazon.” (von Ihering).

Unio ambiguus Kuster, Conch. Cab., 1851, p. 165, pl. xLvuit,

Hier.

Castalia ambigua SowERpy, Conch. Icon., XVII, 1869, pl. 1,
fig. 1a-c.

Tetraplodon ambiguus, (part), Stuwpson, Syn., 1900, p. 863.

Tetraplodon baro von IHERING, Abhandl. Senckenb. Naturf.
GES 2271 OTC prey:

TETRAPLODON QUADRILATERUS (d’Orbigny).

Shell rather large, triangular rhomboid, subsolid, inflated,
inequilateral; beaks high and full, with very strong, wide,
radial ribs, which extend almost to the base; posterior ridge
very high, sharply angled, ending in a blunt point near the
base of the shell; anterior end narrow and rounded; base
lightly curved; posterior end sharply and obliquely truncate,
raised to an angle behind the short ligament; dorsal slope
radially sculptured near the beaks; epidermis brownish, thick,
dull, showing growth lines; pseudocardinals subcompressed,
split, vertically striate; laterals single in the right valve, double

TETRAPLODON T1199

in the left, obliquely or feebly. vertically striate; beak cavities

deep, rounded; anterior scars impressed; nacre bluish-white.

Length 77, height 55, diam. 41 mm.

Length 68, height 50, diam. 40 mm.

Tropical South America east of the Andes.

Castalia quadrilatera d’OrpicNy, Guer. Mag., 1835, p. 42; Voy.
Am. Mer., 1843, p. 509, pl. LX XIII.

Tetraplodon quadrilaterum StMPson, Syn., 1900, p. 864.

Mya ambigua Woop, Ind. Test. Rev., 1856, p. 200, pl. 1
(supp.), fig. 9.

Castalia acuticosta Hurr, Moll. Nouv., III, 1857, p. 77, pl. xiv,
fig. 3.—SoweErsy, Conch. Icon., XVII, 1869, pl. 111, figs. 12,
12a, 12b.

Castalia latiquadrata Sowersy, Conch. Icon., XVII, 1869, pl.
i, fig. 10.

Close to ambiguus, but larger, thinner, less inflated, with
stronger, wider ribs, which are more developed on the posterior
slope than in that species. The hinge is more delicate, the later-
als less vertically striate

TETRAPLODON CorDATUS (H. and A. Adams).

Shell but slightly inflated, triangular rhomboid, inequilateral ;
beaks full, high, widely rounded, having numerous, rounded,
radial ridges separated by grooves about their own breadth,
the central ridges coalesce below and all end on a line about
midway over the disk; posterior ridge high, slightly double
below, sharp above, ending in a blunt point at the base of the
shell: dorsal line straight, short, meeting the oblique posterior
truncation at a decided angle; base line nearly straight ; surface
with decided, concentric sculpture; epidermis olive; nacre
bluish.

Length 87, height 65 mm.

British Guiana.

Castalia cordata H. and A. Apams, Gen. Rec. Moll., II, 1857,
p. 50g, III, pl. cxx, figs. 2, 2a—Sowersy, Conch. Icon.,
MVE T8609, pla, fe: 8:

Tetraplodon quadrilaterum, (part), SIMPSON, Syn., 1900, Pp.
864.

I 200 TETRAPLODON

H. and A. Adams figure a young shell and credit the species
to Humphry, but do not describe it.

The description by Sowerby of this form is inadequate and
the figure shows a shell much resembling 7. quadrilaterus. It
may, however, be distinct. It seems to be more strongly, con-
centrically sculptured and to have shorter, narrower, more nu-
merous umbonal ridges, which end higher up on the shell, and
the inner ones coalesce below, while in quadrilaterus they do
not.

TETRAPLODON OVATUS (Sowerby ).

Shell subquadrately triangular, solid, inequilateral; beaks
full and high, rather sharp, having a few, strong, widely
spaced radial ribs, which extend about half way over the disk
and suddenly end at one of the growth lines; anterior end cut
away above, rounded below; base line curved; outline of dorsal
slope oblique, elevated to a decided angle in the middle; pos-
terior ridge full, sharp above, ending in a blunt, point near the
base of the shell, the outline above this point being slightly
incurved; epidermis pale olive with concentric, darker bands.

Length 66, height 52 mm.

Brazil.

Castalia ovata SowERBy, Conch. Icon., XVII, 1869, pl. 1, fig. 4.
Tetraplodon ovatus SIMPSON, Syn., 1900, p. 864.

Sowerby never gave any measurements or descriptions of
the interior of his Naiades and for that reason I am unable to
fully compare this with quadrilaterus, to which it seems closely
allied. The radial bars are wider and more widely spaced than
in quadrilaterus, they end suddenly and evenly near the middle
of the disk, the color is lighter and is banded.

TETRAPLODON RETUSUS (Hupé).

Shell almost regularly triangular, inflated, solid, somewhat
inequilateral, with a short ligament; beaks very high, full,
sculptured with a few, wide, radial ridges separated by nar-
rower grooves; the ridges do not extend half way over the
disk; the rest of the shell is rudely and irregularly concentric-
ally sculptured; posterior ridge high, narrowly rounded, ending

TETRAPLODON I20I

in a blunt point near the base of the shell; above the posterior
ridge on the decidedly truncate posterior slope there is a
broad, radial furrow, which ends in a slight sinus; dorsal slope
subangular behind the ligament; pseudocardinals solid, sub-
compressed, rough but not split; laterals somewhat vertically
striate; beak cavities deep, round; anterior scars deep; nacre
white, iridescent behind.

Length 65, height 49, diam. 41 mm.

Guiana; Amazon ?

Castalia ambigua Sowerpy, Conch. Man., 1830, fig. 140.
Castalia retusa Hurt, Mol. Nouv., III, 1857, p. 75, pl. xiv, fig.

2.—SowErsBy, Conch. Icon., X VII, 1869, pl. 1, fig. 2.
Tetraplodon retusus SIMPSON, Syn., 1900, p. 864.

Close to 7. ambiguus and it may be only a variety of that.
It differs in having only a few, wide radial ridges on the
umbones, which extend but a short distance over the disk, in
being strongly and irregularly concentrically sculptured, and
in having more compact, less split-up pseudocardinals.

TETRAPLODON QUADRATUS (Sowerby).

Shell solid, subquadrate or subrhomboid, inequilateral ; beaks
very full and high, turned forward, with a few strong radial
ribs, which extend about one-third of the distance from the
beaks to the base, the rest of the shell nearly smooth; posterior
ridge much elevated, decidedly rounded, apparently bordered
by sulci at each side, ending in a point at the base of the shell;
epidermis straw-colored: teeth strong; anterior scars deep,
small; nacre apparently pinkish.

Length 26, height 22 mm.

Guiana.

Castalia quadrata SowERBy, Conch. Icon., XVII, 1867, pl. 1,

NSS. 7eas De
Tetraplodon quadratus Stmpson, Syn., 1900, p. 864.

This may be only the young of a form, which becomes much
larger when mature, but the shell is described as solid. Its
smooth, straw-colored surface and the rounded cord-like pos-
terior ridge should distinguish it from any others.

1202 TETRAPLODON

TEPRAPLODON SCHOMBERGIANUS (Sowerby).

Shell biangular subquadrate, thin, concentrically wrinkled,
somewhat inequilateral; beaks moderately high and rounded;
posterior ridge elevated and rounded, ending in a blunt point
a little above the base of the shell; post-dorsal slope elevated
into a low wing, which is rounded behind the ligament and
obliquely truncate behind ; umbonal region having rather feeble,
wavy, radial sculpture, which does not extend far over the
disk ; epidermis copper-colored ; teeth thin, lamellar.

Length 50, height 40 mm.

Guiana.

Castalia schombergiana Sowerby, Conch. Icon., xvir, 1869,

pl. i, fig. 3:

Tetraplodon schombergianus Simpson, Syn., 1900, p. 864.

A thin species with lamellar teeth, feeble umbonal sculpture

and coppery epidermis.

Group of Tetraplodon multisulcatus.

Shell small, somewhat compressed, with a moderate posterior
ridge, and covered throughout with delicate ridges ; teeth more
unionoid than in the typical ‘l’etraplodons.

Animal unknown.

TETRAPLODON MULTISULCATUS (Hupé).

Shell subtriangular, somewhat compressed, inequilateral ;
beaks only moderately full, sculptured with numerous delicate,
radiating, more or less zigzag ridges, which extend over the
whole shell; posterior ridge not greatly elevated, subangular
above, ending in a blunt point near the base of the shell; an-
terior end narrowed, cut away above and below, narrowly
rounded; dorsal slope elevated into a low wing, which is
obliquely trunate behind the ligament; epidermis fuscous,
greenish-tinted ; teeth vertically striate; nacre whitish, pearly.

Length 42, height 30, diam. 23 mm.

Brazil.

TETRAPLODON 1203

Castalia multisulcata Hupt, Moll. Nouv., III, 1857, p. 75, pl.
X1v; fig: 4.
Tetraplodon multisulcatus SIMPSON, Syn., 1900, p. 865.
Castalia multicostata SowERBy, Conch. Icon., XVII, 1869, pl.
I, figs. 9, ga, 9b.
Castalia ambigua BLAINVILLE, Man., 1825, p. 539, pl. LXvn,
fig. 4.
For a Tetraplodon this shell is but little inflated. It is cov-
ered throughout with somewhat delicate subzigzag, radiating
ribs.

TETRAPLODON ECARINATUS (Mousson).

Shell subtriangular, not very solid nor greatly inflated,
scarcely inequilateral; beaks only moderately high, sculptured
with numerous radiating ridges, which cover the entire shell ;
these are crossed by concentric threads over the whole surface ;
anterior end narrowed and rounded; base line rounded; dorsal
slope obliquely truncate, angled a little behind the ligament ;
epidermis fuscous;. posterior ridge rather low, subangulate
above; teeth compressed, serrate; beak cavities deep; nacre
pearly, iridescent.

Length, 47, height 35, diam. 25 mm.

Puerto Nuevo, Magdalena River, Colombia.

Castalia ecarinata Mousson, Mal. Bl, XVI, 1869, p. 185.—

PrerrFer, Nov. Conch., IV, 1876, p. 140, pl. cxxx1, figs. 9, 10.
Tetraplodon ecarinatus SIMPSON, Syn., 1900, p. 865.

The beaks in this species are placed only a little in front of
the center; the whole surface is strongly sculptured with from
22 to 24 radial ribs, which are crossed by strong growth lines.

TETRAPLODON CROSSEANUS (Hidalgo).

Shell subrhomboid, subsolid, compressed, inequilateral, sculp-
tured with numerous, curved, radial coste, the anterior end
granular, the posterior end nearly smooth; beaks rather low ;
anterior end widely rounded, cut away a very little below; base
line nearly straight; post-dorsal outline strongly curved from
the beaks to the rather sharp basal point at the termination of

1204 CASTALINA

the rounded posterior ridge; epidermis bronze-color; teeth
subcompressed ; nacre light wine-color.

Length 25, height 20, diam. 11 mm.

Imbabura, Ecuador.

Castalia crosseana Htwatco, Jl. de Conch., XIII, 1865, pp. 316

and 420, pl. xiv, fig. 2.

Tetraplodon crosseanus SIMPSON, Syn., 1900, p. 865.

This species is more nearly rhomboid in form than any of the
Tetraplodons. The figure, which is not very finely finished,
represents the epidermis as a sort of olive-color, raved with
burnt brown.

Genus CASTALINA von Ihering, 1891.

Castalina von IHERING, Zool. Anzeiger, 1891, p. 478.

Shell somewhat triangular, inflated, but having the sides a
little flattened, solid, with a strong posterior ridge, the sub-
truncate posterior slope rising almost to a wing above; beaks
full, high, with nearly strictly radial sculpture ; surface slightly,
irregularly, concentrically sulcate, sometimes a little corrugated ;
posterior slope generally plicate or corrugated ; epidermis thick,
rayless, blackish; hinge plate arched, wide; two to several
radial pseudocardinals in each valve; two vertically or oblique-
ly striate laterals in the left valve and one in the right; beak
cavities deep; anterior muscle scars deep, united; nacre whit-
ish.

Animal, probably very much like that of Tetraplodon, but
with the mantle closed or open at the branchial and anal
openings.

Type, Castalina martensi von Ihering.

The species, which are placed in this group, are evidently
closely allied to the genus Tetraplodon, but have, on the whole,
more unionoid characters. The shells are generally more com-
pressed, the radial sculpture is more feeble, the teeth are not
so strongly vertically striate. In Castalina the pseudocardinals
are radial, while in Tetraplodon they are not. In the latter
group the mantle is closed behind into siphons while in Casta-
lina it may be open or closed.

CASTALINA 1205

KEY TO SPECIES OF CASTALINA.

Shell with strong posterior folds. C. undosa.
Smooth or but feebly plicate behind.
Almost strictly rhomboidal., C. orbignyt.
Subrhomboid or subtriangular.
With strong, elongated umbonal ridges, C. psammoica.
Umbonal ridges short.
Post-dorsal groove well developed. C. martensi.
Post-dorsal groove scarcely developed. C. nehringi.

Group of Castalina martensi.
Characters as in the genus.

CASTALINA MARTENSI von Ihering.

Shell irregularly rhomboid, slightly inflated, having the disks
a little flattened, solid, inequilateral; beaks moderately full and
elevated, their sculpture consisting of a few wide, rather feeble,
radial ridges, separated by narrow grooves, these ridges do not
extend over the disk; posterior ridges well developed, narrowly
rounded; above it is a deep, wide, radial groove, which usuaily
ends in a slight sinus on the border of the dorsal slope ; anterior
end somewhat narrowed, rounded; base line curved; dorsal
slope obliquely truncate, there being a rounded point at the
hinder end of the posterior ridge; surface irregularly, concen-
trically sculptured, there sometimes being a few, faint wrinkles
on the dorsal slope; epidermis thick, brown, rather dull;
pseudocardinals radial, split up into three or four divisions in
each valve, but slightly roughened; laterals double in the left
valve, single in the right, slightly vertically or sometimes ob-
liquely striate; nacre dirty whitish or brownish-purple, thick-
ened in front; beak cavities deep; anterior scars HPL eset

Length 73, feeht 53, diam. 32-mm.

Southern Brazil.
Castalina martensi VON IWERING, Zool. Anz., XIV, 1801, p

7; Arch. ftir Nat., 1893, p. 81, pl. 1, fig. 5.—Si1mpson,

Syn., 1900, p. 865.

The shell is rather more elongated and rhomboid than either
of the allied forms.

1206 CASTALINA

CASTALINA NEHRINGI von Jhering.

Shell short, subrhomboid, somewhat inflated, solid, slightly
inequilateral; beaks full and high with very feeble, radial
sculpture, which does not extend far over the umbonal region ;
posterior ridge high and angled above, the shell having its
greatest diameter at the ridge, ending in a rounded point behind
at the shell’s base; dorsal line short, nearly straight, meeting
the obliquely truncate dorsal slope at an angle; base nearly
straight; surface irregularly, concentrically sculptured, with
a few wrinkles on the dorsal slope; epidermis dark brown,
thick: pseudocardinals radial, nearly smooth; laterals short,
obliquely striate; beak cavities deep; nacre dirty white, thick
in front.

Irength 57, height 47, diam. 28 mm.

Southern Brazil.

Castalina nehringi voN HERING, Zool. Anz., XIV, r8g1, p.
477; Arch. fur Nat., 1893, p. 75, pl. 10, fig. 4—SrimPpson,
Syn., 1900, p. 865.

A shorter shell than C. martenst,; it has higher beaks, a more
elevated, sharp posterior ridge, straighter base, and smaller,
smoother teeth than that species. The radial furrow behind
the posterior ridge is scarcely developed.

CASTALINA PSAMMOICA (d’Orbigny).

Shell rhomboid triangular, subinflated, solid, inequilateral ;
beaks rather full and high, their sculpture consisting of wide,
low ridges separated by wide grooves and extending half way
over the disk; posterior ridge high, narrowly rounded, ending
in a blunt point at the base of the shell; dorsal line short,
lightly arched ; posterior end having a long, oblique truncation ;
base a little curved; anterior end cut away a little above,
rounded below; surface with strong, irregular growth lines
and feeble traces of radial sculpture; epidermis pale brownish
or greenish-brown ; pseudocardinals about three in each valve,
radial, comparatively smooth; laterals two in the left valve
and one in the right with faint, oblique, granular striation ; beak
cavities deep; nacre bluish-white, thickened in front.

Length 68, height 50, diam. 33 mm.

Tributaries of the Rio de la Plata.

CASTALINA 1207

Unio psammoica d’Orricny, Guer. Mag,. 1835, p. 35; Vay.
Am. Mer., 1843, p. 608, pl. Lxx1, figs. 4-7——Kusrer, Conch.
Cab. Unio, 1861, p. 263, pl. Lxxxvitl, fig. 4.

Castalina psammoica von [HErRtNG, Arch. fir Nat., 1893, p. 79.
—Simpson, Syn., 1900, p. 866.

Margaron (Unio) psammoicus Lea, Syn., 1852, p. 19; 1870,
Bp, 30:

Unio psammoicus SowERwy, Conch. Icon., XVI, 1868, pl. xc111,
fig. 507.

This species has been placed with Unio, but von Ihering
correctly referred it to his new genus Castalina. It is more
triangular than C. martensi, has stronger and more extended
beak sculpture, the surface is subdecussated, and the teeth are
not so strong, nor are they vertically striated.

CASTALINA UNDOSA (von Martens).

Shell subtriangular, solid, slightly inflated, inequilateral;
beaks high and full, their sculpture feebly radial; posterior
ridge prominent, angled, often curved upward in the middle,
placed near the post-dorsal border, ending behind in a rounded
point near the shell’s base; base line lightly curved; surface
rudely and irregularly, concentrically sculptured, the abrupt,
subtruncate dorsal slope covered with strong plications ; epider-
mis thick, blackish; pseudocardinals more or less split up,
radial, and, with the laterals, vertically striate; beak cavities
deep; nacre bluish-white, not greatly thickened in front.

Length 63, height 53, diam 30 mm.

Southern Brazil.

Castalia undosa Von Marrens, S. B. Nat. Fr., 1885, p. 148;

Conch. Mitth., III, 1885, p. 19, pl. xLu, figs. 2, 3.

Castalina undosa Simpson, Syn., 1900, p. 866.

This may be at once separated from the other allied species
by its strong folds running nearly across the dorsal slope. The
upper anterior region of the shell is sometimes corrugated.

Group of Castalina crbignyt.

Shell irregularly rhomboid, somewhat compressed, equilater-
al, anterior end rounded, posterior truncate, having a wide,
shallow, radiating furrow above the rounded posterior ridge,

1208 CASTATI ELLA

which causes a sinuosity in the outline; epidermis brownish-
yellow ; hinge crenate; one pseudocardinal in the left valve and
two in the right, which are jagged or somewhat broken up;
laterals elongate and striate.

CASTALINA ORBIGNYI (Hupé and Deville).

Shell subrhomboid, almost or quite equilateral, ponderous,
but little inflated; beaks high and rounded, apparently without
sculpture; posterior ridge well developed, narrowly rounded,
terminating in a blunt point at the base of the shell; above it
there is a wide, radial furrow that ends in a slight sinus below;
hinge line arched, straight and sloping in front of and behind
the beaks; posterior end obliquely truncate; base almost
straight; anterior end cut away below, narrowly rounded
above; pseudocardinals ragged, laterals short; nacre whitish,
thickened in front.

Length 97, height 77, diam. 50 mm.

Upper Amazon.

Unio orbignyi Huré and Deviiir, Rev. et Mag., 1850, p. 645,

ploxvi, tig 1:

Margaron (Unio) orbignyi Lea, Syn., 1852, p. 24; 1870, p. 37.
Castalina orbignyi SIMPSON, Syn., 1900, p. 866.
Unto orbignyana Hurt, Moll. Nouv., IIT, 1857, p. 83, pl. xvi,

fig. I.

Unio dorbignyanus SowERBy, Conch. Icon., XVI, 1868, pl.

XCVI ie: 523:

Unio orbignyanus PasrE,, Conch. Sam., III, 1890, p. 162.

A large species, which is more nearly rhomboid in outline
than any of the others. The surface appears to be strongly
and irregularly, concentrically striate; the beaks are, according
to the authors, without sculpture, but the specimen figured is
slightly eroded in this region. The epidermis is light brown.

Genus CASTALIELLA Simpson, 1900.

Castaliclla SIMPSON, Syn., 1900, p. 866.

Shell subtriangular, greatly inflated, subsolid, and strongly
sulcate; beaks high, the sculpture regularly radiate; posterior
ridge well defined and sharp; hinge line narrow, arched; there

CASTALIELLA 1209

are two vertically striate pseudocardinals in the right valve,
the lower the larger and split, separated by a parallel-sided
socket, and three in the left standing side by side, the middle
one the largest, the lower two torn, with a few small tubercles
in each valve behind them; one lateral in the right valve and
two in the left, granular, and showing traces of vertical stria-
tion; beak cavities deep, not compressed ; nacre purple.

Animal unknown.

Type, Castalia sulcata Krauss.

CASTALIEFLLA SULCATA (Krauss).

Shell subtrapezoid or suborbicular, inflated, subsolid, inequi-
lateral; beaks full and rather high, sculptured with a few radial
bars, of which the anterior are short and faint, while those at
the posterior ridge extend well out on the disk; posterior ridge
well developed, subangular, ending in a blunt point above the
base of the shell; hinge line arched, much elevated behind the
beaks; dorsal slope obliquely subtruncate; anterior end and
base rounded; surface covered with strong, even, concentric
ridges, which become a little blurred in front of the posterior
ridge; on the posterior slope there are in addition a few
wrinkles; epidermis reddish-brown, shining; nacre a little
thicker in front.

Length 50, height 45, diam. 31 mm.

Surinam.

Castalia sulcata Krauss, Zeits. fiir Mal., 1849, p. 99.
Castaliella sulcata SIMPSON, Syn., 1900, p. 867.

Unio kraussiti Lua, Pr. Ac. N. Sci. Phila., VI, 1853, p. 376.
Margaron (Unio) kraussti Lea, Syn., 1870, p. 35.

A peculiar species, apparently most closely related to Cas-
talina and possibly to be referred to that as a subgenus. The
decided regular, concentric sculpture and purplish nacre are
characters which I have not seen in any related group. In the
shells of Castalina the disks are somewhat flattened; in this
species they are convex.

Lea received this shell from Dr. Dunker under the name of
Castalia sulcata Krauss. Believing it to be a Unio, he placed
it in that genus, and the name sulcatus being preoccupied in
Unio, he changed it as above.

I21IO CALLONAIA

Genus CALLONAIA Simpson, 1900.

Callonaia SIMPSON, Syn., 1900, p. 867.

Shell triangular, thin, inflated, with very high, full beaks
which appear to be without sculpture; a very high, sharp pos-
terior ridge extends to the base of the shell, above which it is
decidedly truncated; anterior end somewhat pointed above,
rounded below; ligament very short; surface nearly smooth,
but somewhat sulcate anteriorly; epidermis bright, greenish-
yellow, shining; hinge line strongly arched; teeth compressed,
high; two pseudocardinals in each valve, all interlocking and
side by side; one lateral in the right valve and two in the left,
a little ragged and granularly, vertically striate; beak cavities
very deep, not compressed; muscle scars superficial; nacre
brilliant, bluish-white, radiately striate posteriorly.

Animal unknown.

Type, Castalia dupret Recluz.

CALLONAIA DUPREI (Recluz).

Shell subtriangular, inflated, rather thin, slightly inequilater-
al; beaks very high and full; ligaments short and broad; hinge
line much arched; upper anterior outline from the beaks for-
ward obliquely truncate, below this it is narrowly rounded and
the anterior base is slightly cut away; base line nearly straight ;
posterior basal point sharp; surface with delicate growth lines,
which are stronger anteriorly ; epidermis pale yellowish-green,
shining, darker and dull-colored on the posterior slope; nacre
slightly thickened in front.

Length 70, height 56, diam. 42 mm.

Length 68, height 53, diam. 35 mm.

Great lakes of Para, Brazil.

Castalia duprei REcLUz, Rev. Zool. 1843, p. 305, pl. xxxv.—

CuHENU, Man., 1850, II, p. 149, fig. 738.

Unio duprei Cattow and RErEvE, Conch. Nom., 1845, p. 58.
Margaron (Prisodon) duprei Lea, Syn., 1852, p. 18; 1870,

Deze
Callonaia duprei Stimpson, Syn., 1900, p. 867.

Castalia dolabella SowrrBy, Conch. Icon., XVII, 1869, pl. 111,
figs. 13a, 13D, 13¢.

HYRIA E20

A remarkable and beautiful Naiad, which is apparently
related to Tetraplodon and Castalina, but cannot be referred
to either. The posterior truncation is more abrupt and the
posterior ridges are more sharp and elevated than in any
Unione that I am acquainted with. When the shell is held so
that the eye falls direct on the anterior dorsal portion the out-
line presented is that of a blunt wedge.

Genus HYRIA Lamarck, 18109.

Hyria LAMARCK, An. sans. Vert., VI, 1819, p. 81.
Triplodon Spix, Test. Fluv. Bras., 1827, p. 35.
Naia Swainson, Tr. on Mal., 1840, p. 379.

Shell subrhomboidal, solid, slightly inflated, narrower and
dorsally winged in front, and having a post-dorsal wing; pos-
terior ridge often double, causing the shell to be biangulate
behind; beaks low, with strong, nearly radial sculpture, the
central bars coalescing below, the whole continuing as strong,
radial and zigzag ridges over more or less of the disk; epider-
mis thick, greenish when young, brownish or blackish when
old; there are two or more rather short, compressed pseudo-
cardinals in each valve, which are much split up into denticles ;
one lateral in the right and two in the left valve; teeth often
somewhat vertically striated; dorsal scars numerous; nacre
whitish.

Animal with mantle lobes united together behind and fur-
nished with two short, contractile siphons. (J. E. Gray.)

Type, Hyria corrugata Lamarck.

In 1753 Klein (Testamen ‘Méthodi, p. 135, pl. 9, fig. 36)
used the name Tyiquetra for the shell, which has since been
known as Hyria syrmatophora Gronovius. In 1817 Schu-
macher founded the genus Prisodon (Essai Nouv. Systéme,
p- 138), in which under section @ he placed his P. obliquus,
a smooth species considerably drawn out, and in section b he
put P. truncatus, which is probably the same as the Castalia
ambigua of Lamarck. These certainly belong to two genera.
Dr. Lea in the Synopsis used Klein’s name for the winged shell
(Hyria corrugata Lamarck), and used the name Prisodon for

R22 HYRIA

Schumacher’s section b, (P. truncatus Schum). Wea erred in
this, because Klein was not a binomial author, and his name
can not be used. In the Proceedings of the U. S. National
Museum, XVIII, 1896, p. 315, I restored the name of Prisodon
Schumacher to the first section, pointing out that the P. obli-
quus Schumacher must stand as its type. Two years after
Schumacher’s name appeared Lamarck published the generic
name Hyria in the Animaux sans Vertébres, VI, 1819, p. 81,
and placed in it first his H. avicularis, which equals Schu-
macher’s P. obliquus, and secondly H. corrugata. I now be-
lieve that these corrugated forms are generically distinct from
the smooth ones, and as Schumacher’s Paxyodon is almost
certainly founded on one of the smooth species, Lamarck’s
name //yria can be used by elimination for the corrugatus and
allied forms.

KY TO SPECIES OF Hyrta.

Shell with radial pseudocardinals, H. stevenst.
Pseudocardinals more or less longitudinal.
Entire surface subradially sculptured, H. rugosissima.

Later growth usually not radially sculptured.
Triangular, earlier growth radially sculptured; later
growth concentrically sculptured. FH. latialata.
Rhomboid, only a few strong umbonal ridges.
HH. transversa.
Subrhomboid, surface more or less radially sculptured.
FT. corrugata.
Subgenus Hyrta s. s.

Characters as in the genus.
Type, Hyria corrugata Lamarck.

Hyria cCorRUGATA Lamarck.

Shell subtrapezoid, convex or slightly inflated, varying from
almost thin to solid, in'equilateral; beaks low, subcompressed,
sculptured with strong, subradial ribs, which usually converge
in front of the posterior ridge and are often divaricate along
it; this sculpture often extends more or less over the disk
and occasionally becomes zigzag or subnodulous; posterior

ELYRIA 1213

ridge well developed, often subangular above and semi-double

below, where it ends in a feeble biangulation; dorsal outline

arched, extending into a decided wing in front and behind;
anterior end narrowed, cut away below, posterior end usually
obliquely truncate, often incurved; epidermis greenish-brown ;
pseudocardinals compressed, much split up; laterals long and
straight in young shells, short and curved in old ones, all the
teeth more or less vertically striate; nacre usually lurid, some-
times silvery, thicker in front in old shells.

Length 107, height 63, diam. 27 mm.

Length 94, height 60, diam. 34 mm.

Eastern Peru to Guiana; south throughout Brazil.

Hyria corrugata LAMARCK, An. sans Vert., VI, 1819, p. 82.—
SOWERBY, Rec. and Foss. Shells, 1823, No. XVI, fig. d;
Conch. Man., 1839, fig. 144.—REEVE, Conch. Syst., I, 1841,
p. 120, pl. xc, fig. 2—KusteEr, Conch. Cab. Unio, 1856, p.
140, pl. x1, fig. 1—CHENU, Man., 1859, II, p. 149, fig. 733.
—REEvE, Elem. Conch., II, 1860, pl. xxx1, fig. 179. -SOWER-
BY, Conch. Icon., XVII, 1869, pl. 1, fig. 1—S1mpson, Syn.,
1900, p. 868.

? Umo corrugata BLAINVILLE, Man., 1825, p. 539, pl. Lxvu,
fies ie

Margaron (Triquetra) corrugata Lea, Syn., 1852, p. 17; 1870,
Dp: 25.

Triquetra corrugata H. and A. Apams, Gen. Rec. Moll., II,
1857, p. 508.

? Triplodon rugosum SPrrx, Test. Fluv. Bras., 1827, p. 35, pl.
KEIN, MISS ee Ly 2

Hyria rugosa DrsuayeEs, Enc. Meth., II, 1827, p. 151, pl.
Cexnvin, figs 2:

Mya angulata Woop, Ind. Test. Sup., 1828, p. 3, pl. 1, fig. 12.

Margarita (Unio) angulatus Lea, Syn., 1836, p. 10; 1838,
Pats:

Hyria exasperata SowrERsy, Conch. Icon., XVII, 1860, pl. 1,
iregaere
This seems to be an abundant species and subject to great

variation, and for that reason it has received many names.

1214 HYRIA

Some shells are strongly sculptured throughout, while others
are partially so or nearly smooth. Some apparently full grown
specimens are thin and but little inflated; others are solid and
full.

HyrIA RUGOSISSIMA Sowerby.

Shell subrhomboid, convex, rather solid, inequilateral, with
a nearly straight dorsal line, which is winged before and be-
hind; beaks low, compressed sculptured with very strong,
subradial ridges, which curve toward each other and unite
below; the sculpture is carried over the entire shell, being
divaricate on the moderately elevated, subangular posterior
ridge and often corrugated and subnodulous; anterior end with
a small wing above, rounded and slightly cut away below; base
line curved, fullest behind the middle; posterior end obliquely
truncate with a wing and often an incurved outline above;
epidermis greenish-brown ; pseudocardinals compressed, some-
what split; laterals curved, strong, remote, with the other teeth
somewhat vertically striate; nacre flesh-colored, not much
thickened in front.

Length 125, height 80, diam. 38 mm.

Length 107, height 85, diam. 35 mm.

Amazon River.

Hyria rugosissima SOwERBY, Conch. Icon., XVII, 1869, pl. 111,

fig. 5 SIMPSON, Syn., 1900, p. 869.

Very close to corrugata, but a larger, much more strongly
sculptured species. Several specimens of different ages are
before me, all of which are heavily sculptured throughout. It
is less inflated, as a rule, than corrugata, and the anterior end
is a little wider.

HyriA LATIALATA Sowerby.

Shell almost regularly triangular, compressed with a low
anterior dorsal wing and a very high triangular posterior one;
posterior ridge subangulate, ending at the base of the shell;
between this point and the hinder base of the wing the shell
is almost squarely, subtruncate ; beaks low, their sculpture con-
sisting of rather delicate, subradial ridges, the inner ones of

HIYRIA L205

which coalesce below; this sculpture is continued about half
way over the disk and beyond that it is suddenly replaced by
rather strong, concentric ridges; epidermis greenish-brown.

Length 118, height 97 mm.

Guiana.

Hyria latialata SowErsy, Conch. Icon., XVII, 1869, pl. u,

fig. 4—Simpson, Syn., 1900, p. 869.

Sowerby gives a fine figure of this species, but no dimensions
and does not describe the interior. It is remarkable for being
almost regularly triangular and for having rather fine, subradial
sculpture on the earlier growth, which suddenly changes to con-
centric sculpture.

HyrIA TRANSVERSA Hupeé.

Shell subrhomboid, solid, subinflated, somewhat inequilat-
eral; beaks rather full, having a few, very wide, subradial
ridges, which extend only a short distance over the disk; pos-
terior ridge double, ending in a wide biangulation below the
median line; anterior end somewhat narrowed, rounded, with
only a feeble wing above; post-dorsal wing only moderately
high, obliquely truncate behind ; surface rather smooth; epider-
mis brownish-black ; hinge strong ; teeth somewhat solid ; nacre
rose-tinted.

Length 100, height 60; diam. 35 mm.

Brazil.

Hymna transversa Hurt, Moll. Nouv., ITI, 1857, p. 79, pl. xv,
fig. I—SowERBy, Conch. Icon., XVII, 1869, pl. 1v, fig. 7—
SIMPSON, Syn., 1900, p. 860.

An elongated, subrhomboid form remarkable for its fine,
wide, short, subradial bars at and below the beaks.

Subgenus TRIQUETRANA Simpson, 1900.

Triquetrana SIMPSON, Syn., 1900, p. 860.

Shell compressed, with a feebly developed posterior wing;
thickened in front; each valve with about three, somewhat
divergent pseudocardinals, which are sometimes nearly smooth
and at others break into denticles; one granular lateral in the

1216 PRISODON

right valve and two in the left, which are sometimes obliquely

and faintly vertically striate; external sculpture much as in

Hyria.

Animal unknown.

Type, Unio stevensi Lea.

HyRIA STEVENSI (Lea).

Shell subtriangular, subcompressed, moderately solid, ine-
quilateral; beaks low, with numerous, subradial ridges, the
inner of which coalesce below, the sculpture being extended
over the entire shell and zigzagged in front; posterior ridge
double, ending in a wide, feeble biangulation below; dorsal
and basal outlines curved; anterior end rounded, narrowed,
very slightly winged above; posterior dorsal region elevated
into a low wing, which is obliquely subtruncated behind; epi-
dermis greenish-brown ; pseudocardinals radial, somewhat split
up, sometimes nearly smooth; laterals remote, delicate, with
faint vertical striz; nacre lurid purplish, thicker in front.

Length 62, height 44, diam. 21 mm.

Length 64, height 47, diam. 21 mm.

Yuruari River, Guiana.

Unio stevenst Lea, Pr. Ac. N. Sci. Phila., I, 1871, p. 188; Jl.
Ac. N. Sei. Phila., VII, 18745>p, 22; pl vi, fig..19;"Obs:,
ON 18745°p 326 pl: va hie 0;

Hyria stevensi SIMPSON, Syn., 1900, p. 8609.

This species is smaller than any of the others and differs
from them all in having regularly radial pseudocardinals.

It bears much the same relation to Hyria that Castalina does
to Tetraplodon, its teeth being more unionoid than those of the
other species.

Genus PRISODON Schumacher, 1817.

Triquetra KLx1n, Tent. Methodi Ost., 1753, p. 135.

Prisodon SCHUMACHER (part), Essai Nouv. Syst., 1817, p. 138.

Paxyodon SCHUMACHER, Essai Nouv. Syst., 1817, p. 1309.
Shell aviculiform, solid, somewhat inflated, with a well-

developed posterior ridge, the area above it being excavated,

PRISODON WD 7

its outline from the hinder basal point to the end of the post-
dorsal wing generally incurved; posterior slope often having
a radial row of plications, as in Cristaria; surface slightly con-
centrically sculptured and having delicate radiating lire
throughout, so that the surface is microscopically reticulated ;
beaks full, but not elevated, without sculpture as far as
noticed ; epidermis yellowish-green or brownish, shining, often
bronzy ; hinge narrow under the beaks, widening in front and
behind; left valve with two or more elongated, compressed
pseudocardinals, which show a tendency to break into denticles,
and two laterals; right valve with two or more similar pseudo-
cardinals and a single lateral; laterals vertically, granularly
striate.

Animal with the labial palpi triangular, the hinder parts free
as in Unio, not united posteriorly; branchiz large, equal in
size. (Troschel.)

Type, Mya syrmatophora Meuschen.

The apparent want of beak sculpture, the smooth, slightly
decussated, shining and often metallic surface, the post-dorsal
plications, which when present, are similar to those of Cris-
taria, are, I think, characters of sufficient importance to justify
the separation of these species generically from Hyria.

KEY TO SPECIES OF PRISODON.

Shell long, subrhomboid or subtrapezoid.

Small, scarcely winged. P. brownianus.
Large.
Moderately winged. P. obliquus.
Wings greatly produced horizontally. ERTectus:

Shell short, subtrapezoid, sides compressed. P. complanatus.
Shell subtriangular.

With a cord-like posterior ridge. P. syrmatophorus.
Posterior ridge low.
Wings small. P. castelnaudt.
Wings large, the hinder elevated, P. alatus.

Shell elliptical or obovate, compressed. P. orton.

1218 PRISODON

Subgenus PRISODON s. s.

Characters as in the genus.
Type, Mya syrmatophora Meuschen.

PRISODON SYRMATOPHORUS (Meuschen).

Shell subtriangular or subtrapezoid, more or less inflated,
solid, somewhat inequilateral; beaks full, more or less elevated,
apparently without sculpture; posterior ridge high, generally
narrowly rounded, often cord-like, occasionally semi-double
below, ending at the shell’s base in a point or a narrow biangu-
lation; dorsal line usually straight, ending in a wing before and
behind; anterior end narrowed, cut away and rounded below;
base straight or curved; posterior end obliquely or almost
squarely truncate, its outline often incurved; surface having
delicate strize of growth and fine, radiating lines and sometimes
a few folds below the ligament; epidermis shining, greenish,
greenish-yellow or brownish, often with metallic tints; teeth
elongated, rather solid but compressed; pseudocardinals two or
more in each valve; one lateral in the right valve and two in
the left, all of them sometimes slightly vertically striate ; muscle
scars not deep; nacre bluish, flesh-colored or purplish.

Length 102, height 70, diam. 35 mm.

Length 85, height 52, diam. 34 mm.

Guiana; Brazil.

Triquetra subvirdis Kien, Meth. Ost., 1753, p. 135, pl. 1x,
fie. 36.—H. and A. Apams, Gen. Rec. Moll., II, 1857, p. 505;
Ti, pics ess ka:

Margaron (Triquetra) subviridis Lea, Syn., 1852, p. 17; 1870,
p. 25.

Mya syrmatophora MruscHen in Gronovius, Zooph., 1781,
pl. xvi, fig’ 1, 2:—Woon, Ind, Tést.;, 1825, p: 12, spl. 1,
fig. 30D.

Hyria syrmatophora Sowrersy, Rec. and Foss. Shells, XVI,
1823, fig. d; Conch. Man., 1839, fig. 143.—RkEEvE, Conch.
Syst., I, 1841, p. 120, pl. xc, fig..1—Woop, Ind. Test. rev.,
1856, p. 17, pl. u, fig. 36.—Hupr, Moll. Nouv., III, 1857,
p. 79, pl. xv, fig. 2—Sowerpy, Conch. Icon., XVII, 1869,
pl. v, fig. 2. .

PRISODON 1219

Unio syrmatophora Dresuayes, Tr. Elem., II, 1853, p. 219, pl.

KkIKG figss10, £1:

Margarita (Unio) syrmatophorus LEA, Syn., 1836, p. 11; 1838,

Bk:

Prisodon syrinatophorus Simpson, Syn., 1900, p. 870.
? Paxyodon ponderosus SCHUMACHER, Ess. Nouv. Syst., 1817,

pe 140; pl ky Hg. 3.

Hyria avicularis var. b. LAMARCK, An. sans Vert., VI, 1819,

p. 82.

Quite variable in size, outline and degree of inflation as well
as color. In some specimens the posterior ridge is raised up
into a strong cord; in others it is merely angular. In old shells
the ligamental patch is large and distinct.

PRISODON COMPLANATUS (Hupé).

Shell subrhomboid or subtrapezoid, somewhat inequilateral,
subcompressed or subinflated, slightly thickened; beaks not
greatly elevated; posterior ridge widely rounded, ending in a
blunt, rounded point near the base; dorsal outline nearly
straight, arched up a little in the middle; winged in front and
behind; anterior end rounded, narrowed and cut away below;
base line curved; posterior end obliquely truncate, incurved ;
epidermis brownish-black ; pseudocardinals strongly, vertically
striate ; nacre bluish-white, iridescent.

Length 85, height 70, diam. 35 mm.

Guiana.

Hyria complanata Hurt, Moll. Nouv., IIT, 1857, p. 80, pl. xv,
fig. 3—Sowerrsy, Conch. Icon., XVII, 1869, pl. rv, fig. 9.
fAfyria syrmatophora Kuster, Conch. Cab. Unio, 1856, p. 141,

ple xnl, fie,
Prisodon complanatus Stmpson, Syn., 1900, p. 870.

This species seems to differ from the syrmatophorus in havy-
ing a much lower, widely rounded posterior ridge, which ends
below in a widely rounded point a little above the base of the
shell. The pseudocardinals are more strongly striate and it is
probably darker colored, as a rule, than syrmatophorus.

1220 PRISODON

PRISODON ALATUS (Sowerby).

Shell irregularly triangular, somewhat inflated, slightly ine-
quilateral; dorsal outline strongly incurved, carried out into a
narrow elongated wing in front and into a wide, much pro-
duced, upcurved wing behind; beaks low and not much swollen;
posterior ridge apparently angled, but slightly elevated, ending
in a widely rounded projection at some distance above the base;
base much rounded; anterior end narrowed, cut away and
rounded below, its outline sinuous; posterior end greatly in-
curved in the middle; surface nearly smooth, olive-brown.

Length from tip to tip of wings 115, from tip of front wing
to post-basal point 115, extreme height 85 mm.

Guiana.

FAyria alata SowrRpy, Conch. Icon., XVII, 1869, pl. v, fig. 13:
Prisodon alatus Simpson, Syn., 1900, p. 871.

A form, which seems to have had a most rampant develop-
ment. The wings are excessively produced, the outlines below
them are greatly incurved. The base line is rounded; the
lower posterior part of the shell is likewise rounded.

PRISODON CASTELNAUDI (Hupe).

Shell large, triangular, convex or subinflated, inequilateral,
quite solid; beaks rather full and high; posterior ridge rounded,
having a blunt, rounded termination near the base; base line
elongated, very slightly curved; anterior end greatly narrowed,
rather sharply winged; dorsal outline nearly straight, being
produced into a wing behind the beaks; dorsal slope obliquely
truncate, shorter than the dorsum; surface rather strongly,
concentrically wrinkled; epidermis yellowish-green; pseudo-
cardinals somewhat compressed, and, with the laterals, verti-
cally striate; nacre white, bluish or iridescent on the border.

Length 143, height 90, diam. 45 mm.

Brazil.

Hyria castelnaudi Hurr, Moll. Nouv., ITI, 1857, p. 81, pl. xvi,

fig. 1—SoweErpy, Conch. Icon., XVII, 1869, pl. rv, fig. 8.
Prisodon castelnaudi StMpson, Syn., 1900, p. 871.

This may be only a form of obliquus, but its outline is almost
triangular, the base forming the longest side, the dorsum, the

PRISODON 1227

next longest, and the dorsal slope the shortest. The blunt,
posterior point is at the base of the shell instead of being
elevated as in obliqguus. According to Hupe it must be more
ponderous than that species. |

PRISODON OBLIQUUS Schumacher.

Shell large, elongated, irregularly sutriangular, inequilateral,
solid; beaks full but not greatly elevated; dorsal outline
straight, slightly incurved or curved upwards in the middle,
ending in a sharp, narrow wing in front and a blunt oné behind ;
posterior ridge well developed, narrowly rounded, sometimes
semi-double below, ending in a point at some distance above
the base; surface rather strongly, concentrically sculptured,
with traces of radial sculpture; the young shells are sometimes
plicate on the upper part of the dorsal slope; epidermis pale
to dark tawny or brownish, often tinted green, shining ; pseudo-
cardinals compressed, elongated, split up and ragged; laterals
remote; muscle scars impressed; nacre flesh-colored.

Length 165, height 80, diam. 43 mm.

Amazon drainage; southward through Brazil.

Prisodon obliquus SCHUMACHER, Ess. Nouv. Syst., 1817, p.
139, pl. x1, fig. 2—Simpson, Syn., 1900, p. 871.

Hyria obliqua Parer, Conch. Sam., III, 1890, p. 189.

Hyria avicularis LAMARCK, An. sans Vert., VI, 1819, p. 82.—
Grouce, Wil IntaiLam S271: 6 aplo 1x, fossa; 50.—
Wyart, Man. Conch., 1838, p. 67, pl. v, fig. 4—DELESSERT,
Rec. Coq. Lam., 1841, pl. xu, fig. 9 —HANLEy, Biv. Shells,
1843, p. 214, pl. xxiv, fig. 11—TroscuEL, Arch. fur Nat.,
XIII, Pt. 1, 1847, p. 271, pl. v1; fig. 3—CuHENu, Man., 1859,
II, p. 149, fig. 734—SoweErsy, Conch. Icon., X VII, 1869, pl.
tt, figs. 6a, b.

Unio avicularis DEsHAYEs, Tr. El. Conch., 1839, p. 18, pl. Xx1x,
figs: IO; 14:

Hyria avicularia GUERIN, Icon. Reg. An., 1844, II, pl. xxvim,
fig. 8.

Unio caudatus WAGNER, Test. Fluv. Bras., 1827, p. 35, pl.
XXVIE figss 1, 2:

I222 PRISODON

Diplodon furcatum Sprrx, Test. Fluv., Bras., 1827, p. 35, pl

SVU, fies: aoe:

Hyria elongata Swainson, Ex. Conch., 1841, p. 29, pl. xxiv.
Triquetra elongata H. and A. Apams, Gen. Rec. Moll., II, 1857,

p. 508.

This species is considerably elongated ; the post-basal point
is elevated to some distance above the base line; the base is
somewhat rounded. In young shells the posterior wing is
often greatly produced and elevated and the outline of the
dorsal slope is much incurved, but in old specimens the wing is
low and worn away behind. :

PRISODON RECTUS (Sowerby).

Shell elongated, solid, strongly winged before and behind,
inequilateral ; beaks full and somewhat elevated; posterior ridge
semi-double, elevated, ending behind in a faint biangulation at
the base of the shell; dorsal outline curved upward; anterior
and posterior wings extended; outline of dorsal slope greatly
incurved above; outline of anterior end incurved under the
wing, rounded and cut away below; base line nearly straight;
surface irregularly, concentrically striate; epidermis chestnut-
colored.

Length 130, height 53 mm.

South America ; locality unknown.

FAlyria recta SowERBy, Conch. Icon., XVII, 1868, pl. v. fig. ro.
Prisodon rectus SIMPSON, Syn., 1900, p. 871.

An elongated, almost rhomboid form with considerably pro-
duced wings ; the dorsal and basal outlines being nearly straight
and parallel. The posterior ridge seems to be elevated above
the rest of the shell.

PRISODON BROWNIANUS (Lea).

Shell rather small, elongated, subrhomboid, inflated, sub-
solid to solid, inequilateral; beaks full and high; posterior
ridge strong, narrowly rounded, ending in a blunt point at
the base of the shell; dorsal line nearly straight, scarcely
winged before or behind; surface with strong, concentric
growth lines and traces of radial sculpture, greenish-brown,

PRISODON R223

somewhat shining; pseudocardinals much split, subradial; na-
cre soiled white.

Length 52, height 28, diam. 23.5 mm.

Length 61, height 39, diam. 24 mm.

Amazon River.

Unio brownianus Lea, Tr. Am. Phil. Soc., 1838, p. 108, pl.

IV Hoe nO Obes tl, 1838. p 108, pl xxiv, fig.-116.
Margarita (Umo) brownianus Lea, Syn., 1838, p. 13.
Prisodon brownianus SIMPSON, Syn., 1900, p. 871.

Hyria browniana SOwERBY, Conch. Icon., XVII, 1869, pl. v,

fig. 12.

Margaron (Triquetra) browniana Lea, Syn., 1852, p. 17;

1870, p. 26.

Triquetra browniana H. and A. Apams, Gen. Rec. Moll., II,

1857, p. 508.

Two specimens, the type and another, from the Lea collec-
tion are before me and they differ decidedly in several char-
acters. The type is the smaller, very solid, much inflated, and
has strong, much split, elongated pseudocardinals. The other
is larger, less inflated, thinner and has rather small pseudo-
cardinals. Its small size, subrhomboid form, and the almost
total absence of wings will distinguish it.

Subgenus HyrraAna Simpson, 1900.

Hyriana SIMPSON, Syn., 1900, p. 872.

Shell solid, compressed, elliptical, with a slight posterior
dorsal wing, and a strong one anteriorly, a well-defined but low
posterior ridge ending in a point well above the base, inflated
at post-basal region, distinctly sulcate; beaks low, apparently
not rayed; epidermis shining, light yellowish-brown; hinge
line evenly curved; pseudocardinals numerous, much split into
denticles and crooked; two laterals in the left valve and one
(no doubt) in the right; beak cavities very shallow; dorsal
scars numerous, anterior scars deep; nacre whitish, radially
grooved along’ the pallial line.

Type, Unio ortonii Lea.

1224 DIPITLLODON

PRISODON ORTONIL Lea.

Shell irregularly obovate or elliptical, compressed, solid,
very inequilateral; beaks apparently rather low and little in-
flated; posterior ridge not greatly elevated, very narrowly
rounded, ending in a blunt point just below the median line;
dorsal and basal outlines rounded; anterior end with a wing
above; post-dorsal region almost wingless; surface with mod-
erately strong, concentric ridges; epidermis pale brownish;
pseudocardinals split into a number (in the left valve 8) of
denticles, which run in a sinuous direction across the hinge
plate; laterals of left valve two, curved; anterior scars, im-
pressed; nacre bronzy, iridescent.

Length 135, height 79, diam. 33 mm.

River Napo, Ecuador.

Umio- orton Lea, Pr. Ac N> Se: Phila. XI) 1868; p.-16ns
JL ACIN. Sci. sPhila Vileteoanpe2s ply cine eas (Obss
XT, 1860, ps Sineplanii dio. 134)

Margaron (Unio) ortonu Lea, Syn., 1870, p. 28.

Prisodon ortonti SIMPSON, Syn., 1900, p. 872.

I have seen only a single left valve of this, the type. The
anterior wing 1s gone and the epidermis is somewhat eroded.
The shell has been injured when young, which has probably
caused a long, tow, radial furrow that runs in front of the
posterior ridge. The space occupied by the pseudocardinals is
not so long proportionally as in typical Prisodon.

Genus: DIPLODON, Spx, 1827.

Diplodon Srrx, Test. Fluv. Bras., 1827, p. 33, pl. xxvI.

Shell elliptical, rounded, elongated or trapezoidal, with rath-
er low beaks, which are more or less distinctly radially sculp-
tured, the ridges usually curved and approaching below, with
a low or scarcely developed posterior ridge; surface slightly,
concentrically sculptured, sometimes broken into fine nodules
or corrugations; epidermis dull, rayless; hinge with two com-
pressed pseudocardinals in the right valve and one slender
lateral and two compressed pseudocardinals, one in front of

DIPTLODON 1225

the other, and two laterals in the left valve: nacre bluish to
white, dull, often blotched ; beak cavities shallow: dorsal scars
numerous, forming a row in the beak cavity parallel with the
hinge line.

Animal with the marsupium occupying nearly the whole
length of the inner branhiz, a few ovules sometimes being
found in the outer gills ; branchiz rather large, angular at base,
inner much the larger, united their whole length to the ab-
dominal sac ; palpi scarcely or somewhat projecting posteriorly ;
mantle very thin, thickened on the edges; branchial opening
papillose, separated from the smooth anal opening by a strong
bridge: superanal opening not closed below.

Type, Diplodon ellipticum Spix.

Kry ‘TO GRouPsS oF DIPLopon.

On account of the similarity of characters of a large propor-
tion of the forms of this genus and the fact that the beak sculp-
ture is eroded away in nine-tenths of the specimens, it does
not seem possible to me to construct a key that will lead to
the species. lor the same reasons I fear that the following
key to the groups will not prove very satisfactory.

Shell generally short.
Having radial beak sculpture.
Obovate to suborbicular.

Moderately solid. Sect. Cyclomya.
Rather thin. Sect. Bulloideus.
Subquadrate, inflated. Group of D. quadrans.
Without radial beak sculpture. Subgenus Levirostris.

Shell more or less elongated.
Beak sculpture of broken lines.
Shell elliptical or subtrapezoid.
Rather solid, bars of beak sculpture strong, slight-

lv coalescing below. Group of D. lacteolus.
Thin or scarcely solid, bars of beak sculpture nar-
row, not coalescing. Group of D. granosus.

Posterior ridge high; shell pointed behind: beak
sculpture of strong narrow ribs.
Group of D. burroughianus.

1226 DIPLODON

Shell elongated, subtrapezoidal, inflated.
Group of D. parallelipipedon.
Beak sculpture of broken, curved bars.
Beak sculpture strong, irregular, extending over the
disk. Group of D. dorsuosus.
Beak sculpture moderate, of small area.
Shelli covered with pustules.
Group of D. novehollandie.
Shell scarcely or not at all nodulous.
Oval to elliptical. Group of D. menszeizi.
Long, rhomboid. Group of shuttleworthii.

Subgenus DIPr.opon s. s.

Beak sculpture consisting of unbroken ridges, covering the
whole beaks.

Animal having the labial palpi rounded below and at pos-
terior base, scarcely. projecting behind.

Type, Diplodon ellipticum Spix.

Group of Diplodon lacteoius.

Shell elliptical to subtrapezoidal, inflated, subsolid, with a
low posterior ridge, sometimes having a slight posterior dor-
sal wing; one or two central pairs of bars of the beak sculp-
ture usually joining below; pseudocardinals, sometimes slight-
ly dentellate.

Animal having the characters of the genus.

DiIPLoODON J,ACTKOI,US (Lea).

Shell solid, unevenly elliptical or subrhomboid, subinflated,
inequilateral, with a full rounded posterior ridge, which ends
behind below the median line; beaks moderately full, raised
but little above the dorsal border, sculptured with strong,
radial ridges; surface irregularly sulcate; epidermis yellow-
ish or greenish-brown, sometimes dark brown, dull or slightly
shining ; left valve with two subcompressed, but strong, pseu-
docardinals. which are often rough and split up, and two

DIPLODON 1227

curved laterals, the lower stronger; right valve with two pseu-

docardinals, the upper compressed, the lower often split, with

a deep scar at their bases, with one lateral ; beak cavities shal-

low, showing a few, large dorsal pits; muscle scars irregular ;

nacre white, sometimes having a dull purplish tint, thicker in
front.

Length 80, height 50, diam. 30 mm.

Length 72, height 42, diam. 26 mm.

Length &3, height 56, diam. 35 mm.

Argentina; Paraguay; Uruguay; Southern Brazil.

? Unio delodonta LAMARCK, An. sans Vert., VI, 1819, p. 77.—
DELESSERT, Rec. Coq. Lam., 1841, pl. xu, fig. 7—CHENU,
HE Conch: 1858.epl.) x11, figs. 1,. 1a:

Margarita (Unio) delodontus Lea, Syn., 1836, p. 26; 1838,
Da 20:

Unio delodontus HANLEY, Biv. Shells, 1843, p. 194, pl. xxz,
fig. 56.—Kuster, Conch. Cab. Unio, 1861, p. 234, pl. Lx xvi1It,
fig. 5.

Margaron (Unio) delodontus Lea, Syn., 1852, p. 29; 1870,
p. 46.

Diplodon delodontus SIMPSON, Syn., 1900, p. 873.

Unio deiodon Strozet, Mat. Mal., Pt. 1, 1874, p. 71.

Unio lacteolus Lea, Tr. Am. Phil. Soc., V, 1834, p. 40, pl. vt,
fos Obsial. 1634. pets2; ple yi, fe. 10.

IT am unable to decide what Lamarck’s delodontus is from
his brief latin description. Dr. Lea examined Lamarck’s
shells and suspects that the delodontus equals his lacteolus,
but is not sure of it. I think under the circumstances it would
be best to use Lea’s name, as his species is properly described
and figured, while Lamarck’s description gives no locality or
account of radial beak sculpture. The species is a very varia-
ble one and appears to be abundant over a wide region. There
is much variation in form, inflation, solidity, color and charac-
ter of the pseudocardinals. After carefully comparing Lea’s
wheatleyanus with a lot of shells recently received from South-
ern Brazil I am doubtful whether it should be separated from
lacteolus.

1228 DIPT,ODON

DIPLODON WHEATLEYANUS (Lea).

Shell subrhomboid, subinflated, solid, inequilateral; beaks
not full or high, sculptured with very strong, radial ridges;
posterior ridge well developed, subangular, ending below in
a blunt point near the base of the shell; surface rudely and
unevenly, concentrically sculptured, with traces of radial sculp-
ture, somewhat plicate on the posterior slope ; epidermis brown-
ish-green, sub-shining; left valve with two subcompressed,
ragged pseudocardinals and two laterals, the inner higher;
right valve with two pseudocardinals, the upper small and
compressed, and one somewhat double lateral; dorsal scars
numerous and deep; anterior adductor scars small, behind
them a deep crescentic scar on the base of the pseudocardinals ;
nacre white, slightly thicker in front.

Length 70, height 47, diam. 30 mm.

Argentina.

Unio wheatleyanus Lea, Pr. Ac. N. Sci. Phila., VII, 1856, p.
o45Opss Vi 1857,p. 25, ple xx, fies 2a 5s) Ae. Niesen
Phila., 1858, p. 308, pl. xxrx, fig. 23—Sowersy, Conch.
Icon., XVI, 1868, pl. x1, fig. 487.

Margaron (Unio) wheatleyanus Lea, Syn., 1870, p. 50.

Diplodon wheatlevanus Stwpson, Syn., 1900, p. 875.

DtPLopoN RHOMBEUS (Wagner).

“Shell round-ovate or oblong-ovate, inflated in front, nar-
row behind, solid, transversely striate or sulcate; anterior end
neither angulate nor plicate. Dorsal margin oblique, curved;
beaks anterior, not very high. Anterior margin obliquely trun-
cate, posterior rounded. Hinge curved; cardinal tooth heavy,
compressed, bifid, striate; laterals substriate, single in the left
valve, double in the right. Beaks depressed, eroded. Umbones
plano-convex. Interior of the shell smooth, shining, pearly.
Posterior muscular impression distinct, with two smaller ones
adjacent, anterior shallow. Epidermis brown; nacre bluish-
white.

Length 3, height 2.1 inches.” (Wagner).

3razil.

DIPLODON 1229

Unio rhombeus Wacner, Test. Fluv. Bras., 1827, p. 34, pl.
XXVIII, figs. 1, 2——HANLxy, Biv. Shells, 1843, p. 208, pl.
RECMe Moe. 20;

Margarita (Unio) rhombeus Lua, Syn., 1836, p. 39; 1838, p.
2m

Margaren (Unio) rhombeus Lea, Syn., 1852, p. 38; 1870, p.
61.

Diplodon rhembeus Stmpson, Syn., 1900, p. 873.

“The form of this species differs greatly in the height of
the beaks. It is distinguished from Unio peruvianus Lam.
by being neither plicate nor angulate.”

DIPLODON PAULISTA (von lhering).

“Shell sulcate, elliptical, inequilateral, rounded in front, pos-
-teriorly obtusely angulated and rounded. Not very thick;
beaks rather low, with undulating, radiate folds on the ante-
rior and posterior slopes near the apices. Epidermis green or
brownish-green, without rays. Cardinal teeth lamellar, thick ;
laterals rather long, curved, or nearly straight. Nacre bluish-
white either dull or iridescent.

Length (males) 48-51, height 59-60, diam. 31 mm.

Length (females) 54-57, height 61-65, diam. 32-35 mm.

The beaks are situated at from .22 to .26 of the length and
the hinge at from .64 to .72 of the length.” (von Ihering).

S20, Paulo Brazile
Unio paulista von IHERING, Arch. fiir Nat., 1893, p. 93, pl. Iv,

7, |
Diplodon paulista SIMPSON, Syn., 1900, p. 873.

“Unio pauiista differs from U. coriaceus Dkr. resp. multi-
striatus Lea, in the less wrinkled and bright green epidermis
and in the low development and granulation of the secondary
radial strie. Ul. psammactinus Bronn is a similar species, but
in that the epidermis is a darker olive-brown with stronger
growth-lines and the numerous, fine, radial stria spread down
widely over the posterior slope and the umbonal fold. Finally
this species is also related to U. greetfeanus, but that species
is Jarger, with a darker epidermis, without granulation in front
of the beaks and with less sharply marked sexual dimorphism.”

1230 DIPLODON

DIPLODON AMPULLACEUS (Lea).

“Shell smooth, oblong, very much inflated, inequilateral, ob-
tusely angular behind and rounded before; substance of the
shell somewhat thick, thicker before; beaks prominent and in-
flated; ligament rather small and dark brown; epidermis dark
brown, rugosely striate, without rays and with rather distant
marks of growth; umbonial slope rounded and much inflated ;
posterior slope elliptical, somewhat carinate, rather wide, very
dark brown and with an impressed line in each valve; car-
dinal teeth small, oblique, lamellar and double in both valves;
lateral teeth long, nearly straight, and corrugate; anterior
cicatrices confluent and slightly impressed; dorsal cicatrices
placed across the cavity of the beaks; cavity of the shell deep
and rounded; cavity of the beaks very shallow and rounded;.
nacre white and iridescent.

Length 2.5, height 1.5, diamy 2,1 in.” -Gyea)).

South America.

Unio ampullaceus Lea, Pr. Ac. N. Sci. Phila., X, 1866, p. 34;
Ji, Aco IN: “Sei. (Phila. - Vis, 1868, 9. 260, plxx xy, shes 83%
Obs, ll, 1860,"p..20) plo x xxv. hien52-

Margaron (Unio) ampullaceus Lea, Syn., 1870, p. 53.

Diplodon ampullaceus SIMPSON, Syn., 1900, p. 874.

“A single specimen only of this species was received. The
beaks are much eroded, but still an indistinct indication re-
mains of the divergent character of the tips. In outline it is
closely allied to mexicanus Phil., but differs. entirely in the
teeth and the color of the nacre. It is also very near to char-
ruanus d’Orb.. but is more inflated and not so wide. It re-
minds one of blandingianus (nobis), but is more quadrate than
that shell and more oblique. In the specimen before me there
are slightly impressed lines running from the beaks to the
anterior half of the margin, which give the surface a rugose
character. There is also a slight emargination at the posterior
basal margin, which may not pertain to all other specimens.”

DrIPrLopon wyMAntt (Lea).

Shell large, subrhomboid, solid, subinflated, inequilateral,
with moderately full, slightly raised beaks having uneven.
radial sculpture: posterior ridge high, rounded, ending in a

DIPTODON 1231

blunt point behind about at the base of the shell; above it on
the posterior slope there is a wide, shallow, radial depression ;
surface with fine, concentric growth lines; epidermis chestnut-
color, shaded with green at the umbonal region, smooth and
shining except on the somewhat roughened border; left valve
with two radial pseudocardinals, which are much split up and
one granular lateral, with a vestige of a second above it;
right valve with two pseudocardinals, the lower greatly di-
vided, the upper compressed ; behind these there is a vestigial
tooth, and one somewhat double, granular lateral; dorsal scars
large; anterior scars deep; posterior scars well-impressed ;
nacre white, almost silvery, thickened in front and iridescent
behind.

Tength tot, height 66, diam. 40 mm.

Uruguay River; South America.

Unio wymanu Lea, Pr. Ac. N. Sci. Phila., IV, 1860, p. go;
WONG Ne Scie ivlast- Vile TG0s4 an Bol. Plex IIh,, eo. 200:
Obs., X, 1863, p. 17, pl. xtat, fig. 289.—SowerrsBy, Conch.
Keon SOV 1rs68; ply Lx ext, fie 440:

Margaron (Unio) wymanu Lea, Syn., 1870, p. 35.

Diplodon wymanii Stmpson, Syn., 1900, p. 874.

Umo- apprmus Era, Pr Ac. N. Sci. Phila., X,1866, p.. 34 5 Jil.
aoe Nocheoimlas Vile t66s, p20, ply xxxiit, ig.76 7 @Obs.,
OH SO9mp. 2 sce pl ox XI 1182. 78.

Margaron Unto apprimus Lea, Syn., 1870, p. 46.

Diplodon apprimus Stmpson, Syn., 1900, p. 874.

This is perhaps the finest Diplodon known. It is a solid,
rhomboid shell with a fine, shining chestnut epidermis, the sur-
face delicately concentrically sculptured above, the sculpture
becoming more rude on the border. The pseudocardinals are
much split up; the nacre is white and fine. I am now con-
vinced that Lea’s U. wymani and apprimus are identical.

DIPLODON EXPANSUS (Kuster).

“Shell subovate, convex, solid, irregularly striate, shining,
reddish-brown, rounded in front, subtruncate behind; um-
bones fiat, eroded; dorsal slope compressed, obtusely angulat-

1232 DIPLODON

ed; cardinal teeth rather stout, trifid in the left valve; laterals .
moderate, somewhat curved; nacre white.

Length 52, height 31, diam. 16.5 mm.”’ (Kuster).

Type locality, “Rio Conigo, near New Freiberg, Brazil.”
Unio expansus Kuster, Conch. Cab. Unio, 1856, p. 149, pl.

S. 9 omy
Diplodon expansus Simpson, Syn., 1900, p. 874.

I know nothing of this. It looks more like an Australian
than a South American form, and is quite likely a D. australis.

DiPLODON PECULIARIS (Lea).

“Shell smooth, quadrate, somewhat compressed at the sides
and inflated on the umbonal slope; inequilateral, obtusely an-
gular behind, rounded before; substance of the shell some-
what thick, slightly thicker before; beaks a little prominent,
slightly inflated with divergent folds at the tips; ligament
small and very dark; epidermis greenish-brown, without rays
and with very indistinct lines of growth; umbonal slope in-
flated and rounded; posterior slope narrow, elliptical, with an
indistinct impressed line in each valve; anterior cicatrices con-
fluent, rather small and slightly impressed ; posterior cicatrices
confluent, large and very slightly impressed; dorsal cicatrices
in a row across the centre of the cavity of the beaks; cavity
of the shell shallow and wide; cavity of the beaks very shal-
low and rounded; nacre bluish-white and iridescent.

Length 2, height 1.3, diam. .9 in.” (Lea).

Paraguay.

Unio pecuharis Lea, Pr. Ac. N. Sci... Phila, X, 1866, p. 33;
Jl. Acad. N. Sei, Phila., VI, 1868, p. 265, pl. xxxiv, fig: 80;
Obs., XIT, 1869, p. 25, pl. xxxtv, fig. 80.

Margaron (Unio) peculiaris Lea, Syn., 1870, p. 47.

Diplodon peciuliaris Stimpson, Syn., 1900, p. 874.

Unio paraguayensis Lea, Pr. Ac. N. Sci. Phila., X, 1866, p.
24 Ac Ne Sct. Phila.) Vij 18687 p: 270, plaxxxvy, hess5:
Obs., XII, 1860, p. 31, pl. xxxv, fig. 85.

Margaron (Unio) paraguayensis Lea, Syn., 1870, p. 45.

? Unio nitidulus Kuster, Conch. Cab. Unio., 1848, p. 226, pl.
EXXVE, fee:

DIPLODON 1238

“In outline peciuliaris is near to bengalensis (nobis), but in
other respects it is very different, having divergent folds on
the beaks, a white and thicker nacre, etc. Of all the South
American species, with which [ am acquainted, it most closely
resembles zymaniw (nobis), but may be easily distinguished
by its darker epidermis, its greater inflation and in being a
smaller species. ‘There is a slight indication of triplication
of the cardinal tooth of the left valve in both the specimens.”

DrPLopoN FIRMUS (Lea).

“Shell smooth, elliptical, somewhat inflated, very inequilat-
eral, rounded before and behind: substance of the shell rather
thick, thicker before ; beaks slightly prominent ; ligament rath-
er long and light brown; epidermis greenish-brown, without
rays, with distant marks of growth; umbonal slope rounded
and inflated ; posterior slope narrow, elliptical, and very slight-
ly carinate, with indistinct impressed lines in each valve; car-
dinal teeth somewhat thick, compressed and double in both
valves; lateral teeth long, lamellar and somewhat curved; an-
terior cicatrices confluent, rather smail and deeply impressed ;
posterior cicatrices confluent, large and slightly impressed ;
dorsal cicatrices placed in a row across the centre of the cavity
of the beaks; cavity of the shell rather shallow and wide; cav-
ity of the beaks shallow and rounded; nacre silver-white and
very iridescent.

Length 2.4, height t.4, diam. I in.” (Lea).

Brazil.

Unio trmus Lea, Pr. Ac. N..Sci. Phila., X, 1866, p. 33; Jl. Ac.
Ne oct Phila. V1, 1868, p. 267, pl. xxiv, fic./82>Obs., XI.
1800 .pL 27 pls SIV. He. &

Margaron (Unio) firmus LEA, Syn., 1870, p. 45.

Diplodon firmus Stimpson, Syn., 1900, p. 874.

“In outline firmus is closely allied to caliginosus (nobis),
but it is a heavier species, with a brighter nacre and a less dark
epidermis. In the specimens before me the nacre is much
worn and the substance of the shell eroded. The beaks are
so much eroded that there are no remains of divergent folds,

1234 DIPLODON

with which they were, no doubt, once clothed. It is nearly
allied to paraguayensis herein described, but differs much in
the elliptical outline.”

Var. bettgeri (von Thering).

“Shell lower, with the posterior end subrostrate and angu-
lated.” (von Jhering).
San Paulo, Brazil.
Unio firmus Lea var. bettgeri von InERtNG, Arch. fiir Nat.,
1693; Pp. ,lOG lave e Laie
Diplodon firmus var. battgeri SIMPSON, Syn., 1900, p. 874.

DipLODON URUGUAYENSIS (Lea).

Shell subrhomboid, somewhat inequilateral, with full but
not high beaks; posterior ridge full and rounded, ending be-
hind in a rounded point near the base of the shell; posterior
slope hollowed out; surface finely, concentrically sculptured ;
epidermis greenish and brownish, somewhat banded, the hind-
er half of the shell darker; left valve with one compressed,
very rough pseudocardinal and two straight laterals; right
valve with two compressed pseudocardinals, the upper small,
and one lateral; anterior muscle scars small, impressed; nacre
white, tinted blue, thicker in front.

Length 70, height 45, diam. 30 mm.

Uruguay River, South America.

Unio uruguayensis Lea, Pr. Ac. N. Sci. Phila., IV, 1860, p-
903. Jl Ac. N. Sci. Phila V> 16635 p. 388. pl. xu. dis. 2056
Obs., X, 1863, p. 24, pl. xiv, fig. 298.—Sowerrpy, Conch.
Icon., XVI, 1868, pl. Uxxxtv, fig. 448.

Margaron (Unio) urwguayensis Lesa, Syn., 1870, p. 46.

Diplodon uruguayensis SIMPSON, Syn., 1900, p. 875.

Very close to D. wymanii and possibly only the young of
that. It differs in having the peculiar dark posterior end, the
coloring of which seems to be a very wide, feeble ray, and in
the teeth. The pseudocardinals of D. wymanii are subradial
and much split, those of this species are compressed and not
split; the laterals of qwymanii are curved and granular, those
of wruguayensis are straight and nearly smooth.

DIPI.QDON 1235

DreLopon RubUS (Lea).

“Shell smooth, elliptical, thick, inflated, inequilateral, emar-
ginate behind, obliquely rounded, before ; substance of the shell
thick and ponderous, thicker before; beaks thick and promi-
nent; ligament rather short, thick and light brown; epidermis
dark brown, lighter towards the beaks, roughly striate, the
marks of growth being rather close and irregularly impressed
into furrows, which are crossed by a few, indistinct, impressed
furrows from the beaks to the margin; umbonal slope raised
and rounded; posterior slope broad, rather flat, with a low
keel rising from a deep, broad furrow; cardinal teeth rather
small, somewhat elongate, striate, crenulate, and double in
both valves; lateral teeth somewhat long, rather thick, granu-
late, thickened towards the end and curved; anterior cicatrices
distinct, large and deeply impressed; posterior cicatrices con-
fluent, rather large and well impressed; dorsal cicatrices well
impressed and placed in a row across the centre of the cavity
of the beaks; pallial cicatrix irregular and deeply impressed ;
cavity of the shell deep and rounded; cavity of the beaks
rather deep and subangular ; nacre white, disposed to be pink-
tsh at the anterior margin and iridescent.

Weneihes. neisht 22) diam. 1-4.in, (UVeay:

Rio de la Plata.

Umornidus Ura Pr Ac: Nat-Se. Phila.” 11.1850; p--187;
Ji. Ac. Nat. Sci. Phila., IV, 1860, p. 266, pl. x11, fig. 146;
Obs., VII, 1860, p. 84, pl. xuit, fig. 146.—Kusrer, Conch.
Cabs Unio, 1e61,-p. 2600 plot ex xvinl dio 1.

Margaron (Unio) rudus Lea, Syn., 1870, p. 50.

Unio rudis Pater, Conch. Sam., III, 1890, p. 166.

Diplodon rudus Stupson, Syn., 1900, p. 875.

“There was a single specimen only of this species sent to
me by Dr. Von dem Busch. It is much stouter than Uniones
are usually from South America, and perhaps is more nearly
allied to wheatleyanus, (nobis), from the Rio Negro than any
other species. It approaches to delodontus Lam., but is thicker
and more rotund than that species. It may be distinguished
at once from wheatleyanus by its greater thickness, by the

1236 DIPLODON

swollen beaks, the furrow on the posterior slope and the size
and form of the cardinal teeth, which are peculiar in this. ‘The
beaks of this specimen being much eroded, it is impossible
to say what may be the character of the tips, but they are likely
to have rayed ribs, like most South American Unionide, but
not so much so as in wheatleyanus. ‘The specimen before me,
as described above, is rugose, with a few irregular transverse
and radiating furrows, which may not exist on all specimens.
It is dark brown and roughly striate near the margin, and
smoother and light brown towards the beaks.”

DIPLODON GREEFFEANUS (von Ihering).

“Shell sulcate, elliptical or suboblong, inequilateral, rather
compressed, rounded before, obtusely angulate behind; valves
rather thick; beaks not prominent, with accessory, radiate,
undulating striz on the posterior slope. Epidermis greenish-
brown, obsoletely radiate. Cardinal teeth long, lamellar rather
stout; laterals long and somewhat curved. Nacre silvery,
moderately iridescent.

Length 64, height 39, diam. 22 mm. Beaks situated at 1-4
of the length.” (von Ihering).

Sao Paulo, Brazil.

Unio greeffeanus von [HERING, Arch. fiir Nat., 1893, p. 96,

pl. iv, fig. 8.

Diplodon greefianus Stimpson, Syn., 1900, p. 875.

DrpPLopON PIGER (Lea).

Shell subrhomboid or obovate, subsolid, inflated, inequilat-
eral, with full but low beaks, having radial sculpture; post-
dorsal part slightly winged, the wing ending in an angle caused
by the truncation of the posterior slope; posterior ridge well
developed, subangular, ending behind in a blunt point near
the base of the shell; base and anterior end rounded, the latter
with an obfuse angle above: surface with fine concentric sculp-
ture; epidermis olive, feebly banded, scarcely shining; left
valve with one compressed pseudocardinal and a vestige of
another in front of it. with two delicate, curved laterals, the

DIPT,ODON 12377

lower higher; right valve with two curved, lamellar pseudo-

cardinals, the upper small, and one lateral; dorsal scars large;

muscle impressions shallow ; nacre bluish-white.
Lengh 55, height 40, diam. 25 mm.
Uruguay River, South America.

Unio piger Lea, Pr. Ac. N. Sei. Phila., 1V, 1860, p. 90; Jl. Ac.
NEScimehilas: Vi 186035 pase7aplexky, tig. 2063 Obs:, Xp.
23, pl. xiv, fig. 296.—Sowersy, Conch. Icon., XVI, 1868,
ply ixxx1v, fig. 440,

Margaron (Unio) piger Lea, Syn., 1870, p. 46.

Diplodon piger Stmpson, Syn., 1900, p. 875.

A neat, subinflated, finely concentrically sculptured species.

DIPLODON PRUNOIDES (Lea).

“Shell smooth, elliptical, very ventricose, inequilateral,
rounded before and behind; substance of the shell rather
thick, somewhat thicker before; beaks somewhat prominent ;
ligament rather short and thin; epidermis dark brown, with-
out rays; umbonal slope raised and rounded; posterior slope
wide and cordate; cardinal teeth compressed, oblique and very
much crenulate, double in the right and disposed to be treble
in the left valve; lateral teeth long, lamellar and corrugate ;
anterior cicatrices confluent, rather small and well impressed ;
posterior cicatrices confluent and slightly impressed; dorsal
cicatrices placed nearly in the centre of the cavity of the beaks ;
cavity of the shell very deep and rounded; cavity of the beaks
deep and rounded; nacre silver-white.

Length 2, height 1.3, diam. 1.1 in.” (lea).

SouthwAmenrtcas:s
Unio prunoides Lea, Pr. Ac. N. Sci. Phila, XII, 1868, p. 150;

HieAce Ne sen hla. .aV I 1868, paseeaply iim tovns6 Obss,

XE, 1860; peS3y pl. Li, fis: 136;

Margaron (Unie) prunoides L&A, Syn., 1870, p. 47.
Diplodon prunoides StMPson, Syn., 1900, p. 875.

“A single specimen, which was found among several of U.
corrugata Lam. in the collection of the Academy of Natural
Sciences. I have little doubt but that it is a native of some of

1238 DIPLODON

the rivers of South America. The beaks are very much eroded.
If they were perfect in the specimen, their character would,
I think, prove the truth of this suggestion. The character of
the cardinal teeth is similar to some of the South American
species. In the left valve it is treble, the anterior division be-
ing very small, the middle one being the largest. In the right
valve the cardinal tooth is double. The anterior cicatrices are
so confluent as to show no disposition to be separated. There
is no appearance of this specimen ever having had rays, but
it is very far from being a perfect individual, and young and
perfect ones may be rayed.”

DiPLODON BESKEANUS ( Dunker).

Shell small, trapezoidal, subinflated, subsolid, inequilateral
with rather low beaks, which are but little inflated, their sculp-
ture radial; posterior ridge moderate, ending in a blunt point
behind near the base, above it on the posterior slope there 1s a
wide, shallow, radial depression, which ends in an emargina-
tion along the truncated border; dorsal line slightly curved,
high behind; anterior end much narrowed and rounded; base
line nearly straight; surface finely, concentrically striate ; ept-
dermis dark olive or olive-green, scarcely shining; left valve
with a lamellar pseudocardinal and a vestige of another below
and in front of it, with two delicate, remote laterals; right
valve with two long pseudocardinals, the upper small, and
one lateral; dorsal scars few, adductor scars small and super-
ficial; nacre bluish-white, somewhat iridescent.

Length 38, height 25, diam. 15 mm.

Brazil.

Unio beskeanus DunxKeER, Zeits. fur Mal., V, 1848, p. 182.
Margaron (Unio) beskeanus Lea, Syn., 1870, p. 61.
Diplodon beskeanus StMPSON, Syn., 1900, p. 875.

So far as I know this species has never been figured. There
is in the Lea Collection a single shell labeled Unio beskeanus
Dunker and presented by Dr. Dunker under that name, and
from it I have drawn the above description. It is decidedly
trapezoidal, being much wider behind than in front; the beaks

DIPILODON 1239

are considerably eroded, yet vestiges of radial sculpture re-
main. It may be a young shell. It is near suavidicus, but is
less solid and inflated and is smoother and more decidedly
trapezoidal.

DIPLODON LOCELLUS (Lea).

“Shell smooth, elliptical, very much inflated, inequilateral,
somewhat rounded before and subtruncate behind: substance
of the shell thin; beaks rather prominent, swollen, with di-
vergent folds at the tips ; ligament very small and light brown;
epidermis dark brown, obscurely rayed, with distant marks of
growth, striate on the anterior half: umbonal ridge rounded
and very much inflated; posterior slope elliptical, rather wide,
with an indistinct furrow in each valve; cardinal teeth small,
very much compressed, very oblique and double in both valves:
lateral teeth rather small, nearly straight, thin and lamellar;
anterior cicatrices confluent and slightly impressed ; posterior
cicatrices confluent and scarcely visible ; dorsal cicatrices placed
above the centre of the cavity of the beaks; cavity of the shell
deep and wide; cavity of the beaks very shallow and rounded;
nacre bluish-white and iridescent.

Length 1.8, height 1.2, diam. 8 in.” (Lea).

Argentina.

Unio locellus Lua, Pr. Ac. N. Sci. Phila., X, 1866, p. B45 alts
Ac. N. Sci. Phila., VI, 1868, p. 264, pl. xxxim, fig. 79; Obs.,.
MAME 1869) ps 2451p xxxin, fie, 70:
Margaron (Unio) locellus Lea, Syn., 1870, p. 47.
Diplodon locellus Stmpson, Syn., 1900, p. 876.

“Of this well characterized little species there was only a
single specimen received. In outline it is near to bengalensis,
(nobis), but it is more inflated, has larger teeth and a thicker
and white nacre. It differs from ampullaceus, herein describ-
ed, in being elliptical, more inflated over the umbones, and
being a much lighter shell. The beaks well display the diver-
gent folds at the tips, a character so well denoting its South
American origin.”

1240 DIPILODON

DireLopon suAvipicus (Lea).

“Shell smooth, eblong, somewhat compressed, very inequi-
lateral, rounded before and truncate behind, dorsal and basal
lines nearly parallel; swollen before the umbonal slope and
flattened at the side; beaks a little prominent, with rather short
divergent and re-entering ribs at the apex; ligament short and
thin; epidermis yellowish-olive, minutely striate, apparently
without rays; umbonal slope subangular ; posterior slope raised
nearly into a wing; cardinal teeth small, compressed, crenu-
late, oblique and double in both valves; lateral teeth long,
lamellar, single in the right and double in the left valve; an-
terior cicatrices confluent; posterior cicatrices confluent; dor-
sal cicatrices placed in the centre of the cavity of the beaks;
cavity of the shell rather deep and rounded; cavity of the
beaks rather shallow and angular; nacre bluish-white and very
iridescent. :

Length .8, height .6, diam. .4 in.” (Lea).

Amazon.

Umo suavidicus LEA, Pr. Ac. N. Sci. Phila., VIII, 1856, p. 95;
Obs Vi-Aass7. p. 20; pl xxix, fee 24 ACUN, Sei Pinas
Iiig1858,p: 300; pl. Kxix} fis. 24.

Margaron (Unio) suavidicus Lua, Syn., 1870, p. 54.

Diplodon suavidicus SIMPSON, Syn., 1900, p. 876.

“A single small specimen of this species, evidently quite
young. I should suppose about one-fourth grown. The above
diagnosis, therefore, may be found to be, in many respects,
incorrect, when mature individuals shall be examined. The
oblong outline of this shell is remarkably regular. The costz
of the beaks are smaller on the posterior and anterior slopes
and several of them form re-entering angles on the posterior
slope and on the sides. This species has some affinity to char-
ruanus VOrb., but differs in being more oblong, in having
smaller coste on the beaks and in having the posterior slope
more elevated.”

DIPLODON BROWNITI (Lea).

Shell small, obovate, compressed, solid, inequilateral, with
low, flat, strongly radially ribbed beaks; posterior ridge low
but well defined, ending in a blunt point behind about on the

DIPLODON 1241

median line; dorsal line high behind; dorsal slope subtruncate ;
anterior end narrow, rounded; base line curved, full behind;
surface with fine concentric growth lines; epidermis bronzy-
green, subshining ; left valve with two rough pseudocardinals,
the anterior small, and two laterals; right valve with two pseu-
docardinals, the upper small, with one lateral; dorsal pits deep ;
muscle scars small, shallow ; nacre bluish-white.

Length 28, height 19, diam. 9 mm.

South America. ?

Unio: brown Lea, Pr. Ac. N. Sci. Phila., VIII, 1856, p. 95;
@bsiaVileiss7) pe 27, pl xxi fie, 225) Jl AcoN: Sei; -Phala.,
Pie SsSip. 3407, pl. «xr, fe. 22.

Margaren (Unio) brown Lea, Syn., 1870, p. 61.

Diplodon brownii Stmpson, Syn., 1900, p. 876.

Dr. I,ea had a single specimen of this shell, which he mark-
ed “Mocha?” It is, 1 am sure, a South American species close
to suavidicus, as the beaks are strongly and regularly radially
sculptured. It is more compressed and smoother than suavidi-
cus, though having a similar outline. ‘Two small shells, which
Dr. Lea called U. brownti, are the former without doubt. The
type of brownti is probably a young shell.

DrPLopon J.EA1 Simpson.

Shell small, subinflated, solid. inequilateral, subrhomboid,
with full but not high beaks, which are badly eroded in the
only specimen seen; posterior ridge full, widely rounded, end-
ing behind in a rounded point near the base line; posterior
slope truncated behind and angled above; surface closely, but
feebly concentrically sculptured, showing traces of radial sculp-
ture; epidermis dark brown, subshining; left valve with two
somewhat split-up pseudocardinals, the anterior smaller, and
two delicate laterals; right valve with one stronger dentilate
pseudocardinal and a smaller smooth one above it, with one
lateral; anterior scars large and impressed ; nacre bluish-white,
thicker in front.

Length 32, height 21, diam. 15 mm.

Brazil.

1242 DIPLODON

Margarita (Unic) inodestus L&A, Syn., 1836, p. 32; 1838, p. 22.

Margaron (Unio) modestus Lea, Syn., 1852, p. 33 ; 1870, p. 54.

Unio modestus H. and A. Apams, Gen. Rec. Moll., II, 1857,
P. 493.

Diplodon leai Simpson, Syn., 1900, p. 876.

It is a small, rather solid, inflated, rhomboid shell, with a
brown epidermis, which scarcely shows a tint of green.

Lea credits this to Ferussac in his Synopsis, but I do not
think it has ever been described by that author or anyone else.
In 1856 Kuster properly described and figured a species in the
Conchylien Cabinet (Vol. Unio, p. 147, pl. xii, fig. 2) under
the name of Unio modestus, which he credits to Charpentier’s
manuscript, a different shell from that referred to by Lea and
the Adams brothers. If the latter was never described the
name modestus can not be used for it, as it was first properly
applied to another species.

DirpLopon RHUACOICUS (d’Orbigny ).

“Shell elongate-oblong, inflated, thick, smooth or concen-
trically rugose; epidermis greenish-brown ; beaks radially cos-
tate; anterior end short, rounded; posterior end elongate, ob-
tuse, obliquely truncate ; within bluish-white.

Length 63 mm., compared with the length: height 51/100,
diam. 43/100, length of posterior margin 67/100; apical angle
145°. .(d Orbigny):

Uruguay.

Unio rhuacoica d’Orpicny, Guer. Mag., 1835, p. 35; Voy. Am.

Mer., 1843, p. 606, pl. LxIx, figs. 4, 5.

Margaron (Unio) rhuacoicus Lea, Syn., 1870, p. 54.
Diplodon rhuacoicus SIMPSON, Syn., 1900, p. 876.

Unio rhyacoicus von Marrens, Mal. BL, XV, 1868, p. 195.
Monecondylea rhyacoeca Pa'rer, Conch. Sam., HI, 1890, p.

174.

“This species is rounded at the ends like U. charruana, but
is to be distinguished by its shape, which 1s very much more
elongated, narrower, with the dorsal and ventral margins par-
allel and also more inflated. It is possible, nevertheless, that
this species, in spite of these differences found in a good num-

DIPI,ODON 1243

ber of specimens, may prove to be only a variety of U. charru-
ana, with which it was found. We collected it in a brook near
Maldonado and in the Rio Canelon grande, near Montevideo,
Republic of Uruguay. It is rare.”

DIPLODON CHARRUANUS ( d’Orbigny ).

Shell decidedly rhomboid, subinflated, solid, finely, concen-
trically striate; epidermis yellowish-brown: inequilateral, with
a high, rounded posterior ridge, which ends behind in a round-
ed point at the base line; beaks rather full and high, strongly
radially sculptured ; left valve with a large, much split-up pseu-
docardinal and a somewhat double lateral; right valve having
a similar split pseudocardinal and a double lateral; anterior
scars impressed ; nacre whitish, blotched in the cavities, thicker
in front.

Length 63, height 35, diam. 24 mm.

Uruguay.

Unio charruana d’Oreicny, Guer. Mag., 1835, p. 35; Voy. Am.

Mer., 1843, p. 606, pl. Lxx1, figs. 8-14.

Margarita (Umo) charruanus Lea, Syn., 1838, p. 20.
Margaron (Unio) charruanus La, Sym; 1852, p. 29; 1870, -

Pp. 54.

Unio charruanus Sowrersy, Conch. Icon., XVI, 1868, pl. xcrm,

figs. 505, 505a, 5050.

Piplodon charruanus Stupson, Syn., 1900, p. 876.
Unio faba d’Orbicny, Mag. Zool. 1835, p. 35; Voy. Am. Mer.,

1843, p. 606, pl. Lxx1, figs. 8-11.

Margarita (Unio) faba La, Syn., 1838, ps 21
Margaron (Unio) faba Lea, Syn., 1852, p. 31; 1870, p. 50.

More decidedly rhomboid than D. rhuacoicus. ‘The speci-
mens in the Lea Collection, which were received from d Orbig-
ny under the name Unio charruana, are young and rather
brenzy. In the larger the laterals are partially reversed.

DreLopon carpira (von Thering).

Shell oblong, subsolid, nearly evenly elliptical, subinflated.
inequilateral, with a rather full, rounded posterior ridge, which
ends behind at or below the median line: beaks moderately

1244 DIPILODON

full, raised above the dorsal line, their sculpture not seen;
growth lines rather strong, in some cases being elevated into
slight, concentric ridges ; epidermis dark olive, brown or black,
scarcely shining; left valve with two lamellar pseudocardinals
and two remote laterals ; right valve with two compressed pseu-
docardinals, the upper smaller, and one lateral; dorsal scars
numerous ; muscle scars impressed ; nacre bluish, a little thick-
ened in front.

Jjength 55, height 29, diam. 22 mm.

Uruguay; Southern Brazil.

Unio caiptra von IHERING, Arch. fiir Nat., 1893, p. 98, pl. rv,

fie. O:

Diplodon caipira SiMvSON, Syn., 1900, p. 877.

A nearly evenly elliptical form, sometimes a little rhomboid,
rather closely and finely, concentrically sulcate, and quite dark
colored. It seems to be close to D. ellipticus, but is not so
much pointed behind and lacks the post-basal inflation of that
species.

DipLopon PpicEus Lea.

“Shell smooth, elliptical, somewhat inflated, very inequilat-
eral, somewhat rounded behind and obliquely rounded before;
valves somewhat thick, slightly thicker before; beaks slightly
‘prominent; epidermis shining, black, striate and obscurely
rayed or without rays, with rather distant marks of growth;
ligament small and dark brown; umbonal slope somewhat
raised and rounded ; posterior slope compressed, elliptical, with
an obscure furrow on each valve; cardinal teeth rather small,
compressed, lamellar, oblique, single 1n the left and double in
the right valve; lateral teeth rather long, somewhat thin and
curved; anterior cicatrices rather small, well impressed, con-
fluent with the lower but distinct from the upper; posterior
cicatrices confluent, rather large and slightly impressed; dor-
sal cicatrices well impressed and placed across the cavity of
the beaks; cavity of the shell rather deep and wide; cavity of
the beaks shallow and rounded; nacre bluish-white and irides-
cent.

Length 1.8, height 1.1, diam. -7 in.” (Wea).

Uruguay River, South America.

DIPLODON 1245

Umo piceus Lua, Pr. Ac. N. Sci. Phila., 1V, 1860, p. 91; Jl.
CON oct, Ehilay,.VietsOs; pa 367, pl. xn, fig. 287 - Obs.; X,
T8632, pit5, pl. xn, fies 287.

Margaron (Umo) piceus Les, Syn., 1870, p. 53.

Diplodon piceus SIMPSON, Syn., 1900, p. 877.

“Three specimens. ‘They all differ slightly in the ellipticity
of outline. One being a little wider and the other not quite
so much so as that figured. It is very near to lugubris (nobis)
in outline and in the blackness of the epidermis, but in the
nacre it differs entirely, as it does in the cardinal teeth. It is
also very near in outline to lepidus, herein described. ‘The
single cardinal tooth in the left valve is very unusual. The
blackness of the epidermis is very striking and apparently it
is without rays. In looking through the valve the hue is
greenish, and one of the specimens exhibits obscure rays. The
beaks of all the three are eroded, and I cannot therefore de-
scribe the undulations of the tips. From indications in the
exposed nacre I have no doubt that this species has diverging
undulations at the tips. The transverse striz are coarse, al-
most amounting to sulcations. The cardinals are nearly on
the same curve with the lateral teeth.”

DIPLODON SUPPOSITUS nN. s.

Shell oblong, elliptical or subrhomboid, subcompressed, sub-
solid; posterior ridge nearly or entirely wanting; beaks rather
low, their sculpture consisting of a number of short, straight,
radial bars; surface with numerous fine growth lines; epider-
mis olive or brownish, bronzy, generally shining; left valve
with two compressed pseudocardinals and two laterals; right
valve with two pseudocardinals, the upper small, and one lat-
eral, teeth all delicate; nacre bluish-white, thickened a little
in front.

Length 50, height 26, diam. 14. mm.

Length 55, height 32, diam. 19 mm.

Southern Brazil, numerous localities.

Diplodon piceus (part), Simpson, Syn., 1900, p. 877.

A form with few decided characters, yet one which does not
seem to quite equal any other. The young are often brilliant

1246 DIPLODON

and of various shades of green, showing the closest relation-
ship with many of the forms on the west side of the Andes.
The older shells often have the dorsal and ventral lines al-
most parallel and a decidedly bronzy epidermis much like that
of D. auratus.

This species was received from von Ihering under this name,
but, so far as I have been able to ascertain, it has never been
published.

DipLoODON WAGNERIANUS Simpson.

“Shell ovate-oblong, ventral margin slightly incurved ; trans-
versely sulcate, anterior end roundly attenuate, posterior nar-
row and rounded. Hinge consisting of one, heavy, crenulate
and sometimes bifid cardinal tooth and two, compressed, elon-
gate laterals in the right valve and two crenulate cardinals and
a single, very long, very thin, crenulate lateral in the left. Beaks
incurved, in young specimens with simple, longitudinal folds,
in the adults eroded. Umbones plano-convex, not rugose.
Margins acute, simple. Cavity smooth, shining, pearly. Epi-
dermis olive-brown, nacre bluish.

Length 2.1, height 1 inch.” (Wagner).

Type locality, Rio Sao Francesco, Brazil.

Unio ellipticus Wacnerr, Test. Fluv. Bras., 1827, p. 33, pl. xx,
figs. 1, 2.—Kustrer, Conch. Icon. Unio, 1861, p. 238, pl. Lxxx,
fig. 2-—SowrErsy, Conch. Icon., XVI, 1868, pl. xxiv, fig.
382.

Margaron (Unio) ellipticus Lea, Syn., 1852, p. 21; 1870, p. 31.

? Diplodon wagnerianum SIMPSON, Syn., 1900, p. 877.
Barnes applied the name Unio ellipticus in 1823 to a species

which is believed to be igamentina. Wagner placed his shell

in Unio in the text, but Spix called it Diplodon ellipticum in
the plate.

Var. santanus von Ihering.

“Mr. Garbe collected numerous examples in the Rio Santa
Maria, a tributary of the Rio Doce. The largest measures 42
mm. in length. The ventral margin runs nearly straight from
the upper anterior end in a posterior and downward direction

DIPLODON 1247

to the last quarter of the length of the shell, whence it again
ascends. The angle in which the two parts of the ventral mar-
gin meet posteriorly is not as distinct as in the typical speci-
mens collected by Spix in the Rio Sao Francisco, This reason
and the somewhat smaller dimensions induce me to regard the
specimens from the Santa Maria River as a distinct subspecies,
which I name santanus.’ (von Ihering ).

Diplodon ellipticus santanus von TuERinc, Abhandl. Senckenb.

Natuni. Ces,, 32° 1910, p. 1345

DieLopon avrHiops (Lea).

Shell oblong, convex, subsolid, with a straight dorsal line,
the posterior slope rather abruptly truncated, the basal line
slightly curved; posterior ridge high, subangular ; dorsal slope
with a few, irregular wrinkles, beaks low, rather full, their
sculpture not seen: surface with irregular, subsulcate sculp-
ture; epidermis black, scarcely shining; left valve with two
compressed, small, ragged pseudocardinals and two delicate
laterals; right valve with two pseudocardinals, the upper very
small and one straight lateral; nacre whitish, somewhat thick-
er in front.

Length 53, height 27, diam. 18 mm.

Uruguay and Paraguay Rivers; southern Brazil.

Umo ethiops Lea, Pr. Ac. N. Sci. Phila., IV, 1860. Plots):

Aes Ne Sct Phila., V,) 1863, p. 377) pl. x1. fig. 285; Obs.,
2G 1803, p13, pla. xin, fie. 285.

Margaron (Unio) ethiops Lua, Syn., 1370s 53.
Diplodon ethiops Simpson, Syn., 1900, p. 877.

I have only seen a single dead specimen, not in good condi-
tion, the tvpe. The dorsal line is quite straight; the post-
ridge is high and subangular, the dorsal slope has a few wrink-
les and the epidermis is almost jet black throughout.

Var. piracicabanus (von Ihering).

“Valves thick; posterior extremity rounded; lateral teeth
straight or slightly curved.’ (von Ihering).
Piracicaba, San Paulo, Brazil.

1248 DIPILODON

Unio ethiops Lea, var. piracicabana von TuerRiInc, Arch. fir
Nat., 1893, p. 102.
Diplodon e@ethiops var. piricicabana SIMPSON, Syn., 1900, p.

——

2
S77.
DripLopon pivaricatus (Lea).

“Shell elliptical, transverse, somewhat compressed, very in-
equilateral; substance of the shell thin; beaks covered with
beautiful folds diverging from their apex; ligament rather
short and slender; epidermis greenish, smooth; cardinal teeth
small, compressed, double in the right valve and single in the
left; lateral teeth long, rather thin and nearly straight; ante-
rior cicatrices slightly confluent ; posterior cicatrices confluent ;
dorsal cicatrices situated in the centre of the cavity of the
beaks; cavity of the beaks shallow and subangular; nacre
white and iridescent.

Length i:4, height .9, diam: <S.anches.~ (Gea):

South America.

Unio divaricatus Lea, Tr. Am. Phil. Soc., V, 1834, p. 64, pl.
ix, fig. 24; Obs., I, 1834, p. 176, pl. 1x, fig. 24 HANLEY,
Biveohells, 1843). 197..pl. XxUl, die. 36.

Margarita (Unio) divaricatus Lea, Syn., 1836, p. 29; 1838, p.
2M,

Margaron (Unio) divaricatus Lea, Syn., 1852, p. 31; 1870, p.
49.

Diplodon divaricatus SIMPSON, Syn., 1900, p. 878.

Credited by Lea to Egypt, but no doubt a South American
species, as it has radial beak sculpture and appears to belong
to this group.

DIPLODON PERPLEXUS N. Ss.

Shell long elliptical or subrhomboid, convex, inequilateral,
rather solid, usually subtruncate in front; posterior slope
curved or feebly truncate; posterior ridge low, rounded, end-
ing behind in a rounded point a little below the median line;
beaks scarcely inflated or elevated above the dorsal line, with
numerous, strong, uneven, radial bars, the central pair coalesc-
ing below ; surface with numerous, fine, concentric ridges ; ep1-

DIPLODON 1249

dermis olive-green or brownish, somewhat shining, often show-
ing the rest marks; left valve with one compressed pseudocar-
dinal, sometimes with a small one in front, the lower surface
of the tooth often excavated, and two slender laterals; right
valve with two pseudocardinals, the lower larger and ragged
and one lateral; dorsal scars small and numerous; anterior
scars impressed; there is a small deep crescent-shaped scar at
the base of the pseudocardinals; nacre bluish-white, often
blotched, a little thickened in front.

Length 73, height 42, diam. 24 mm.

Lake Portero near Maldonado, Uruguay.

I feel very great hesitation about launching new species of
the genus Diplodon, but there are several forms from Southern
Brazil and adjacent regions that | cannot refer to any known
species and the above is one of them. It has no striking char-
acters, but is a simple, elongated, scarcely inflated form, often
slightly truncated anteriorly. Some specimens show feeble,
radial sculpture on the center of the disk, and it sometimes be-
comes plicate. Other shells are entirely destitute of such
sculpture.

DIPLODON MIMUS 0. s.

Shell small, long rhomboid, convex, solid, inequilateral, the
beaks much eroded in the specimens seen; posterior ridge low,
widely and decidedly double, ending behind in a wide biangula-
tion at the base line; dorsal and ventral lines nearly parallel ;
surface very finely, concentrically sculptured ; epidermis brown,
tawny on the center of the disk, scarcely shining; left valve
with two pseudocardinals, the posterior small, and two remote
laterals; right valve with two pseudocardinals, the lower
strong,-and one lateral; muscle scars well impressed; beak
cavities shallow, with a few pits; nacre dull whitish, lurid pur-
ple within, thicker in front.

Length 37, height 28, diam. 17 mm.

Iguape, Brazil.

A small solid, rhomboid species, which almost exactly mim-
ics in external appearance some of the varieties of Unio com-
planatus. The dirty nacre is finely, radially sculptured out-
side the pallial line in some specimens.

1250 DIPLODON

DIPLODON TRIVIALIS, n. S.

Shell elliptical or obovate, convex, subsolid, inequilateral,
nearly evenly rounded before and behind; beaks moderately
full, raised somewhat above the dorsal line, which is incurved
in front of them, their sculpture numerous, fine, radial bars;
posterior ridge scarcely developed; surface unevenly, rather
finely sulcate ; epidermis black or dark brown, somewhat cloth-
like when fresh, subshining and tinted green when rubbed;
left valve with two compressed pseudocardinals, the anterior
one sometimes feeble, and two remote, delicate laterals; right
valve with two compressed pseudocardinals, the upper small,
and one lateral; dorsal pits few, under the hinge and parallel
with it: muscle scars shallow; nacre bluish-white, often
blotched. j

Length 52, height 33, diam. 20 mm.

Taboticabal, San Paulo, Brazil.

This species is a little wider behind than in front and is
nearly evenly rounded at both ends. A number of specimens
were sent by von Ihering from the type locality.

Group of Diplodon granosus.

Shell elliptical to subtrapezoidal, somewhat compressed,
rather thin, beaks low, the sculpture irregularly radial, the
ridges narrow and sharp, separated by wide, trough-like
spaces, the outer in particular often becoming somewhat nod-
ulous or corrugated, the inner approaching and united below ;
surface sometimes slightly concentrically ridged and granose ;
teeth delicate, compressed; nacre bluish.

_Animal unknown.

DipLopoON GRANOSUS ( Bruguiere).

Shell long elliptical or subrhomboid, subcompressed to quite
convex, subsolid, inequilateral; beaks neither high nor full,
having irregular, radial, granular sculpture; posterior ridge
iow, sometimes rounded, often slightly angular or biangulate,
ending behind in a blunt, rounded point below the median line ;
surface delicately, often unevenly, concentrically sculptured,

DIPLODON 1251

generally more or less granose; sometimes having wavy,

zigzag or chevron-shaped granular bars; occasionally it is

nearly smooth and shows traces of radial sculpture; teeth del-
icate, compressed; each valve with two pseudocardinals, the
posterior one in the left often nearly wanting; two laterals in
the left valve and one in the right; nacre whitish, often lurid
in the cavities, thicker in front.

Length 50, height 26, diam. 15 mm.

Length 58, height 35, diam. 1g mm.

Length 58, height 28, diam. 18 mm.

Length 39, height 21, diam. 14 mm.

Brazil: Guiana.

Umo granosa Brucirrr, Jl. de Hist. Nat., I, 1792, p. 107, pl.
Vitis. 93, 4.—_DrsiAves, Ene. Meth, If, 1827) -p. 161, pl.
CCXLIX, fig. 2.

Unio granosus Haniey, Biv. Shells, 1843, p. 182, pl. xxu1,
ovo

Margarita (Unio) granosus Lea, Syn., 1836, p. 17; 1838, p. 16.

Margaron (Unio) granosus Lea, Syn., 1852, p. 23; 1870, p. 34.

Diplodon granosus Simpson, Syn., 1900, p. 878.

Unio multistriatus Lea, Tr. Am. Phil. Soc., IV, 1831, p. 91,
plea te 22) Obs. £-1834.-p, 101, pl. xm, fis. 22 _HaAn-=
Ley, Biv. Shells, 1843, p. 176, pl. xx, fig. 35.—CnHenu, IIl.
Conch., 1858, pl. x1, figs. 2, 2a, 2b—Sowerrsy, Conch. Icon.,
XVI, 1868, pl. LXxxv, fig. 455.

Margarita (Unio) multistriatus Lea, Syn., 1836, p. 13; 1838,
Do lae

Unio multistriata d’ORvicNy, Voy. Am. Mer., 1843, p. 607.

Unio pfetfferi DunKegr, Zeits. fur Mal., V, 1848, p. 181.—
PFEIFFER, Nov. Conch., II, 1866, p. 151, pl. xxx1x, figs. 4-9.

Unio psammactinus Puitippr, Conch., III, 1848, p. 79, pl. v,
ie. 2-—ouster, Conch. Cab. Unies 1856, p. 159; pl. XLv,
fig. 6.

Umo famelicus Gouin, Pr. Bost. Soc. N. H., III, 1850, p. 2094;
Ds Exply Exp) XU 1852) piagemnes: +440) 544b-—Sow-
ERBY, Conch. Icon., XVI, 1868. pl. Lxxv, fig. 391.

Margaron (Unio) famelicus Lea, Syn., 1852, p. 34; 1870, p.
54-

1252 DIPILODON

Unio niloticus SowERBy, Conch. Icon., XVI, 1868, pl. Lxx111,

fig. 374.

An exceedingly variable species and one which seems to
be quite abundant. Bruguiere’s figure in the Encyclopedie
Methodique fairly well represents a phase of this protean
shell. I feel quite sure that Dunker’s Unio pfeifferi is merely
a form of this with rather strong, chevron-shaped sculpture,
and it is quite probable that granuliferus and rufofuscus are
only varieties of it. Usually, though not always, the more
strongly sculptured specimens have a dull brownish epidermis,
while the smoother forms are more glossy and sometimes
green-tinted. I think there can be no doubt that Lea’s multi-
striatus is the equivalent of granosus, but I do not believe
that this equals Wagner’s Unio ellipticus. The entire group,
of which this is typical, is very puzzling.

DIPLODON SEMIGRANOSUS DN. S.

Shell rather small, irregularly long elliptical or long ovate,
subcompressed or convex, inequilateral, with a low rounded
posterior ridge, above which is a wide, shallow, radial sulcus;
beaks slightly elevated above the dorsal line, not swollen, sculp-
tured with 18 or 20 slightly curved, broken or subnodulous
ridges: surface with feeble, concentric sculpture, which is
crossed by exceedingly faint. radial lira and in addition is
often subgranulous; epidermis olive or yellow-green, some-
times nearly black in old shells, dull or subshining ; left valve
with one small, subcompressed pseudocardinal, a vestige of a
second behind it, and two remote laterals, the upper small;
right valve with two compressed pseudocardinals and one
lateral; nacre dirty bluish-white, somewhat thickened in front.

San Paulo River; Ponte Grande; Os Perus, Brazil.

A large number of specimens of a little Diplodon were sent
by Dr. von Ihering to the National Museum from several lo-
calities, which I at first referred to D. granosus with much
doubt. It is solider and less high than that species; it is more
elliptical or ovate, sometimes being drawn out somewhat be-
hind; it is greener-colored and not so granose as that species
often is.

DIPLODON 1253

DirlopON GRANULIFERUS (Dunker).

Shell subelliptical, small, subcompressed, inequilateral, sub-
solid ; beaks low, their sculpture not described; posterior ridge
low and rounded, ending behind in a blunt, rounded point near
the base line, surface sculptured with fine, granulous, curved,
wavy, subradial ridges ; epidermis olivaceous ; pseudocardinals
delicate ; laterals lamellar and curved; nacre iridescent.

Length 34, height 22, diam. 12 mm.

Province of Rio de Janeiro, Brazil.

Unio granuliferus DUNKER, Zeits. fur Mal., V, 1848, p. 182.—

PFEIFFER, Nov. Conch., II, 1866, p. 150, pl. xxx1x, figs. 1-3.
Diplodon granuliferus Simpson, Syn., 1900, p. 870.

Umo graniulifer Parrr, Conch. Sam., III, 1890, p. 154.

I have never seen this species, which may be merely a form
of D. granosus. ‘The curved rows of nodules are slightly di-
varicate along the posterior ridge. It is more nearly elliptical
than any specimens of granosus that I have seen.

DrIPLODON EFFULGENS (Lea).

Shell subtrapezoidal, rather small, subsolid, subcompressed,
inequilateral, with apparently low beaks, their sculpture not
observed; anterior end narrowed and rounded; post-dorsal
region elevated almost into a wing; post-dorsal slope subtrun-
cate; posterior ridge low and rounded, ending behind in a
rounded point near the base line; surface sculptured with fine,
concentric ridges and showing vestiges of granulation and
radial sculpture; epidermis greenish-brown, shining ; left valve
with one subcompressed. irregular pseudocardinal with some
uneven denticles behind it and two small, remote laterals;
right valve with two pseudocardinals, the upper much com-
pressed, the lower prolonged backward and much split up.
with one lateral: nacre !urid whitish, thicker in front.

Length 50, height 30, diam. 16 mm.

Brazil.

Uniovenulsens Wea, Pr. Ac. N: Secu, Phila, VIII, 1856; p: 94;
ine vce Ne Ser ehila., lt, 1857, joe nl. XXVIII, fis. es

Obs: Vij 1857, p23, pl. xXxvin, a 18.

1254 DIPILODON

Margaron (Umo) effulgens Lea, Syn., 1870, p. 35.
Diplodon effulgens Simpson, Syn., 1900, p. 879.
Unio eurhynchus Kuster, Conch. Cab. Unio, 1861, p. 237, pl.

LXXIX, fives:

Apparently close to D. granosus, but more trapezoidal and
more solid. ‘The peculiar pseudocardinals differ from those
of that species. Lea states in the Observations that this shel!
is in the cabinet of Dr. Budd, but does not claim to have it in
his own. The type, from Dr. Budd, is now in his collection.

DreLopon RurFOoFUSCUS (Lea).

Shell short rhomboid, convex, rather solid, inequilateral,
with low, scarcely inflated beaks; post-dorsal part high, sub-
angulate where it meets the truncation of the posterior slope;
posterior ridge full but widely rounded, ending in a rounded
point at the hase line; surface sculptured with concentric
ridges; the umbonal region is marked with subnodulous, fine,
chevron-shaped bars, this pattern fading out on the body of
the shell, though over its whole surface there are traces of
nodules and radiating lines; epidermis rich dark chestnut.
lighter in the umbonal region, subshining ; left valve with two
low, subcompressed pseudocardinals and two curved laterals;
right valve with a high, subcompressed pseudocardinal, a
small one above it, and one lateral; muscle scars small; nacre
dirty bluish-white, thickened in front.

South America.

Unio rufofuscus Lea, Pr. Ac. N. Sci. Phila., IX, 1865, p. 76;
flo Ac Ne Sci. Phila: V1, S68, p51282, pl xk ite o):
Obs., XII, 1860, p. 42, pl. xxx1x, fig. 96.

Margaron (Unio) rufofuscus Lea, Syn., 1870, p. 31.

Diplodon rufofuscus StMPSON, Syn., 1900, p. 88o.

This has much the appearance of a very short, solid D. gran-
osus, near which species it was placed in the Synopsis. The
type is in the Lea Collection, probably donated by Signor Paz.
after the twelfth volume of the Observations was published.
Perhaps a member of the Jacteolus group. ‘There are a num-
ber of species, which possess characters of both groups and
might almost as well be placed in one as the other.

DIPLODON 1255

DIPLODON DEMERARAENSIS (Lea).

Sheil rhomboid oblong, inequilateral, convex, rather solid;
beaks moderately full, sculptured with radial bars; surface
strongly concentrically sulcate ; epidermis olive-brown, rayless ;
pseudocardinals subcompressed striate, erect, double in both
valves ; laterals somewhat curved; nacre white and iridescent.

Length 38, height 23, diam. 13 mm.

Demerara.

Unto demararaensis Lea, Pr, Ac. N. Sci. Phila., XI, 1859, p.

E52
Unio demeraraensis Lua, Jl. Ac. N. Sci. Phila., IV, 1860, p.

253epl. XMKIX, Ag. 133; .Obs., Wil, 1860, p. 71, pl. xxxix,

fig. 133.—RreveE, Conch. Icon., XVI, 1865, pl. xx, fig. go.
Margaron (Unio) demeraraensis Lea, Syn., 1870, p. 36.
Diplodon demararaensis SIMPSON, Syn., 1g00, p. 88o.

Unio demarasensis Patri, Conch. Sam., III, 1890, p. 150.

I have never seen this shell; the type, which is the only
specimen known, being in the Cumingian collection. Were
it not that Dr. [ea distinctly states that it has radial beak sculp-
ture of the South American type, I should be sure that it was
a young Unio dysoni, which species is figured beside it in the
Observations. ‘The form, the slight biangulation behind, the
strong sulcation and the character of the teeth would seem to
place it with or close to Nephronaias dysoni. JI am not at all
sure that it should not be made the type of a separate group.
By an error this was written demararaensis in the Synopsis.

DiPLopON LEPTDIOR (Lea).

Shell oblong, somewhat rhomboid, scarcely subsolid, convex,
inequilateral ; heaks not very full. rising a little above the dor-
sal line, their sculpture a number of rather strong, straight,
radial ridges, the middle ones converging a little below ; pos-
terior ridge low, rounded, with a feeble radial rib above it;
surface with close. fine growth lines; epidermis yellowish-
green, the hinder half of the shell darker and there is some-
times a broad, dark. concentric, central band, the whole smooth
and shining ; the two pseudocardinals of the left valve are com-

1256 DIPIODON

pressed, the posterior one feeble, the two laterals are delicate

and lamellar ; right valve with two compressed pseudocardinals,

the upper small, and one lateral; nacre bluish-white, a little
thicker in front.

Length 52, height 29, diam. 17 mm.

Uruguay River.

Unio lepidus Lea, Pr. Ac. N. Sci. Phila., IV, 1860, p. 91; Jl.
Ac. N: Sei. Phila;, V,)1863;"p! 390; plo, figs 200; 1Obsoe,
1GO3; p25, splay 1, 12> 200!

Margaron (Umo) lepidier Lia, Syn., 1870, p. 53.

Diplodon lepidior Stmpson, Syn., 1900, p. 880.

The dorsal and ventral lines are nearly parallel, the anterior
end being a trifle narrowed. ‘The surface is smooth and shin-
ing, of much the same texture and appearance as many of the
forms of this group west of the Andes. First called lepidus
by Lea, but changed by him to lepidior because lepidus had
been used by Gould for a Unio.

DIPLoDON PARCUS (Lea).

Shell long and nearly evenly elliptical, convex, inequilat-
eral, with moderately full beaks, which are elevated a little
above the dorsal line, their sculpture about sixteen, rather
strong, straight ridges; posterior ridge moderate, rounded;
growth lines irregular; epidermis smooth, shining, yellow
green, slightly bronzy, with a light. median, concentric band;
left valve with one compressed pseudocardinal with a vestige
of another behind it and two delicate laterals ; right valve with
two pseudocardinals, the upper very small, and one straight
lateral ; beak cavities shallow; nacre pale blue.

Length 37, height 18, diam. 14 mm.

South America.

Unio parcus izes, Pr Ae INegset Phila xe 1866! ep.634 3):
Ac. ON? Sei. Phila.; Vipts68; pi 262; plxxxam, fies 77>: Obs...
XS 1860) 5p.22, plyacxoci, is 77:

Margaron (Unio) parcus Lea, Syn., 1870, p. 47.

Diplodon parcus SIMPSON, Syn., T9Q00, p. 880.

Probably a young shell. It is more inflated than most mem-
bers cf this group, but it has the smooth, bronzy epidermis of
many of its members.

DIPLODON 1257

DiPLODON CHILENSIS (Gray).

Sheil long elliptical, subrhomboid or slightly obovate, scarce-
ly subsolid, subcompressed, inequilateral; beaks neither full
nor elevated, sculptured with delicate, narrow, radial ridges;
posterior ridge almost wanting, ending behind in a wide,
rounded point below the median line; surface with delicate,
concentric sculpture; epidermis greenish or greenish-olive,
shining ; teeth delicate, compressed; left valve with one pseu-
docardinal and two laterals; right valve with two pseudocar-
dinals and one lateral; nacre bluish or purplish, generally
bright and iridescent.

Length 66, height 33, diam. 19 mm.

Length 57, height 32, diam. 16 mm.

Island of Chiloe, Chile.

Unio chilensis Gray, Spic. Zool., 1828, pl. vr, fig. 12—PHuI-
tpi, Conch., III, 1847, p. 9, pl. 1v, fig. 2—KustEr, Conch.
Cab. Unio, 1862, p. 282, pl. xcv, fig. 12.—Sowersy, Conch.
leony XV I, 1867, ple ivi, fie. 286.

Diplodon chilensis SIMPSON, Syn., 1900, p. 88o.

Unio smithu Gray and Pripcron, Griff. Cuv., XII, 1834, p.
600; pl. xx, fig) 3:-—FIANr Ey, Biv. Shells, 1843, p: 195, pl.
XMM, fe. 58:

Margarita (Unio) smith Lea, Syn., 1836, p. 27; 1838, p. 20.

Margaron (Umo) smithtii Lea, Syn., 1852, p. 30; 1870, p. 48.

Unio auratus Puitippr, Conch., III, 1847, p. 9, pl. 1v, fig. 1.

Margarita (Umo) auratus Lea, Syn., 1836, p. 31; 1838, p. 22.

Margaron (Umo) auratus Lea, Syn., 1852, p. 33; 1870, p. 53.

Umo araucanus Puiiipri, Conch., III, 1847, p. 50, pl. rv, fig.
3.—Kuster, Conch. Cab. Unio, 1862, p. 283, pl. xcv, fig. 3.

Margaron (Unio) araucanus Lea, Syn., 1870, p. 53.

Unio araucana Hupr, Gay’s Hist. Chile, 1854, p. 317.

Umio caseblance PuivipPi, Zeitz. fiir Mal., V, 1848, p. 176.

Umo casablance Preirrer, Nov. Conch., III, 1869, p. 481, pl.
CLV, fess T2:

Margaron (Unio) casablance Lea, Syn., 1870. p. 53.

Diplodon caseblance Simpson, Syn., 1900, p. 882.

Unio fragilis Sowrrsy, Conch. Icon., XVI, 1856, pl. xxx, fig:
P55: :

1258 DIPLODON

Unio longus Puiiippr, Mal. BL, XVI, 1860, p. 44.—PFEIFFER,

Noy, Conch, TU, 1860, p. 477; pl. cir, ies. 122:

Unio cotcolchaguensis Puiirpt, Mal. Bl., XVI, 1869, p. 47.—

Prrtrrer, Nov. Conch., III, 1869, p. 484, pl. civ, figs. 9, Io.
Unio foncki PHitrer1, Mal. Bl., XV, 1869, p. 49.—PFEIFFER,

Nov. Conch., III, 1869, p. 483, pl. crv, figs. 5, 6.

Unio funcki Parre,, Conch. Sam., III, 1890, p. 153.
Diplodon cuprinus SIMPSON, Syn., 1900, p. 883.

An abundant and variable form.. In the Synopsis, I united
four of Philippi’s species under the name caseblance and am
now of the opinion that all of them should be referred to this
species. In a general way the shell is oblong, sometimes wider
behind than in front: the posterior end may be nearly rounded
or somewhat pointed below the median line; it is rather thin
and subcompressed, the epidermis is bright and nearly smooth ;
the teeth are almost lamellar. There are shells in the National
Museum collection from Brazil, which I can hardly separate
from this species.

In the Synopsis I changed Sowerby’s Unio fragilis to cup-
rinus because the former name had been used for a Unio.
Since the issue of the Synopsis I have become convinced that
his fragilis should also go in the synonymy of D. chilenszis.

DireLopon soLipuLus ( Philippi).

Shell subelliptical, the dorsal line a little more rounded than
the basal line, subinflated, rather solid, inequilateral, with
moderately full, high beaks, whose sculpture is radial; pos-
terior ridge low, rounded, ending behind in a rounded point
below the median line; dorsal line incurved in front of the
beaks; epidermis lightly, concentrically striated, brownish
green; pseudocardinals solid, subcompressed ; laterals curved ;
nacre bluish-white, tinted purple.

Length 54, height 33, diam. 20 mm.

Near Santiago ; Chile.

Unio sohdulus Puitiprs, Mal. Bl, XVI, 1869, p. 46—PFEIF-

FER, Nov. Conch., III, 1869, p. 480, pl. crm, figs. 9, Io.
Diplodon solidulus Simeson, Syn., 1900, p. 881.

DIPI,ODON 1259

A rather short, inflated, solid species, but from the figure
I should say it was a member of the granosus group. I have
never seen the shell.

DirPLepon GAssiest (Kuster).

Shell subrhomboid, subsolid, a little narrower in front, com-
pressed or subcompressed, inequilateral; beaks probably low
but so eroded in the specimens seen that their characters can
not be made out; posterior ridge scarcely developed, widely
rounded ; dorsal line curved, ending behind in a rounded point
at the base; base line straight or a little curved; surface with
fine, irregular growth lines; epidermis dark, olive or bronzy-
green, a little darker on the posterior slope; left valve with
two pseudocardinals, the anterior higher and subcompressed,
the posterior low and imperfect, with two delicate, curved lat-
erals, the upper the smailer; right valve with two compressed
pseudocardinals, the upper small, and one lateral; anterior
scars impressed ; posterior scars superficial ; nacre bluish-white,
darker and blotched in the cavities, considerably thicker in
front.

Length 52, height 28, diam. 15 mm.

Chile.

Unio gassiest Kuster, (part), Conch. Cab. Unio, 1856, p. 148,

pie xan, fie. 4.

Diplodon gassiesi SIMPSON, Syn., 1900, p. 881.
? Unio auratus REEVE, Conch. Icon., XVI, 1865, pl. xxix, fig.

150.

The younger shells of this species are slightly rounded on
the basal line; the old shells become developed at the posterior
end, which grows downward until the base line is straight.
The nacre is thickened in front and lurid in the cavities; the
posterior pseudocardinal of the left valve is low and feebly
developed.

DipLopon APLAtuS (Reeve).

Shell oblong, subrhomboid, convex, subsolid, inequilateral ;
dorsal line irregularly curved, ending behind at the base in a
wide subtruncation or broad rounded point; posterior ridge

1260 DIPLODON

moderate, rounded or faintly double ; beaks raised a little above
the dorsal line, moderately full, sculptured with a few, widely
spaced, narrow, short, radial bars, the central pair coalescing ;
surface with fine, concentric sculpture, becoming much strong-
er on the later growth; epidermis bronzy-olive in front, rich
bronzy-brown behind: left valve with a sort of double, com-
pressed, rough pseudocardinal and two curved laterals; right
valve with two compressed pseudocardinals, the upper small,
and one lateral; muscle scars impressed; nacre bluish-white,
lurid purplish in the cavities, slightly thicker in front.

Length 67, height 34, diam. 21 mm.

Island of Chiloe, Chile.

Unio aplatus Reeve, Conch. Icon., XVI, 1865, pl. xxvim, fig.

143.

Diplodon aplatus Simpson, Syn., 1900, p. 881.

A little larger, more inflated, and more bronzy than D.
gassiest. J,ea has a shell from Cuming, which agrees very
closely with Reeve’s figure of aplatus. The nacre is not quite
so much thickened in front as is that of gassiest.

DieLopon MorIn (Philippi).

Shell long rhomboid, the dorsal and ventral lines parallel,
subcompressed, inequilateral, subsolid; beaks low with short,
radial bars; epidermis pale yellowish-brown or greenish-brown
on the front half of the shell, rather suddenly becoming dark
green on the posterior half; there are sometimes a few, scat-
tered rays on the anterior part ; teeth compressed ; nacre bluish~-
white.

Length 67, height 40, diam. 21 mm.

Southern Chile.

Unio moline Puu.trrr, Conch., III, 1847, p. 50, pl. 1v, fig. 4.—

Kuster, Conch. Cab. Unio, 1862, p. 281, pl. xcv, fig. I.
Diplodon moline Simpson, Syn., 1900, p. 881.

Unio auratus Sowerry, Conch. Icon., XVI, 1866, pl. xiv, fig.

245.

The almost exactly rhomboid form and the peculiar pattern
of color would seem to be pretty good characters by which

DIPLODON 1261

this might be distinguished from nearly allied forms. Sower-
by’s Unio auratus seems to be a young shell of the same thing.
Its beaks are perfect and therefore a little higher than those
of the specimens figured by Philippi, which are eroded, and
Sowerby’s shell shows more scattered rays.

DIPLODON MopDEstTUS (Kuster).

Shell oblong, subtrapezoid, subinflated, subsolid, inequilat-
eral; beaks low, their sculpture not seen; surface apparently
strongly, concentrically striate; posterior ridge rounded, end-
ing behind in a blunt point on the nearly straight base line ;
epidermis fuscous, shining; pseudocardinals subsolid; laterals
short ; nacre bluish-white.

Length 58, height 32, diam. 20 mm.

Chile.

Unio modestus Kuster, Conch. Cab. Unio; 1856, p. 147, pl.
Xi, toa:

Diplodon modestus SIMPSON, Syn., 1900, p. 881.

Unio ianthinus Puitipri, Mal. Bl., XVII, 1860, p. 47.—PFEIF-
eeR, Nov. Conch., III, 1869, p. 485, pl. civ, figs. 11, 12.

Unio vaidivanus Puiirerpr, Mal. Bl., XVI, 1860, p. 48.—PFEIF-
FER, Nov. Conch., III, 1869, p. 479, pl. c111, figs. 7, 8.

Unio montanus Putrirrt, Mal. BL, XVI, 1869, p. 48.—PFEIF-
FER, Nov. Conch., III, 1869, p. 482, pl. civ, figs. 3, 4.
Credited to Charpentier manuscript by Kuster.

At the time of writing the Synopsis I was inclined to believe
that this species equaled some of Philippi’s Chilean species,
but more careful study of the figures and descriptions lead
me to believe it is different. It seems to be rather more solid
and inflated like the forms, which were placed by Philippi
under D. ianthinus. A dorsal view of Charpentier’s species
shows that both ends are suddenly narrowed into blunt points.

DrIeLopon ATRATUS (Sowerby).

Shell rather short, obovate, subrhomboid, subcompressed,
scarcely subsolid, inequilateral, with slightly raised beaks hav-
ing delicate, radial sculpture; posterior ridge low, rounded,
ending in a rounded point behind near the base, the posterior

1262 DIPLODON

end above it obliquely subtruncated ; surface apparently finely,
concentrically sculptured; epidermis brownish-green; teeth
compressed ; nacre bluish-white.

Length 48, height 26, diam. 15 mm.

Length 50, height 30, diam. 17 mm.

Peru; Chile:

Unio atratus SowrRny, Conch. Man., 18309, fig. 148.
Diplodon atratus SiMPSON, Syn., 1900, p. 881.
Unio limensis Kuster, Conch. Cab. Unio, 1856, p. 146, pl

SI) ona eo fie Te
Unio jacobeus PHitipp:, Mal. Bl., XVI, 1869, p. 44.—PFEIF-

FER, Nov. Conch., III, 1860, p. 478, pl. ci, figs. 3, 4.
Unio landbecki Putiiprr, Mal. Bl., XVI, 1869, p. 45.—PFEIF-

rer, Nov. Conch., IIT, 1860;-p:-479, pl: cu, hes. 5, 6:
Unio diplodon Puuarri, Mal. BL, XVI, 1869, p. 46.—PFEIF-

FER, Nov. Conch., III, 1869, p. 483, pl. crv, 7, 8.

I have united under the oldest name several of Philippi’s
so-called species whose differences are so trifling that they
do not seem to me to be worthy of varietal rank. Philippi
bestowed names on every conceivable variation among the
Uniones of Chile and it seems to me to be quite likely that a
large series of specimens from that region would show that
a farther reduction of names was necessary. Those which
I have thrown together under the name atratus are rather
short and obovate or subrhomboid in outline. Their author
does not say whether they are sculptured or not or anything
regarding the degree of smoothness of the surface. Unio dip-
lodon Philippi may belong here.

DirpLopon optusus (d’Orbigny ).

“Shell ovate, compressed, rather thick, concentrically ru-
‘gose; epidermis greenish-brown, umbones smooth, ends ob-
tuse, rounded, posterior end elongate; nacre bluish-green.

Length 66 mm. In proportion to the length, the height is
55-100, the diameter 34-100, length of the posterior margin
77-100; apical angle 157°.” (d’Orbigny).

La Laguna, Province of Valparaiso, Chile.

DIPLODON 1263

Unio obtusa dOrricny, Guer. Mag., 1835, p. 35; Voy. Am.

Mer., 1843, p. 610.

Diplodon obtusus Simpson, Syn., 1900, p. 882.

“This species is close to U. patagonica, but is distinguished
by its much larger size, more obtuse extremities and by its
more rugose surface.”

Said by d’Orbigny to be of Ferussac, but he does not say
where that author described it and I do not know where. If
the species be a valid one, it will probably have to have a new
name. d’Orbigny did not describe it until 1843. In 1835 he
quotes it as “obtusa Fer.,” but gives no description and refers
it to depressa Less., (1830), from New South Wales. The
obtusa (Fer.) d’Orbigny of 1835 would fairly seem to be a
synonym of depressa and the name could not be used again for
the Chilean species when finally described in 1843. Until the
status of the species is definitely determined, it hardly seems
worth while to rename it.

DriPLopoN RHUACONICUS (Kuster).

Shell subrhomboid, a little wider behind, convex, inequilat-
eral with only moderately full beaks, whose sculpture consists
of strong, radial bars extending well onto the disk: posterior
ridge somewhat double, ending behind in a feeble biangula-
tion just below the median line: surface densely, concentric-
ally striate and sulcate; epidermis very dark, showing the
growth lines; pseudocardinals compressed, the posterior one
in the left valve imperfect ; nacre bluish-white.

Length 53, height 30, diam. 16 mm.

Uruguay.

Brazil.

Unio rhuaconicus Kuster, Conch. Cab. Unio, 1856, Pp. 14'5;) pl:

Sebi fig, 5)

Diplodon rhuaconicus Stupson, Syn., 1900, p. 882.

This is very different from dOrbigny’s rhuacoica.

Kuster states that this is Unio rhuaconicus Pfeiffer teste
Charpentier. I know nothing of it beyond the figure and

1264 DIPLODON

description in the Conchylien Cabinet. It is almost jet black,
but the rest lines are exhibited in the figure. It seems to be
remarkable for its very strong, even sculpture, which extends
out well on to the disk.

DipLopon CHILOENSIS (IXuster).

Shell long elliptical, moderately convex, inequilateral,
smooth ; anterior end narrowly rounded; posterior part ending
in a rounded point just below the median line, and at the end-
ing of the low, rounded posterior ridge; beaks scarcely ele-
vated, their sculpture unknown; surface smooth, pitch black.

Length 66, height 37 mm.

Island of Chiloe, Chile.

Unio chiloénsis Kuster, Conch. Cab., 1856, p. 161, pl. xxxv,

fig. 6.

Diplodon chiloénsis Stweson, Syn., 1900, p. 882.

Kuster gives no account of the teeth, nacre or degree of
solidity of his species. It is rather evenly elliptical in outline
and this character and the jet black epidermis ought to distin-
guish it from nearly allied forms. J/uster gives a figure of
Unio chiloénsis, which he credits to Philippi in sched. under
this name. He also credits the species to Philippi in the Ab-
bildungen under the name Unio auratus.

DIPLODON FRENZELLIN (von Lhering).

Shell oblong, subcompressed or convex, quite solid, inequi-
lateral, with the dorsal and ventral lines nearly parallel; ante-
rior and posterior ridge nearly or quite wanting; beaks low,
not inflated, their sculpture consisting of fifteen or sixteen
nearly straight, radial ridges, the middle ones converging, the
spaces between them strongly, concentrically striate; surface
covered with coarse, uneven, concentric ridges ; epidermis pale
tawny or yellowish-green, shining, somewhat bronzy ; left valve
with two small pseudocardinals, the anterior compressed, the
posterior imperfect, and two remote laterals; right valve with
two pseudocardinals, the lower larger, and one remote lateral ;
beak cavities shallow with two or three deep dorsal scars in

DIPLODON 1265

each; nacre dirty white, lurid in the cavities, thickened and
solid in front.

Length 71, height 35, diam. 20 mm.

Length of a younger shell 50, height 26, diam. 12 mm.

Patagonia; Chile; Os Perus, San Paulo, Brazil.

Umo frenzellu von InErRinc, Arch. fir Nat., 1893, p. 3, pl.

RVs 12)

Diplodon frenzellii SIMPSON, Syn., 1900, p. 882.

Dr. von Ihering sent two shells to the National Museum
which are probably this species. The form is oblong and al-
most evenly rounded at the ends, there is no posterior ridge,
but one or two feeble raised lines on the posterior slope. The
shell is quite solid and strongly sulcate, of a peculiar yellow-
ish-green with a bronzy or metallic tint. Von Ihering states
that it is sometimes brown.

DIPLODON HUAPENSIS Bartsch.

“Shell thin, elongate, elliptical, drawn out posterio-ventrally
into a blunt beak, compressed dorsally, from a line extending
from the umbones to the posterior-dorsal margin of the beak
and somewhat pinched in its subcentral ventral half. Dorsal
margin slightly curved, its posterior third sloping regularly
obliquely downward. Anterior margin abruptly curved, fall-
ing off a little more gradually toward the ventral than the
dorsal edge. Posterior extremity evenly rounded. — Ventral
margin somewhat concave in the middle. Periostracum brown
on the posterior dorsal portion of the shell, grading to wax-
yellow streaked with brown on the anterior ventral parts. Sur-
face marked with nunierous lines of growth, the stronger ones
of which are usually darker colored than the general surface,
and numerous fine, crinkly, radiating lines, which are best de-
veloped on the anterior half, and gradually diminished in
prominence posteriorly. Beak cavities shallow. Pseudocardi-
nals in the right valve two, narrow, weak, sublamellar, and
very oblique, the dorsal one decidedly notched and stronger
than the ventral, which is rugose. Left pseudocardinal nar-
row, slender, slight, notched, and cut into many fine tubercles.

1266 DIPLODON

Right lateral only moderately curved, very slender, slightly
roughened, more so on the inner than on the outer edge. Left
laterals thin, and lamellar, inner one larger and better devel-
oped than the dorsal, both with roughened edges. Nacre blu-
ish, with many spots of livid olive, which are more numerous
and extensive in the dorsal part of the shell than ventrally.
Posterior part iridescent.

Length 55, height 25.9, diam. 14.5 mm.” (Bartsch).

Type locality, Victoria Island, Lake Nahuel Huape, Argen-
tina.
Diplodon huapensis Bartscu, Pr. U. S. Nat. Mus., XXX,

1906, p. 394, pl. XXVI!I-XXIX.

“The shell in a general way recalls Diplodon caswblance
Philippi and Diplodon frenzellii Ihering, but can readily be
distinguished from them by its narrower outline.”

DIPLODON MARTENSI (von Ihering).

Shell long rhomboid, a little wider behind, subinflated, sub-
solid, quite inequilateral, with tow beaks whose sculpture is
not-shown in the figure; posterior ridge low, rounded, ending
behind in a rounded point at the base of an oblique posterior
truncation and near the basal line; base line a little incurved
in the middle, full behind the emargination; surface smooth,
greenish-chestnut ; pseudocardinals sublamellar; laterals re-
mote; nacre silvery, iridescent.

Length 50, height 29, diam. 21 mm.

Southern Brazil.

Unio martensi voN InERING, Arch. fur Nat., 1893, p. 100, pl-

Iv, fig. 10.

Diplodon martensi Stmpson, Syn., 1900, p. 882.

DIPLODON DUNKERIANUS (Lea).

Shell oblong, irregularly elliptical, a little wider behind, in-
equilateral, scarcely subsolid; beaks rather low, not inflated,
their sculpture rather strong, sometimes corrugated, radial
bars, the posterior ones extending well over the disk; poste-
rior ridge well developed, somewhat biangulate, there being

DIPILODON 1267

one or two faint, radial ridges above it; posterior slope sub-
truncate; base angularly inflated near the hinder end of the
shell, the posterior point-of which is faintly biangulate and on
the median line; surface with delicate, close, raised growth
lines ; epidermis nearly black, lighter at the umbonal region ;
left valve with one Jamellar pseudocardinal with sometimes

a blurred vestige of a posterior one, and two delicate laterals ;

right valve with two long pseudocardinals and one lateral ;

beak cavities shallow: nacre bluish, silvery,

Length 57, height 29, diam. 17 mm.

Rio Macacon, Rio Janiero, Brazil; New Granada.

Unio dunkerianus Lea, Pr. Neen Sa. Phila., VIII, 1856, p.
94; Obs., VI, 1857, p. 25, pl. xxviur, fig. 20; Jl. Ac. N. Sci.
Phila., I11, 1858, p. 303, pl. xxvii, fig. 20.—KusrEr, Conch.
Cab. Unio, 1862, Pp. 290, pl. xcu, fig. 6.—Sowerey, Conch.
Icon., XVI, 1868, pl. xc, fig. 485.

Margaron ( Unio) dunkerianus Lea, Syn., 1870, Ps 32:

Diplodon atratus ( part), Simpson, Syn., 1900, p. 882.

Lea has two specimens in his collection, one from Dr. Dun-
ker, said to some from Rio Janiero, and the other, which he
has figured, from New Granada, presented by Verreaux. They
are undoubtedly identical and seem to have as distinguishing
characters the angular post-basal swelling, the glossy black
epidermis, which is lighter above, and the lengthened posterior
beak sculpture.

DieLopon BINNEY (Lea).

Shell long elliptical, pointed on the median line behind, with
the posterior base somewhat angularly swollen and the pos-
terior slope subtruncated., subcompressed, thin: posterior ridge
low, sub-biangulate: beaks low and somewhat compressed,
eroded in the only specimen seen, but showing distinct, radial
sculpture extending some distance out on to the disk; surface
irregularly, concentrically sculptured : epidermis olive or
bronzy-green, scarcely shining; left valve with an anterior
compressed pseudocardinal, the hinder one a mere low tubercle

and two delicate laterals; right valve with two compressed

1268 DIPLODON

pseudocardinals, the upper small, and one lateral; nacre bluish-

white.

Length 55, height 29, diam. 15 mm.

South America.

Unio binneyt Lea, Pr. Am. Phil. Soc., IV, 1845, p. 165; Tr.
Am: PhilvSoc7 ek, 1eqsiip: 77, pe Vie: les Ops-0V> pe76.
pest; plaviy igs 13:

Margaron (Unio) binneyi Lea, Syn., 1852, p. 29; 1870, p. 46.

Diplodon binneyi Simpson, Syn., 1900, p. 878.

Dr. I,ea received this shell from Dr. Griffith and it is labeled
“Alabama” with a question, though he credits it to the South-
ern States in his description. ‘The type, the only shell I have
seen, though eroded at the beaks shows radial sculpture plain-
ly, some of this extending on to the healthy epidermis. It is
thinner than dunkerianus, is much more strongly sulcate, is
lighter colored and not so shining, and has shorter pseudocar-
dinals. It probably groups with it.

DIPLODON AUREUS Simpson.

Shell oblong, irregularly elliptical, subsolid, convex, inequi-
lateral; dorsal outline more strongly curved than that of the
base; beaks moderately full, their sculpture radial; posterior
ridge low and rounded, ending behind in a bluntly rounded
point a little above the base; surface strongly, concentrically
sculptured ; bronzy, olivaceous-yellow, shining ; pseudocardinals
small, crenated; those of the left valve united; there are two
compressed ones in the right valve, the upper smaller; left
valve with two remote laterals; right valve with one; muscle
scars impressed ; nacre bluish-white, stained dull purple in the
cavities.

Length 60, height 30, diam. 20 mm.

Length 68, height 34, diam. 22 mm.

Chile.

Unio auratus Kustrr, Conch. Cab. Unio, 1856, p. 161, pl.

XLVI, fig. 3.

Diplodon aureus Simpson, Syn., 1900, p. 883.

A fine species, of which the Lea Collection contains a good

specimen. The radial sculpture occupies but a small area, the

DIPILODON 1269

surface is strongly, concentrically sculptured, and the epider-
mis is shining, and is a rich bronzy, olivaceous-yellow. Kuster
supposes this to be the Unio auratus of Swainson and Philippi,
which is quite a different thing. I therefore give it a new
name.

DIPLODON CORIACEUS (Dunker).

‘Shell oval, subrhomboid, subcompressed, surface mostly
coriaceous, granulose; epidermis olivaceous; anterior end
short ; posterior end produced ; beaks small; nacre bluish-white,
opaque.

Length 100, height 60, diam. 35 mm. ?

Rio Negro, Province of Rio Janeiro, Brazil.

Umio coriaceus DUNKER, Zeits. fiir Mal., V, 1848, p. 181.
Diplodon coriaceus SIMPSON, Syn., 1900, p. 883.

I know nothing whatever of this species save the descrip-
tion and a few remarks in Latin given by its author. Von
Thering mentions it in a list as from the Rio Negro in southern
Brazil.

DIPLODON CHILDRENI (Gray).

Shell irregularly elliptical, being slightly curved on the dor-
sal line and much more strongly curved below, inequilateral,
apparently little inflated and rather thin; beaks moderately
full, eroded in the specimen figured; posterior ridge low,
rounded, ending behind in a rounded point above the centre
of the base; from this point upward the posterior end of the
shell is somewhat truncated; surface showing the rest periods,
dark reddish-brown ; teeth compressed; nacre apparently blu-
ish-white.

Length 74, height 47 mm.

South America.

Unio children Gray, Griff. Cuv., XII, 1834, p. 600 (index),
plex shes,

Margarita (Unio) childreni Lea, Syn., 1836, p. 25; 1838, p. 19.

Margaron (Unio) childreni Lea, Syn., 1852, p. 28; 1870, p. 44.

Diplodon childreni Stwpson, Syn., 1900, p. 883.

T2710 DIPLODON

Griffith gives a figure of this shell and merely the name,
Umio childreni, in the index and six words of description.
The laterals are slender and nearly straight; the region of the
pseudocardinals is badly eroded and these teeth are not clearly
shown in the rather poor figure. The coloring shows the epi-
dermis to be dark reddish-brown, and the nacre bluish-white.
[ know nothing of the species beyond what I have stated, but
should place it in the granosus group of Diplodon. Griffith
states that it is from South America and Lea says it is from
Chile. It is higher in proportion than D. chilensis, and the
ventral line is more inflated than in any other species I have
placed in this group.

DIPLODON SANTA-MARL& N. s.

Shell olong, subrhomboid, wider behind, inequilateral, com-
pressed, with a low, rounded posterior ridge; beaks low, with
numerous, curved, radia! ridges, which are sometimes granu-
lous and slightly zigzagged, the central bars coalescing below ;
surface covered with fine, concentric sculpture; epidermis
brown, sometimes olive-green and bronzy when young, scarce-
ly shining, often cloth-like ; left valve with a single, compressed
pseudocardinal, the posterior one often almost or wholly want-
ing and two remote, nearly straight, laterals; right valve with
two long lamellar pseudocardinals, the upper smaller, and one
lateral; muscle scars well marked; nacre bluish-white, lurid
in the cavities, a little thicker in front.

Length 63, height 33, diam. 18 mm.

Length 46, height 27, diam. 15 mm.

3razil?

A peculiarly quadrate, compressed form with brown epider-
mis and fine, concentric sculpture. The posterior tooth in the
left valve is wanting or nearly so in a large number of the
shells I have seen.

Specimens under this name were received by the National
Museum from von Ihering. I have not been able to discover
that it has ever been published.

DIPLODON 1271

Group of Diplodon burroughianus.

Sheil elliptical, moderately solid, inflated, sharply pointed
behind, with a high, well-developed posterior ridge; beaks
rather full; the sculpture consisting of regularly radiating,
widely separated, sharp ridges, the intervening grooves round-
ed out ; epidermis smooth, dark olive with lighter bands; pseu-
docardinals compressed, rough, vertically ridged, usually trifid
or quadrifid in each valve; laterals curved, compressed ; mus-
cle scars smooth; nacre white, silvery.

Animal unknown.

DIPLODON BURROUGHIANUS (Lea).

Shell ovate, subinflated, rather solid, inequilateral, with full
but not elevated beaks, whose sculpture consists of strong, un-
even, radial ridges; posterior ridge well developed, angular,
ending behind in a point on the median line; surface sculp-
tured with irregular, strong, concentric ridges, and having
traces of radial sculpture ;epidermis ashy-green and dark brown
in alternating, concentric bands; left valve with two compress-
ed, roughened pseudocardinals, the posterior small, and two
curved laterals; right valve with two pseudocardinals, the
upper small, and one lateral; hinge line narrow and rounded
between the two sets of teeth; muscle scars shallow ; nacre sil-
very, iridescent behind.

Length 88, height 58, diam. 35 mm.

Length 71, height 43, diam. 26 mm.

Parana River, South America.

Unio burroughianus Lea, Tr. Am. Phil. Soc., V, 1834, p. 67,
pl. x, fig. 27; Obs., I, 1834, p. 179, pl. x, fig. 27, HANLEy,
Biv. Shells, 1843. p. 197, pl. xxt1, fig. 2—Sowersy, Conch.
Icons, XV 11866, plo XxxiI, 160:

Margarita (Unio) burroughianus Lea, Syn., 1836, p. 29; 1838,
Pe 2.

Margaron (Umo) burroughianus LEA, Syn., 1852, p. 31; 1870,
p50:

Diplodon burroughianus Stmeson, Syn., 1900, p. 883.

1272 DIPILODON

Almost evenly elliptical in outline. There is sometimes a
very slight post-dorsal wing and the base line is occasionally
a little produced behind the middle. Old shells become quite
dark and the banding fades out; in younger specimens the
bands are quite distinct.

DipLopon TRIFIDUS (Lea).

Shell long ovate, solid, scarcely inflated, very inequilateral,
with high, rather full beaks, which are sculptured with numer-
ous, strong, radial bars that extend well out on to the disk;
posterior ridge strong and decidedly angled, ending behind in
a point a little below the median line; surface with faint, con-
centric sculpture; epidermis smooth, almost shining, dark and
light olive-green in concentric bands; left valve with two high,
very ragged pseudocardinals with a feeble third one between
them, the middle one split up, and two curved laterals; right
valve with one strong, ragged pseudocardinal, a very small
one above it. and a divided lateral; muscle scars small, im-
pressed; dorsal scars distinct; nacre bluish-white, somewhat
silvery.

Length 42, height 22, diam. 15 mm.

Argentina.

Umovirsidus Waa, Pr Ac. NScm Phila 1V 8601p, Soni:
Ac. Nese Phila., V, 1863, p..386, pl. xis, 2055 Obs.
1863; p22, pl: XETV, fie: 205,

Margaron (Unio) triidus Tea, Syn., 1870, p. 50.

Diplodon trifidus SIMPSON, Syn., 1900, p. 884.

The type, the only specimen ] have seen, may be a young
shell, though it is quite solid. This species is more solid and
elongated than 7). burrowghianus and its pseudocardinals are
much ruder and rougher.

DIPLODON IHERINGI (Clessin?).

Shell small, nearly evenly elliptical, inequilateral, subsolid,
convex, with a well developed, subangular posterior ridge,
which ends behind in a point at the median line; beaks mod-
erately full, not much elevated above the dorsal line, with

DIPILODON 1273

numerous subradial bars, which point downward and_back-
ward, anterior end subtruncate; surface finely, concentrically
striate ; epidermis brownish or brownish-green, banded, scarce-
ly shining; left valve with two compressed pseudocardinals,
the hinder one feeble, and two delicate, curved laterals; right
valve with one compressed pseudocardinal and a vestige of
another above it, with one lateral; muscle scars impressed ;
nacre bluish, tinted yellow in the cavities.

Length 28, height 20, diam. 13 mm.

Guahyba, Brazil.

Umio theringi SIMPSON, Syn., 1900, p. 894.

This is a neat species, the smallest of the Diplodons and
quite distinct from all others. It is less drawn out behind than
either of the species placed in this group.

T have not been able to discover whether this species has
ever been described or not.

Group of Diplodon paszi.

Shell subtrapezoidal, rounded in front and strongly biangu-
late behind; the wavy beak sculpture extending well over the
disk ; epidermis olive; pseudocardinals ragged, with a tendency
to break into denticles.

DreLopon PAzt (Hidalgo).

Shell unevenly ovate or subrhomboid, subsolid, convex, the
dorsal line curved; post-dorsal slope subtruncated; posterior
ridge double below, ending a little above the base in a slight
biangulation ; post-dorsal region a little produced ; between this
and the posterior point the base line is feebly incurved; beaks
apparently not high, their sculpture consisting of strong, sub-
nodulous, subradial ridges, the central ones coalescing ; below
these ridges become somewhat zigzagged and they extend al-
most to the border of the shell; later growth apparently des-
titute of sculpture; epidermis olivaceous; pseudocardinals and
laterals granular; nacre bluish-white.

Length 37, height 23 mm.

Imbabura, Ecuador.

1274 DIPILODON

Castalia pazi Hiparco, Jl. de Conch., XVI, 1868, p. 353, pl.
MTT. fis 6. .
Diplodon pazi Stmpson, Syn., 1go0, p. 884.
Not so distinctly biangulate behind as D. hyleus, the sculp-
ture nodulous and inclined to break up below into a zigzag
pattern. I have no doubt but what this is a Diplodon.

DieLopon HYLAUS (d’Orbigny).

Shell somewhat rhomboid, solid, convex, inequilateral, with
a nearly straight dorsal line; the post-dorsal slope having a
straight oblique truncation; posterior ridge distinctly double
below, ending behind a little above the base in a decided bian-
gulation; post-basal region a trifle swollen; surface covered
for about half way down from the beaks with strong, curved,
radial ridges, one or two of the central pairs coalescing; the
outer portion of the shell appears to have sulcate, concentric
sculpture; epidermis greenish-brown; teeth apparently rather
strong; nacre bluish-white.

Length 44, height 24, diam. 17 mm.

Bolivia; Paraguay River.
Umo hylea VOrsicNy, Guer. Mag., 1835, p. 36; Voy.-Am.

Mer., 1843, p. 607, pl. LxIx, figs. 8, 9.
Margaron (Umo) hyleus Lea, Syn., 1852, p. 21; 1870, p. 31.
Unio hvleus SowerBy, Conch. Icon., XVI, 1868, pl. xcri, fig.

500.
Diplodon hyleaus Stmpson, Syn., 1900, p. 884.
Unio guaraniana d’OrpiGNy, Guer. Mag., 1835, p. 37; Voy.

Am. Mer., 1843, p. 608, pl. Lx1x, figs. 10-12.

Unio guaraniana d’Orbigny seems to me to be only a young
hyleus. The post-dorsal point is a little more elevated than
that of the last named.

Group of Diplodon parallelipipedon.

Shell elongated, subtrapezoidal, inflated, obliquely truncate
behind, posterior ridge strong; beaks rather low, sculpture of
nearly or quite strictly radial bars with concave spaces be-
tween; epidermis dark; pseudocardinals compressed in the

DIPI,ODON 1275

young, granular, vertically striate and breaking into denticles
in the old shell; laterals long, curved, granular, often verti-
cally striate ; anterior scars smooth, distinct.

DIPLODON PARALLELIPIPEDON (Lea).

Shell greatly elongated, subrhomboid, rather solid, inflated,
very inequilateral ; beaks full and somewhat elevated above the
dorsal line, their sculpture a few, strong, short, radial bars;
posterior ridge high, angled on the earlier growth, ending be-
hind in a point near the base line; surface having irregular,
concentric sculpture; epidermis bright, dark bottle-green with
narrow, concentric bands of light green; left valve with two
pseudocardinals, the anterior high, rough and subcompressed,
the hinder low, with two straight, granular laterals ; right valve
with two compressed pseudocardinals, the upper eniall and one
lateral having a vestigial one at its base; all the teeth showing
indications of vertical striation; anterior scars deep; posterior
scars impressed; nacre silvery-white, a little thicker in front:

Length 85, height 32, diam. 27 mm.

Rio de la Plata system.

Unio parallelipipedon Les, Tr. Am. Phil. Soc., V, 1834, p. 60,
pie vai ne. 20 Obs. 11834) p.172,, pl. vill, fie. 20.--Kus-
TER, Conch. Cab. Unio, 1861, p. 220, pl. Lxx1v, fig. 2—Sow-
ERBY, Conch. Icon., XVI, 1868, pl. Lxxxix, fig. 478.

Margarita (Unio) parallelipipedon Lea, Syn., 1836, p. 35;
1838, p. 24.

Margaron (Unio) parallelipipedon Lea, Syn., 1852, p. 36;
1870, p. 58.

Diplodon parallelipipedon Simpson, Syn., 1900, p. 884.

Unio bonplandt VALeNCIENNES, Continuation of Hiomivoidys
Zool. Obs., 1827.

A. striking, elongated species, which is remarkable for the

wide, bottle-green belts alternating with narrower ones of
lighter color.

DipLopon PATAGONICUS (d’Orbigny).

Shell oblong, subrhomboid, rather solid, very inequilateral.
subinflated, with a strong, rounded posterior ridge, which
curves up a little in the middle and ends behind in a rounded

1276 DIPILODON

point at the base of the shell; anterior end slightly truncated
or round; base line straight or faintly incurved; surface with
feeble, uneven, concentric sculpture; epidermis dark brown to
jet black, scarcely shining ; left valve with one or two subcom-
pressed, rough, pseudocardinals and two laterals; right valve
with two pseudocardinals, the upper smaller, and one lateral;
laterals with granular vertical striz; anterior scars deep;
there is a crescent shaped scar at the base of the pseudocar-
dinals ; posterior scars large; nacre dirty bluish-white, darker
in the cavities of the valves, a little thicker in front.

Length 88, height 40, diam. 27 mm.

Patagonia.
Unio patagonica d’OrpicNy, Guer. Mag., 1835, p. 37; Voy.

Am. Mer., 1843, p. 610, pl. Lxx, figs. 1-4.
Margarita (Unie) patagomicus Lea, Syn., 1838, p. 25.

Unio patagonicus HAN Ey, Biv. Shells, 1843, p. 208, pl. xxu,
fig. 16.—-Rreve, Conch. Icon., XVI, 1865, pl. xx1, fig. 93.
Margaron (Unio) patagonicus Lea, Syn., 1852, p. 38; 1870,

peOks
Diplodon patagonicus SYMPSON, Syn., 1900, p. 885.

Not quite so decidedly pointed at the posterior base as
acutirostris; the pseudocardinals are not so much split up and
the nacre is not so clean, yet probably the two run together.

DIPLODON ACUTIROSTRIS (Lea).

Shell elongated, convex, very inequilateral ; with beaks prob-
ably somewhat full; posterior ridge strong, curved upward in
the middle and ending in a point at the extreme base; base
line incurved in front of the hinder point; anterior end de-
cidedly truncated and ending in a right angle above; surface
unevenly, concentrically sculptured, dirty olive, not shining;
there is a large pseudocardinal in each valve split up into nu-
merous, rough, radial teeth; one lateral in each valve, that of
the left somewhat double; both are granular and show traces
of vertical striation; anterior scars small and deep; posterior
scars oblique ; nacre bluish-white, a little thicker in front.

Length 80, height 40, diam. 24 mm.

South America.

DIPLODON 127-7

Unio acutirostris Lea, Pr. Ac. N. Sci. Phila., X, 1866, p.-34;
JiRNce Nee se hla Vil 18608. p. 270, pl. xxxv, fig. 84.
Obs;, XM 1860; p. 30, pli xxxv, fic. 84.

Margaron (Unio) acutirostris Lea, Syn., 1870, p. 58.

Diplodon acutirostris Stmpson, Syn., 1900, p. 885.

I am very doubtful whether this is more than a form of
d’Orbigny’s patagonicus. I have only seen one shell, the type,
which is badly eroded. The teeth and nacre differ somewhat
from those of specimens of that species in the Lea Collection
and it is a little more decidedly truncate in front, but the differ-
ences are only of degree and there seems to be considerable
difference in these characters among the shells I have seen.

Group of Diplodon quadrans.

Shell subtrapezoid, slightly truncate in front, nearly equilat-
eral, greatly inflated, its greatest diameter below the beaks,
from which it is wedge-shaped in front and behind, solid,
with a decidedly rounded posterior ridge; epidermis brownish,
concentrically striate; beaks full, but not high; ligament long
and slender; pseudocardinals large, compressed, striate, and
crenulate, double in the right valve, single in the left; laterals
curved, crenulate; beak cavities rounded; anterior cicatrices
deep, confluent ; nacre white.

Animal unknown.

DIPLODON QUADRANS (Lea).

Shell short, subrhomboid, inflated, somewhat inequilateral,
rather solid; beaks full, but not very high; posterior ridge full,
rounded, ending behind in a rounded point at the base; ante-
rior end somewhat truncated, subangular above ; surface strong-
ly, concentrically striate; epidermis dark brown; pseudocardi-
nals compressed, the anterior one in the left valve small; lat-
erals decidedly curved; anterior muscle scars deeply impress-
ed; posterior scars shallow; nacre white and iridescent, thick-
ened in front.

Irength 93, height 68, diam. 52 mm.

South America (?).

1278 DIPLODON

Unio quadrans Lea, Pr. Ac. N. Set. Phila., IV, 1850, p. 306;
JL Ac? NY Scn: Phila; IV, 1860,.p. 360, pl. ax, ie ese
Obs:, WE, 1860, 'p: 42, pl es:

Margaron (Unio) quadrans Lea, Syn., 1870, p. 36.

Diplodon quadrans Simpson, Syn., 1900, p. 885.

This shell, which is in the Wheatley collection, is supposed
to have come from Texas. Nothing like it has been reported
by any one else from that state and there seems to be nothing
from the Texan or Mexican region that is in any way related
to it. The umbonal region is so eroded that no traces of beak
sculpture remain, but the character of the teeth, the general
appearance, color and sculpture seem to aily it to the forms of
South America. The greatest degree of inflation is well for-
ward and from this it is rather regularly wedge-shaped in
front and behind.

Subgenus Cyclomya Simpson, 1900.

Cyclomya SIMPSON, Syn., 1900, p. 886.

Shell obovate to suborbicular, narrowed in front, produced
just behind the center of the base, generally slightly pointed
about the middle of the posterior end, with a scarcely percep-
tible posterior ridge and a slight dorsal wing behind; beaks
high, irregularly radial; hinge line strongly arched, curved.
behind and incurved in front of the beaks; the lower pseudo-
cardinal in the right valve largest, often much split up into
denticles, those of the left valve variable, generally dentilate ;
two jiower anterior scars deep, united, the upper very deep,
separate.

Animal having the gills rather short, inner the longer,
united throughout to the abdominal sac, outer subangular be-
low; palpi large, projecting behind; branchial opening large,
with a few stout papille; anal opening separated from the
branchial by a bridge, but not separated from the superanal
opening.

Type, Unio funebralis Lea.

DIPLODON 1279

Section CYCLOMYA s. s.
DipLopON PATEI,LOIDES (Lea).

Shell unevenly rhomboid, short, somewhat compressed,
rather solid, slightly inequilateral; beaks moderately full and
elevated above the dorsal line, sculptured with radial bars;
dorsal line curved in in front of the beaks and upward behind
them; posterior ridge full and rounded, ending behind in a
blunt point just below the median line, above this point the
shell is obliquely truncated; base swelled at and behind the
middle; anterior end narrowed and pointed; surface rudely
and unevenly, concentrically sculptured, showing traces of
radial sculpture; epidermis dark brown, scarcely shining; left
valve with two compressed, ragged pseudocardinals, the hinder
small, and two curved laterals; right valve with two pseudo-
cardinals, the upper small, and one lateral; laterals granular ;
muscle scars well marked; nacre white, somewhat silvery,
thicker in front.

Length 75, height 59, diam. 28 mm.

Amazon River.

Unio patelloides Lea, Pr. Ac. N. Sci. Phila., 1V, 1860, p. 89;
Ji-Ac N: Sct. Phila.;-V ; 1863,'p..383, pl. xii, fg. 297; Obs.,
XX) 1803.-ps 1On pl. XL; fe. 207.

Margaron (Unio) patelloides Lea, Syn., 1870, p. 56.

Diplodon patelloides Stmpson, Syn., 1900, p. 886.

A rudely sculptured species with distinct traces of radial
grooves, with a rich brown epidermis. The pseudocardinals
are more compressed than those of D. funebralis ; it is sharper
in front and behind and not so swollen in the post-basal region.

DIPLODON PER-EFORMIS (Lea).

Shell irregularly obovate, subsolid, subinflated, inequilateral,
with only moderately full or elevated beaks, whose sculpture
is radial; posterior ridge well defined and subangular, ending
behind in a point a littie above the median line; above this
point the shell is obliquely truncated; anterior end narrow and
rounded; base very full just behind the middle; surface very
slightly, concentrically sculptured ; epidermis bottle-green ; left

1280 DIPILODON

valve with two small pseudocardinals and two remote laterals ;

right valve with two pseudocardinals, the upper very small,

and one lateral; muscle scars shallow ; nacre bluish-white.

‘ Length 44, height 32, diam. 20 mm.

Uruguay River, South America.

Unio pereformis Lema, Pr. Ac. N. Sci. Phila., IV, 1860, p. 90;
ji. Ac. N. Set. Phila.; V, 1863, p:'384,.-pl xumit, fie. 292; @bs:,
X, 1863, p. 20, pl. xr, fig. 292.—Sowersy, Conch. Icon.,
XVI, 1868; pl: LX xxiv, fig. 443:

Margaron (Umo) perejormis Lea, Syn., 1870, p. 55.

Diplodon pereformis SIMPSON, Syn., 1900, p. 886.

Probably the type, the only shell I have seen, is a young
shell. It is considerably inflated and very much produced just
behind the middle of the base.

DIipLODON FONTAINIANUS (d’Orbigny).

Shell unevenly obovate cr subtrapezoidal, scarcely inflated,
the greatest diameter being in the middle of the shell, the front
part being wedge-shaped, with moderately full but not high
beaks, which are situated in front of the center, the dorsal line
in front of them strongly incurved; beak sculpture radial,
sometimes subnodulous; posterior ridge full, rounded, ending
behind in a rounded projection near the base; dorsal line
curved behind the beaks, obtusely angled where it meets the
posterior truncation; surface with fine, concentric growth
strie, often with faint traces of radial sculpture; epidermis
greenish-brown to blackish, scarcely shining; left valve with
one or two compressed pseudocardinals, the two often grown
together, with two curved, remote laterals; right valve with
two elongated pseudocardinals, the lower the larger, and one
lateral; muscle scars shallow ; nacre bluish-white, a little thick-
er in front.

Length of type 48, height 36, diam. 20 mm.

Length 70, height 52, diam. 28 mm.

Uruguay River and its affluents; Parana River, southern
Brazil.

Unio fontaimana dOrpicny, Guer. Mag., 1835, p. 36.

DIPLODON 1281

Unio foutainianus Hantuy, Biv. Shells, 1856, p. 384, pl. xx,
fig. 27—Sowerry, Conch. Icon., XVI, 1868, pl. LXxxvII,
fig. 400.

Moargaron (Unio) fontainianus Lea, Syn., 1870, p. 56.

Dipleden fontainianus SIMPSON, Syn., 1900, p. 886.

Unio fontaineana d’OreIGNY, Voy. Am. Mer., 1843, p. 605,
Disierxe hos: 6,7:

The type is a young shell. The species seems to show a
good deal of variation in minor characters such as details of
form, color and the iike, but ail the shells I have seen are
wedge-shaped in front when viewed from above and all have
elongated, compressed pseudocardinals. Those in the left
valve are sometimes double, but often more or less united.

Var. decepius n. v.

Shell unevenly obovate, subinflated, rather solid; left valve
with two radial, short pseudocardinals, which are often split
up into a number of denticles, with two remote laterals; right
valve with two pseudocardinals, the upper smaller, the lower
often split up, and behind it there are often small denticles on
the hinge plate, with one granular lateral.

Guahyba, Brazil.

I have before me a large number of specimens of this form
and a number of others, which I refer to the var. gratus.
Both vary considerably and seem to differ constantly only in
the character of the pseudocardinals. In fontainianus and
gratus they are long and compressed, both are more commonly
united in the left valve and though sometimes roughened they
are never divided. In the form I have called deceptus the
pseudocardinals are short and much split up, they are usually
more or less radial and there are generally a number of den-
ticles behind those of the right valve. Young shells show these
characters as well as the old ones.

Var. -gratus (lea).

Shell more decidedly wedge-shaped in front than the type
when viewed from above; epidermis smoother, lighter colored
and subshining; post-dorsal wing a little more angled behind.

Uruguay River, South America.

1282 DIPLODON

Unio gratus Lea, Pr. Ac. N. Sci. Phila., IV, 1860; p. 91; Jl.
Ac. Ny Sti, Phila., V,.1863; p.382) pl. ximn, fe. 2q0:-Obs.,
X, 1863, p. 18, pl. xii, fig. 290.—Sowersy, Conch. Icon.,
XVI, 1868, pl. LX xxv, fig. 444.

Margaron (Umio) gratus Lia, Syn., 1870, p. 56.

Diplodon gratus SIMPSON, Syn., 1900, p. 886.

After critically comparing the type of Unio gratus Lea and

a large amount of additional material with d’Orbigny’s de-
scription and figure of Unio fontainiana and with what I con-
sider authentic specimens of that form, I believe that they are
mere varieties of the same thing. Lea’s shell differs in being
lighter colored and perhaps a little sharper on the post-dorsal
angle, but the other characters seem to agree very well through-
out.

DipLopon Ro1uNDuS (Wagner).

Shell short obovate or subtriangular, subcompressed to
slightly inflated, subsolid, inequilateral; beaks somewhat ele-
vated, their sculpture a few, short, radial bars; post-dorsal
slope raised into a low wing and more or less abruptly trun-
cated behind; anterior end narrowed and rounded; post-basal
region much produced; surface sculptured with fine, uneven
concentric striz, and having traces of radial sculpture; epi-
dermis olive or brownish with a soft smoky tint, feebly rayed
in young shells; left valve with two compressed pseudocardi-
nals, the hinder smaller, and two curved laterals; right valve
with two pseudocardinals and one lateral; dorsal scars few
and deep; muscle scars small, shallow ; nacre bluish-white, sil-
very and iridescent behind, a little thicker in front.

Length 37, height 32 mm. (figured type).

Length 67, height 55, diam. 28 mm.

Length 70, height 54, diam. 33 mm.

Brazil.

Unio rotundus Wacner, Test Fluv. Bras., 1827, p. 34, pl. xxv,
figs. 3, 4—Meortcanp, Mem. His. Soc. Gen., 1838, p. 49, pl.
Iv, figs. 12-14.—Kuster, Conch. Cab. Unio, 1856, p. 160, pl.
xLVI, figs. I, 2—Sowerny, Conch. Icon., XVI, 1868, pl.
LXXIT, Hist sao:

DIPLODON 1283

x

Margaron (Unio) rotundus La, Syn., 1870, p. 56.
Diplodon rotundus SiMPSON, Syn., 1900, p. 886.

The shell figured in the Testacea Fluviatilia is apparently
quite young and, if the figure is correct, it is faintly rayed. [
have before me several shells which belong to the Lea Collec-
tion, which were believed by Dr. Lea to be the Unio rotundus
of Wagner, and | am inclined to think that they are. The sur-
face is rather smooth and shining and has a peculiar soft
smoky tint. The nacre is rich and bright for a Diplodon.

DIPLopON bISCULUS (Lea).

Shell much compressed, subsolid, short obovate, inequilat-
eral, with moderately full beaks, whose sculpture is irregularly
radial ; dorsal line incurved in front of the beaks and elevated
behind them; post-dorsal region elevated into a slight wing,
which is abruptly and almost squarely truncated posteriorly ;
posterior ridge rounded; anterior end narrowed and rounded ;
posterior base full; surface finely, concentrically striate; epi-
dermis dirty green, sometimes faintly rayed; left valve with
one split-up pseudocardinal and two curved laterals; right
valve with two pseudocardinals, the lower dentilate or divid-
ed, and one lateral ; nacre bluish, thicker in front.

Length 40, height 36, diam. 15 mm.

Length 45, height 40, diam. 15 mm.

Uruguay River, South America.

Unio disculus Lea, Pr. Ac. N. Sci. Phila., IV, 1860, p. 91; JI.
Ac. N. set: Phila: V, 1863, p. 385, pl. xuiv, fig. 203 Obs.,
XO 1862p. 21, pl XEiv tie. 202.

Margaron (Unio) disculus Lea, Syn., 1870, p. 55..

Diplodon disculus SIMPSON, Syn., 1900, p. 887.

All the material, which I have seen, including the type, is
probably young. ‘The shell is much compressed, narrowed and
rounded in front, largely produced at the post-base and widely,
almost squarely truncated behind. It is much more squarely
truncate behind than any closely related species.

DIPLODON FUNEBRALIS (Lea).

Shell nearly orbicular, but a little narrowed in front, being
slightly drawn out and rounded at the upper anterior part,

1284 DIPILODON

compressed, solid, inequilateral; dorsal line almost regularly
curved from the anterior to the posterior ends, very high in
the middle where it is slightly winged; beaks rather low, not
elevated above the dorsal line; posterior ridge low ; above it is
a shallow, wide, radial depression, which ends in a feeble sinus
behind; base line rounded, full behind the middle; surface
with low, fine, concentric ridges, with a trace of radial sculp-
ture; epidermis almost black, thick, scarcely shining, peeling
off and showing the white shell beneath; left valve with one
much-split-up pseudocardinal and two short, remote, strongly
curved laterals; right valve with two pseudocardinals, the
upper compressed and small, the lower dentilate, with a ves-
tigial tooth behind it, and one curved lateral; muscle scars
small; nacre white, dull, blotched in the shallow cavity, very
thick along the anterior border where it is granularly, radially
striate; pallial line remote from the border.

Length 76, height 67, diam. 23 mm.

Uruguay River.

Unio funebralis Lea, Pr. Ac. N. Sci. Phila., IV, 1860, p. 91;
jl. Ac. N. Sci. Philas Vj 18633\p. 37S. pli xr tiess286- Ols,
X, 1863, p. 14, pl. x1, fig. 286.—-SoweErsBy, Conch. Icon.,
XVI, 1867, plo ivis, fies200:

Margaron (Umo) funebralis Lea, Syn., 1870, p. 55.

Diplodon funebralis Simpson, Syn., 1900, p. 887.

The decided compression, the very high, curved dorsal line,
the thickened nacre in front, which is granularly, radially
striate, and the pallial line set far in from the border distin-
guish this species from others.

DIPLODON PARANENSIS (Lea).

Shell disposed to be quadrate or pentagonal, subinflated to
inflated, solid, inequilateral; beaks high and somewhat full,
sculptured with strong, uneven, radial ribs; area in front of
them incurved, area behind them curved outward; posterior
slope truncated, the outline sometimes incurved ; posterior end
blunt ; base very much swollen at or a little behind the middle ;
anterior end narrow and rounded ; surface covered with coarse,
uneven, concentric sculpture; epidermis brownish to blackish ;

DIPLODON 1285

pseudocardinals irregular and much split up; laterals curved,

strong, two in the left valve and one in the right; muscle

scars small; nacre whitish, sometimes dull purple in the cavi-
ties, much thicker in front.

Length 92, height 78, diam. 38 mm.

Length too, height 76, diam. 47 mm.

Uruguay and Parana rivers.

Unio paranensis Lea, Tr. Am. Phil. Soc., V, 1834, pl. xiv,
fig. 42; Obs., I, 1834, p. 211, pl. xiv, fig. 42—HANLgEy, Biv.
Shells, 1843, p. 202, pl. xx1, fig. 3—KustrEr, Conch. Cab.
Unio, 1861, p. 253, pl. LXxxv, fig. 3—Sowerpy, Conch. Icon.,
XVI, 1866, pl. 11, fig. 268.

Margarita (Unio) paranensis LEA, Syn., 1836, p. 33; 1838, p.
23

Margaron (Unio) paranensis Lea, Syn., 1852, p. 34; 1870. p.
55:

Diplodon paranensis Stimpson, Syn., 1900, p. 887.
Apparently abundant and quite variable in form and color

of epidermis.

DIPLODON NOCTURNUS (Lea).

Shell short obovate, convex, rather solid, inequilateral, nar-
rowed and rounded in front, full in the post-dorsal and post-
basal regions; beaks somewhat elevated but not inflated; sur-
face unevenly sulcate; epidermis dark, scarcely shining, green-
ish-brown, the hinder half of the shell being much darker;
pseudocardinals small, two in each valve; there are two small
laterals in the left valve and one in the right; muscle scars
small: nacre lurid whitish, thicker in front.

Length 72. height 60, diam. 28 mm.

Uruguay River.

Unio nocturnus Lea, Pr. ie c. No Ser Pinla:, TV; 1860; .p.. 91 ;
ieAcoN. Se Phila., V.,.1863, po 480; pla xii, ties 288; Obs.,
Xe (86a pelo ple XLAL, fg. 288.

Margaron (Unio) nocturnus Lea, Syn., 1870, p. 56.

Diplodon paranensis (part), Stimpson, Syn., 1900, p. 887
At the time I wrote the Synopsis ie type of this latter shell

was mislaid. J,ea states in his description that it is without

1286 DIPILODON

rays. Recently the type came to light and on carefully washing
it the anterior half of the shell is seen to be bottle-green and
the hinder half almost black and there are indications of a
few, faint rays at the median part of the shell. This and the
smaller, less split-up pseudocardinals lead me to believe that
it may be distinct.

Section BuLLOIDEUS Simpson, 1900.

Bulloideus SIMPSON, Syn., 1900, p. 887.

Shell rounded, inflated, thin, nearly equilateral, truncate be-
hind and slightly so before, with a rather sharp posterior ridge
and a dorsal wing; beaks full, rather high, regularly radial ;
epidermis smooth, bronzy-olive; pseudocardinals compressed,
much elongated, disposed to be split into denticles, two in the
right valve and one in the left; laterals two in the left valve
and one in the right; dorsal scars few and scattered in the
rather shallow cavities; nacre bluish.

Type, Unio bulloides Lea.

DIPLODON BULLOIDES L,ea.

Shell short elliptical, almost squarely truncate behind, thin,
nearly equilateral; post-dorsal line straight, meeting the trun-
cation behind nearly at a right angle; beaks full but not great-
ly elevated; posterior ridge well-developed, subangular; pos-
terior slope excavated and wrinkled; surface strongly, uneven-
ly, concentrically sculptured, with traces of radial sculpture;
epidermis yellowish-green, bronzy ; left valve with one pseudo-
cardinal and two laterals; right valve with two pseudocardi-
nals, the upper smaller, and one lateral, all the teeth lamellar ;
muscle scars shallow; nacre bluish-white, rather dull.

Length 47, height 40, diam. 27 mm.

Rio de la Plata.

Unio bulloides Lea, Pr. Ac. N. Sci. Phila., III, 1859, p. 187;
Jix Ac. Ne-Sei. Phila.) EV, 1860, p: 264; pl. 211 hes 44
Obs., VII, 1860, p. 82, pl. xii, fig. 144. —Kuster, Conch.
Cab. Unio, 1861, p. 186, pl. tix, fig. 2—SowrrBy, Conch.
Icon., XVI, 1868, pl. Lxxxvutt, fig. 275.

Margaron (Unio) bulloides Lea, Syn., 1870, p. 55.

Diplodon bulloides Stmpson, Syn., 1900, p. 887.

DIPILODON 1287

‘The only specimen I have seen, the type, is not in first class
condition. It is a short elliptic shell almost squarely truncate
behind, the truncation meeting the dorsal line almost at a right
angle. The epidermis is a peculiar yellow-green with a bronzy
hue. It is less elongated than D. solistanus and more trun-
cated behind.

DIPLODON SOLIsIANUS (d’Orbigny ).

Shell obovate, subinflated, rather thin, wedge-shaped in
front when viewed from above, nearly equilateral ; beaks full
and high, with strong, evenly radial bars, the central ones di-
verging ; posterior ridge well defined, subangular, ending be-
hind in a blunt point on the median line; above this point the
shell is obliquely truncated and this truncation meets the dor-
sal line with an angle; anterior end somewhat narrowed and
rounded; surface unevenly but strongly concentrically sculp-
tured, with faint traces of radial sculpture, often with strong,
radial ridges anteriorly; posterior slope wrinkled; epidermis
dull brown; left valve with two compressed, long pseudocar-
dinals, which are sometimes united, and two remote, curved
laterals ; right valve with two pseudocardinals, the upper small,
and one lateral, beak cavities well impressed; muscle scars
small, shallow: nacre bluish-white, dull; pallial line not im-
pressed.

Length 72, height 53, diam. 34 mm.

Rio de la Plata and its affluents.

Unio solisiana d’Orpicny, Guer. Mag., 1835, p. 35; Voy. Am.
Mer., 1843, p. 604, pl. LxIx, figs. I-3.—SoweERBy, Conch.
Icon., XVI, 1868, pl. xcr11, fig. 508.

Diplodon solisianus SIMPSON, Syn., 1900, p. 887.

A rather thin, obovate species with uneven, concentric and
faint radial sculpture. The beak sculpture is strictly radial.

DIPLODON VARIABILIS (Maton).

Shell nearly orbicular but somewhat truncated behind, the
truncation joining the nearly straight dorsal line almost at a
right angle; beaks placed about at the center, full but not
high, with strong, strictly radial sculpture; posterior ridge

1288 DIPILODON

moderate; posterior slope with a faint, radial depression; sur-

face roughly, concentrically striate; epidermis greenish-brown ;

pseudocardinals and laterals lamellar; nacre purplish.
Length probably 32, height 30 mm.
Rio de la Plata.

Mya variabiis Maton, Tr. Linn. Soc. Lond., X, 1811, p. 327,
pl. xxiv, figs. 4-7——Woop, Ind. Test., 1825, p. 13, pl. m1,
fig. 38.05 tev. ed., 1950. p77 pi ie Bc.

Unio variabilis d’OrpicNy, Voy. Am. Mer., 1843, p. 604, pl.
LXXI, figs. 1-3.—Sowerpy, Conch. Icon., XVI, 1868, pl.
LEXIV; fie. 381.

Margarita (Unio) variabilis Lea, Syn., 1836, p. 33; 1838, p. 23.

Margaron (Unio) vaniabilis Lea, Syn., 1852, p. 35; 1870, p. 56.

Diplodon variabilis Simpson, Syn., 1900, p. 888.

Mytilus matoniana d’Orpicny, Guer. Mag., 1835, p. 35.

Unio matonianus Pazret, Conch. Sam., III, 1890, p. 158.

?Umio membranacea HANLEY, Biv. Shells, 1843, p. 202, pl.
SOX, foe:

Unio membranaceus Puttaprr, Conch., IIT, 1848, p. 80, pl. v,
fig. 4.—Kutstrr, Conch. Cab. Unio, 1862, p. 284, pl. xcv,
hg. 5.

Maton gives four figures, one of which is an interior and

another 1s of a young shell, which I am sure belongs to a dif-

ferent species. His shell differs from bulloides, being more
nearly orbicular, less sharply truncated posteriorly, in having
apparently a lower posterior ridge with a feebler excavation
above it and in the color of the nacre, which, he says, is pur-
plish.

Subgenus Hyrimert,A Swainson, 1840.

Hyridella Swainson, Treat. on Mal., 1840, p. 380.

Beaks rather low, sculpture consisting of curved, generally
nodulous ridges, which approach below but usually have a
smooth area of shell between them; surface sulcate or some-
times corrugated and nodulous; epidermis rayless ; teeth rather
delicate, compressed, often somewhat rudimentary.

Animal having the embryos occupying the inner gills for
the most part, which are united for their entire length to the

DIPLODON 1289

abdominal sac; outer gills pointed below in the middle; palpi
triangular ; branchial opening papillose ; anal opening smooth,
not separated from the superanal opening.

Type, Unto australis Lamarck.

Section HyRIDELLA S. Ss.

Shell covered with concentric, sulcate sculpture; pseudocar-
dinals well developed, compressed ; laterals delicate, sometimes
imperfect.

Group of Diplodon dorsuosus.

Shell somewhat rhomboid, inflated solid, with rather full
beaks, the sculpture consisting of very strong, subradial, cor-
rugated ridges, which curve toward each other below, those
in the center sometimes joining, this sculpture extending well
out on the disk; upper part of posterior slope having slight
radial folds.

DipLopon porsuosus (Gould).

Shell oblong, subrhomboid, convex or subinflated, subsolid,
inequilateral ; beaks but slightly elevated, their sculpture coarse
and strong, consisting of subradial, corrugated or nodulous
bars, which curve towards each other; this sculpture extends
out on to the disk and becomes very irregular; anterior end
slightly narrowed and rounded; posterior end almost squarely
subtruncated; posterior ridge full and rounded; dorsal line
lightly arched; base line straight; surface with faint, irregu-
lar, concentric sculpture and traces of radial grooves; the mid-
dle of the disk is often faintly pustulous; epidermis almost
black, shining ; pseudocardinals compressed, more or less dou-
ble in each valve; laterals remote, short; nacre bluish, much
thicker in front.

Length 59, height 35, diam. 22 mm.

Length 50, height 33, diam. 19 mm.

Nepean River, Australia.

Unio dorsuosus Goutp, Pr. Bost. Soc. N. H., III, 1850, p. 296;

U.S: Expl, Exp., XII, '852, p: 430, figs. 540, 5400, 540b.
Margaron (Umo) dorsuosus Les, Syn., 1852, p. 21.
Diplodon dorsuosus SIMPSON, Syn., 1900, p. 880.

1290 DIPILODON

Unio napeanensis Conrab, Pr. Ac. N. Sci. Phila., V, 1852, p.
105. fln Ac N.- Sci. Phila., 185452 prs2q6; pls Sexvi, he. 4
—Rerve, Conch. Icon., XVI, 1865, pl. xx1m, fig. 2.

Muargaron (Unio) napeanensis Lea, Syn., 1852, p. 20; 1870,
prego:

Distinguished by its strong and peculiar beak sculpture,
which often extends one-third of the way over the disk and
by having the posterior end almost squarely subtruncate. The
epidermis is black and polished. The type of Unio dorsuosus
Gould, which is before me, is a young and light-colored speci-
men and napeanensis Conrad is the adult state of the same.

DieLoDON GLENELGENSIS (Dennant).

Glenelg River, Victoria.
Unio glenelgensis DENNANT, Pr. Roy. Soc. Vict., X, 1898, p.
112; pl: av:
Diplodon glenelgensis SIMPSON, Syn., 1900, p. 889.
The description of this species is not accessible to me and
I am therefore obliged to omit it.

Group of Diplodon menziezt.

Shell subrhomboid; beak sculpture not strong, consisting
of broken, nodulous ridges curving toward each other below,
with generally a smooth space between, not extending over the
shell.

Animal as in the subgenus.

DIPLODON MENZIEZI (Gray).

Shell subelliptical or subrhomboid, compressed, rather thin,
inequilateral; beaks neither high nor full, having the charac-
teristic sculpture of the group; posterior ridge low and widely
rounded; anterior end a little narrowed, rounded; dorsal and
basal lines lightly curved, the latter often slightly fuller be-
hind the middle; dorsal slope obliquely subtruncated or round-
ed; surface with irregular, concentric sculpture, sometimes hav-
ing in addition faint, somewhat wavy, broken, radial sculpture ;
epidermis greenish-olive, dull or faintly shining’; teeth com-

DIPLODON 1291

pressed ; laterals elevated, lamellar; muscle scars shallow ; na-
cre bluish, a little thicker in front.

Length 60, height 36, diam. 14 mm.

Length 83, height 49, diam. 21 mm.

New Zealand.

Unio menziezi GRAY, In Dieffenbach’s N. Z., II, 1843, p. 257.

—? Muserave, Phot. Conch., 1863, pl. 11, fig. 1.

Diplodon menziezi SIMVSON, Syn., 1900, p. 889.
Unto menziesianus REEVE, Conch. Icon., XVI, 1865, pl. xx1x,

Hoe ESS.

Margaron (Unic) menzient Lea, Syn., 1870, p. 46.

An exceedingly variable species, some of the mutations of
which are probably worthy of varietal names. Quite a num-
ber of the specimens before me are diseased and as a result
the shells are considerably distorted. Some of the normal
shells are almost evenly elliptical; some are slightly obovate ;
still others are more or less rhomboid.

Var. aucklandicus (Gray).
More elongated than the typical form and subrhomboid ;
umbones radiately wrinkle-ridged.
Length 73, height 40.5, diam. 20 mm.
Unio aucklandica Gray, In Dieffenbach’s N. Z., II, 1843, p.
Zila
? Unio aucklandicus Sowrrsy, Conch. Icon., XVI, 1866, pl.
SOS dO ts O:
Margaron (Unio) aucklandicus Lea, Syn., 1870, p. 45.
Diplodon menziezi (part), SIMPSON, Syn., 1900, p. 880.
The above, though quite distinct typically, absolutely blends
into the type.

Var. rugulosus n. n.

Shell small, more solid and inflated than the type.
Length 49, height 31, diam. 19 mm.
Length 53, height 34, diam. 18 mm.
Unio rugatus Huron, Tr. N. Z. Inst., XVI, 1884, p. 216.
Diplodon menziesi var. rugatus SIMPSON, Syn., 1900, p. 889.

1292 DIPILODON

The name rugatws was applied previously to a European
Unio by Rossmassler; hence I have changed Hutton’s name
to rugulosus. ‘This seems to be a small form of menziezi,
which sometimes merges into hochstetteri.

Var. hochstetteri (Dunker).

Smaller generally than the type, shorter, more blunt behind,
but higher than rugulosus.

Length 51, height 33, diam. 10 mm.

Length 49, height 34, diam. 11 mm.
Unio hechstetteri DUNKER, Mal. Bl, VIII, 1862, p. 153—Sow-

ERBY, Conch. Icon., XVI, 1868, pl. Exxxvi, fig. 463.
Diplodon mensiezi var. hochstelleri Stwpson, Syn., 1900, p.

88o.

Nearly all the specimens I have seen of this and rugulosus
are diseased and more or less distorted.

Suter believes this to be only a pathologic form of menziezi.
Ife says in a letter to the author that he has seen the same kind
of disease among small rugulosus.

Var. depauperatus (Hutton).

Shell very thin, oblong, compressed ; anterior end very short,
rounded; posterior end slightly winged, very obliquely trun-
cated ; dorsal margin gently ascending, slightly arched ; ventral
margin sinuated in the middle; pseudocardinals minute, com-
pressed, smooth, only one in the left valve; laterals low and
thin.

Length 60, height 30, diam. 15 mm.

Lake Lakapuna Auckland; New Zealand.

Unio depauperatus Hurron, Tr. N. Z. Inst., XVI, 1884, p.

216.

Diplodon menziezi var. depauperatus SIMPSON, Syn., 1900, p.

Soo.

This may be a valid species, but as it has never been figured,
so far as I am aware, and, as there do not seem to be any
decided distinguishing characters to it, I place it here. I have
never seen anything I could satisfactorily refer to it. Its
slightly sinused base seems to be its best character.

DIPLODON 1293

Var. acutus Suter.

“Distinguished from the species by the very distinctly ros-
trate posterior end, the nearly total absence of radial sculpture,
and by being more compressed. Only young shells show traces
of radially arranged nodules near the beaks. The basal mar-
gin is generally more straight than in typical menziesi. The
beaks are much corroded in all the specimens I have. The shell
is rather thin, yellowish-brown, with strong, concentric sculp-
ture, approaching D. rugata Hutton. The interior is nacreous-
olive, the hinge not different from that of the species.

Length 70, height 40, diam. 16 mm.” (Suter).

Type locality, Lake Omapere, New Zealand.

Diplodon menziesi subsp. acuta SutTER, Pr. Mal. Soc. London,

WANE TOO7, Dp. 230 xox OSs Lie 2:

“The outline of this subspecies is very nearly that of D.
depauperata Hutton, but the hinge is very different; it also
has almost exactly the outline of Anodonta complanata Zeig-
ler of Europe.”

Var. lucasi Suter.

“Shell oblong-ovate, very much compressed, thin and frag-
ile, inequilateral, beaks low, eroded ; surface with close, strong-
ly pronounced rest-marks and between them a few lines of
growth, all close together and foliated at the anterior end. In
the adult specimen the middle part has distinct, radiate, nod-
ulous sculpture, partly V-shaped, but no such ornamentation
is to be found on the young specimens. The straight dorsal
margin is subparallel to the ventral margin, which is slightly
sinuate; the anterior margin is angularly rounded, the poste-
rior obliquely truncated and slightly produced. Nearly the
whole shell is covered with a thin ferrugineous coating; the
epidermis is olive-green. waxy. The ligament 1s small, not
much raised. In the right valve the two pseudocardinals are
compressed, small; the upper anterior tooth is a small, smooth
lamella, the lower tooth is more elevated, conoidal and strong-
ly crenate ; the lateral tooth is almost straight, thin and rugose
at its posterior portion. In the left valve there is a rather long,
compressed. lower, anterior, rugose pseudocardinal, the upper

1294 DIPLODON

tooth is quite rudimentary, the upper lateral tooth is a little
higher and more rugose posteriorly than the other. Interior
bluish-white. pearly, a little blotched with olive in the umbonal
cavity, where there are rather large and deep dorsal scars. The
adductor muscle scars are shallow. The young specimens are
slightly winged.

Length 45. height 24, diam. 8 mm.” (Suter).

Type locality, Lake Manapouri, New Zealand.

Diplodon menziesi subsp. lucasi Surer, Trans. N. Z. Inst.,

XXX VIF, 1904, p230; figs. 2, 3.

‘This subspecies is nearest to the typical aucklandica, but
is distinguished from it by its exceptionally compressed form,
the thinness of the shell, the strongly marked and close, con-
centric lines, the more tapering posterior margin, and the
feebly developed pseudocardinals. The radiate, nodulous sculp-
ture is found in many specimens of menziest and its sub-
species.”

DIPLODON WAIKARENSIS (Colenso).

An unfigured species having the posterior slope keeled,
sharp, the primary tooth large and much crested. It is a large
form having a length of 88 millimeters and a height of 57.
.According to Suter it lives in quiet, pure water and he believes
it to be a variety of D. menziezt. I am inclined to think it
distinct on account of the keeled posterior slope. The descrip-
tion of this species is inaccessible to me at present.

Suter (1. c.), says that Colenso’s diagnosis is incorrect, and
that the shell is not keeled. He considers it a synonym of
menzlesi. :

Waikare Lake, New Zealand.

Umio waikarensis CoLeNso, Tasm. Jl. N. Sci., IT, 1845, p. 250,
footnote.
Diplodon waikarensis Simpson, Syn., 1900, p. 890.—SUTER,

Trans. N-Z. Inst., XXOCVM, sq04)p.235.

DIPLODON ZELEBORI (Dunker).

Shell long rhomboid, rather solid, convex or subcompressed,
inequilateral; beaks small, sharp, with subnodulous, curved,
subradial ridges; posterior ridge narrowly rounded above,

DIPLODON 1295

widely rounded below and ending in a blunt point at the base
of the shell; there is in most cases a sort of low, short, radial
anterior ridge at the umbonal region and between this and the
posterior ridge there is a radial depression; surface with ir-
regular, concentric sculpture; occasionally showing faint cor-
rugations on the disk; epidermis thick, blackish sometimes
tinted brownish or greenish; pseudocardinals small, stumpy in
old shells, but compressed in young ones; laterals granular;
nacre bluish, thicker in front.

New Zealand.

Unio zelebori DUNKER, Reise der Nov., 1867, p. 15, pl. 1, fig.

28. |
Margaron (Unio) zelzbori Lea, Syn., 1870, p. 52.

Diplodon zelebori Simpson, Syn., 1900, p. 890.

Close to varieties of menziezi, but solider and more evenly
long rhomboid. The epidermis is darker and thicker than in
‘that species, the median radial impression on the umbonal re-
gion is peculiar; the pseudocardinals in an adult state are
stumpy, while in menziczi they are compressed. ‘This species
shows a few well-impressed dorsal scars.

DipLopoN FLYENSIS (Tapperone Canefri).

Shell short rhomboid, convex, apparently rather thin, inequi-
lateral; beaks but slightly elevated; anterior end regularly
rounded, a little narrower than the posterior end; basal and
dorsal lines nearly straight; dorsal slope obliquely subtrun-
cate, curving into the dorsal region; surface densely and del-
icately, concentrically striate; epidermis fuscous-olive ; pseudo-
cardinals small, short, subcompressed; laterals lightly arcu-
ate; nacre flesh-white, iridescent.

Length 49, height 35, diam. 19 mm.

Fly River, New: Guinea.

Unio flyensis TAPPERONE CANEFRI, Ann. Mus. Genov., XIX,

1903) p.293, Hg. 1:

Diplodon flyensis Stmpson, Syn.. 1900, p. 890.

I have never seen this species, but the excellent figures by

its author show it to be a Diflodon without doubt and closely

1296 DIPLODON

related to the forms of Australia. The other Papuan Union-
idze are evidently most nearly related to species of Southeastern
Asia. The presence of this true Hyridella in Papuan waters
is another point in favor of the theory of a recent connection
of this great island with Australia by way of Torres Straits.

DIPLODON VITTATUS (Lea).

Shell subelliptical or subrhomboid, convex or subinflated,
subsolid, inequilateral; beaks slightly elevated and _ inflated ;
posterior ridge rounded or feebly double; surface very finely,
concentrically striate; epidermis yellowish-olive, with dark,
narrow rest marks, subshining; teeth rather delicate ; pseudo-
cardinals compressed; laterals curved; nacre whitish to dirty
purplish, iridescent behind, thickened in front.

Length 64, height 43, diam. 25 mm.

Length 56, height 36, diam. 21.5 mm.

Australia.

Uno vitiatus Vea, Pr..Ac. N. Sci. Phila., ITI, 1850; p: 153;
jl. Ac. N..Sci..Phila., 1V, 1860, p, 240,-pl. xxxvani, fie, 128%
Obs., VII, 1860, p. 67, pl. xxxvitt, fig. 128.—Reeve, Conch.
Icon., XVI, 1864, pl. xxitt, fig. 83.

Margaron (Umno) vittatus Lea, Syn., 1870, p. 35.

Diplodon vittatus Simpson, Syn., 1900, p. 8go.

The type of this shell is not in the Lea collection, but a
specimen presented by Mr. Cuming to Dr. Lea is. It differs
considerably from the type, being subrhomboid, somewhat nar-
nowed in front, in having short pseudocardinals and lurid pur-
plish nacre, while the type is nearly elliptical, has somewhat
elongated pseudocardinals and white nacre. Both agree in the
external color, a sort of yellowish-olive with well-defined, dark
rest marks and in this character differ from australis, to which
it seems to be closely allied.

DIPLODON LESSONI (Kuster).

Shell oblong, a little narrower in front, inequilateral, sub-
inflated; dorsal outline somewhat arched; base line nearly
straight: anterior end rounded; posterior end widely and al-
most squarely subtruncated; epidermis nearly black; surface

DIPILODON 1297

concentrically sulcate striate; pseudocardinals conical ; laterals
elongated, lightly curved; nacre bluish-white, shining.

Length 60, height 41, diam. 25 mm.

New South Wales.

Unio lessoni Kuster, Conch. Cab., 1856, p. 135, pl. XXXVI,

fig. 4.

Diblodon lessoni SiMpson, Syn., 1900, p. 890.
Unio australis Kuster, Conch. Cab., 1861, p. 230, pl. LXXvuJ,

fie. 6.

I am not at all sure that this is not D. napeanensis. The fig-
ures are taken from specimens in which the umbonal region
is badly eroded. The shape of the shell, its color and that of
the epidermis agree closely with the same characters in napea-
nensis, but the pseudocardinals are represented as conical. In
the latter species they are compressed or subcompressed in all
the specimens I have seen.

DreLopon AustTRALIS (“Lamarck,” Hanley).

Shell elliptical, slightly obovate or subrhomboid, thin to sub-
solid, convex to inflated, more or less inequilateral ; beaks mod-
erately full and elevated, their sculpture not observed; poste-
rior ridge but little elevated, subangular or rounded; there is
often a sort of low, wide, radial ridge at some distance in
front of the posterior ridge, the base line being full where it
ends; surface with rather strong, irregular, concentric sculp-
ture; epidermis pale olive to dark brownish, scarcely shining ;
pseudocardinals compressed, one in each valve, with some-
times a feeble second one in the right valve; laterals delicate,
remote, often short, single in the right valve, often double in
the left: muscle scars shallow; nacre dull, whitish or bluish,
sometimes a little thicker in front.

Tength 62, height 41, diam. 24 mm.

Length 67, height 42.5, diam. 28 mm.

Australia ; ‘Tasmania.

Unio australis LAMARCK, An. sans. Vert., VI, 1819, p. 80.—

Han ey, Biv. Shells, 1843, p. 192, pl. xx1, fig. 25.—PHIL-

appr, Conch, Lil, 1848, p: 81, pl: vy figs 5.

1298 DIPLODON

Margarita (Unio) australis Liza, Syn., 1836, p. 25; 1838, p. 19.
Hyridella australis Swainson, Tr. on Mal., 1840, p. 285.
Margaron (Unio) australis Lea, Syn., 1852, p. 28; 1870, p. 44.
Diplodon australis Simpson, Syn., 1900, p. 890.

? Unio depressus Lesson, Voy. Coquille, 1830, II, p. 427, pl.

Vie. 5.

Margarita (Unio) depressus Lua, Syn., 1836, p. 32; 1838, p.

22.

Margaron (Unio) depressus Les, Syn., 1852, p. 33; 1870, p.

54.

Unio ambiguus Pritiprt, Conch., III, 1847, p. 47, pl. m1, fig. 2.
Sowersy, Conch. Icon., XVI, 1868, pl. Lxix, fig. 355.
Unio shuttleworthi Kuster, Conch. Cab. Unio, 1856, p. 152,

pl X11v, tie: 2:

Unio philippianus Kuster, Conch. Cab. Unio, 1861, p. 235, pl.

WRK UX ren 2
Unio balonnensis Conrad, Pr. Ac. N. Sci. Phila., V, 1850, p-

ro; Jl Ac.N: Sei; Philac ii 18547-p: 205.) pls-sexvi, iss. ee
? Unio dantellu Vita, Jl. de Conch., XTX, 1871, p. 328.
Unio bednalli Tate. Where?

Apparently an abundant, widely distributed species, and
quite variable. The exterior is usually somewhat strongly
and irregularly sculptured, the epidermis is pale olive to brown-
ish, the teeth are small and sometimes almost feeble.

Var. legrandi (Petterd).

This form is larger than aastralis and in some cases a solide
shell. ‘Two shells from Tasmania bearing the name Unio le-

grandi from Suter appear to be but a variety of australis. One
of them is obovate, quite solid and dark, the other is sub-
rhomboid, thinner and lighter colored. A third shell, which
is probably this, is labeled “Australia’’ and is obovate and
rhomboid.

Length 96, height 60, diam. 35 mm.

Length 78, height 50, diam. 28 mm.

Australia; Tasmania.
Unio depressus Reeve, Conch. Icon., XVI, 1864, pl. xvit, fig.

SI. .

DIPTLODON 1299

Unio legrandi Prrrerp, Pr. R. Soc. Tasm., 1887, p. 22; 1888,
p. 81.

Diplodon australis var. legrandi Simpson, Syn., 1900, p. Sol.

DiIpPLoDON JEFFREYSIANUS (Lea).

Shell subrhomboid, convex, subsolid or rather thin, some-
what inequilateral; beaks slightly elevated, scarcely inflated ;
anterior end rounded; base and dorsal lines lightly curved;
posterior end obliquely subtruncate; posterior ridge low,
rounded ; above it there are one or two low, rather wide, radial
ridges ; surface with close, fine, concentric sculpture ; epidermis
pale ashy brownish to brownish-olive, subshining; teeth deli-
cate, compressed; pseudocardinals double in the left valve,
single in the right; laterals single in each valve, remote: mus-
cle scars shallow ; nacre bluish-white or flesh-colored.

Length 73, height 45, diam. 23 mm.

Australia.

Umo jeftreysianus Lea, Pr. Ac. N. Sci. Phila., I, 1871, p. 188;
Ji. Ac..N. Sci. Phila., VIII, 1874, p. 23, pl. vir, fig. 20; Obs.,
AMT, 1874, p. 27, pl. vir; fie. 20.

Diplodon jeffrevsianus Simpson, Syn., 1900, p. 801.

The type consists of two matched valves and I am a little
dubious as to whether the species is a valid one. One valve,
the right, is darker, more strongly sulcate, and duller colored
than the left. his matched pair is considerably more com-
pressed than any specimens I have seen of australis, and it

has the super-posterior ridges, which I have not seen in that
shell.

DipLopon pRoFUGUS (Gould).

Shell oblong, narrowed a little in front, subrhomboid, sub-
compressed or convex, subsolid; beaks somewhat nearer the
anterior end, rather full; posterior ridge low, rounded; ante-
rior end rounded; dorsal and basal outlines lightly curved or
nearly straight; surface with irregular, strong, concentric
sculpture: epidermis dirty greenish; teeth delicate: pseudo-

1300 DIPLODON

cardinals double in each valve; laterals remote; nacre bluish
or flesh-colored, thicker in front.

Length 75, height 42, diam. 22 mm.

Hunter’s River, New South Wales.

Unio profugus Gouip, Pr. Bost. Soc. N. H., 1850, p. 295;

U..S..xph Exp.,. XII, 1852; p.-420;) figs.549 55430. 542d:
Margaron (Unio) profugus Lea, Syn., 1852, p. 20.

Diplodon profugus SiMPSON, Syn., 1900, p. 891.

A single right valve labeled ““Type” from Hunter’s River,
New South Wales, is in the National Museum collection, be-
sides a smaller shell from Paramatta, which is shorter in pro-
portion. [I am somewhat doubtful as to the validity of this
species. ‘The type is more elongated, more compressed, and
rather lighter colored than any specimens of australis 1 have
seen, but the outline of the smaller shell is intermediate be-
tween the two.

DiPpLopON MORETONICUS (Reeve).

Shell subrhomboid, oblong, somewhat inequilateral; beaks
moderately full; posterior ridge well developed, rounded, end-
ing in a broadly rounded point at the base of the shell; dorsal
line lightly curved; anterior end rounded; base line straight;
dorsal end obliquely striate; epidermis fuscous-black.

Length of figure 71, height 42.5 mm.

Tasmania.

Unio moretonicus ReKve, Conch. Icon., XVI, 1865, pl. xxiv,

fig. 118.

Diplodon moretonicus SIMPSON, Syn., 1900, p. 89QT.
Margaron (Unio) mortonicus Lea, Syn., 1870, p. 43.

While Reeve’s figure is a good one, his description of this
species is utterly inadequate. It is quite probable that he had
before him a Unio obesus blandingianus from Florida, as his
figure and brief, incomplete description absolutely agree with
that.

DIPLODON CULTELLIFORMIS (Conrad).

Shell somewhat elongate, subelliptical, subobovate or slight-
lv rhomboid, inequilateral, scarcely subsolid, compressed ; beaks

DIPTODON F301

neither full nor high, with subradial, curved bars, which draw
towards each other below; posterior ridge full, rounded, end-
ing in a point below the median line; dorsal and ventral lines
lightly curved or nearly straight, the latter often full behind
the middle; anterior end slightly narrowed, rounded; dorsal
slope obliquely truncate; surface with flne, concentric sculp-
ture, sometimes with feeble, radial markings in front; epider-
mis greenish-brown; pseudocardinals compressed, disposed
often to be double in each valve: nacre bluish, thicker in front.

Length 59, height 29, diam. 19 mm.

Australia.

? Umo depressa I,AMARCK, An. sans. Vert., VI, 1819, p. 79.—
“Drlessert, ec. Coq. lam, 1340, pl x11, fies 5=—CuEeNu,
Ill; Conch., 1858, pl. x1, figs. 4, 4a.

Umio depressus Conran, Jl. Ac. N. Sci. Phila., 1854, p. 295, pl.
REG MWs ha

Unto cultellifornus Conrap, Pr. Ac. N. Sci. Phila., V, 1850,
pore:

Margaron (Unic) cultelliformis Lea, Syn., 1852, p. 32; 1870,
De 52:

Diflodon cultelliformis Stmpson, Syn., 1900, p. 802.

Unio paramattensis Lea, Pr. Ac. N. Sci. Phila., VI, 1862, p.
WOE Ace IN» Sci. Phila Vi 1866, p. 00; pl. xx, ote: -5@,;
Ops Xi 1867, pod, pl, xx, fie, 50.

Margaron (Unio) paramattensis Lea, Syn., 1870, p. 35.
Conrad’s description of Unio cultelliformis agrees exactly

with Lea’s U. paramattensis, numerous authentic specimens of

which are before me.

I cannot identify Lamarck’s Unio depressus with any cer-
tainty from his very meager description. As the name de-
pressus was used for a Unio in 1801 by Donovan I am obliged
to use another for this.

DIPLOpON -LUTULENTUS (Gould).
Shell elongated, subrhomboid, compressed, quite inequilater-

al, sometimes slightly falcate, subsolid; beaks low; posterior
ridge low, widely rounded ; anterior end slightly narrower than

2302 DIPLODON

the posterior, rounded; dorsal and ventral lines nearly straight
and parallel; dorsal slope slightly and obliquely subtruncate ;
surface covered with fine, irregular, concentric sculpture, often
slightly corrugated or subnodulous on the disk; epidermis in
young shells clouded, greenish, yellowish and brownish, dark-
er in old shells; pseudocardinals small, subcompressed in
young shells, becoming stumpy and often faint in old shells;
laterals lamellar; nacre bluish, iridescent and thin behind,
thick in front; dorsal scars few, distinct.

Length 61.5, height 28, diam. 12.5 mm.

Length 58, height 31.5, diam. 14.5 mm.

New Zealand, common according to Gould.

Unio lutulentus Goutp, Pr. Bost. Soc. N. Hist., II, 1850, p.
295; US. Expls Exp, XCUR i852. ps) 428h fies. 842, -“Gaea.
542b, 542c.—Rerve, Conch. Icon., XVI, 1865, pl. xxv, fig.
122.

Margaron (Ume) lutulentus Lea, Syn., 1852, p. 32; 1870, p.
ise

Diplodon lutulentus Simpson, Syn., 1900, p. 892.

A puzzling form, which in some cases approaches danger-
ously close to forms of mensziezit. There are three valves in
the National Museum collection marked “Type,” which do not
agree very closely with the figures in Gould’s Atlas. The
figures show a rather brightly colored shell, while these valves
are dull and, as is often the case with this species, coated with
a deposit of oxide of iron. The description tallies well with
other shells in the National Museum collection collected by
the Wilkes’ Exploring Expedition. In general the species is
more elongated than any of the forms of menziezi, more solid,
has shorter pseudocardinals, which become stumpy and faint
with age. The nacre is more strongly and suddenly thickened
in front in this shell.

DipLoDON WILSONT! (Lea).

Shell oblong, elliptical, convex, inequilateral, thin; beaks
rather full, sharp; posterior ridge low, rounded; dorsal and
basal outlines very slightly curved, nearly parallel; anterior
and posterior ends rounded, the latter-a little produced on or

DIPLODON T303

below the median line; surface delicately, concentrically stri-

ate; epidermis pale olive-green, feebly rayed and having a

metallic luster, sometimes banded; teeth very delicate, com-

pressed; pseudocardinals double in the right valve, single in
the left; laterals double in the left valve, single in the right;
nacre bluish-white, iridescent.

Length 52, height 24.5, diam. 13.5 mm.

Australia.

Umo wilsonu bua Pr Acy IN: ser Phila., 1850, ps 153) Jl. Ac.
Nevocieehilas IV. 1860, 9 257.4pl. ob, fies 137: Obs., VIL
p. 74. pl. xt, fig. 137.—Sowerry, Conch. Icon.,.X VI, 1868,
pl. Lxxxvil, fig. 474.

Margaron (Unio) wilson Lea, Syn., 1870, p. 47.

Inplodon wilsonit SIMPSON, Syn., 1900, p. 892.

Umo (Alasmodon) stuarti ApbAMS and ANGaAs, Pr. Zool. Soe.
ond, 1863, p: 417:

Unio stuarti Sowerry, Conch. Icon., XVI, 1866, pl. Liv, fig.
270.

Anodon stuartt SowEerBy, Conch. Icon., XVII, 1867, pl. xxxiv,
figs. 136, 126a, 136b.

Margaron (Unio) stuarti Lea, Syn., 1870, p. 52.

Margaritana stuarti Pret, Conch. Sam., III, 1890, p. 174.

Anodonta stuarti Paster, Conch. Sam., III, 1890, p. 185.

A delicate, somewhat shining species with.a slight metallic
luster and having compressed, rather feeble teeth. A speci-
men from the Stuart Expedition labeled Unio stuwarti Adams
and Angas, agrees perfectly with Lea’s figures and description
of U. wilsonii and with the description of Adams and Angas
of Unio (Alasmodon) stuarti, and Sowerby’s Unio stuarti and
Anodon stuarti. The original description states that the shell
is plicate posteriorly and one of the National Museum shells
shows traces of plication in that region. Another specimen
whose beaks are somewhat eroded, shows traces of radial
sculpture.

DrpLopon EVANS! (Adams and Angas).

Shell short, elliptic rhomboid, or subquadrate, thin, scarcely
inflated or convex, inequilateral ; beaks full and somewhat ele-
vated ; posterior ridge rounded; dorsal outline nearly straight.

130 DIPLODON
oo

with a low wing, behind which it is bluntly, obliquely truncate
on the dorsal slope; anterior end rounded, subangulate above;
base line curved, fullest behind the middle; surface with finely
striated epidermis and showing in the middle of the disk a
few, subradial or oblique markings ; teeth delicate, compressed ;
pseudocardinals double in the right valve and single in the
left ; laterals double in the left valve, single in the right ; nacre
bluish or purplish, rich and brilliant.

Length 53, height 37 mm.

Lagoon of the Lower Murray River, Australia.

Unio (Alasmodon) evansi ApAMs and AnGas, Pr. Zool. Soc.

Lond, 1864,1p:,20:

Umo evanst Sowerby, Conch. Icon., XVI, 1867, pl. vt, fig.

285.

Margaron (Umno) evansi Lea, Syn., 1870, p. 56.
Margarttana evansi Patri, Conch. Sam., III, 1890, p. 173.
Diplodon evansi Simpson, Syn., 1900, p. 892.

A single young specimen labeled Unio evansi Adams and
Angas is in the Lea Collection without locality and it agrees
well with the original description of that species and with
Sowerby’s figure of it.

Section CucumartA Conrad, 1853.

Cucumaria Conrap, Pr. Ac. Nat. Sci. Phila., VI, 1853, p. 260.
Cucumeria SIMPSON, Syn., 1900, p. 893.

Shell elongated, trapezoidal, widest behind ; pseudocardinals
irregular, small, not well developed, showing a tendency to
break into denticles ; laterals feeble ; pallial line strongly pitted ;
nacre much thicker in front.

Type, Unio nove-hollandie Gray.

Group of Diplodon nove-hollandie.

Shell having the posterior two-thirds overed with irregular
nodules, which radiate somewhat from the posterior ridge.
DIPLODON NOVA'-HOLLANDIA (Gray).

Shell much elongated, subcompressed or scarcely subinflat-
ed, rhomboid, somewhat solid; inequilateral, a little narrower

DIPI,ODON 1305

in front; beaks probably not much elevated or inflated; pos-
terior ridge full, rounded; anterior end rounded, cut away a
little below ; base line nearly straight; posterior end obliquely
truncate above, rounded below; surface with uneven, concen-
tric sculpture, the hinder two-thirds covered with irregular
pustules, which are strongest on the posterior part of the
shell: sometimes they are arranged in broken ridges; epider-
mis brownish or blackish; left valve with two small, stumpy
pseudocardinals and two remote, faint laterals; right valve
with two pseudocardinals, the upper very small, and one re-
mote lateral; dorsal scars few, well exposed in the shallow
beak cavities; adductor scars shallow, the small ones imme-
diately under the pseudocardinals, deep; pallial line crenated ;
nacre dirty bluish, often lurid purple in the cavities, much
thicker on the anterior base.

Length 132, height 50, diam. 32 mm.

Australia.

Unio nove-hollandie Gray, Pr. Zool. Soc. Lond., 1834, p. 57.

Margarita (Unio) nove-hollandie LEA, Syn., 1836, p. 17; 1838,
Da 16:

Margaren (Unio) nove-hollandie Lea, Syn., 1852, p. 23; 1870,
P- 35-

Diplodon nove-hollandie Stmrson, Syn., 1900, p. 893.

Unio cucumoides Lea, Proc. Am. Phil. Soc., 1840, p. 285; Tr.
Ai Pint SOc. Vill. 1842. py. 192. pl. vip fies 2: Obse bil
1842, p. 30. pl. vil, fig. 2—Han ey, Biv. Shells, Sup., 1856,
p. 382, pl. xxiv, fig. 4—Cueny, Ill. Conch., 1858, pl. xxvit,
figs. 3, 3a, 3).—Kuster, Conch. Cab. Unio, 1861, p. 219,
pl. xxiv, fig. 1—Rereve, Conch. Icon., XVI, 1865, pl. x1x,
fig. 80.

Margaron (Unio) cucumoides Tea, Syn., 1852, p. 21; 1870,
pit.

-? Unio cumingianus DUNKER, Zeits. fiir Mal., 1853, p. 53.

A striking species, which differs from D. websteri in being
more elongated, narrower in proportion in front, in having a
higher posterior ridge, along which lies its greatest diameter,
and in having the anterior two-fifths of the shell nearly free

1306 DIPLODON

from nodules. The line of juncture between the noduled and
non-nodulous area runs obliquely nearly parallel with the
posterior ridge.

Group of Diplodon shuttleworthiu.

Beak sculpture consisting of strong, irregularly radiate,
curved, nodulous bars; surface of shell somewhat sulcate, but
not nodulous.

DrIeLopON SHUTTLEWORTHII (Lea).

Shell much elongated, rather solid, scarcely subinflated, sub-
rhomboid, inequilateral ; beaks low, subcompressed, sculptured
with radial bars, which curve towards each other; posterior
ridge elevated, rounded above, sometimes more or less double
below; dorsal line slightly curved; base line nearly straight ;
anterior end narrowed, rounded, often cut away below; dor-
sal slope obliquely truncated; lower part of dorsal end round-
ed or feebly biangulate; surface with rather strong, concen-
tric sculpture; posterior part of the shell covered with strong,
subradial, more or less nodulous, ribs; epidermis thick, black-
ish, rather dull; pseudocardinals weak, often smooth and al-
most obsolete in old shells; laterals remote, single and ele-
vated in the right valve, double and feeble in the left; dorsal
scars distinct ; anterior scars double, impressed ; posterior scars
elongated ; pallial line crenated ; nacre bluish to lurid purplish,
thicker in front.

Length 132, height 51, diam. 31 mm.

Australia.

Umo shuttleworthu Lea, Pr. Ac. N. Sci. Phila., VIII, 1856,
p94; Jl. Ac. Ny Se. Phila Ti 857; p. 304, ply aac dis:
19; VI, 1857, p. 24, pl. xxvii, -fig. 19.—SoweErsBy, Conch.
Icon., XVI, 1866, pl. xxxit, fig. 167.

Margaron (Unio) shuttleworthti Lea, Syn., 1870, p. 36.

Diplodon shuttleworthti Simpson, Syn., 1900, p. 893.

? Unio mutabilis Reeve, Conch. Icon., XVI, 1865, pl. xxiv, fig.
112.

DIPLODON 1307

Unio angasi SowERpy, Conch. Icon., XVI, 1867, pl. Lv, fig. 282.
Margaritana angasi Pairet,, Conch. Sam., III, 1890, p. 172.
Anodonta angasi Pret, Conch. Sam., IL], 1890, p. 17

A most striking species, which until lately has appeared to
be quite distinct from any other. The sculpture of the pos-
terior part of the shell extends forward to an oblique line in
front of and nearly parallel with the posterior ridge covering
over half of the shell. In some specimens there is more or
less feeble, nodulous scu!pture in front of this line. The dark
thick epidermis is inclined to peel off; the pallial line is decid-
edly crenate.

DIPLODON WEBSTERI Simpson.

Shell long rhomboid, compressed, inequilateral, subsolid
when young, rather solid when old; beaks low, subcompressed,
pointed, their sculpture consisting of a few, curved, subradial,
broken bars; anterior end rounded, developed almost into an
angle above; base line nearly or quite straight, parallel with
the dorsal line; posterior end rounded below, obliquely trun-
cate above, the point of junction of this truncation with the
dorsa! line almost angulate ; posterior ridge low and rounded ;
surface with strong, irregular, concentric growth lines and
covered throughout with pustules; these are strongest and
somewhat lachrymose on the disk in front of the posterior
ridge: in young shells there is a short row of strong, irregular
knobs on the posterior ridge; epidermis yellowish-ash to dark
brown or blackish-clouded green in young shells, nearly uni-
form black in old ones; left valve with two small, subcompress-
ed, granular pseudocardinals and two remote, straight later-
als, the upper the stronger; right valve with two pseudocar-
dinals, the upper small, with one lateral; dorsal scars few,
placed well below the hinge line; adductor scars shallow ; nacre
bluish-white, blotched in the cavities, greatly thickened on the
anterior base in old shells.

Length 67, height 33, diam. 14 mm.

Waiuku, New Zealand.

Diplodon websteri Stmeson, Naut., XVI, 1902, p. 30.—DALL,

Proce SssNat Mus. SOCK Ve T90s) ps ist, pl. xxx, digs:

ees

1308 DIPLODON

This species is evidently very closely related to D. nove-
hollandie Gray, but it differs from it in being more compress-
ed, shorter, in having its dorsal and ventral outlines more
nearly parallel, and in being covered with pustules throughout.
In that species the strongest sculpture is on and behind the
posterior ridge; in websteri the nodules of this region are faint
and low. Mr. Webster, who sent me specimens, states that
they are not adult, but that he has one four inches in length.

DipLopON MUTABILIS (Lea).

Sheil much elongated, widest behind, subrhomboid or sub-
trapezoid, rather thin, compressed, inequilateral; beaks but
little elevated, subcompressed, showing somewhat extended,
curved, subradial, slightly nodulous bars; posterior ridge full,
widely rounded, ending in a blunt point at the base of the
shell; base slightly incurved medially, full behind the middle;
dorsal line curved; anterior end narrowed, rounded; dorsal
slope obliquely truncated; surface nearly smooth, brownish-
olive; teeth rather feeble; pseudocardinals short, somewhat
dentilate ; laterals nearly straight; nacre bluish, a little thicker
in front.

Length 55, height 26, diam. 13 mm.

Murray River, Australia.

Unio niutabins La, Pro Acs .N; Sci: -Phila., [Ply 18s5o,.puer52):
fi Ac. IN, Sci. Phila, TV,.1860, p. 248, pl. xxv hes 27
Obs.; VIL, 1860;:p. 66, pl. xxxvilr fie. 127.

Margaron (Umio) mutabilis Lea, Syn., 1870, p. 53.

Diplodon mutabilis Stueson, Syn., 1900, p. 894.

The type is not in the Jea Collection, which contains two
smaller shells. It is much more elongated and narrowed in
front than paramattensis and the base is more nearly straight.

Subgenus L-evrrostris Simpson, 1900.

Levirostris SIMPSON, Syn., 1900, p. 804.

Shell irregularly quadrate, thin, inequilateral, compressed,
rounded and narrowed in front, somewhat biangulate and trun-
cate behind; beaks rather low, without sculpture; surface fine-

DIPLODON 1309

ly. concentrically grooved; epidermis delicately lamellated and
serrate; pseudocardinals small; laterals elongated; anterior
muscle impressions small, well marked ; posterior scars super-
ficial; nacre bluish-white. :

Animal unknown.

Type, Unio stagnorum Dautzenberg.

DiPLoDON STAGNORUM (Dautzenberg).

Shell irregularly obovate, compressed or convex, thin, in-
equilateral; beaks but slightly full or elevated, apparently
without sculpture; anterior end cut away above and below and
produced forward into a rounded point; posterior end wid-
ened, irregularly rounded; dorsal and basal outlines curved ;
posterior ridge widely rounded; surface concentrically sculp-
tured; epidermis brownish, finely lamellate; pseudocardinals
small, apparently not well developed; laterals elongated, del-
icate, curved; nacre bluish-white, brilliant.

Length 48, height 33, diam. 17.5 mm.

Congo River, Africa.

Unio stagnorum DAUTZENBERG, Bull. Acad. Belg., XX, 1890,
pas72aple ig ties. 7,120: :
Diplodon stagnorum SIMPSON, Syn., 1900, p. 894.

A peculiarly shaped species, having the anterior end pro-
duced forward on the median line to a blunt point, and the pos-
terior end wide and irregularly rounded. Dautzenberg states
that the beaks are smooth. I am inclined, from his careful
description and figures, to place the species in the genus Dip-
lodon.

SPECIES INCERT# SEDIS.

DireLopon PANCO von thering.

“Shell of moderate size, solid, more or less oval or oblong
in outline and somewhat inflated. The anterior end is smaller
than the posterior and quite evenly rounded, whereas the pos-
terior is obliquely truncate. Dorsal margin slightly convex,
postero-dorsal angle obtusely rounded, posterior margin
oblique, nearly straight. Ventral margin almost straight,
slightly convex in the centre. Beaks not prominent, much

1310 DIP1.ODON

eroded, in front of them at the anterior end of the dorsal mar-
gin is a small lunule 2-2.4 mm. in width. The ligament does
not reach to the end of the dorsal margin. Epidermis smooth,
blackish-brown, alternating with black, polished, elevated, con-
centric zones, between which are the remnants of numerous,
lamellar, concentric growth-lines. The greatest diameter is at
about the centre of the total length and the anterior portion of
the shell towards the beaks is somewhat flattened. Nacre blu-
ish-white, thicker in front. The two cardinal teeth of the right
valve are almost lamellar but rather thick and straight, the
laterals are straight in the middle but oblique at both ends.
The cardinal tooth of the left valve is incurved on the lower
side.

Length 55, height 33, diam. 22 mm.” (von Thering).

Type locality, Rio Panco, a tributary of the Rio Doce in
Espirito Santo, Brazil.

Diplodon panco von THERING, Abh. senck. Naturf. Ges., 32,

IQIO, p. 132, pl. 12, figs. 6a-b.

“Other specimens vary somewhat in form. A low posterior
ridge is sometimes developed. The size of the lunule is also
a variable feature. The nacre in some shells is a pale yellow-
ish-red towards the ventral margin. ‘The beak sculpture con-
sists of from 12 to 13 broad, rounded ridges, of which the
seventh and eighth meet at an acute, V-shaped angle.”

DipLopon GARBEL von thering.

“Shell solid, thick-set, with widely separated beaks. The
specimen figured has the beaks greatly eroded and in front of
them a colossal, broad lunule 8 mm. in diameter. ‘The anterior
end is very short, rather low and regularly rounded. The
hinder end is obliquely truncate, extending down in a decided,
rounded, post-basal point. Ventral margin concave in the
middle, but becoming convex as it approaches the posterior
point. The dorsal margin is bent sharply downwards in front
of the beaks, behind them slightly convex. Epidermis black-
ish-brown, shining, occasionally with squamose growth-lines
and here and there with fine, radial wrinkles. A moderate

DIPLODON 1311

keel extends from the beaks to the hinder end. ‘The cardinal
teeth are sublamellar, but quite solid and jagged. The lateral
teeth are strongly curved and very long, so that, especially in
the left valve, they reach beyond the obtuse postero-dorsal
angle. ‘The muscular impressions are deep; that of the upper
anterior retractor lies at the base of the cardinal tooth, that of
the under retractor is confluent with that of the adductor. The
nacre 1s white with irregular, oily spots.

Length 39, height 25.5, diam. 20.5 mm.” (von Ihering).

Vicinity of Rio Doce on the Rio Sao Jose and the Lagoa
Jupurana, Brazil.

Diplodon garbet voN IHERING, Abh. Senck. Naturf. Ges., 32,

1910, p. 133, pl. 12, figs. 7a-b.

“The numerous specimens vary considerably in form, ac-
cording as the posterior end is round or pointed. Presumably
this is owing to sexual dimorphism. The width of the lunule
is also subject to considerable variation. The beak sculpture
consists of ten or twelve short, radial ridges, of which the
seventh and eighth meet at a sharp angle. In proportion to
the size of the shell these radial ridges are very short and
therefore quickly disappear owing to the erosion of the beaks.
The largest examples are from 42-43 mm. long. This species
stands quite isolated among the known species of Brazilian
Uniones.”

DiPLopON HARTWRIGHTI von Ihering.

“Shell of medium size, nearly oval, moderately inflated and
rather thin-shelled. Anterior end slightly pointed and regu-
larly rounded. The dorsal margin is slightly convex, almost
straight, the ventral margin convex, the height being greatest
at the last fourth of the length of the shell and from there it
ascends to the pointed posterior end. The obliquely truncate
posterior end is biangulate by reason of the well-developed
posterior ridge. The growth-lines are very close and in the
middle of the disk fine and thread-like, becoming wavy and
lamellose posteriorly. The beaks are eroded, but the remnants
or radial sculpture are visible. Epidermis dark olive-green,

1 ee ; DIPILODON
-)

almost black, with here and there fine, radiating grooves ex-
tending from the beaks. The greatest diameter is nearly in
the middle of the shell. Nacre very iridescent. In the right
valve are two lamellar cardinal teeth and a slender lateral ; in
the left valve the cardinal tooth has an auxiliary lamella above
it, separated by a groove. Above the lateral of the right valve,
towards the hinder part, is a slender lamella representing a
rudimentary second lateral. The beaks rise but little above
the narrow hinge. ‘The muscular impressions are not very
deep, especially the posterior ones; the anterior retractor scar
is separate and distinctly marked.

Length 409, height 27, diam. 20 mm.” (von Thering).

Type locality, Lagoa, Alagadinha, Goyaz, Brazil.
Diplodon hartwrighti von TreRtnc, Abh. Senck. Naturf. Ges.,

32, 1910, p..L35, pls 12, figs. 8a-b:

The following are unfigured and uncertain species.

Unio depressa d’Oreicny, Guer. Mag., 1835, p. 34.

Unio fokkesi DuUNKER, Zeits. fur Mal., IX, 1853, p. 54.
Rio de la Plata, Brazil. According to von Ihering, this

equals U. wheatleyanus Lea.

Unio koseretzi Cyrssin, Mal. BI., X, p. 172.

~ River Guahyba, Brazil.

Unio macropterus DuNnKER, Zeits. fiir Mal., III, 1846, p. 109.
srazil.

Unio paraguayanus VON MARTENS, S. B. Ges. Nat. Fr., 1895,
P- 34-

Unio sealandicus Pte, C. Sam., III, 1890, p. 172. Said to
be of Gray. Where?

Unio damnoica @OrRrIGNy. Where?

Unio guahybe von [itERING.

Unio ethicpiformis VON THERING.

Unio bischotfi VON HERING.

Unio sebastan@ VON IHERING. |

Unio sancta-paule VON THERING.
I do not know where the last five species are described, and

they probably have never been published.

SPATHA 133

Family MUTELID.

Shell usually without sculpture throughout; beaks smooth
or but faintly corrugated, never exhibiting the remains of an
embryonic shell; with or without teeth, which, when present,
are irregularly taxodont, the shell showing vestiges of them in
all the genera; nacre soft, richly tinted, generally surrounded
with a wide, prismatic border; escutcheon large, distinct ; pal-
lial line usually simple, but sometimes having a slight sinus
posteriorly.

Animal having the labial palpi large, rounded below, gen-
erally without free points, scarcely or not at all united poste-
riorly ; anal and superanal openings not separated ; mantle gen-
erally closed behind into branchial and anal siphons, which are
always separated by a strong bridge; marsupium occupying
the inner gills; embryo a lasidium, composed of three seg-
ments, the anterior head-like, the median bearing a single shell,
the posterior tail-like.

Genus SPATHA Lea, 1838.

Spatha Lex, Ir. Am. Phil: Soc., V1, 1838, p. 141, footnote.
Spathella BourcuicNat, Esp. Ouk., 1885, p. 13.
Leptospatha RocHEBRUNE and GERMAIN, Mem. Soc. Zool. Fr.,

AVAL 1904; p- 25.

Shell elliptical ; beaks very slightly or not at all sculptured ;
left valve having a faint, compressed tooth under. and in front
of the beak, which fits into a corresponding depression in the
right valve; the entire hinge area often covered with longi-
tudinally folded epidermal matter; escutcheon dark, sharply
triangular; beak cavities shallow, with a single, elongate, deep
scar in each; two large anterior muscle scars and two posterior
ones, the upper small.

Animal having the palpi longer than wide, semicircular, at-
tached along the upper edge, not united; mantle margin united
behind so that the branchial and anal apertures are closed; on
the under margin the mantle is entirely open; outer branchize
united to the mantle to their extremity; inner the larger, free

1314 SPATHA

from the abdominal sac; foot tongue-shaped, thick; anal and
branchial openings separated by a strong bridge. S$. rubens
Lamarck (Troschel).

Type, Anodonta rubens Lamarck.

So far as is known, this entire group is confined to Africa.
I have placed the species in two subgenera, S‘patha typical, in-
cluding those forms with smooth or concentrically sculptured
shells and .4spatharia of Bourguignat with broken, corrugated
sculpture. I know nothing of the soft parts of the latter
group, but the shells have the same general arrangement of
muscle scars as the true Spathas. In placing species in the
two groups of the typical subgenus, it is possible that some
errors may have been made, as the groups are founded on the
beak sculpture, which is often entirely eroded away. Unfor-
tunately, as with the African Unionide, there are a large num-
ber of species that the writer has not seen. I have, therefore,
followed very largely the excellent work of Germain, who has
had the advantage of access to many of the original types and
the large amount of material collected by the recent French
expeditions.

Subgenus SPATHA Ss. s.

Shell solid, having faint, concentric beak sculpture.
Type, Anodonta rubens Lamarck.

Group of Spatha rubens.

Sculpture of the beaks following the growth lines; shell
solid.

SPATHA RUBENS (Lamarck).

Shell large, elliptical or elliptic rhomboid, usually solid, con-
vex to subinflated, inequilateral ; beaks moderately full, some-
what elevated, nearly smooth or having a few, faint, concen-
tric ridges; posterior ridge low, rounded; anterior end round-
ed; dorsal outline curved; base straight or curved; posterior
end usually obliquely subtruncate above, ending in a blunt

point below the median line; surface irregularly, concentric-
ally striate or sulcate; epidermis coppery, tinted green on the

SPATHA 1355

earlier growth, shining: hinge with a vestigial, curved, com-

pressed tooth in the left valve a little in front of the beak and

a corresponding depression in the right valve, which is cov-

ered with epidermal matter; muscle scars impressed; there

are two large ones in the anterior end of each valve and one in
each posterior end; one large deep dorsal scar in each valve
at or behind the beak; nacre generally coppery, iridescent.

Length 140, height 87, diam. 45 mm.

Length 114, height 74, diam. 40 mm.

Length 107, height 68, diam. 40 mm.

Length 130, height 75, diam. 40 mm.

Nile; Niger; Senegal; other points in West Africa.

Anodonta rubens LAMaRcK, An. sans. Vert., VI, 1819, p. 85.
CAMEL TAUD, Voy aa Vicroes IV p: 202: Atlas Il, 1826) pl:
LX, fig. 12—AvpouIn, Savigny’s Exp.. de l’Egypte, Co-
quilles, 1827, pl. vi1.—DersHayvers, Enc. Meth., II, 1827, p.
M47 plCCl, NSS: let!

Inridina rubens Ranc, Nouv. Ann. Mus., 1835, p. 314.

Platiris (Spatha) rubens Lea, Syn., 1838, p. 33; 1852, p. 55;
1870, p. 89.

Spatha rubens Cresstn, Conch. Cab. Ano., 1853, pl. vit, fig. 1
1876, p. 185, pl. Lx1, fig. 1—H. and A. Apams, Gen. Rec.
Molly, MM, 1857, p. 507.; 111, pl. cxix, figs. 3, 3¢.—CuHENU,
Man., 1859, II, p. 148, fig. 729.—Srmpson, Syn., 1900, p.
806.

Anodon rubens Sowrrey, Conch. Icon., XVII, 1867, pl. m1,
figs:

Anodonta clap pertoni Ka:nic, Duchane and Clapperton’ Si iirav=
els, 1826.

Anodonta splendens Dr Cristorort, Crist. and Jan. Cat.,
rSg2i(r)).

Iridina solida Anton, Verz. der Conch., 1839, p. 16.

Anodonta solida Kuster, Conch. Cab. Ano., 1853, p. 50, pl.
KC ey I

Spatha wissmant von Martens, S. B. Nat. Fr.,. 1883, p. 73
Conchs-Mitth; MWD) 1885 (Cr), pergo0;cpl: xxvit.

Spatha rubens var. wismanni GERMAIN, Bull. Mus. Hist. Nat.,
1O@7- p25; Arch. Zool. HxpmetGenr (5), 1, 1900,-p: 55:

1316 SPATHA

Spatha rotundata von Martens, Besch., 1897, p. 242, fig. d.
Spatha rubens var. rotundata GERMAIN, Arch. Zool. Exp. et

Gen., .¢5) , 4, 1900, p- 55.

The above measurements will show that this species is quite
variable in size and form, as all of them are from adult speci-
mens. There is much variation in the color of the nacre,
which in some shells is quite dark, while it is light in others.
A young specimen 70 millimeters long, which came with other
shells in the National Museum from the Nile, has bluish-white
nacre with scarcely a tint of purple.

Germain, (1. c.), considers von Martens’ wissmani and ro-
tundata entitled to varietal rank.

Var. cailliaudi von Martens.

Shell long elliptical or long subrhomboid, subsolid or solid;
epidermis brownish-red, duller than in the type; nacre rose-
colored or white.

Length 149, height 94, diam. 49 mm.

Length 142, height 87, diam. 49 mm.

Length 97, height 58, diam. 33 mm.

Anodonta rubens Aupourn in Savieny, Icon. Moll. Eg., 1827,
pl vars rh
Spatha caillaudi von Martens, Mal. BI., XIII, 1866, p. 9.—

Jickett, L. and S. W. Moll., 1874, p. 259, pl. vit, fig. 1—

Koset, Icon., new ed., II, 1886, p. 27, pl. xvi, fig. 267.
Spatha rubens var. cailliaudi Simpson, Syn., 1900, p. 896.

I have before me a fine specimen of this, said to come from
Alexandria, F.gvpt, which agrees with the description and
with Jickeli’s figure. I am inclined to believe it a mere va-
riety of S. rubens, because IT have seen shells of that species
with the brown, somewhat roughened epidermis and dark cop-
pery nacre and the young shell previously mentioned with the
polished epidermis and whitish nacre.

Var. chudeaui Germain.

“Shell large, subtrapezoidal, slightly elongate, valves quite
inflated, very thick and heavy; dorsal margin convex, slightly
ascending ; ventral margin slightly sinuous, meeting the dorsal

SPATHA 1317

margin at a decided angle ; anterior region very short, rounded ;
antero-dorsal angle strongly projecting; posterior region well
developed, slightly subtruncate, a little more than twice as
long as the anterior; dorsal ridge very obtuse; beaks well an-
terior, not prominent. much eroded; ligament very strong;
anterior muscular impressions very deep; posterior deep; pal-
lial medium. E:pidermis very deep brown, almost black ; lines
of growth strong and irregular, more feeble anteriorly ; nacre
bright rose-salmon, very iridescent.

Length 126, height 86, at the beaks 52, diam. 54 mm.” (Ger-
main).

Type locality, Ie Mamoun, Senoussi Country and Le Grib-
ingul.

Spatha rubens chudeaut GERMAIN, Bull. Mus. Hist. Nat., 1907,

p. 65; PAfrique Cent: Fr., 1907, p. 552, fig. 91.

“This magnificent variety is distinguished from the typical
form by the very anterior position of the beaks ; by the greater
development of the posterior region, which terminates in a
regularly rounded extremity; by the greatest height being
more distant from the beaks; finally by the very divergent dor-
sal and ventral margins. In this last character, this variety
recalls the appearance of Spatha kirki Ancey. In both of these
shells, the dorsal margin is similarlv very regularly convex
from the postero-dorsal angle to the ventral margin.”

SPATHA RENEI Jousseaume.

‘Shell solid, depressed, equivalve, inequilateral, rounded in
front, broader, compressed and subrotund behind, lines of
growth irregularly concentric, epidermis olivaceous-black ;
umbones not prominent, eroded, placed at 1-3 of the length;
dorsal margin curved ; ventral rounded; hinge sinuous, enden-
tulous; nacre iridescent, flesh-colored, violaceous under the
beaks.

Length 81, height 56, diam. 25 mm.” (Jousseaume).

_ Type locality, The Niger at Bamakou and Kougaba.
Spatha renei JoUSSEAUME, Bull. Soc. Zool. Fr., XI, 1886, p.
22, pl. x10, figs. 3, 3a.—GERMAIN, l’Afrique Cent. Fr., 1907,

P- 553:

1318 SPATHA

Spatha rubens cailliaudi (part), Simpson, Syn., 1900, p. 896.

Germain, (1. c.), considers this a valid species, which differs
“very distinctly” from $. rubens. In deference to his opinion,
I have copied the original description.

SPATHA BELLAMYI Jousseaume.

“Shell solid, heavy, black, oblong oval, depressed, equi-
valve, inequilateral, distantly and concentrically striate; de-
pressed and rounded in front, depressed and acuminate behind ;
umbones not prominent, eroded; dorsal margin curved, gib-
bous; ventral rather rounded, constricted in the middle; hinge
sinuous, edentulous ; nacre pearly-while.

Length r1o, height 77, diam. 33 mm.” (Jousseaume).

Type locality, The Niger at Koulikono.

Spatha bellamyi JousskAuME, Bull. Soc. Zool. Fr., XI, 1886,
p. 491, pl. xi, fig. 2, 2a—GrrMaArN, Arch. Zool. Exp. et
Gen, 205) Loo ph ee

Spatha rubens cailliaudi (part), Simpson, Syn., 1900, p. 896.
Germain, (1. c.), having accorded specific rank to this form,

] repeat the original description.

SPATHA CORNEOLA Rochebrune.

“Shell subtetragonal, solid, broadly rounded in front, subdi-
lated and slightly sinuous behind, deeply, concentrically sul-
cate, sulci becoming lamellose and unequal at the extremities ;
dorsal margin slightly incurved; ventral margin concave; um-
bones not prominent, deeply eroded, coppery ; epidermis brown,
corneous, shining; nacre pale red, livid, with a marginal band
iridescent with rose and blue.

Length 96, height in front 42, in the centre 51, behind 50,
diam. 36 mm.” (Rochebrune).

Type locality, Mokaka, Congo.

Spatha corneola ROoCHERRUNE, Bull. Soc. Mal. Fr., III, 1886,
p. 9.—SIMPSON, Syn., 1900, p. 902.

Spatha ganciniensis RocHesrune, Bull. Soc. Mal. Fr., III,
1886, p. 9—GERMAIN. Arch. Zool. Exp. and Gen., (5), I,
1909, Pp. 55.

Spatha gancinenis Simpson, Syn., 1900, p. 902.

Germain, (1. c.), unites these two forms under the name of
ganciniensis, but corneola has precedence.

SPATHA 1319

SpATHA I,Fpstt Jickeli.

Shell subrhomboid, scarcely inflated, somewhat inequilateral,
subsolid ; beaks but little elevated, sculptured with well-marked
concentric striz, which extend over the whole shell; posterior
ridge low, rounded; anterior end rounded, subangulate above,
a little narrower than the posterior end; dorsal and ventral
lines nearly straight; posterior end obliquely truncate above,
rounded below the middle ; epidermis fuscous-olive ; hinge cal-
loused, edentulous ; nacre white or rose-colored, pearly.

Length 98, height 64, diam. 33 mm.

Upper Egypt; Senegal.

Spatha lepsii Jicket1, Faun. L. and S. W. Moll., 1874, p. 265,

pl. 1x, fig. 4.—Stmpson, Syn., 1900, p. 806.

Spatha rubens var. lepsii GERMAIN, Arch. Zool. Exp. et Gen.,

(5), I, 1900, p. 55.

Exceedingly close to S. chaiziana, from which it differs in
being a little more elongated, more strongly sculptured, less
brilliant and more obliquely truncated behind. I think it quite
probable that a good series would show absolute connection
between them.

SPATHA CHAIZIANA (Rang).

Shell rather short, subrhomboid, subinflated, slightly inequi-
lateral, subsolid; beaks somewhat prominent; posterior ridge
moderately full, rounded ; dorsal outline lightly arched, straight
or incurved a little in front of the beaks; base straight or in-
curved in the middle, full behind the middle; anterior end
narrowed, rounded, angled above; posterior end almost square-
ly subtruncate behind, rounded below; surface feebly, concen-
trically sculptured, almost smooth and shining except at the
ends; color tich reddish-brown, ashy-tinted at the umbonal
region; muscle scars shallow; dorsal scars narrow, not deep;
nacre coppery or salmon-tinted, rich and brilliant, having a
metallic lustre.

Length 82, height 56, diam. 33 mm.

Senegal; Niger; Upper Nile; West Africa.

Anodonta chaiziana Ranc, Mem. Aceph. Senegal, (Nouv.

Arch: Mus), 1835; -p. 13, pl. xxviit.

1320 SPATITA

Margarita (Anodonta) chaiziana Lea, Syn., 1838, p. 30.
Anodon chaiziana Catiow and Reeve, Conch. Nom., 1845, p-

66.

Margaron (Anodonta) chaziana Lua, Syn., 1852, p. 49; 1870,

Pp. 79.

Spatha chaziana Ciesstn, Conch. Cab. Ano., 1876, p. 187, pl.

LXIU, figs. 3, 4-—-SIMPSON, Syn., 1900, p. 896.

A fine specimen from the Morelet collection from Dr. Wel-
witsch bearing the above name is before me and from it the
above description was drawn. Its comparative smoothness,
and richer color distinguish it from .S. lepsi, if these charac-
ters are constant. There are no teeth in the shell I have de-
scribed.

SPATHA TAWAI Rang.

Type locality, Senegal.

Anodonta tawai Ranc, Nouv. Ann. Mus., 1834, p. 14.
Anodonta tawi SIMPSON, Syn., 1900, p. 902.
Spatha tawai GERMAIN, l’ Afrique Cent. Fr., 1907, p. 5553 Arch..

Looker <p. et Gen..* (5) 5 0c G00), p50:

The original description is not accessible to me at the pres-
ent time. Germain, (1. c., 1907), remarks: “The Spatha tazwat,
according to the types in the Museum of Paris, is a shell which
differs from Spatha chaiziana only by its much smaller and
noticably more compressed form and by its clearer epidermis,
which is a magnificent, very brilliant green. It is extremely
probable that the two species are synonymous and that S. tazvaz
is only the immature form of S. chaiziana.”

SpATHA INNES! Pallary.

“The Spatha cailliaudi von Martens is a large species, which
has been well figured by Cailliaud (Atlas H, pl. 60, fig. 12),
under the name of Anodonta rubens and by Jickeli, pl. vit,
fig. I.

The name of Anodonta rubens was applied by Lamarck to a
form from Senegal, different from the Egyptian species and
for this reason M. von Martens gave to the species figured by
Cailliaud the name of that traveller. We have not found im

SPATHA 1321

the collections of Dr. Innes Bey this remarkable species; all
the specimens of Spatha sent to us belong to a form much
smaller and proportionally more inflated and with thicker
valves. This form was certainly referred to Spatha cailliaudi
by Jickeli, for he cites (p. 260) specimens corresponding in
dimensions to ours.

Our species is quite near to Spatha chaiziana Rang of south-
ern Africa, but differs by its thicker and more inflated shell,
its somewhat more rostrate form and finally in general appear-
ance. It differs equally from Sfatha arcuata Cailliaud (loc.
cit., pl. 61, fig. 5) by its smaller size and straight, not depressed,
posterior extremity.

The Spatha innesi, like all the species ot the genus, has the
nacre of a beautiful deep rose-color.

Length 60, height 37, diam. 25 mm.” (Pallary).

Type locality, The Upper Nile.

Spatha innesi PaLLary, Bull. Inst. Egypt, III, 1903, p. 97, pl.

Tee ee

“This species in its external appearance quite resembles
Chambardia locardi Bgt. But the Chambardias are “charac-
terized by the right valve being decidedly less strong, smaller
and notably less inflated than the left valve, especially in the
umbonal region,” this is not the case in the Spatha innesi.”

SPATHA TRISTIS Jousseaume.

Shell oblong, scarcely subinflated, subsolid, inequilateral ;
beaks slightly prominent; posterior ridge rounded, ending in
a blunt point a little below the median line; dorsal margin light-
ly arched; base nearly straight; anterior end a little narrower
than the posterior end, rounded, sometimes subangulate above ;
dorsal slope obliquely truncate; surface having irregular
growth lines and traces of radial sculpture; epidermis black-
ish, subshining ; anterior scars elongated, impressed ; posterior
scars shallow, elliptical ; nacre lurid but shining, having shades
of yellowish-gray and green.

Length 65, height 37, diam. 22.5 mm.

Upper Senegal.

1322 SPATIIA

Spatha tristis JoussEAuME, Bull. Soc. Zool. Fr., XI, 1886, p.

497.—SIMPSON, Syn., 1900, p. 897.

Spatha rochebrunei JousseauME, Bull. Soc. Zool. Fr., XI,

1886, p. 494, pl. xiv, figs. 1, 1a—-GeRMAIN, Arch. Zool. Exp.

et Gen., (5), I, 1909, p. 56.

A rather small species with a dark, somewhat lurid, sub-
shining surface, the epidermis showing traces of radial and
feather-like wrinkling. The nacre is a peculiar combination of
tints, and though lurid, is shining.

Germain, (1. c.), refers S. rochebrunei Jouss. to chaiziana
Rang as a synonym.

SPATHA TRAPEZIA von Martens.

Shell somewhat irregularly obovate, inflated, solid; some-
what inequilateral; beaks scarcely elevated; posterior ridge
rather full, narrowly rounded, curved, ending a little below the
median line in a blunt point; dorsal outline curved; anterior
end rounded, slightly narrowed ; base curved and fuller behind
the middle; posterior end obliquely subtruncate above; surface
nearly smooth; epidermis greenish, brownish posteriorly ; na-
cre bluish-white.

Length 70, height 39, diam. 22 mm.

Length 66, height 35.5, diam. 26 mm.

ake Victoria Nyanza.
Spatha trapesia voN Marvrens, Besch., 1897, p. 243, fig.—

SIMPSON, Syn., 1900, p. 879.

Solider and more obovate than S. tristis, having a some-
what elevated, curved posterior ridge. It is more produced
behind the middle of the base than that species and has a
bluish-white nacre.

Var. senilis von Martens.

The variety sznilis seems like a stunted form of the above.
The posterior point is somewhat drawn down and the shell
is smaller than the type.

Length 58, height 33, diam. 20 mm.

Spatha trapezia var. senilis von Marvens, Besch., 1897, p. 244.

—SIMPSON, Syn., 1900, p. 870.

SPATHA 1323

SPATHA DROUETI Chaper.

Shell somewhat elongated, trapezoidal, subinflated, subsolid,
inequilateral, beaks pointed but not high; posterior ridge
rounded, ending in a blunt point near the base of the shell ;
anterior end narrowed, rounded: dorsal outline curved ; base a
little incurved medially ; dorsal slope obliquely truncate; sur-
face lightly, concentrically striate; epidermis brownish or
blackish, slightly wrinkled and showing traces of radial sculp-
ture; hinge edentulous; muscle scars shallow; nacre lurid
greenish, somewhat iridescent.

Length 69, height 37, diam. 24 mm.

Assinie, Africa. |
Spatha droueti CHaprr, Bull. Soc. Zool. Fr., X, 1885, p. 43,

pl. 1, figs. 1-3.—Stmpson, Syn., 1900, p: 897.

A rather small species, of which two specimens from the
author are before me. It is considerably wider behind than in
front; the base is incurved medially and full behind the mid-
dle; the dark, subshining surface shows faint retriculation.

SPATHA MARTENS! Sturany.

“Shell large, ventral margin slightly incurved, posterior
margin obliquely descending and thus forming a beak, of which
‘the point is nearly on the line of the ventral margin. Epider-
mis dark brown; nacre slightly rose-red.

Length 137, height 77, diam. 21 mm. Beaks situated at near-
ly 2-7 of the length.” (von Martens).

Type locality, stream falling into Lake Victoria Nyanza.
Spatha martensi SturaAny in Baumann, Durch Massai, 1894,

p. 12, pl. xxv, fig. 39.—von Martens, Besch., 1897, p. 244.

—SIMPsON, Syn., 1900, p. 897.

Spatha cailliaudi var. martensi GERMAIN, Arch. Zool. Exp. et

Geni? (5) 1, 1909,-p:. 55.

The original description not being accessible, I have copied
that of von Martens, who remarks that “it appears to differ
from S. cailliaudi only in the lower position of the beak.”

Germain, (1. c.), considers it to be only a variety of cailliaudi.

1324 SPATHA

SPATHA KIRKI (Ancey).

Shell subtrapezoid, subinflated, inequilateral, narrowed in
front, gradually increasing in height to the hinder end of the
ligament; beaks apparently moderately elevated; anterior end
rounded ; base full behind the middle; dorsal slope raised into
a low wing and roundly and obliquely subtruncate behind ;
posterior ridge well developed, subangulate, curved, ending in
a point at the base of the shell; surface lightly, concentrically
sculptured, greenish-brown or blackish-brown; nacre reddish
or whitish.

Length go, height 55, diam. 29.5 mm.

Shire River and Lake Nyanza.

Spathella kirki ANcey, Bull. Soc. Zool. Fr., VII, 1894, p. 220,

figs. 4-6.

Spatha kirki Stmpson, Syn., 1900, p. 897.

This species is decidedly trapezoid in general outline, much
narrowed in front, and high, almost winged on the post-dorsal
region. ‘The posterior end is obliquely curved.

Var. liedert von Martens.

Somewhat more elongated than the type, the height to length
is as I to 2; the anterior dorsal edge falls off less quickly and
the posterior edge raises less. Nacre rose-red.

Length 110, height 61, diam. 32 mm.

Spatha kirki var. liederi voN MARTENS, Besch., 1897, p. 245.—

SIMPSON, Syn., 1900, p. 897.

SPATHA MABILLEI Jousseaume.

Shell oblong. widest behind, subsolid, inequilateral, scarcely
inflated ; beaks somewhat elevated; anterior end narrowed and
rounded ; posterior end considerably wider, obliquely subtrun-
cate above, rounded below; dorsal line curved; base incurved
medially, full behind the middle; surface with irregular growth
lines, having radia! markings on the anterior half; epidermis
blackish ; nacre brilliant blue, tinted green; anterior scars deep,
the larger placed near the border and is oval in outline.

Length 52, height 29, diam. 20 mm.

Type locality, Senegal River.

SPATITA 1325

Spatha mabillei JoussEAuME, Bull. Soc. Zool. de Fr., XI, 1886,
p. 495, pl. xiv, figs. 2, 2a.—SimMrson, Syn., 1900, p. 879.—
Germain, l'Afrique Cent. Fr., 1907, p. 555-

‘This is exceedingly close to S. droweti and may be merely a
form of that. It seems to be higher in proportion to length,
to have more brilliant nacre and deeper anterior scars.

Germain, (1. ¢.), says: “This species 1s certainly very close
to Spatha chaiziana, but is to be distinguished by its more
compressed form and less developed and more widely rounded
posterior region.”

Var. mamounensis Germain.

“Shell subrectangular, compressed; valves moderately thick,
solid; dorsal margin nearly straight, slightly ascending; ven-
tral margin straight, nearly parallel to the dorsal margin; an-
terior region moderately developed, semi-circular; posterior
region sub-oval, scarcely twice as long as the anterior; beaks
very slightly projecting; ligament 14.5 mm. long; anterior
muscular impressions moderate, posterior feeble. Epidermis
deep chestnut, almost black, very brilliant; lines of growth
moderate and irregular; nacre violaceous, quite iridescent.

Length 61, height 40.5, at beaks 20.5, diam. 23 mm.” (Ger-
main).

Type locality, Le Mamoun, Senoussi Country.

Spatha mabillei var. mamounensis GERMAIN, Bull. Mus. Hist.
Nati s10074 p.07--1 Adnique Cent. lr51007, p. 556; fig. .92-
“Compared with the type, the variety mamounensis is dis-

tinguished by its less elongated form; by its posterior region

much less elongated with the margin more regularly convex ;
by its straight dorsal margin, nearly parallel to the ventral
margin; by its shorter ligament; etc.”

SPATHA ADANSONI (Jousseaume).

Shell elongated, subrhomboid, somewhat inflated, thin, in-
equilateral; beaks moderately full; posterior ridge rounded,
ending in a point at a little distance above the base: dorsal
and basal lines almost straight and parallel; anterior end

1326 SPATHA

rounded; dorsal slope obliquely subtruncate; surface strongly,
concentrically sculptured; epidermis fuscous, with a yellow-
ish border; nacre pearly, rose-colored.

Tength 92, height 49, diam. 27 mm.

Upper Senegal.

Spathella adansoni JousseaumE, Bull. Soc. Zool. Fr., XI, 1886,

p- 408, pl. xiv, figs. 4, 4a.

Spatha adansoni Simpson, Syn., 1900, p. 808.

Very close to and perhaps equal to S. wahlbergi. It is more
strongly, concentrically sculptured and rather more rhomboid
according to the figure than any of the specimens of that spe-
cies that I have seen and it is a little more inflated.

SPATHA WAHLBERG! (Krauss).

Shell elongate elliptical, convex, subsolid, inequilateral ;
beaks slightly prominent, with very delicate, concentric sculp-
ture; dorsal and ventral outlines nearly straight and parallel;
anterior end rounded: posterior end rounded, but slightly in-
clined to be pointed at or below the median line; surface deli-
cately and irregularly concentrically striate ; epidermis reddish-
brown, sometimes greenish-tinted; anterior scars impressed,
the principal one situated close to the edge of the shell and
elongated; dorsal scar shallow; nacre varying from purplish
to coppery.

Length 90, height 45, diam. 23 mm.

Length t1o, height 55, diam. 31 mm.

Tropical and Southern Africa.

Tridina wahlbergi Krauss, Sud Af. Moll., 1848, p. 19, pl. 11,

fig. 1.

Platiris (Spatha) wahlbergi Lea, Syn., 1852, p. 55; 1870, p.

So.

Spatha wahlbergi Ciesstn, Conch. Cab. Ano., 1876, p. 187, pl.

LX1, fig. 1—S1mrson, Syn., 1900, p. 808.

Mutela wahlbergi Smita, Ann. and Mag., VIII, 1891, p. 319.
Spatha natalensis Lea, Pr. Ac. N. Sci. Phila., VIII, 1864, p.

1133 Jl. AceNeSci.. Phila: Vi, 1866, p> 645 pl ex, fie Go.

Obs., XI, 1867, p. 68, pl. xx, fig. 58.—C Lessin, Conch. Cab.

Ano., 1876, p. 189, pl. Lx11, figs. 7, 8.

SPATHA 127;

Platiris (Spatha) natalensis LEA, Syn., 1870, p. 89.
Several shells are before me, which I refer to the above
species, among them Lea’s natalensis.

Var. hartmanni von Martens.

The concentric sculpture is well developed and over most
of the surface very fine radiating striz are seen. The epider-
mis is olive-green.

Length 94, height 45.5, diam. 26.5 mm.

Tropical and southern Africa.

Spatha hartmanii voN Martens, Mal. BI., XIII, 1866, p. 10.—
JicKxet1, Faun., 1874, p. 263, pl. vin, fig. 2—Crxssin, Conch.
Cab. Anc., 1875, p. 190, pl. LxJ, figs. 2, 3——GzRMAIN, Arch.
Zool. Exp. et _Gen.,.(5.), 1900, p: 56.

Anodon tabula Sowrrey, Conch. Icon., XVII, 1867, pl. xv111,
fig. 68.

Anodonta tabula Pavren, Conch. Sam., III, 1890, p. 185.

Spatha wahlbergi (part), Stmpson, Syn., 1900, p. 808.
There is a large shell in the National Museum collection

without locality that I refer to this variety of wahlbergi. The

description and figure of S. hartmanni agree with that of
wahlbergi except in the degree of development of the sculp-
ture. The shell above mentioned is 131 millimeters in length,

68 in height and 34 in diameter.

Gemain, (1. c.), considers this a valid species.

Var. bourguignati Bourguignat.

Height almost or quite one-half the length, the posterior
part of the hinge line slightly elevated, and angled where it
joins the obliquely truncate dorsal slope; base straight or
slightly incurved medially.

Lake Nyassa.

Spatha bourguignati Bourcutenat, Esp. Ouk. et Tan., 1885, p.

12.—Germatn, l’Afrique Cent. Fr., 1907, p. 560.

Spathella bourguignati Bourcuicnat, Moll. Af. Eq., 1889, p.

LOZ, ply Vy figs Ts!

Spatha wahlbergi var. bourguignati SIMPSON, Syn., 1900, p.

808.

1328 SPATHA

Spathella spathuliformis Bourcuicna?, Moll. Af. Eq., 188y,
p. 199, fig.

Spatha wahlbergi spatuliformis VON Martens, Beschalte, 1897,
p. 248, pl. vit, fig. 18.

Leptospatha spathuliformis ROCHEBRUNE and GERMAIN, Mem.
Exp: etiGens \(5) Letoag: p57:

Spatha (Leptospatha) spathuliformis Germain, Arch. Zool.
Exp, ret Gens 2(5 is L009) p: 57:

Spathella bloyett Bourcutcnat, Moll. Af. Eq., 1889, p. 198, pl.
VILE, fig i3:

Spatha bloyeti von Martens, Besch., 1897, p. 249.
Germain, (1. c.), considers this form entitled to specific rank,

and (1. c., 1909), distinguishes spathuliformis specifically from

bourguignati.

Var. dorsalis von Martens.

“The beaks are further forward, being situated at 2-7 to 1-4
of the length, consequently the posterior margin is longer; the
distance from the beaks to the end of the hinge is nearly or in
some examples quite equal to one-half of the length of the
entire shell. Impressions of the umbonal muscles only slightly
lengthened.

Length 136, height 67, diam. 41 mim.

Length 127, height 63.5, diam. 33 mm.

Length 85, height 42, diam. 21 mm.”’ (von Martens).

Type locality, Ilindi and Myesse, both in Ugogo and the
Zambezi River.

Spatha wahlbergi var. dorsalis voN MARTENS, Besch., 1897, p.
247.—GERMAIN, Arch. Zool. Exp. et Gen., (5), I, 1909, p.
50.

As Germain, (1. c.), considers this form worthy of varietal
rank, I give the original description.

SPATHA BOzAST (Rochebrune and Germain).

“Shell transversely elongate oblong, inequilateral, subsolid,
pale olivaceous-brown, with regular lines of growth, which be-
come lamellose below; umbones minute, slightly eroded, con-
tiguous; dorsal margin somewhat curved; ventral margin al-

SPATIIA 1329

most straight, quite deeply incurved in the middle; anterior
margin elongate, rounded; posterior margin produced in a
long, subacute beak ; ligament long ; anterior muscular impres-
sion deeply impressed, long elliptical; posterior ovate, lacri-
mzform ; nacre pale rose-color, bluish on the margin and shin-
ing.

Length 85, height 38, diam. 24 mm.” (R. and G.)

Type locality, Lake Rodolphe.
Spathella bozasi ROCHERRUNE and GERMAIN, Bull. Mus. Hist.

Nat., 1904, p. 144.
Leptospatha bozasit RocHEBRUNK and GERMAIN, Mem. Soc.

BOO ia eV TOO4, pp. 20,. pl) meee 7

“It is to Spatheila bloyeti Begt., that this form appears to
approach the nearest; it differs, however, by its markedly
greater elongation, by the more produced anterior region, by
the more pronounced median curve of the ventral margin, by
the longer curve of the dorsal margin, by the much longer,
brown, less prominent ligament and, finally, by the different
color.”

SPATHA BRUMP'I (Rochebrune and Germain).

“Shell oblong ovate, compressed, inequilateral, solid, rather
heavy, yellowish-brown, shining: lines of growth broad, dis-
tant, in front and, especially behind, broadly laminose; um-
bones eroded, rather prominent, subinflexed, contiguous; dor-
sal margin almost straight; ventral convex, slightly undulated ;
anterior end ovate; posterior end dilated, produced in a sub-
compressed, and slightly decurved beak; ligament long and
rather prominent; anterior muscular impression biplex, trap-
ezoidal, the anterior alone deeply impressed; posterior sub-
quadrate ; within dirty rose-color, cretaceous, scarcely shining.

Length 80, height 42, diam. 25 mm.” (R. and G.)

Type locality, The Omo, opposite the Makoua Mountains.
Spathella brumpti Rocugesrung and Germain, Bull. Mus.

Hist. Nat., 1904, p. 144. .

Leptospatha brumpti RocHEBRUNE and GERMAIN, Mem. Soc.

Zoot Kovels. 26, pl, Tr he 6:

1330 SPATHA

“This fort approaches the Spathella bourguignati Ancey,
but differs in its less elongated shape, the anterior margin is
oval and not elliptical, the posterior end is wider and much
less rostrated, the ventral margin is decidedly convex and
not oval elliptical, the beaks are more prominent and, finally,
by its larger size.”

SPATHA MAITENGUENSIS Sturany.

“Shell elongate, quite regularly oval, dark brown with faint
olive-green bands. ‘The dorsal margin of the right valve ex-
tends above the Jeft principally in the umbonal region and an-
teriorly. ‘The ventral margin is nearly straight, being only
very slightly incurved in the middle, the posterior portion hor-
izontal, scarcely ascending; posterior extremity rounded. The
length of the shell is to the diameter as 2:1; the beaks are
situated in the first fourth of the length.

Length 88, height 46, diam. 25 mm., the anterior end is 20
mm. long.” (Sturany).

Type locality, Maitengue River, Matabele Land.

Spatha maitenguensis StURANY, Denk. Ak. Wien LX VII, 1898,

p. 628, pl. m1, fig. 66.

“This new form is indeed closely related to Spatha wahlbergi
var. dorsalis and Sp. wahlbergi var. spatuliformis, but can-
not be united to either and even less to typical Sp. wahlbergi.
In order not to bring confusion into the synonymy, I have pro-
visionally separated it as a species.”

SPATHA LACUSTRIS Simpson.

Shell long obovate, subsolid, convex, inequilateral; beaks:
small, somewhat sharp; posterior ridge rounded; dorsal line
nearly straight; basal line lightly incurved in front of the
middle, full behind; anterior end narrqwed, rounded; poste-
rior end rounded, slightly produced in the middle; post-dorsal
region lightly winged, angular behind the ligament; epidermis
fuscous chestnut, pale at the beaks, dark and intensely colored
on the dorsal slope, where it is somewhat waxy and shining ;
nacre pale rose.

Length 08, height 52 mm.

Lake Nyassa.

SPATHA 1331

Spatha enceyi Bourcutcnat, Mem. Soc. Zool. Fr., VII, 1894,
Be 2a tio 7:

Spatha lacustris Stmpson, Syn., 1900, p. 898. — GERMAIN,
lV’ Afrique Cent. Fr., 1907, p. 564; Arch. Zool. Exp. et Gen.,
(5), I, 1909, p. 57.

Appears to be close to S. kirki, but is more elongated and
not so pointed behind. It is rather wider in front than that
species. Changed from S. anceyi, as there is another species
with that name.

Germain, (1. c.), considers this to be a form of S. bourguig-
nati.

SPATHA NYASSAENSIS Lea.

Shell obovate, compressed, rather solid, inequilateral ; beaks
low, pointed with faint, broken, concentric sculpture; posterior
ridge low, narrowly rounded, ending below the median line;
anterior end narrowed, rounded; dorsal and basal lines lightly
curved, the latter full behind the middle; posterior slope ob-
liquely subtruncate; surface with low, irregular, concentric
sculpture; epidermis dark tawny; nacre flesh-colored; muscle
scars impressed.

Length 53, height 31, diam. 13.5 mm.

Lake Nyassa.

Spatha nyassaensis Lea, Pr. Ac. N. Sci. Phila., VIII, 1864, p.
109; Jl. Ac. N. Sci. Phila., VI, 1866, p. 36, pl. xt, fig. 33;
Ob., XI, 1867, p.-40, pl. xu, fig. 33.—?CLessrn, Conch.
Cab. Ano., 1876, p. 190, pl. Lxi1, figs. 3, 4—SimPson, Syn.)
1900, p. 808. )

Platiris (Spatha) nyassaensis Lea, Syn., 1870, p. 80.

Spathelia nyassaensis ANcEY, Bull. Soc. Zool. Fr., VI, 1894,
Pp. 228.

Spatha nyassana Bourcuienat, Bull. Soc. Mal. Fr., VI, 1880,
p. 38.

T have before me the type and a young specimen of this
species. Its compressed form and pale epidermis will distin-
guish it from related species.

1332 SPATIIA

SPATHA APPROXIMANS Preston.

“Shell closely allied to S. myassensis Lea, (Proc. Zool. Soc.
London, 1877, p. 719), but broader posteriorly, more acum-
inate, and covered with a periostracum much paler in color;
the interior of the shell is exceedingly finely granulate.

Long. 64, lat. 100 mm.” (Preston).

Type locality, Shiré River, at a point from 3 to 4 kilometres
to the south of Lake Nyassa.

Spatha approximans Preston, Ann. Mag. Nat. Hist., (8), VI,

ps 63; ply Vertis. 14:

SPATHA MARNOI Jickeli.

Shell long obovate, convex, subsolid, inequilateral; beaks
slightly elevated; dorsal outline arched from the anterior end
to the posterior point, a little fuller behind the ligament; an-
terior end narrowed and rounded; base straight or lightly in-
curved medially, full behind the middle; posterior end round-
ed, somewhat developed just below the median line; surface
evenly, concentrically sculptured; epidermis shining, yellow-
ish-fuscous, with three curved, green rays on the dorsal slope;
hinge lightly calloused ; nacre pale rose, pearly.

Length 85, height 40.75, diam. 23.5 mm.

Marno, Abyssinia.

Spatha marnoi Jicket3, L. and S. Moll. N. Ost.-Af., 1874, p.

264, pl. viti, fig. 3-—Simpson, Syn., 1900, p. 899.

Spatha marmot GerMaAtIn, Arch. Zool. Exp. and Gen., (5), I,

TQOQ, p. 55.

Approaches S. nyassaensis, but is larger, more elongated,
more sharply sculptured, and has three green, rather broad
rays on the posterior slope, which do not appear in either of
Lea’s shells.

SPATHA FOURTAUI (Pallary).

“Tn its external appearance this Naiad so closely resembles
Spatha marnoi figured in Jickeli, pl. vitt, fig. 3, that at first
we considered it to be a form minor, the more so as the hinge

of that species has not been figured. But the description (p.
264) leaves no doubt in regard to the distinctness of the two

SPATHA 1333

xu

species. Jickeli, indeed, savs “cardo leviter callosus, edentulus.
Facies interns pallide rosea . . .,” which applies well to a
Spatha. Our species, on the contrary, has a filiform hinge
and the interior of the valves is a grayish-blue, two charac-
ters, which belong only to the genus Spathella. Besides being
smaller, the S. fouwrtaw differs also by its more slender form
and slightly more angulated posterior margin.” (Pallary).
No dimensions given. Length of figure 62.5, height 209.5
mm.
Type locality, Upper Nile.
Spathella fourtaui Partary, Bull. Inst. Egypt, III, 1903, p.
Oy plaa, tig.. 3:

SPATHA SUBAS3QUILATERA von Martens.

Shell long elliptical, subcompressed, solid, almost equilateral,
the full high beaks being placed a very little in front of the
center and nodulously costate; dorsal and basal lines nearly
straight ; anterior end rounded; posterior end bluntly pointed
on the median line; surface strongly, concentrically sculptured,
olive-green; nacre pale bluish; muscle scars large and im-
pressed.

Length &o, height 56, diam. 24 mm.

Lake Victoria Nyanza.

Spatha subequilatera VoN Mar'tens, Conch. Mitt., II], 1887, p.
1S; Pla XRT nes..S; 0), Besch:, 1807. p.. 246, pl. vin, fie. 16.—
SIMPSON, Syn., 1900, p. 8ga.

Spatha baumanni StuRANY in Baumann, Durch. Massai., 1894,
Dipl 2a pliexsave fic. 28:

Remarkable for having the beaks placed almost in the cen-
ter of the shell. It is a solid species with strong, concentric
sculpture, bluish nacre, and large, well-impressed muscle scars.
The shape is almost evenly long elliptical.

SPATHA SINUATA von Martens.

Shell somewhat elongated, subelliptical, a little wider be-
hind, convex, inequilateral; beaks moderately full; posterior
ridge rounded ; dorsal line lightly curved; anterior end round-
ed; base decidedly incurved medially, full behind the middle ;

1334 SPATHA

posterior end rounded, but somewhat produced a little below
the median line ; surface apparently finely, concentrically sculp-
tured; epidermis reddish-brown, subshining; muscle scars
large, impressed, the two anterior ones confluent; nacre pale
reddish.

Length 77, height 38, diam. 24 mm.

Congo. |
Spatha sinuata von Martens, 5S. B. Nat. Fr., 1883, p. 173;

Conch. Mitt., IT, 1885, p. 190, pl. xxxiv, figs. 5, 6.—Srmp-

SON, Syn., 1900, p. 899.

This species appears to differ from S. mabillei in its larger
size, the color of its epidermis and nacre, and in being more
elongated. von Martens’ description is very brief and does
not touch on all the characters, but the figures are clear and
show a different style of anterior scars from any that I am
acquainted with.

SPATHA BERTILLONIANA Preston.

“Shell moderately flat, rectangularly ovate, solid, scarcely
angled posteriorly, covered with a fine, reddish-chestnut peri-
ostracum, sculptured with coarse, broad, somewhat distant,
concentric growth-lines and very fine, transverse, radiate striz ;
umbones small, not prominent; dorsal margin nearly straight,
somewhat ascending; ventral margin constricted towards the
middle; anterior side squarely rounded; posterior side broadly
produced, bluntly acuminate; anterior adductor scars ovate,
well impressed ; posterior scars broadly ovate, moderately 1m-
pressed ; infra-umbonal visceral scars in right valve broad, in
left valve small, short and deep; pallial margin coarsely de-
fined ; interior of shell nacreous, pinkish-white, iridescent, es-
pecially towards the posterior side, sculptured with fine, inter-
lacing, irregular. wavy striz converging towards the centre
of the shell.

Lonme.5145, at. 97 sam: ».(Preston)).

Type locality, Karonga, north end of Lake Nyassa.

Spatha bertilloniana Preston, Ann. Mag. Nat. Hist., (8), VI,

p. 63,.pl. v, fig. 15.

SPATHA 1335

“A very handsome species, of which the internal sculpture
is most curious and may, in a measure, be compared to the
markings of finger-prints; in the single specimen before me
this remarkable sculpture is much more apparent in the right
than in the left valve.”

Group of Spatha peters.

Shell rather thin and small, greenish or olive; beak sculpture
consisting of faint, more or less oblique, parallel ridges ; hinge
line narrow; teeth scarcely developed; nacre bluish or green-
ish. Animal unknown.

SPATHA PETERS! von Martens.

Shell oblong, thin, subcompressed, inequilateral; beaks
slightly elevated, somewhat pointed; posterior ridge full,
rounded or slightly inclined to be biangulate, ending in a
blunt point a little below the median line; dorsal and basal
lines lightly curved, the latter full behind the middle : anterior
end rounded; posterior end obliquely subtruncate above; sur-
face lightly, concentrically sculptured; epidermis yellowish-
green, sometimes feebly rayed on the dorsal slope; nacre blu-
ish-white to lurid purple; muscle scars but slightly impressed.

Length 67, height 33, diam. 17 mm.

Length 6s, height 32, diam. 19 mm. —

Mozambique; Zanzibar and Uganda.

Spatha peterst voN Martens, Mal. BI., VI, 1860, p. 218, pl.

1, figs. I, 2.—SIMPSON, Syn., 1900, p. 899.

Mutela peterst Cressin, Conch. Cab. Ano., 1875, p. 197, pl.

EX, AS) 162.

Spathella peterst Bourcuicnat, Mol. Af. Eq., 1899, p. 197.
Spatha modesta Lea, Pr. Ac. N. Sci. Phila., VIII, 1864, p. 109;
ieeAes Ni. Sei. Phila. V1. 1866, p. 37. pl: seri, fig, 35 ;-Obs.,

MO IS67, po 40, ple xi, fe. 35=
Platiris (Spatha) modesta Lea, Syn., 1870, p. 89.

Two specimens of this are before me and they are in good
condition save that the beaks are somewhat eroded. The shell
is almost evenly long elliptical, slightly inclined to be rhom-

1336 SPATITA

boid. It is a very little higher at the place where the base is
full than in front. The substance is thin, the epidermis yel-
lowish or tawny-green; nacre lurid purple. [ea’s modesta
is more slender than these shells and has a bluish nacre. von
Martens’ S. petersi as figured seems to stand between the two
lots.

SPATHA ARCUATA (Cailliaud).

Shell somewhat elongate, subrhomboid and arcuate, convex
to subinflated, solid, ineauilateral; beaks but slightly elevated,
apparently having oblique sculpture; dorsal and posterior out-
lines curved, sometimes subangulate behind ‘the ligament; an-
terior end rounded; base decidedly incurved; posterior ridge
rounded; there are sometimes one or two low, radial ridges
above it; surface with irregular, concentric striz; epidermis
dull, greenish or greenish-brown; left valve with a compressed
rudimentary tooth, which fits into a corresponding depression
in the right valve; muscle scars impressed; dorsal scars deep;
nacre whitish or flesh-colored, pearly.

Length 82, height 47, diam. 34 mm.

Length 90, height 48, diam. 31 mm.

Length 8o, height 38, diam. 24 mm.

Eegvpt; Abyssinia.

Anodonta arcuata CaiLiiaup, Voy. a Méroé, IV, 1826, p. 263;
II, pl. ux, figs. 4, 5—?CLEssin, Conch. Cab. Ano., 1874, ’p.
145. pl XEVIT, fies. Tae”

Margarita (Anodonta) arcuata LEA, Syn., 1836, p. 54; 1838, p.
a2:

Tridina arcuata Potirz and MicHaup, Gall. Moll., 1844, p. 146,
PLULV, here:

Margaron (Anodonta) arcuata Lea, Syn., 1852, p. 53; 1870,
Ps3:

Spatha arcuata Jicxeut, L. and S. Moll. N. Ost-Af., 1874, p.
265.—SIMPSON, Syn., 1900, p. 899.

It will be seen by the above measurements that this species
is quite variable in size. It has a heavy shell with a decidedly
arcuate subrhomboid outline, greenish or greenish-brown epi-
dermis and whitish or silvery nacre.

SPATHA 1337

SPATHA CRYPTORADIATA Putzeys.

Shell oblong, rhomboid, inequilateral, convex with dorsal
and ventral lines parallel, both curved up a little in the middle;
posterior slope subtruncate; anterior end rounded ; posterior
ridge low, roundéd, ending behind in a blunt point near the
base of the shell; beaks somewhat raised, their sculpture not
known; surface apparently concentrically ridged, having a
few feeble plications on the posterior slope ; epidermis fuscous ;
nacre pearly, bluish-white, rather thick.

Length 64, height 29, diam. 17 mm.

Leopoldville ; Congo.

Spatha cryptoradiata Putzrys, Proc. Verb. Soc. Mal. Belg.,
1898, pl. xxvu, figs. 14, 15.— SIMPSON, Syn., 1900, p. 90o.—
GERMAIN, I’Afrique Cent. Fr., 1907, p. 562.

Spatha (Leptospatha) cryptoraoita GERMAIN, Mem. Soc. Zool.
Ete EX 1QG0; p, 240
According to the figure this species is sculptured with fine,

broken plications, which run longitudinally or somewhat ob-

liquely to the growth lines.

According to Germain, (1. c. 1907), this peculiar appearance
of the epidermis is not a specific character, but is the result
of the alternate conditions of drought and humidity to which
the species is subjected in its habitat.

SPATHA PROTCHEL (Rochebrune),

“Shell elongate rhomboid, subcompressed, rounded in front,
elongate wedge-shaped behind, slightly gaping; epidermis
smooth, shining, sublamellose, especially in the posterior re-
gion; concentrically, minutely suleate and radiately, broadly
striate; dorsal margin nearly straight; ventral margin sub-
sinuous ; beaks small, eroded, copper-colored ; epidermis brown-
ish-red ; nacre livid in the centre, pale rose towards the mar-
gins, shining.

Length 61, height, in front 22, in the middle 25, behind 28,
diam. 14 mm.” (Rochebrune).

Type locality, Mckaka, Congo.

Spathella protchei RocHEBRUNE, Bull. Soc. Mal. Fr., III, 1886,

p. 8.-Simeson, Syn., 1900, p. go2.

1338 SPATHA

Spatha (Leptospatha) protchei Germain, Bull. Mus. Hist.

Nat., 1900, p. 543, pl. vil, fig. 46.

Germain (1. c.), remarks that this species is related to S.
cryptoradiata Putzeys, but differs, “‘by its more compressed,
more regularly subquadrangular-elongated form; more central
beaks and by the parallelism of the dorsal and ventral mar-

gins.
SPATHA STUHLMANNI von Martens.

Shell elongated, irregularly subrhomboid, solid, subinflated,
inequilateral; beaks apparently but little elevated; posterior
ridge prominent, widely rounded or feebly subangulate, end-
ing in the base-in a blunt, rounded point or feeble biangula-
tion; dorsal outline arched; dorsal slope with a long, oblique
truncation ; anterior end rounded, narrowed a little; base near-
ly straight, full behind the middle; surface concentrically, ir-
regularly sculptured; epidermis blackish; nacre whitish-gray.

Length 71, height 35, diam. 24 mm.

Length 60, height 30, diam. 24 mm.

Lake Albert ; Nyanza.

Spatha stuhlmanni voN Martens, Besch., 1897, p. 250, fig.—

SIMPSON, Syn., 1900, p. goo.

I have never seen this species, but from the figure and de-
scription [ should think it was rather closely related to S.
arcuata. It is not arcuate however, as that species is, the base
line being slightly rounded and full behind the middle.

Var. comocensis Germain.

“It seems to me to be impossible to separate this shell from
von Martens’ species, of which it possesses the principal char-
acters, but from which it is easily distinguished: by its very
noticably less elongated form, by its anterior end more regu-
larly convex with a more prominent anterio-dorsal angle; fin-
ally by its more convex dorsal margin.

The shell is solid, brilliant, olive-green near the beaks, yel-
lowish-brown below ; the lines of growth are quite strong and
irregular ; finally the nacre is slightly salmon-tinted, very iri-
descent.

SPATHTA 1339

Length 62, of antericr region 23, of posterior region 41,
height 36, at the beaks 14, diam. 24.5 mm.” (Germain).
Type locality, Comoe River, near the Gold Coast.
Spatha stuhlmanint var. comocensis GERMAIN, Bull. Mus. Hist.
Nai Xi. 1908, p: 127; -IldeCon.,, V1, 1908, -p. 114; pl.
Ti, Fol.

SPATHA DECORSEI Germain.

“Shell of medium size, elongate rectangular in shape; valves
quite inflated, thick, heavy; dorsal margin almost straight.
slightly ascending; ventral margin decidedly sinuous, parallel
with the dorsal margin; anterior region rather short, rounded ;
posterior region much extended, a little more than twice as
long as the anterior ; dorsal ridge not strong, very obtuse ; beaks
obtuse, not compressed, scarcely prominent, much eroded,
showing a lead-colored nacre; ligament short, quite strong,
18 mm. long; hinge filiform, edentulous; anterior muscular
impressions very deep; posterior quite faint; pallial impres-
sion feeble. [ypidermis a beautiful deep brown, passing into
black anteriorly and posteriorly, much eroded towards the
beaks; lines of growth not strong and very irregular; nacre
bluish-white, slightly iridescent.

Length 86, height 42, of umbones 39, length of anterior re-
gion 27, of posterior region 63, diam. 34 mm.” (Germain).

Type locality, Le Mamoun, Senoussi Country.

Spatha (Leptospatha) decorsei GrrmMatn, Bull. Mus. Hist.
Nat., 1904, p. 4690; Afrique Cent. Fr., 1907, p. 557, pl. lith.
feos.

“This species is to be distinguished from the Spatha (Lepto-
spatha) stuhlmanni von Martens by its subparallel dorsal and
ventral margins: by its anterior region less shortly truncate ;
by its posterior region more elongated, but terminating in a
beak much less sharp and not central and decidedly truncate as
in Sp. stuklmanni, but decidedly basal and broadly convex; by
the ventral margin not convexly upcurved towards the pos-
terior region, but descending and very decidedly sinuous in the
central part, etc.”

1340 SPATHA

Var. persinuata Germain.

“Differs from the type by its general form being higher to-
wards the posterior region; by its posterior region much more
sloping and terminating in a beak much shorter, decidedly con-
vex and placed very low; by its ventral margin very much
more sinuous; by its maximum diameter being nearer to the
dorsal margin; by its stronger ligament, etc. Epidermis very
dark brown, almost black, deeply and extensively eroded in the
umbonal region, showing a lead-colored nacre; lines of growth
more regular and stronger than in the type; nacre Prussian
blue, slightly iridescent.

Length 74, height 39, of beaks 33, length of anterior region
24, of posterior region 52, diam. 29 mm.”’ (Germain).

Type locality, Le Mamoun, associated with the type.
Spatha (Leptospatha) decorseit var. sinuata GERMAIN, Bull.

Mus. Hist. Nat., 1904, p. 460.
Spatha (Leptospatha) decorsei var. persimuata GERMAIN, |’Af-

rigue Cent.F i, 1007; p. 558; 12. 03:

“I have changed the name that I had previously given to
this variety because there is already a Spatha sinuata Martens
and the use of the same name might lead to confusion.”

SPATHA SUBRENIFORMIS (Sowerby).

“Shell compressed, solid, thick, somewhat arched, oblong,
reticulated with close, concentric wrinkles and radiating striae,
brownish-green, white within, bluish towards the margin; pos-
terior side angular, acuminated at the end; dorsal margin
straight; lateral margin obliquely convex, middle depressed ;
ventral margin arched; anterior end rather short, with short
dorsal margin, umboes smooth, prominent.

Length (of figure) 60, height 30 mm.” (Sowerby).

‘Type locality, Lake Nyassa.

Anodon subreniformis SowERBy, Conch. Icon., XVII, 1867, pl.

XIv, fig. 50.

Anodonta subrenifornus Pate, Conch. Sam., III, 1890, p.

185.

Spatha subreniformis SIMPSON, Syn., 1900, p. 900.

SPATHA 1341

“In form resembling An. senegalensis, but much flatter and
with a more reticulated surface. An. senegalensis is also char-
acterized by a radiating posterior rib, which is wanting in the
present species.”

SPATHA PFELFFERIANA (Bernardi).

Shell oblong, subrhomboid, apparently convex and subsolid,
inequilateral ; beaks somewhat elevated ; posterior ridge round-
ed, ending near the base in a blunt rounded point, with a
slight, radial ridge above it; surface smooth, with concentric
strie; epidermis greenish-black; muscle scars well marked:
nacre blackish-green behind, lighter in front.

Length 72, height 36 mm.

Gaboon; West Africa.

Margaritana pfeifferiana Bernarpi, Jl. de Conch., IV, 1860,

Dasoh spe xi ties: Thee
Margaron (Margaritana) pfeifferiana Lea, Syn., 1870, p. 68.
Spatha pfeifferiana Stmpson, Syn., 1900, p. goo.

Spatha pfetfferi GrrmMain, Arch. Zool. Exp. et Gen., (5), I,

IQOQ, Pp. 50.

The description given by M. Bernardi is very brief, several
of the important characters being entirely omitted. I have
based the above description largely on the excellent figures.
The species is remarkable for its dark color within and with-
out, being a blackish-green throughout.

Germain, (1. c.), remarks that it is, “perhaps, only a variety
of S. tawai Rang.

SPATHA DAHOMEYENSIS (Lea).

Shell elongate, subrhomboid, rather thin or scarcely sub-
solid, convex, inequilateral; beaks moderately elevated, with
delicate, oblique sculpture; posterior ridge full, rounded, end-
ing near the base in a bluntly rounded point; dorsal and basal
margins nearly parallel, curved so that the outline of the shell
is slightly arcuate; anterior end rounded, usually a little nar-
rower than the hinder end; posterior end obliquely truncate ;
left valve often having a feeble tooth; muscle scars well mark-

1342 SPATHA

ed, but shallow; nacre bluish or greenish, often tinted or

clouded with salmon.

Length 85, height 38, diam. 19 mm.
Length 55, height 25, diam. 18 mm.
West Africa.

Anodonta dahomeyensis Lea, Pr. Ac. N. Sci. Phila., III, 1859,
p. 1543 dleAc oN, Scr. Phita, cio 1850, @.-20b0 Geen i ence
i41; Obs.;2 VIE, 1860; p.-79;. pl. su; fies 14 ——Cressing:
Conch. Cab; Ano., 1873, p.- 103, pl: XXxxI,-fies. 5. 0:

Anodon dahoinevensis Sowerby, Conch. Icon., XVII, 1870, pl.
RRAVE) As gs

Margaron (Anodonta) dahomeyensis LeA, Syn., 1870, p. 82.

Spatha dahomeyensis SIMPSON, Syn., 1900, p. goo.

Anodonta senegalensis Lea, Pr. Ac. N. Sci. Phila., III, 1859, p.
1543: Ji. 2c. N. Sei. Phila. TV ;-1800,;p.;260.-pl xpiene Ime.
Obs., VII, 1860, p. 78, pl. xu1, fig. 140.—C Lessin, Conch.
Gab. Ano: S735 pl. x xh hose gee

Anodon senegalensis Sowrrpy, Conch. Icon., XVII, 1867, pl.
XU, Sree Scolo7On Pls ex Mi, Monae:

Margaron (Anodonta) senegalensis LEA, Syn., 1870, p. 82.

Spatha senegalensis GeRMAIN, Arch. Zool. Exp. and Gen., (5),
TOO, (oe.

Mutelina senegalica JoussEAUME, Bull. Soc. Zool. de Fr., XI,
1886, p. 488.

Spatha divaricata voN Martens, Besch., 1897, p. 250, pl. vil,
fig. 15.—SIMpPsON, Syn., 1900, p. gOI.—GERMAIN, Arch.
Zool xpyiet Gent. “(s5) Sd 21900! pas 7
A very variable and probably widespread, abundant species.

Lea's Anedonta senegalensis is a little more elongated and in-
flated than some specimens, but does not differ varietally I
think. The surface varies from being almost smooth to con-
centrically sculptured and some shells show traces of radial
sculpture. The epidermis varies from dull greenish to green-
ish-brown. \S. divaricata von Martens seems to be the young
or a small form of S. dahomeyensis. I have seen small speci-
mens of that, which agree in every essential particular. Mar-
tens’ shell is from Lake Victoria Nyanza.

SPATTTA 1343

The National Museum possesses a shell of the above sent
by Ancey and named Mutelina senegalica by Bourguignat him-
self.

Germain, (1. ¢.), erroneously gives priority to senegalensis.
The same author, (1. ¢.), not only gives divaricata specific
rank, but puts it in a group by itself.

SPATHA MARTINI (Rochebrune).

“Shell solid, round elliptical, inequilateral, gaping poste-
riorly ; leek-green with bright yellow at the margins; white at
the umbonal region, very polished and shining, very minutely.
circularly striate; dorsal margin almost straight, oblique; an-
terior margin round; posterior abruptly descending, compress-
ed, subalate; basal margin slightly convex; umbones contigu-
ous, very small, transversely plicate, situated at almost 1-2 of
the length; posterior slope subcompressed, quite distinctly
margined by a bifid sulcus; ligament short, minute, internal ;
nacre pale whitish-yellow.

Length 38, height 27, diam. 15 mm.” (Rochebrune).

Type locality, Bafing River, a tributary of the Senegal.
Mitriodon martini RocHEBRUNE, Bull. Mus. Hist. Nat., 1904,

p. 462.

Spatha (Leptospatha) martini GerMAIN, Arch. Zool. Exp. et

Gens. 5); 1, 1909} p: -40.-

Mitriodon falemeensis ROCHEBRUNE, Bull. Mus. Hist. Nat.,

1904, p. 462.

Mitriodon heudeloti RocHEpRUNE, Bull. Mus. Hist. Nat., 1904,

p. 462.

Germain, (1. ¢.), states that the three species above quoted
are synonymous.

SPATHA COMPLANATA ( Jousseatime).

Shell elongated, convex, thin, somewhat elliptical, inequilat-
eral; beaks but little elevated; anterior end rounded, slightly
narrowed; dorsal and basal outlines nearly straight ; posterior
end obliquely subtruncate above, bluntly pointed below the
median line; surface nearly smooth, the epidermis being near-

1344 SPATHA

ly all denuded in an adult state, the young shell is rose-tinted ;

the old shells are bluish ; nacre pearly, rose-tinted, bluish in the

cavities.

Length 46, height 23, diam. 12 mm.

Upper Senegal; Niger River.

Mutelina complanata JousseAuME, Bull. Soc. Zool. de Fr., XI,
1886, p. 480, pl. x11, figs. 1, 1€a.—GrERMAIN, Arch. Zool. Exp.
et; Gen.5 (5). 1900, p:.57:

Spatha complanata SIMPSON, Syn., 1900, p. goo.

I have never seen this species, which is formed something
like S. dahomeyensis. According to Jousseaume it has the
aspect of Psammobia vespertina. This appearance and the al-
most entire want of epidermis in an adult state would seem
to be good distinguishing characters.

Var. curta (Germain).

“Shell less elongated, the posterior region being in propor-
tion to the anterior very much shorter and higher than in the
typical form; dorsal margin slightly convex, notably ascending
and not subrectilinear: ventral margin decidedly convex.

Length 26, height 15.5, diam. 8 mm.” (Germain).

Type locality, the Chari and the Bangoran.

Mutelina complanata var. curta GerRMAIN, Bull. Mus. Hist.
Nat:, 1907, p. 68; l’Afrique Cent. Fr., 1900, p. 574.

“As in the type the shell is very compressed, thin, epidermis
yellow, tinted with rose, passing to café au lait towards the
beaks and to greenish-yellow towards the margins; the lines
of growth are noticably stronger and more irregular.”

Subgenus Moncevtra Bourguignat, 1885.

Moncetia Bourcuicnat, Esp. Ouk., 1885, p. 34.

Shell long-elliptical, inequilateral, compressed, thick, som-
ber-colored; beaks compressed, smooth, sharp; hinge with a
tubercular eminence near the beak of the right valve, with two
internal ligaments and three groups of muscular impressions.
( Bourguignat).

Animal unknown.

Type, Moncetia anceyi Bourguignat.

SPATHA 1345

SPATHA ANCEY! (Bourguignat).

Shell elongated, subrhomboid, compressed, inequilateral ;
beaks low, sharply striate; dorsal and basal lines nearly paral-
lel, the former arched, the latter slightly incurved so that the
shell is slightly arcuate; anterior end rounded; posterior end
obliquely truncate or subtruncate above; surface rudely and
very irregularly concentrically sculptured, the margins of the
ridges being apparently ragged; epidermis earthy-yellow,
paler at the beaks ; nacre bluish-white, slightly iridescent ; right
valve with a sort of obsolete tooth near the beak, left valve
with a sort of rudimentary lateral; dorsal scars double or
treble.

Length 52, height 24, diam. 13 mm.

Lake Tanganyika.

Moncetia anceyi Bourcuicnat, Esp. Ouk., 1885, p. 34; Icon.

Maly 1888: plexxx,, fier:

Moncetia jouberti Bourcuicnat, Un. and Ir., 1886, p. 63;

Icon. Mal., 1888, pl. xxx, fig. 4.

Spatha anceyi SIMPSON, Syn., 1900, p. got.
Spatha (Moncetia) anceyi GERMAIN, Arch. Zool. Exp. et Gen.,

(5), I, 1909, p. 50.

| have placed this and two other apparently related species,
which their author Bourguignat has put in the genus Moncetia,
as a subgenus under Sfatha. I have never seen any of the
forms belonging to this group and it may be that it should
have generic rank. M. jouwberti seems to me to be merely an
old M. anceyi, which is more arcuate and somewhat drawn out
at the posterior base. The shells gape in front and are thinner
medially.

Germain, (1. c.), unites all the species of Moncetia under
this species.

SPATHA MOINETI (Bourguignat).

Shell compressed, rather solid, arcuate, irregularly rhom-
boid, inequilateral ; beaks low ; dorsal outline strongly arched ;
base incurved; anterior end a little narrowed, subangulate
above; dorsal slope obliquely subtruncate; surface strongly

1346 SPATHA

and irregularly, concentrically sculptured; epidermis suboliva-
ceous-chestnut, slightly shining; nacre subolivaceous to whit-
ish.

Length 55, height 33, diam. 15 mm.

Lake Tanganyika.

Moncetia mometi Bourcuicnat, Un. and Ir., 1886, p. 61; Icon.

Mal., 1888, pl. xxx, fig. 7.

Moncetia rochebruneana Bourcuicnat, Nouy. Mal., 1886, p.

62; Icon. Mal., 1888, pl. xxx, fig. 8.

Spatha monteti Simpson, Syn., 1900, p. gor.

The sculpture is apparently less ragged than in S. anceyi
and the nacre is rose-tinted. The Moncetia rochebruneana, as
figured by Bourguignat in his Iconographie, is a specimen with
the posterior end badly diseased and does not seem to me to
differ otherwise from moineti. The anterior end gapes slightly.

SPATHA LAVIGERINA (Bourguignat).

Shell compressed, somewhat elongated, lightly arcuate, in-
equilateral; beaks low; dorsal outline arched; basal outline a
little incurved ; anterior end rounded, angled above; posterior
ridge having a tendency to be double, ending in a feeble bian-
gulation at the base of the shell, with a faint, wide, radial
ridge above it; dorsal slope lightly, obliquely truncate; sur-
face densely, concentrically sculptured; epidermis fuscous
chestnut to yellowish; sometimes having greenish rays behind ;
nacre white to violet-tinted, bright.

Length 61, height 32, diam. 15 mm.

Jwake Tanganyika.
Moncetia lavigerina BourcuicNnat, Nouv. Mal., 1886, p. 60;

leon. Mal 1888, ‘pl xxx, fig: 6.

Spatha lavigerina Simpson, Syn., 1900, p. got.
Moncetia bridouxi Bourcuicnat, Un. and Ir., 1886, p. 65;

Icon? Mal. ess, pli hie 5. :

‘The posterior end of this is wider than in the other forms
and is somewhat biangulate. The J/. bridouxi seems to me
to be a voung shell, which is slightly rayed behind.

SPATHA 1347

Subgenus AspaTHARTtA Bourguignat, 1885.

Aspatharia BourcuicNat, Esp. Ouk., 1885, p. 14.

Shell elongated rhomboid, somewhat compressed, with a
full, rounded posterior ridge, from which curved rows of fine,
broken corrugations radiate; epidermis dark olive, wrinkled,
rayless; beak sculpture not seen; hinge with a low, slightly
elevated ridge in the left valve in front of the beak; dorsal
scars small; nacre lurid, bluish-green. Animal as in Spatha.

Type, Vargaritana vignoniana Bernardi.

This may be a distinct genus, though its characters seem to
agree fairly well in most respects with those of Spatha. Bour-
guignat does not describe the muscle scars or tell anything of
the nacre.

SPATHA VIGNONIANA (Bernardi).

Shell long rhomboid, rather solid, subcompressed or convex,
inequilateral; dorsal line slightly curved; base line lightly
curved, straight or incurved medially ; anterior end rounded ;
posterior ridge full, narrowly rounded, ending in a blunt point
at or near the base of the sheli; above the posterior ridge there
is a wide, shallow, radial depression; dorsal slope obliquely
truncate, sometimes its outline is a little incurved; surface
closely and sharply sculptured with curved, wavy, subnodulous
ridges, which are divaricate on the posterior ridge ; epidermis
a peculiar lurid greenish-olive, quite dark ; sometimes there is
a sort of feeble ridge in the left valve at the beak; muscle
scars shallow, the front one of the anterior ones vertical and
the hinder one small and horizontal; dorsal scars one or two;
nacre livid, dark, bluish or greenish, sometimes clouded with
salmon.

Length 57, height 28, diam. 15 mm.

Length 58, height 27, diam. 15 mm.

Gaboon, West Africa.

Margaritana vignoniana Bernarnt, Jl. de Conch., VIT, 1858,

Ds 302) pleox, fies 1.

Unio wgnoniana Reeve, Conch. Icon., XVI, 1865, pl. xxv,

fig. 120.

Spatha vigneniana SIMPSON, Syn., 1900, p. 902.

1348 SPATITA

Anodonta vignonana Muscrave, Phot. Conch., 1863, pl. 1
fie. ok

Anodon wvignonanus Rerve, Conch. Icon., XVII, 1870, pl.
NMEX, dios TO:

Margaron (Unic) vignenana Leas, Syn., 1870, p. 32.

Margaron (Margaritana) vignouana Lia, Syn., 1870, p. 67.

Spatha vignont GERMAIN, Arch. Zool. Exp. et Gen., (5), I,
1909, Pp. 57-

? Anodonta rugifera DuNKER, Mal., Bl., V, 1858, p. 225.

y

This remarkable form, of which several specimens are before
me. seems to have most of the characters of the genus Spatha,
hinge, muscle scars, etc. In typical Spatha there is only a
single dorsal scar in each valve, in this species there may be
one or two, while Moncetia may have three. 4. rugifera Dun-
ker probably equals S. vignomiana Bernardi, but there is only
a Latin description. Both were published the same year.

SPATHA CORRUGATA Dautzenberg.

Shell rather solid, convex, oblong, subrhomboid, inequilat-
eral; beaks low; dorsal outline almost regularly curved from
the anterior to the posterior end of the shell; anterior end
somewhat narrowed, rounded, subangulate above; base line
very lightly curved; posterior ridge low, somewhat double,
ending in a wide biangulation at and below the median line;
surface slightly corrugated over the earlier growth, striate on
the later growth; epidermis blackish-chestnut; nacre whitish
at the border, greenish within; hinge thick, edentulous; dor-
sal scars apparently two in each valve; anterior scars as in
S. wignoniana. ;

Jength 70, height 42, diam. 24 mm.

River Niari, West Africa.

Spatha corrugata DAUTZENBERG, Jl. de Conch., XLI, 1893, p.

50, pl. vit, fig. 5—Simpson, Syn., 1900, p. 902.

Quite different in form from S$. wgnoniana, but it has a
sculptured surface, and apparently, from the figure, two dor-
sal scars in each valve. The wide posterior biangulation, and
the evenly, rounded dorsal outline will at once distinguish it

SPATHA 1349

from S. wignoniana. The dimensions given for this species
are, no doubt, erroneous and probably the result of a typo-
graphical error. The statement that the length is 17 milli-
meters should read 70 or 71, I presume.

SPATHA SEMICORRUGATA Preston.

“Shell oblong, solid, covered with a blackish-brown perio-
stracum, which is minutely wrinkled posteriorly, sculptured
with rather coarse lines cf growth and corrugated on the upper
portion of the posterior side; umboes small, situated somewhat
anteriorly; ligament elongate, not prominent; dorsal margin
slightly arched posteriorly, sloping anteriorly ; ventral margin
nearly straight; anterior side angled, bluntly acuminate; in-
terior of shell rosy pink, iridescent, especially towards the
margins.

Long. 51.5, lat. 87 mm.” (Preston).

Type localitv, Lower Congo.

Spatha semicorrugata Preston, Ann. Mag. Nat. Hist., (8),

IVE 2o09) ps G0;;pl.- IV, fig. 7.

SPATHA KAMERUNENSIS Walker.

“Shel! oblong-ovate, somewhat inflated, subsolid; beaks
eroded, but apparently only slightly elevated, sculpture not
observed, placed about 1-5 of the total length from the anterior
end; anterior end regularly rounded; basal and dorsal lines
nearly parallel, slightly diverging posteriorly ; basal line nearly
straight, in some specimens slightly arcuate; dorsal line
straight or slightly curved; dorsal slope oblique ; posterior end
somewhat prolonged and regularly rounded; posterior ridge
rounded, exhibiting in some specimens, a subobsolete angle,
terminating at the lower end of the dorsal slope; dorsal slope
sculptured with fine, radiating ridges, curving upwards to-
wards the hinge; surface of the disk subsulcate with strong
lines of growth, cut by very fine, impressed, radiating lines,
between which the epidermis is minutely and irregularly wrink-
led or festooned; epidermis very dark brown, almost black
towards. the margins; hinge edentulous; beak cavity shallow,
with a single, deep, dorsal cicatrix directly under the beak ;

1350 SPATHA

at the posterior end of the ligament, there is a triangular
notch in the dorsal border of the nacreous area; impressions
of the adductor muscles large, well marked, irregularly oval ;
that of protractor pedis reniform, situated slightly behind and
at the base of that of the anterior adductor; posterior adduc-
tor impression large, oval; that of the posterior retractor small,
elongated-oval, separate from that of the posterior adductor
and situated immediately below the notch at the end of the
ligament ; nacre dark, dull plumbeous, tinged with green, more
intense towards the beak cavity ; scarcely iridescent posteriorly.

Length (of type) 69, height 35.5, diam. 22 mm.” (Walker).

Type locality, Kribi River, 17 miles from Efulen, Kamerun.
Spatha kamerunensis WALKER, Nautilus, XXIV, 1910, p. 38,

pl. 111, figs. I, 2—OrtMANN, Ibid; p. 39.

“Ten specimens, in alcohol, of this very distinct species were
sent by Mr. George Schwab to the museum of the Univ. of
Mich.

By reason of its sculptured surface, it evidently belongs to
the subgenus Aspatharia Begt., as recognized by Simpson
(1900) and Germain (1909).

In size, shape and in the peculiar sculpturing of the surface,
which requires the use of a lens to develop the detail, it is
easily distinguishable from both of the allied species.”

The following are unfigured and unidentified species :
Spatha pangallicensis ROCHEBRUNE, Bull. Soc. Phil., VI, 1882,

P- 33-

Upper Senegal.

Spatha baikiit H. ApAms, Proc. Zool. Soc. Lond., 1866, p. 447.

Niger River.

Spatha anataria Jicket1, Faun. Suss. Moll. N. O. Af., 1874,

p. 266.

Chambardia Bourcutcnat in Servain, 1891. New name for
the Egyptian [ridinide.

Chambardia bourguignati, C. locardiana, C. letourneuxiana,
C. pharaonum, C. rhynchonella, C. rhynchoidea. Some of
these are credited to Bourguignat and some to Servain. I do
not know what they are. They are probably Moncetias.

MUTELA 1351

Genus MUTELA Scopoli, 1777.

Mutela Scopout, Intr. Nat. Hist., 1777, p. 397.
Iridma LAMaRcK, An. sans Vert., VI, 18109, p. 88.
Calliscapha Swainson, Tr. on Mal., 1840, p. 380.
Kufira Gisret, Naturg. Hohe Schul., 1848, p.
Mutelina Bourcuticnat, Esp. Ouk., 1885, p. It.

Shell elongated, slightly inflated, with low, smooth beaks,
and a rounded posterior ridge; surface faintly concentrically
grooved; epidermis rayless; hinge straight, having generally
vestiges of taxodont teeth: dorsal scars an irregular row, ex-
tending downward and forward; muscle scars irregular.

Animal having the palpi longer than wide, not united; man-
tle margin united as far as the foot, so that the branchial and
anal openings are closed; outer branchiz united to the man-
tle to the extremity; inner entirely united to the foot; foot
tongue-shaped, somewhat produced anteriorly. Jridina celes-
tis Lea, (Troschel).

Type, [ridina exotica Lamarck.

Although in a number of cases the shells of this group re-
semble those of Spatha, there are certain reasonably constant
conchological differences. In Spatha the hinge is never den-
tilate, the anterior muscle scars are two in number and dis-
tinct, the adductor scar being placed close to the border of
the shell and usually vertically elongated. The dorsal scars
are deep and distinct, one to three in number, and the valves
are generally well closed all around. In A/utela the hinge is
either dentilate or usually shows vestiges of dentilations, the
anterior scars are irregular, often three in number and faint,
the dorsal scars are numerous and blurred, and the valves gape
at the anterior base and behind. The anatomical differences,
so far as is known are not great. In Spatha the mantle mar-
gin is entirely open below as in the Unionide; in Mutela it is
closed below, the lobes being united as far’ forward as the
foot, as in the marine Pholadide.

1352 MUTELA

Group of Mutela exotica.

Shell elongate, rhomboid, wider and subtruncated behind,
“subsolid.

Murer Exorica (Lamarck).

Shell elongated, scarcely subsolid, somewhat rhomboid, be-
ing wider behind than in front, subinflated, inequilateral ; um-
bonal region somewhat raised and inflated, elongated; poste-
rior ridge full and rounded above, fading out below ; dorsal line
nearly straight ; base line straight or slightly incurved medially,
full behind the middle; anterior end rounded, but cut away be-
low ; posterior end obliquely subtruncate ; epidermis greenish ;
hinge containing a great number of irregular, rudimentary
teeth; nacre brilliant, pale reddish or coppery; muscle scars.
feeble. irregular; dorsal scars forming an uneven row; pallial
line faint, somewhat sinused behind.

Length 155, height 55, diam. 35 mm.

Tropical Africa.

Tridina exotica LAMARCK, An. sans Vert., VI, 1819, p. 89; Enc.
Meth., II, 1827, p. 147, pl. cciv, figs. 1, 1b—SoweErsy,
Conch. Icon., XVI, 1868, pl. 1, fig. 2.—Ctresstn, Conch. Cab.
ATO.) LOgGeepa 2a ls pl wl Moet ile.

Anodonta exotica BIAINVILLE, Man., 1825, p. 538, pl. LXVI,
fige5 3:

Platiris (Iridina) exotica Lna, Syn., 1838, p. 33; 1852, p. 54;
1870, p. 88. :

Mutela exotica SIMPSON, Syn., 1900, p. 903.

Pliodon (Iridina) exotica GERMAIN, Arch. Zool. Exp. et Gen.,.
(551900; ps 58:

Pleiodon exoticus Pa’re., Conch. Sam., III, 1890, p. 188.

Tridina elongata Sowrrby, Rec. and Fos. Shells, VII, 1821, fig.
1.—Sowerey, Conch. Man., 1839, fig. 150.—SwaInson, Tr.
on Mal., 1840, p. 286, fig. 60.—ReEEvE, Conch. Syst., I, 1841,
p. 122, pl. xcir.—Sowrrpy, Conch. Icon., XVI, 1868, pl. 1,
foo ie

Platiris (Spatha) elongata Lea, Syn., 1838, p. 34.

Mutela clongata Prrer, Conch. Sam., III, 1890, p. 187.

Tridina striata OxEN, Isis, 1834, p. 458.

MUTELA 1353

’ Mutela solenifornis Bourcuicnat, Esp. Ouk., 1885, p. 25.

—Bowvrcurenat, Icon. Mal., 1888, pl. xx, fig. 2.

? Mutela bridouxt Bourcuicnat, Un. and Ir., 1886, p. Zines

Icon Mal. 1888, ‘pl. «x11, hes 7T.

A fine species, which is narrowed in front and much cut
away below anteriorly. The teeth extend throughout the
length of the hinge line except at its extreme ends, and while
a majority of them are irregular, many of them set crosswise
of the hinge tine.

MUuTELA DUBIA (Gmelin).

Shell elongated, subrhomboid, rather solid, subinflated, in-
equilateral ; umbonal region full and somewhat elevated, elon-
gated; posterior ridge high, narrowly rounded above, some-
times slightly double below ; hinge line nearly straight; ante-
rior end narrowed, rounded and cut away below; base straight
or slightly incurved medially, fuller near the posterior end;
posterior end obliquely truncate; surface with irregular, con-
centric sculpture; epidermis greenish, sometimes olive When
old; dorsal scars irregular, placed in an oblique row; muscle
scars well impressed, anterior ones irregular; nacre brilliant,
greenish in young shells, coppery in old ones.

Length 106, height 47, diam. 29 mm.

‘Tropical Africa.

Le Mutel Avanson, Hist. Nat. du Sen., 1757, p..234, pl. xvu,
fig 2. :

Mytilus dubia GMELIN, Syst. Nat., 1788, p. 3368.

Anodonta dubia Bosc, Hist. Nat. Coq., III, 1824, p. 144.

Platiris (Spatha) dubia Lea, Syn., 1852, p. 55; 1870, p. 80.

Mutela dubia H. and A. Avams, Gen. Rec. Moll., II, 1857, p.

506; III, pl. cxrx, figs. 1, 1a—Criessin, Conch. Cab. Anco.,

173 pO lO 4,e pl KV, the. 22
Iridina dubia CHeENu, Man., 1859, II, p. 147, fig. 726.

Mvtilus dubius Woop, Ind. Test. Rev., 1856, p. 69, pl. x11,

figs 26:

Mutela dubia Simpson, Syn., 1900, p. 903.
Tridina angustata Sowrersy, Conch. Icon., XVI, 1868, pl. wu,

fig. 5.

1354 MUTELA

Mutela angustata JickeLi, Faun., N. O. Af., 1874, p. 268.—
SIMPSON, Syn., 1900, p. 904.—GERMAIN, l'Afrique Cent.
Fr, 190740) 504;

Most of the characters of this species are the same as those
of WV. exotica. But it is a smaller, solider species, the surface
is more strongly, concentrically sculptured, and the hinge is
edentulous or has only the very, faintest vestiges of teeth.

Further study of material received as M. angustata, since
the Synopsis was published, leads me to believe that Sower-
by’s Ir:dina angiustata 1s a synonym of dubia.

Germain, (1. c.), states that in his opinion the angustata
Sby. should be considered as a variety of M. nilotica Caill.,
“from which it difiers mainly in the divergence, more or less
accentuated, of the dorsal and ventral margins.”

Var. curta Germain.

‘Shell much less elongated, measuring only 99 mm. in length
for a height of 41 mm. and a diameter of 26 mm. Epidermis
emerald-green; nacre rose-salmon, very iridescent.” (Ger-
main ).

Type locality, The Lower Chari.

Mutela angustata var. curta GERMAIN, Bull. Mus. Hist. Nat.,

1906, p. 174, fig. 6; l’ Afrique Cent. Fr., 1907, p. 565, fig. 94.

Var. ponderosa Germain.

“Valves very thick and heavy; heavily encrusted with a cal-
carious deposit ; striz large and undulating ; nacre bright rose-
salmon, very iridescent.

Length 118-149, height 41-64, diam. 28-42 mm.” (Ger-
main).

Type locality, Lake Tchad.

Mutela angustata var. ponderosa GERMAIN, Bull. Mus. Hist.
Nat., 1905, p. 489; Ibid, 1906, p. 56, fig. 1; Afrique Cent.
Fr., 1907, p. 565, fig. 95.

MUTELA NILOTICA (Sowerby).

Shell elongated, irregularly trapezoid, thin, gaping in front;
umbonal region slightly elevated, elongated; posterior ridge
full, widely rounded: dorsal outline lightly arched; posterior

MUTELA 1355

end obliquely truncate, rounded below ; anterior end narrowed,

rounded, very slightly cut away below; base incurved to be-

hind the middle, quite full towards the posterior end; surface
with irregular growth lines; epidermis greenish or olive-green ;
nacre iridescent; hinge edentulous, obsoletely crenulate in
front.

Length 132, height 53 mm.

Tropical Africa.

Tridina nilotica Sowerby, Zool. Journal, I, 1835, p. 53, pl. u.—
? CAILLIAUD, Voy. a Méroé, 1826, pl. Lx, fig. 12—AUDOUIN,
Savicny, Icon. Moll. Egypt, 1827, pl. vi, fig. 2.—CroucnH,
ii eint. lant, 1827, p: 17, pl. x, fig: I1—DrsHaves, Ir.
Hlem., IT, 1853, p. 219, pl. xvii, figs. 6, 7—CHENU, Man.,
1859, Il, p. 148, fig. 727——Sowersy, Conch. Icon., XVI,
LOGS, ple Tt, fig. A,

Platiris (Spatha) nilotica Lea, Syn., 1838, p. 33.

Mytilus niloticus Woop, Ind. Test. Rev., 1856, p. 207, pl. um,
sup. fig. I.

Mutela nilotica H. and A. Apams, Gen. Rec. Moll., II, 1857,
p. 506.—SimPson, Syn., 1900, p. 904.

? Mutela jouberti BouRGUIGNAT, Un. and Ir., 1886, p. 28; Icon.
Mal., 1888, pl. xx, fig. I.

? Mutela vissert BourcuIGNAT, Un. and Ir., 1886, p. 31.

Mutela vysseri BourcuIGNAT, Icon. Mal., 1888, pl. xxt1, fig. 3.
According to Sowerby this species is obliquely inflated be-

hind, but he does not give the diameter. The want of teeth

behind should distinguish it from e-otica, and the hinge line
is more curved and the base fuller behind than in any of the
allied forms.

Var. emini von Martens.

Lower in front and smaller, posteriorly ascending and pro-
portionately swollen, so that the deepening between the pos-
terior dorsal margin and the inflation extending from the
beaks to the posterior end is very small; ventral margin
straight, not incurved; height to length as 2-5.

Length 114, height 45, diam. 34 mm:

Mutela nilotica var. emini yon Martens, Besch., 1897, p. 253-

—SIMPSON, Syn., 1900, p. 904.

1356 MUTELA

MUTELA ALATA (Lea).

Shell trapezoid, subcompressed, subsolid, inequilateral ;
beaks not elevated above the dorsal line; posterior ridge low,
subangulate, the dorsal slope above it being radially exca-
vated so as to produce a wide, shallow furrow; dorsal line
straight, the hinder part raised into a decided wing, which is
almost squarely subtruncate behind; anterior end narrow,
rounded, base nearly straight, slightly incurved medially, the
outline curved up behind; surface with fine irregular, con-
centric sculpture; epidermis yellowish-green, bronzy and iri-
descent ; hinge edentulous ; muscle scars impressed; dorsal and
anterior scars very irregular; posterior scars double; nacre
rose or coppery-tinted, iridescent.

Length &o, height 45.5, diam. 19 mm.

Lake Nyassa.

Spatha alata Lea, Pr. Ac. N. Sci. Phila., 1864, p. 109; Jl. Ac.
N. sci: Phila.51366; p. 35, pl. xu, fie. .31. (Obs. XL 13867. a:
20; pl. XiL, fei.

Platiris (Spatha) alata Lea, Syn., 1870, p. 89.

Mutela alata Ciessin, Conch. Cab. Ano., 1876, p. 196, pl. Lxtt,
figs. 7, 8.—SIMPSON, Syn., 1900, p. 904.

Burtoma alata Ancry, Bull. Mal. Fr., VI, 1889, p. 38.

This is a beautiful species with a rich, iridescent epidermis,

which shows shadings of yellowish-green and bright green.
It is, no doubt, closely related to M. simpsoni, but is more
compressed, is more strongly winged, and does not show the
strong, radial furrows on the front of the disk that Ancey’s
species does. l[ea’s shell shows faint indications of radial
sculpture in front; it also gapes at the anterior base and slight-
ly behind. The posterior end of his shell is somewhat diseased.

MU‘YELA SIMPSONI Ancev.

Shell only slightly elongated, subsolid, gaping in front and
behind, trapezoid, inequilateral, subinflated ; beaks low; dorsal
outline straight in front, lightly winged behind; posterior end
obliquely truncated; anterior end angled above, rounded be-

MUTELA 1357

low; base nearly straight; surface concentrically striate and

furnished in front with a few widely spaced, radial, narrow

grooves; epidermis yellowish-green, iridescent ; hinge slender,
smooth; nacre splendid rose-color, iridescent, whitish on the
border.

Length 72, height 35, diam. 28 mm.

Shire and Karonga rivers, near Lake Nyassa.

Muteia simpsont ANcrEy, Mem. Soc. Zool. de Fr., VII, 1894,
p. 233, fig. 8.—Simpson, Syn., 1900, p. 904.

Mutela alata var. simpsom von Martens, Besch., 1897, p. 253.
—GErMAIN, Arch. Zool. Exp. et Gen., (5), I, 1909, p. 58.
Remarkable for the rather conspicuous radial furrows on

the front half of the disk. The splendid rose-colored nacre

should be a distinguishing character.

MUTELA HARGERI F,. A. Smith.

“Shell irregularly triangular, alate, much compressed and
very inzquilateral, white, covered with an olivaceous periostra-
cum, striate with lines of growth and everywhere painted with
very fine, close, radiating, greenish lines; anterior side short,
obliquely curved, posterior side very broad, obliquely trun-
cated above; ventral margin widely curved; valves thin, slight-
ly raised or ridged in the middle between the umbo and the
posterior side: interior of shell white, pearly, iridescent ; hinge
simple; ligament narrow, elongated, occupying the whole mar-
gin; anterior muscular impression not deep, irregularly round-
ed; posterior obscure, superficial.

Length 104, height 68, diam. 16 mm.” (Smith).

Type locality, Lake Mweru.

Mutela hargert KF. A. Smitu, Proc. Mal. Soc. London, VIII,

1908, p. 14, text-fig.

“Only a single left valve of this species was obtained. The
diameter above given is supposed to be that of a complete spec-
imen. The radiating lines are hair-like and scarcely noticeable
unless specially looked for. Spatha alata Lea, from Lake
Nyassa, is an allied species, but less winged.”

1358 MUTELA

MUTELA BOURGUIGNATI Bourguignat.

Shell somewhat elongated, irregularly rhomboid, rather sol-
id, convex, inequilateral; beaks low; posterior ridge full.
rounded, ending in a rounded point at the base ‘of the shell;
above the ridge there is a wide, shallow, radial. impression ;
dorsal line straight; anterior end rounded, much cut away be-
low ; base curved, full in the middle; posterior end obliquely
truncate; surface regularly, concentrically striate, lightly shin-
ing, olive, obscurely, linearly rayed; hinge with- faint teeth in
front; nacre rich orange with whitish border, iridescent.
Valves widely gaping at anterior base and behind.

Length 53, height 21, diam. 12 mm.

Take Nyanza.

Mutela bourguignati BourGuIGNAT, Esp. Ouk., 1885, p. 8—

SIMPSON, Syn., 1900, p. 904.

Decidedly long rhomboid, with the base somewhat produced
medially. Bourguignat describes the nacre as splendidly iri-
descent, orange with a white border. Credited to Ancey in litt.

Var. smithi von Martens.

‘Proportionately higher and shorter, the height being to

being about 140°; ventral margin very convex in the middle.
Beaks situated at from 2-7 to 1-3 of the length.

Length 75-86, height of beaks 30-33, of wing 32.5-35, diam.
20-24, distance from the beaks to the end of the hinge 35-41
mm.” (von Martens).

Type locality, Lake Victoria-Nyanza.

Mutela bourguignati F. A. Smiru, Ann. Mag. Nat. Hist., (6),

Xs 1602; p. 126, ‘ply 12; ee:

Mutela bourguignati smithi von Martens, Besch., 1897, p.

255.—Grrmuain, Arch. Zool. Exp. et Gen., (5), I, 1909, p-

58.

Var. truncata von Martens.

“Posterior end very short, more rapidly ascending below and
steeper above ; upper posterior angle being about 130°. Height
to length as 1:2.33. Ventral margin only slightly curved.

MUTEL,A T1359

Beaks situated at 1-3 of the length; posterior angle at 4-5 to
5-6 of the length.
Length 85, height at beaks 33, at wing 37, diam. 22, from
the beaks to the end of the hinge 40 mm.” (von Martens).
Type locality, Lake Victoria~-Nyanza.
Mutela bourguignati var. truncata von Marrens, Besch., 1897,
Pa255. pls Vil, figs 17.

- Group of Mutela rostrata.

Shell somewhat inflated, thin, elongated, with a low, round-
ed posterior ridge ending in a point about midway up from the
base; beaks low, smooth; epidermis bluish-green, rayless;
hinge line edentulous or having only the faintest vestiges of
denticles ; muscle scars large, shallow, indistinct ; nacre bluish,
shaded violet.

Animal the same as in typical Mutela.

MUTELA ROSTRATA (Rang).

Shell elongated, thin, convex, irregularly elliptical, inequi-
lateral; beaks somewhat full, elongated, nearly or quite
smooth; dorsal line straight; basal line straight or slightly
curved; anterior end regularly rounded or sometimes slightly
cut away below; dorsal slope often feebly winged, obliquely
truncate; posterior ridge well developed, narrowly rounded,
ending in a rather sharp point about on the median line; sur-
face with fine, irregular, concentric sculpture and faint, radial
markings; epidermis olive-green, usually dark; muscle scars
shallow ; nacre bluish, tinted with violet, sometimes rosy-pur-
plish or salmon-tinted.

Length 104, height 32.5, diam. 17 mm.

Length go, height 32.5, diam. 20 mm.

Tropical Africa.

Iridina rostrata Ranc, Nouv. Ann. Mus., 1835, p. 316.—Po-

T1Ez and Micuaup, Gall. Moll., 1844, p. 147, pl. wvt,. fig. 1.
Spatha rostrata von Martens, Mal. Bl., XIII, 1866, p. 11.
Muteia rostrata Jickrt, Faun., 1874, p. 269.—S1MPson, Syn.,

1900, p. 905.

1360 MUTELA

Mutelina rosirata Bourcuricnat, Bull. Soc. Zool. Fr., II, 1886,
p. 488.—GerMain, Arch. Zool. Exp. et Gen., (5), I, 1909,
Pp. 57:

Indima calestis Lea, Syn., 1836, p. 57; Tr. Am. Phil. Soc., VI,
1838, p. 82, pl. xxm, fg. 70;Obs., IL, 1838p. 82, pl. xxm-
fig. 70.—SoweErsBy, Conch. Icon., XVI, 1868, pl. 1, fig. 3.

Platiris (Spatha) celestis Lea, Syn., 1838, p. 33; 1852, p. 55;
1870, p. 80.

Mutela celestis CLesstn, Conch. Cab. Ano., 1876, p. 193, pl.
WKY oS. eee:

Mutela subdiaphana Bourcutcnat, Moll. Fluv. Ny., 1883, p.
5.—SIMPSON, Syn., 1900, p. 906.

Mutelina thollont RocHEBRuNE, Bull. Mal. Soc. Fr., III, 1886,
Day:

Mutelina thottoni Simpson, Syn., 1900, p. 906.

Mutelina legumen RocHEBRUNE, Bull. Mal. Soc. Fr., III, 1886,
p. 6.—SIMPSON, Syn., 1900, p. 906.

Mutelina prasina RoCHEBRUNE, Bull. Mal. Soc. Fr., III, 1886,
Pp. 7.—SIMPSON, Syn., 1900, p. 906.

Usually thin, dark olive-green and sharply pointed behind
on the median line. In most cases the nacre is deep blue-tinted
with violet and is brilliantly iridescent to rather dull. I have
before me a somewhat solid shell with salmon-tinted purplish
nacre, which is probably this. The shell gapes at the anterior
base and behind.

MurELA MAPILLI (Rochebrune).

“Shell elongate wedge-shape, rather heavy, short in front,
narrowly rounded, gaping; elliptically subrostrate behind ; con-
centrically and deeply sulcate, radiate in front, broadly sul-
cate behind, covered with an undulating, striate epidermis at
the extremities; dorsal margin at first nearly straight, then
incurved and extending in a long, compressed wing; ventral
margin nearly straight; umbones widely eroded, white tinged
with copper-color; epidermis olivaceous-brown; nacre bluish,
copper-color, shining.

Length 75, height in front 16, in the middle 24, behind 26,
diam. 13 mm.” (Rochebrune).

Type locality, Gancini, Congo.

MUTELA 1361

Mutelina mabilli Rocuesrune, Bull. Soc. Mal. Fr., IIT, 1886,
p. 7.— SIMPSON, Syn., 1900, p. 906.

Mutelina mabillei GERMAIN, |’Afrique Cent. Fr., 1907, p. 5609.

Mutelina paludicola Rocuxsrunr, Bull. Soc. Mal. Fr., III,
1886, p. 8.—Simpson, Syn., 1900, p. 906.

Var. frasi (Germain).

“Shell very much longer; dorsal and ventral margins more
divergent ; posterior region more developed, terminating in a
subtruncate, rounded beak, placed very low. Shell quite thick,
solid, epidermis brown-chestnut, slightly reddish posteriorly,
greenish towards the beaks, which are much eroded; lines of
growth strong and irregular ; nacre blue, quite iridescent.

Length 63, height 24, diam. 13 mm.” (Germain).

Type locality, The Niger.

Mutelina mabillei var. frasi GERMAIN, Bull. Mus. Hist. Nat.,

1907, p. 67: l'Afrique Cent. Fr., E909, p. 580, fig. 97.

Var. gailliardi (Germain).

“Shell of medium size, narrowly elongate, slightly siliqui-
form, quite compressed; valves decidedly gaping in front and
very much so behind; dorsal and ventral margins nearly par-
allel; dorsal margin straight; ventral margin nearly straight,
slightly sinuous in the middle; antero-dorsal angle acute; an-
terior region very short, subconical, rounded, decidedly cut
away at the base; posterior region very long, four times as
long as the anterior, terminating in a beak obliquely truncate
and rounded; beaks small, not prominent, incurved, eroded:
dorsal ridge very blunt; ligament 31 mm. long, not prominent,
brownish ; hinge filiform; anterior muscular impressions deep ;
posterior quite deep; pallial line very strongly marked.

Shell quite solid; epidermis yellowish, passing into a deep
brown anteriorly and slightly grayish towards the beaks: lines
of growth irregular, sharp, much stronger and slightly lamel-
lose posteriorly ; nacre bluish, slightly rosy towards the beaks,
very iridescent.

1362 MUTELA

Length 58, height 24, of anterior region 11, of posterior re-
gion 48, diam. 12.5 mm.” (Germain).

Type locality, lake Tchad.

Mutelina mabillei var. gaillardi GERMAIN, Bull. Mus. Hist.

Nat., 1909, p. 477.

“Compared with Mutelina mabillei var. frasi Germain, this
shell is distinguished: By its general form; by its dorsal and
ventral margins being parallel and not divergent; by the pe-
culiar form of the anterior region, which is, besides, very
much shorter; by its mere rounded posterior region; and fin-
ally by its slightly thicker and much more heavy shell.”

MUuTELA FALEMEENSIS (Germain).

“Shell moderately long, decidedly compressed; valves thin,
fragile, gaping at both ends; dorsal and ventral margins very
divergent ; dorsal margin subrectilinear, decidedly. ascending ;
ventral margin convex; anterior region rounded; posterior
region two and one-half times as long as the anterior, re-
markably enlarged and terminating in a large beak, placed
very high: beaks small, not prominent; ligament long and
strong; muscular impressions feeble.

Length 66, height 32, diam. 13 mm.” (Germain).

Type locality, River Faleme, Senegal.

Mutelina falemeensis GERMAIN, Bull. Mus. Hist. Nat., 1907,

p. 67; ’Afrique Cent. Fr., 1907, p. 569, fig. 96.

Subgenus PsEUDOMUTELA Simpson, 1900.

Pseudomutela StMPSON, Syn., T1900, Pp. 905.

Shell rather thin, elongate, wide, round and gaping behind,
cut away and gaping at the anterior base; beaks low; surface
rudely sulcate; a series of irregular, nodulous projections ex-
tends down the low posterior ridge; hinge edentulous, with a
kind of faint, broken internal ligament, with a wide prismatic
streak behind: muscle scars distinct, united, the anterior pro-
tractor, however, separated and irregular; nacre lurid violet,
iridescent behind.

Type, Mycetopus plicatus Sowerby.

MUTELA Eeo8

MUutTELA PLICATA (Sowerby).

Shell much elongated, somewhat obovate, scarcely subsolid,
convex, very inequilateral ; widely gaping in front and behind:
beaks low; posterior ridge slightly developed above, fading
out below; dorsal margin straight; anterior end narrowed,
rounded, cut away below; posterior end almost evenly round-
ed; base nearly straight; surface with irregular, concentric
sculpture, and a series of uneven folds and low humps along
the line of the posterior ridge ; epidermis pale greenish-brown,
subshining ; hinge line narrow in front, wider and showing
the prismatic layer behind, edentulous: muscle scars shallow,
quite irregular; nacre lurid violet, iridescent.

Length 112, height 38.5, diam. 20 mm.

Syene, Upper Egypt.

Mycetopus plicatus Sowersy, Conch. Icon., XVI, 1868, pl. u,
fi 73. ISeHER™ le de Conch. = kX XVilL. 1690, Pp GE —
P#TEL, Conch. Sam., III, 1890, preter,

Platiris (Mycetopus) plicatus Lea, Syn., 1870, p. go.

Mutela plicata Jicxet1, Faun. Moll. N. Ost-Af., 1874, p. 270.
—SIMPSON, Syn., 1900, p. 905s.

Mutelina plicata GERMAN, Arch. Zool. xp. et ‘Gen, (5). 1,
1900, p. 58.

There is a specimen in the National Museum from Syene,
which agrees generally with the shell figured and partly de-
scribed by Sowerby. It is rather darker in color, has lower
beaks, and the foldings on the posterior part are not so regu-
lar as his figure shows. Whether these foldings and humps
are normal or the result of disease I am unable to say.

This is certainly not a Mycetopoda, but is evidently nearer
Miutela than anything. I have placed it in that group as a sub-
genus, though it may be worthy of generic rank.

MUTELA JOULINI (Germain).

“Shell large, narrowly elongate, siliquiform, quite compress-
ed; valves thin, fragile, gaping at both ends, decidedly so in
front, very much more posteriorly ; dorsal and ventral margins
slightly diverging: dorsal margin nearly straight, but slightly

1364 MUTELA

ascending ; ventral margin long and regularly subconvex; an-
tero-dorsal angle well marked; anterior region very short,
rounded, cut away at the base; posterior region remarkably
developed, more than 5 I-2 times as long as the anterior, ter-
minating in a long, well-rounded beak; beaks small, only
slightly prominent, much eroded; dorsal ridge at first promi-
nent, but much reduced towards the extremity ; ligament very
long, strong, somewhat prominent, brilliant brown, length 53
mm ; hinge filiform; anterior muscular impressions quite deep,
posterior feeble, but quite visible, pallial well marked. Epi-
dermis light chestnut-color, yellowish in the centre of the disk
and towards the margins, eroded towards beaks, revealing a
very iridescent, salmon-tinted nacre; lines of growth quite
fine, not very regular, light in the middle, becoming stronger
and somewhat lamellose towards the posterior region; nacre
brilliantly iridescent, salmon-color under the beaks, greenish-
blue towards the margins.

Length 117, height 39 mm. at 55.5 mm. from the beaks, in
front of the beaks 31, length of the anterior region 17.5, of
the posterior region 101, diam. 18 mm.” (Germain).

‘Type locality, The Upper Oubangui.

Mutelina joubini Germain, Bull. Mus. Hist. Nat., 1904, p.
470; l’Afrique Cent. Fr., 1907, p. 572, pl. lith., fig. 2.
“This magnificent species can be compared only with Mutel-

ina plicata Sowerby. It is to be distinguished by its much long-

er posterior region, which is not truncate at the end, but very

regularly ovally rounded; by its greatest height being nearer

to the beaks, which are notably smaller and less prominent,

ree
SPECIES INCERT SEDIS.

MUTELA I, HOTELLERIANA Preston.

“Shell rhomboidal, slightly gaping at both sides, covered
with an olive-green periostracum, marked with coarse, irreg-
ular, concentric lines of growth and indistinct, radiate ridges,
a minute, oblique, striate sculpture being apparent in places
under a lens; umboes small, not prominent, situated very an-

MUTELA 1365

teriorly ; dorsal margin sloping ; ventral margin nearly straight ;
anterior side flattened, rounded; posterior side tumid, some-
what rostrate, sloping above, rounded below; interior of shell
pale livid flesh-color.
Length 85, height 35 mm.” (Preston).
Type locality, Gaboon.
Mutela hotelleriana Preston, Ann. Mag. Nat. Hist., (8), IV,
1909, p. 89, pl. Iv, fig. 6.

MUTELA OPALESCENS Preston.

“Shell moderately thin, irregularly rectangular, posteriorly
angled, covered with a thin olive-brown periostratum, sculp-
tured with fine, irregular lines of growth and fine, transverse,
radiate strize, which are more apparent anteriorly ; unmsbones
eroded, very small, flattish; dorsal margin ascending, ante-
riorly straight, posteriorly very slightly curved at the top of
an almost wing-like expansion ; ventral margin scarcely round-
ed, very slightly constricted towards the middle; anterior side
short, descending obliquely, somewhat excavated; posterior
side produced below, bluntly rounded; hinge teeth obsolete;
adductor scars moderately impressed; pallial impression rosy,
iridescent pink; outer margins opalescent, the radiate striz
very noticeable in the interior of the shell.

Length 73, height 35 mm.” (Preston).

Type locality, Shiré River, at a point from 3 to 4 kilometres
to the south of Lake Nyassa.

Mutela opalescens Preston, Ann. Mag. Nat. Hist., (8), VI,

LOU, ps O2s pl: IV, fo. Ee.

“In places where the periostracum is lacking, through pro-
cess of erosion, the shell appears to be highly iridescent.”

MUTELA CUNEATA Preston.

“Shell differing from M. opalescens by its narrower and
more elongate form, much more solid texture, and in the ad-
ductor and other scars in both valves being much more deeply
impressed ; the interior of the shell is more nacreous and pre-
sents a finely granular appearance, which is not the case in

1366 MUTELA

M. opalescens; moreover the transverse striz do not appear in
the interior of the shell as in that species.
Length of type specimen 81, height 36 mm.” (Preston).
Type locality, Karonga, north end of Lake Nyassa.
“T have before me a good i) Se this shell, the largest
specimen measuring 42.5 by 07 mm.’
Mutela cuneata Preston, Ann. Mag. Nat. Hist., (8), VI, 1910,
p: 62;ple we tiene:

MUTELA ALLUAUDI Germain.

“Shell quite large, generally rectangular-elongate, very glo-
bosely inflated; valves very convex with the greatest diameter
near the dorsal margin, gaping in front and nearly the whole
length of the ventral margin, widely gaping posteriorly ; dor-
sal margin straight; ventral margin straight, very slightly sin-
uous in the middle, parallel to the dorsal margin; anterior re-
gion rounded; posterior region almost regularly rectangular,
almost twice as long as the anterior, obliquely and sharply
truncate at the extremity ; dorsal ridge low ; beaks slightly in-
curved, quite prominent, eroded, and showing an extremely
iridescent nacre; ligament prominent, strong, 40 mm. long,
very beautiful brilliant chestnut-color; hinge filiform; anterior
muscular impressions round and well marked, the posterior
larger and deeper, pallial well marked. Shell thick, solid, quite
brilliant, epidermis a vinous chestnut slightly tinged with yel-
low, lighter near the beaks; lines of growth very fine and
slightly unequal, a little stronger posteriorly ; nacre. very iri-
descent, with coppery reflections near the ventral margin.

Length 84, of auterigr region 30, of posterior region 56,
height 37, diam. 31 mm.” (Germain).

Type locality, Lake Albert-Nyanza.

Mutela alluaudi GermMatn, Bull. Mus. Hist. Nat., 1910, p. 544,

pl. vir, fig. 45.

“This magnificent shell reminds one, by its coloration, of the
species of the genera Pseudospatha and Brazzea of Lake Tan-

ganyika.”’

CHELIDONOPSIS 1367

The following are unfigured Mutelas:

Mutela lavigerina Bourcuicnat, Un. and Ir., 1886, p. 26. Lake
Tanganyika.

Mutela moimeti Bourcuicnat, Un. and Ir., 1886, p. 27. Lake
Tanganyika.

Tridina welwitschu Moreier, Voy. de Angola,, 1868, p. —.

Genus CHELIDONOPSIS Ancey, 1887.

Chelidonura ROCHEBRUNE, S. B. Nat. Fr., 1886, p. 3.
Chelidonopsis ANcry, Conch. Exchange, II, 1887, p. 22—Grr-

mMaAtINn, Arch. Zool. Exp. et Gen., (5), I, 1909, p. 4.

Shell elongated, thin, narrowed in front, gaping on the an-
terior basal part and winged on the front dorsal portion, round-
ed behind, with a pinched-up posterior ridge which develops
into an open or closed tube near its hinder part; the shell end-
ing in a diamond-shaped gap; epidermis shining, slightly, con-
centrically grooved; hinge-line narrow, straight, with faint
vestiges of denticles; a deep furrow inside marking the posi-
tion of the posterior ridge; muscle scars iaint; nacre brilliant,
iridescent.

Type, Chelidonura arietina Rochebrune.

Germain, (1. ¢.), has published an exhaustive study of the
anatomy of this curious group and summarizes his conclu-
sions as follows: “The Clelinodopses possess the typical or-
ganization of the Mutelide, slightly modified by secondary
adaptations due to the modus vivendi peculiar to these animals.
These secondary characters are the presence of two triangular,
posterior prolongations of the mantle, which line the interior
of the aliform extensions of the posterior region; the exist-
ence of a narrow projection of the mantle in consequence of
the deep carinz of the posterior region; the more accentuated
individualization of the anal and branchial siphons, which are
completely united their entire length, while they are generally
free at their posterior extremity in the Mutele and Muteline.
The study of the anatomy thus corroborates the results ob-
tained by the study of the shell and we are to consider the Che-
linodopses as much evolved Mutele.”’

1368 CHELIDONOPSIS

CHELIDONOPSIS ARIETINA (Rochebrune).

“Shell ellipsoidal. anteriorly subcompressed, narrow ; gaping
widely and long; anterior dorsal angle acute; posterior region
roundly ovoid, enormously gaping; surface concentrically sul-
cate with broad sulci; minutely radiately striate; lateral car-
inas twisted backwards in an acute, twisted, sublamellose wing
and minutely recticulated on both sides; dorsal margin straight
in front, somewhat concave behind; epidermis pale shining
olivaceous, brownish posteriorly; nacre iridescent with blue
and rose.

Length 124, height in front 8, in the centre 30, posteriorly
33, diam. in front 9, in the middle 17, behind 40, width of pos-
terior gape 14, height 20 mm.” (Rochebrune).

Type locality, Gancini, Congo.

Chelidonura arietina RocHEBRUNE, Bull. Soc. Mal. Fr., III,
1886, p. 4, pl: 1, figs. 1-4.

Chelidonopsis arietina Stmpson, Syn., 1900, p. 906.—GERMAIN,
Bull. Mus. Hist. Nat., 1908, p. 162, fig. 32; Arch. Zool. Exp.
etiGeny (5), Ie 1900s". 4. pleas foste1-6.

“The Chelidonura arietina differs from its relative the Chel-
idonura hirundo: By its larger size; a shape decidedly ellip-
soidal and not simply elongate; by the acute and not obtuse
antero-dorsal angle; by the size of the posterior wings, the
separation, elongation and twisting of the free extremities of
the carinas; by the reticulation of the shell in the parts near
the carinas; by the valves concentrically sulcate and not slight-
ly striate; and finally by its different color.”

CHEIIDONOPSIS HIRUNDO (von Martens).

Shell elongated, subcompressed, thin, somewhat obovate,
slightly inequilateral ; beaks low or slightly elevated ; posterior
ridge pinched up sharply, and narrowly rounded, curving out-
wards or ending in a tubular process at its hinder termination ;
dorsal line straight, sometimes curved upward in front; an-
terior end very much narrowed, drawn out into a beak above,
rounded, gaping and cut away below; base slightly curved;
posterior end irregularly rounded, having a wide diamond-

CHELIDONOPSIS 1369

shaped gape; surface delicately, concentrically striate, with

faint traces of radial sculpture; epidermis yellowish-green,

brilliant and having a metallic luster, sometimes feebly rayed ;
muscle scars shallow, three in front (two of which are united),
and two behind ; hinge edentulous ; nacre brilliant, violet-tinted.

Length too, height 24, diam. at beaks 14, at posterior ex-
tremity 20 mm.

Length too, height 28.5, diam. at beaks 13.5, at posterior
end 26 mm.

iSongo region.

Spatha hirundo von Martens, S. B. Nat. Fr., 1881, p. 122;
Conch. Mitth., I], 1883, p. 1309, pl. xxvu1.

Chelhidonura hirundo RocHEPRUNE, Bull. Soc. Mal. Fr., III,
1886, p. 2, pl. 1, figs. 5, 6—von Marrens, S. B. Nat. Fr.,
FOO; PL lOl, Piel, tISs 5.) O:

Chelidonopsis hirundo StmMpson, Syn., 1900, p. 900.

A remarkable form, apparently related to some of the Mu-
telas. A specimen before me has each posterior ridge devel-
oped into a tube after the manner of the young spines of
Unio spinesus. Both tubes are more or less open behind; one
is filled in part with nacreous matter, the other is open through-
out its length. Behind these tubes in each valve is a secondary
somewhat aborted tube. ‘The anterior rostrum on each valve
is slightly spreading.

CHELIDONOPSIS ROUBAUDI Germain. a

“The general form of the shell is elongated ellipsoidal, re-
calling that of Psammobia vespertina, much compressed, gap-
ing at both ends; anterior region regularly rounded, decidedly
cut away below; posterior region twice as long, having on
each valve a projecting carina, which extends from the beak
to a point a little above the posterior extremity ; dorsal margin
subconcave, slightly ascending: ventral margin convex, al-
most parallel to the dorsal margin; antero-dorsal angle acute,
postero-dorsal angle rather blunt ; beaks compressed, not prom-
inent, somewhat eroded, situated almost exactly at the anterior
third of the shell; posterior ligament strong, very long, 36
mm. ; anterior ligament thin and delicate; anterior impressions

370 CHELIDONOPSIS

moderate; posterior very faint; pallial line faint. Valves thin,
light, subtransparent, of a very beautiful brilliant olive-green,
passing into a grayish-green posteriorly, with very narrow,
diverging rays, more distinct towards the margins; lines of
growth fine and irregular, a little stronger towards the ventral
margin. Nacre quite iridescent, greenish-blue, sometimes
tinged with orange towards the beaks.

Length 85, of anterior region 30, of posterior region 56,
height 30, in front of the beaks 20, at the beaks 24, diam. 14
mm.’’ (Germain).

Type locality, Stanley Pool.

Chelidonopsis roubaudi GERMAIN, Bull. Mus. Hist. Nat., 1908,
p. 160, figs: 31-33 Arch, Zools Exp. et iGen->.( 5) rend,
Ds Anes. rae:

“The Chelidonopsis roubaudi can only be compared with
Chelidonopsis arietina Rochebrune. It can always be easily
distinguished by the following characters:

a. By its more regularly semi-elliptical form, the anterior
region being much shorter and very much rounder, although
the antero-dorsal angie remains sharp.

b. The posterior ligament is more developed and propor-
tionately stronger. _

c. The anterior region, though presenting the same mode
of articulation, has not the two small, diverging carine near
the dorsal margin, which are present in C. arietina.

d. In C. arietina the posterior region has two, widely ex-
tending, tubular carinas, separated at their extremities, con-
stituting, as it were, two wings. The characters of C. rou-
baudi are quite different: the carinas are not tubular, they
are much less projecting and do not give rise to the wing for-
mation so characteristic of the other species. A comparative
examination of the figures shows, that C. rowbaudi is, evident-
ly, a connecting link between the genera Chelidonopsis and
Mutelina Bet., permitting the definite determination of the
true affinities of Chelidonopsis, which, by the peculiar charac-
ter of the shell, appears widely separated from the other Afri-
can groups.”

BRAZZACA 137 1

Genus BRAZZAA Bourguignat, 1885.

Brazzea BourcvuicNnat, Esp. Ouk., 1885, p. 32.

Shell thin, transparent, brilliant wine-colored, elliptical,
greatly inflated, with a slight post-dorsal wing, and a high,
double posterior ridge; beaks smooth, compressed, but the
region below them full; hinge edentulous, filiform, with two
ligaments, one internal, the other external; there are three:
groups of muscular impressions and several dorsal scars run-
ning in a row from the beak forward and downward; upper
border of the left valve projecting over that of the right,
forming a sinuous wing.

Animal unknown.

Type, Brazzca anceyi Bourguignat.

A set of Naiades inhabiting Lake Tanganyika of rather light
structure, generally inflated, with edentulous hinges. The
upper border of the left valve is said to project over that of
the right. The texture of the shells is generally a rich violet
or wine color, within and without. I cannot help feeling im-
pressed when I look at the figures of the Naiades of Lake Tan-
ganyika that from some cause many of them are more or less
diseased and that the shells in such cases are somewhat dis-
torted or abnormal. And I am inclined to believe that Bour-
guignat and other authors of the new school have selected
these diseased, distorted shells and made of them types of
species.

This appears to be a valid genus, belonging to the Vutelide.
I copy for.the most part Bourguignat’s description, which
leaves out some essential characters. I have never seen any
of the species.

KEY TO SPECIES OF BRAZZ MA.

Umbenal region much elevated and inflated.
Shell long, rhomboid elliptical, wider than high.

bourguignati.

Shell short, height greater than the width ventrosa.
Umbonal region but little inflated.

Shell obovate, short, coulboisi.

Shell long elliptical. . elongata.

Umbonal region not elevated. anceNt.

1372 BRAZZMA

BRAZZ4A ANCEYI Bourguignat.

Shell irregularly elliptical or subrhomboid, inflated, slightly
inequivalve, somewhat inequilateral, thin; beaks not raised
above the dorsal line, flattened; dorsal line straight, winged a
little in front and behind; anterior end rounded, angled above ;
base line curved, fullest behind the middle; posterior ridge
faintly double, curved downward in the middle, ending in a
biangulation at and below the median line; dorsal slope ob-
liquely truncate; surface concentrically striate; splendid violet
wine color, shining, with blackish violet margins; interior col-
ored as the exterior; left valve projecting over the right in a
somewhat sinuous wing.

Length 66, height 47, diam. 36 mm.

Lake Tanganyika.

Braszea anceyi Bourcuicnat, Esp. Ouk. et Tan., 1885, p. 33;
Icon., 1888, pl. xxvii, figs. 1-4.—Stmpson, Syn., 1900, p.
907.

Brazzea anceyt GERMAIN, Arch. Zool. Exp. et Gen., (5), I,
1909, PP. 52, 57:

Brazsea eximia Beurcuicna’, Un. and Ir. Tan., 1886, p. 57;
leone 1888, plaxxix, fe. 35:

This must be a magnificent shell according to the descrip-
tion of its author.

Germain, (I. c.), refers all of Bourguignat’s species to this
as synonyms.

3RAZZHA BROURGUIGNATT Bourguignat.

Shell irregularly subrhomboid, slightly inequivalve and in-
equilateral, subsolid, greatly inflated; beaks somewhat ele-
vated, elongated and much swollen; dorsal outline straight,
ending in a low wing behind; anterior end irregularly round-
ed, subangulate above, cut away below; base straight but full
behind the middle; posterior ridge double, ending in a biangu-
lation at and below the median line; dorsal slope obliquely
truncate; surface concentrically striate, opake blackish-violet,
lighter at the beaks; valves brilliant; nacre violet-wine-color,
splendidly iridescent.

Length 60, height 32, diam. 36 mm.

Lake Tanganvika.

BRAZZ AA 7g

Brazzea bourguignatt Bourcuicnat, Un. and Ir. Tan., 1886,
p. 58; Icon., 1888, pl. xxvin, figs. 5, 6.—Simpson, Siva,
1900, p. 907.

This seems to be one of the few Naiades, whose diameter is
greater than the height. The beaks of this species are elevated
above the dorsal line and are much more swollen than in B.
anceyi, and the shell is more elongated.

Said by Bourguignat to be of Joubert in litt.

BRAZZ&A ELONGATA Bourguignat.

Shell irregularly long elliptical, somewhat inflated, subsolid,
opake, inequilateral, bihiant ; beaks full; dorsal outline curved ;
anterior end narrowed, rounded, slightly angled above; base
line much and evenly curved; posterior ridge well developed,
decidedly double, ending in a well-marked biangulation be-
hind, the region above it very slopingly truncate, surface con-
centrically striate, subviolaceous chestnut, becoming pale yel-
lowish white or violaceous at the beaks; nacre whitish, the
margins pale violet.

Length 78, height 42, diam. 34 mm.

Lake ‘Tanganyika.

Brazzea elongata Pourcuicnat, Un. and Ir. Tan., 1886, p. 51;
Icon., 1888, pl. xx1x, figs. 2, 3.—SiMpson, Syn., 1900, p.
907.

Less inflated and more evenly elliptical than the preceding
species. The color externally and internally is different.

BrRAzzZa&A COULBOISI Bourguignat.

Shell somewhat obovate, subinflated, scarcely inequilateral,
subsolid; dorsal outline arched, most produced at the rather
full beaks ; anterior end narrowed, rounded ; base curved, quite
full behind the middle; posterior ridge double, ending in a
biangulation at and below the median line; dorsal slope ob-
liquely truncate ; surface subopake, violet-blackish ; nacre splen-
did violet wine-color, with metallic, silvery iridescence.

Length 62, height 44, diam. 28 min.

lake Tanganyika.

1374 ARTHROPTERON

Brazsea coulboisi Bourcuicnat, Un. and Ir, Tan., 1886, p.
50; Icon., 1888, pl. xxix, fig. 1—Stmpson, Syn., 1900, p.
907.

The figure shows this shell to be somewhat obovate and but
little elongated. Bourguignat states that it is bihiant.

BRAZZH#A VENTROSA Bourguignat.

Shell scarcely subsolid, greatly inflated, short, scarcely in-
equilateral, inequivalve, bihiant; beaks low, but the umbonal
region is greatly swollen so that the outline of the shell from
an end view is heart-shaped; dorsal line nearly straight ; ante-
rior end evenly rounded; base curved; posterior end beaked;
surface violet-chestnut ; nacre uniform violet wine-color, bril-
liantly iridescent.

Length 64, height 41, diam. 37 mm.

Lake Tanganyika.

Brazsea ventrosa BourcuicNnat, Un. and Ir. Tan., p. 45; Icon.,

1888, pl. Xx1x, fig. 4.—SimMpson, Syn., 1900, p. 907.

This species should be distinguishable by the immense,
rounded umbonal region, the beaks themselves being flattened.

The following are unfigured species :
Brazzea randabeli Bourcuicnat, Un. and Ir., 1886, p. 46.
Brazzea moimeti Bourcuicnat, Un. and Ir., 1886, p. 47.
Brazzsea jourdyi Bourcuicnat, Un. and Ir., 1886, p. 48.
Brazzea charbonnieri Bourcutcnat, Un. and Ir., 1886, p. 52.
Brazzea lavigerma Bourcuicnat, Un. and Ir., 1886, p. 53.
Brazzea bridowxt BourRGuIGNAT, Un. and Ir., 1886, p. 54.
Brazzea newcombiana BourcuIcnat, Un. and Ir., 1886, p. 55.

All from Lake Tanganyika.

Genus ARTHROPTERON Rochebrune.

Arthropteron Rocuerrune, Bull. Mus. Hist. Nat., 1904, p.

400. :

‘Shell ovoid, somewhat thick, quite inflated, abruptly round-
ed in front, subelongate behind, edentulous ; umbones subcon-
tiguous, small: ligament long, curved, partly covered; in the
region behind the beaks forming an area like a pen, concave,

PLEIODON 1375

WwW

elongated, longitudinally minutely striate, striz occasionally
interrupted ; muscular impressions feeble.

This genus is characterized by an area situated behind the
beaks, in the form of a pen, long elliptical in shape, deeply
channeled, subangulated. with fine longitudinal striz, some-
what interrupted, the widest part is near the beaks, from
whence it decreases in size, becoming pointed at the point of
contact with the posterior margin.” (Rochebrune).

Type, Arthropteron ouassouloui Rochebrune.

ARTHROPTERON OUASSOULOUT Rochebrune.

“Shell ovoid, rather thick, inequilateral, somewhat gaping
below and behind; pale olivaceous-yellow, irregularly striate,
subfoliaceous sulcate posteriorly; dorsal margin convex in
front, straight behind; anterior end rather wide, obtuse; pos-
terior rounded, slightly narrow; beaks contiguous, small, ob-
tuse, eroded, situated at 1-3 of the length, area not conspic-
uous ; ligament long, somewhat prominent ; nacre pearly, white,
here and there rosy-blue.

Length 69, height 41, diam. 25 mm.” (Rochebrune).

Type locality, Region of Ouassoulou, French Soudan.
Arthropteron ouassouloiui ROCHEBRUNE, Bull. Mus. Hist. Nat.,

1904, p. 461, fig. I.

Arthropteron ouassoulouensis GERMAIN, Arch. Zool. Exp. et
Genco (5), 1000;..p. 52, fies 44.

Genus PLEIODON Conrad, 1854.

Pleiodon Conran, Jl. Ac. N. Sci. Phila., VU, 1834, p. 17

Shell elliptical, inflated, solid, with a rounded posterior ridge,,
and full, smooth beaks; epidermis smooth, shining, generally
rayless; hinge plate wide, nearly straight, set with strong, ir-
regular, taxodont teeth throughout its length; beak cavities
moderate, with a row of dorsal scars running obliquely down-
ward and forward; anterior and posterior muscle scars well
defined.

Animal with the palpi semilunar, united to the mantle by a
straight border, longer than wide; outer gills generally larger
than the inner, united their whole length to the mantle;

1376 PLEIODON

inner united to the abdominal sac; genitalia ocupying each
side the lateral part of the visceral mass as far forward as the
foot; mantle closed below the branchial siphon, and united
into branchial and anal siphons; anal opening rather small:
branchial large, separated by a solid bridge, which solders to-
gether the extremities of the four branchiz: both orifices have
a thickened inner edge; the branchial being furnished with
short tubercles or granules: mantle united below posteriorly
one-fourth its length; foot large and strong; adductor mus-
cles strong. (Pelseneer. )

Type, Iridina ovata Swainson.

In this small group the taxodont teeth, which are more or
less characteristic of the Mutelidze, are strongly developed. I
have used the name Cameronia of Bourguignat in a subgeneric
sense.

Subgenus PLEIODON s. s.

Characters as in the genus.

PLEIODON OVATUS (Swainson).

Shell generally irreguiarly obovate, subinflated, solid, slight-
ly inequilateral; beaks full and high; posterior ridge rounded,
ending in a rounded point about on the median line, above it
there is a radial, shallow excavation or furrow, which some-
times ends in a light sinus at the obliquely truncate margin of
the dorsal slope; dorsal outline lightly arched, anterior end a
little narrowed, rounded, often subangulate above; base line
curved, fullest behind the middle; surface nearly smooth, con-
centrically striate and having indications of radial sculpture ;
epidermis dark olive-green, lighter at the beaks; hinge with
numerous, irregular, taxodont teeth, the anterior ones oblique,
the posterior ones somewhat V-shaped; dorsal scars forming
irregular rows running from the beaks towards the anterior
base; muscle scars lightly impressed; nacre whitish to pale
‘violet, sometimes greenish, often brilliantly iridescent.

Length 114, height 64, diam. 37 mm.

Length 105, height 64, diam. 42 mm.

West Africa.

PLEIODON eS Van

Iridina ovata Swainson, Phil. Mag., LXI, 1823, p. 112. —
ReErvE, Conch. Syst., I, 1841, p. 122, pl. xcu1; Elements of
Conch., {I, 1860, pl. xxxin, fig. 184.—Cr&ssin, Conch. Cab.
HOO 75.) 230. pl. Exe, fie. 2): eC, fies. 2)

Platiris (Iridina) ovata Lea, Syn., 1838, p. 33; 1852, p. 543
1870, p. 88.

Pleiodon ovata Conran, Jl. Ac. Nat. Sci. Phila., VII, 1854, p.
208.

Pleiodon ovatus CHENU, Man., 1859, II, p. 148, fig. 728.—
SOWERBY, Conch. Icon., XVI, 1866, pl. 1, fig. 1.—Simpson,
Syn., 1900, p. 908.

Phodon ovatus GERMAIN, Arch. Zool. Exp. et Gen., (5), I,
TQ09, P. 59.

Iridma evotica CHuprREN, Brande’s Jl., XV, 1823, p. ?

Pleiodon macmurtriei Conrav, Jl. Ac. Nat. Sci. Phila., VII,
LO34-ep- 13. ple Xt:

Margarita (Pleiodon) macmurtriet Lea, Syn., 1836, p. 55.

Iridina valeus JAy, Cat., 1850, p. 70.

Mutela valeus H. and A. Apams, Gen. Rec. Moll., II, 1857, p.
500.

Platiris (Iridina) leati Lea, Syn.. 1852, p. 54; 1870, p. 88.

Pleiodon leati H. and A. Apams, Gen. Rec. Moll. II, 1857, p.
500.

Pleiodon splendens Conran, Jl. Ac. Nat. Sci. Phila., VII, 1854,
p. 290.

Iridina splendida CHENU, Ill. Conch., 1858, pl. v, figs. 2, 2a.
20 26, 2d:

A well-known and abundant species. The hinge is strong
and flat, the teeth are very numerous and extend its whole
length. At the beaks the hinge plate is narrow, the teeth in
front of and behind them for some distance are narrow and
somewhat radial; at the hinder part of the hinge they become
more or less V-shaped. The shell is less elongated than that
of P. laudeauz.

Var. pachyodon Bourguignat.

Pleiodon pachyodon Bourcuicnat, Moll. Egypt and Ab., 1879,
P. 43.—SIMPSON, Syn., 1900, pf. 909.

1378 PLEIODON

Pliodon ovatus var. pachyodon Germain, Arch. Zool. Pxpw ck
Gen., (5), I, 1909, pp. 44, 59, fig. 41.
This form from Le Bafing, Senegal, characterized by its ex-
ceedingly heavy hinge, Germain, (1. c.), considers worthy of
varietal rank.

Subgenus CAMERONIA Bourguignat, 1870.

Cameronia BourcutcNnat, Moll. Egypt and Ab., 1870, p. 42.

Anterior end of the hinge plate usually (not always) split
up lengthwise into irregular teeth, which bear tubercles on
their surfaces.

The mantle of P. spekii has a decided pallial sinus behind.
( Pelseneer. )

Type, Jridina spekii Woodward.

PLEIODON SPEKIT Woodward.

Shell elongated, solid, somewhat variable in form, long ellip-
tical, long ovate or slightly obovate, more or less inflated, in-
equilateral ; beaks full. elevated and elongated ; posterior ridge
rounded: dorsal outline arched; anterior end rounded, some-
times narrowed and subangulate above; base straight, curved
or lightly incurved medially ; posterior end usually bluntly
pointed; surface nearly smooth; epidermis dark chestnut to
reddish-brown, somewhat shining ; hinge ‘with irregular, taxo-
dont teeth, the anterior part having cross teeth; muscle scars
- well marked; nacre whitish to violet, brilliant.

Length 120, height 50, diam. 45 m.

Length 141, height 67, diam. 45 mm.

Length 107, height 44, diam. 41 mm.

Lake Tanganyika.

Iridina (Pleiodon}) spekii Woovwarn, Pr. Zool. Soc. Lond.,

1959; p. 346, pl. XiViNediey 2°
Pleiodon spekti SowKrey, Conch. Icon., XVI, 1866, pl. 1, fig. 2.
Platiris (Iridina) spekui Lea, Syn., 1870, p. 88.

Cameronia spekii Bourcuicnat, Moll. Egypt and Ab., 1870,

Pp. 43.

PLEILODON 1379

Tridina speku Ci.essinx, Conch. Cab. Ano., 1875, p. 232, pl. Lxx,

fig. 2.

Pleiodon (Cameronia) spekit Crosse, Jl. de Conch., XXIX,

1881, p. 130.

Pleiodon speku Smiru, Proc. Zool. Soc., 1881, p. 296, pl.

XXXIV, figs. 31, 31a.—-SIMPSON, Syn., 1900, p. 909.

Mutela (Iridina) spekiui von Martens, Besch., 1897, p. 256.

Phiodon (Cameronia) speket GerMAIN, Moll. L. Tan., 1908,
pos

Pliodon speket GERMAIN, Arch. Zool. Exp. et Gen., (5), J,

1909, p. 59. 3
Cameroma gigantea Bourcuicnat, Un. and Ir., 1886, p. 68;

Icon. Mal., 1888, pl. xxxv, fig. 1.

Cameroma admirabilis BourcuicNat, Un. and Ir., 1886, p. 69;

Tcon, Malyn1888,, pls XxcxIv, fie. I
Cameronia coulboisi Bourcuicnat, Un. and Ir., 1886, p. 77;

Icon. Mal., 1888, pl. xxxz1, figs. 1, 2.

Cameronia josseti Bourcuicnat, Un. and Ir., 1886, p. 82;

Icon. Mal., 1888, pl. xxxu1, fig. 3.

Cameronia paradovxa BourcuicNat, Un. and Ir., 1886, p. 91;

Teon. Mal, 1888) pl. xxxai, fig. 4.

Cameronia bridoux? BourcuiGnat, Un. and Ir., 1886, p. 71.
Pliodon (Cameronia) bridouxi GERMAIN, Moll. L. Tan., 1908,

p. 84, figs. 43, 44.

All the specimens of Cameronia I have seen seem to be more
or less diseased and therefore quite variable in form. ‘The
group has apparently furnished Bourguignat with a capital
opportunity to found a great number of so-called species on
every possible trivial variation and deformity.

PLEIODON LANDEAUI ( Bourguignat).

Shell subetliptical or subrhomboid, not much elongated,
somewhat inflated, solid, slightly inequilateral; beaks high,
long and full; dorsal outline arched, most produced at the
beaks; anterior end narrowed, rounded, angled above; base
line curved; posterior end obliquely truncate above, rounded
below ; surface concentrically striate; margins dark chestnut ;
beaks greenish, the rest of the shell yellowish-chestnut ; nacre

1380 PLEIODON

splendidly white and iridescent ; teeth irregular and continuing
more or less throughout the hinge.
Length 92, height 48, diam. 35 mm.
Lake Tanganyika.
Cameronia landeaui Bourcvicnat, Un. and Ir., 1886, pow74
Icon. Mal., 1888, pl. xxx1, fig. 3.
Pleiodon landeawt Simpson, Syn., 1900, p. 909.
Less elongate than ?. spekii and having the dorsal line more
arched.

PLEIODON BOURGUIGNAT! ( Bourguignat ).

Shell much elongated, very solid, inflated, inequilateral ;
beaks and umbonal region full, high and elongated; dorsal
and basal outlines lightly curved; anterior and posterior ends
almost evenly rounded, the latter a little the wider; surface
roughly, concentrically striate, almost black; valves gaping
at the anterior base; nacre rosy white, brilliantly iridescent :
hinge plate wide and flat, having a few, irregular, strong,
nearly vertical teeth behind the beaks and three or four small
tubercles in front of them; muscle scars large and deep.

Length 130, height 51.5, diam. 48 mm.

Lake Tanganyika.

Cameronia bourguignati Bourcuicnat, Esp. Ouk., 1885, p.

26; Icon: Mal., 1888; pl. xxx.

Pleiodon bourguignati SIMPSON, Syn., 1900, p. 9OO.

Apparently a very good species. In outline it is almost
evenly long elliptical, the beaks are very prominent, the sur-
face black and the epidermis somewhat shaggy behind. Very
solid, with a wide hinge plate and a few strong teeth.

Credited to Ancey im litt. by Bourguignat.

PLEIODON GIRAUDI (Bourguignat).

Shell elongate-ovate, inflated, thick, solid, gaping anteriorly,
lightly striate, shining, blackish-brown, reddish-brown towards
the umbones; dorsal margin straight, oblique; anterior margin
rounded, somewhat cut away below; basal margin slightly in-
curved; posterior end extended in a very obtuse, rounded
beak; umbonal region greatly inflated; beaks very prominent,

PLEIODON 1381

recurved; anterior portion of the hinge edentulous, posterior
lamella elongate, obtuse, narrow and serrate with obtuse tuber-
cles; nacre white, tinged with rose, bluish towards the mar-
gins.
Length 119, height 55, diam. 45 mm.
Type locality, Mpala, Lake Tanganyika.
Cameronia giraudi Bourcuicnat, Not. Prod., 1885, p. 107.—
SIMPSON, Syn., 1900, p. QIO.
Phiodon (Cameronia) giraudi Germain, Moll. L. Tan., 1908,.
p. $5; figs: 47, 48.
Cameronia charbonnieri RouRGUIGNAT, Un. and Ir., 1886, p.
83.—SIMPSON, Syn., 1900, p. 909.
Pliodon (Cameronia) charbonnieri GERMAIN, Moll. L. Tan.,
1908, p. 85, figs. 45, 46.
C&meronia lavigeriana BourcuicNnat, Un. and Ir., 1886, p. 85.
Cameronia lavigerina SIMPSON, Syn., T9OO, p. QTO.
Cameronia lavigeriei GERMAIN, Moll. L. Tan., 1908, p. 87.
Germain, (1. c.), figures the types of giraudi and charbon-
mert and considers them synonymous. He also unites with
them C. lavigeriana Bet. as a mutation “characterized by the
great development of the rostral part.”

PLEIODON VYNCKEI ( Bourguignat).

Shell oblong, acutely rostrated at the lower posterior ex-
tremity, somewhat incurved in the middle of the basal margin;
thick, opaque. shining; quite heavily striate; black, brown
towards the umbones; nacre pale rose-color, whitish and very
iridescent at the margins; valves gaping at both ends, greatly
inflated, especially in the umbonal region; dorsal margin
curved; anterior end rounded; basal margin straight; poste-
rior end arcutely rostrate; umbones anterior, prominent, much
inflated, but laterally compressed anteriorly; cardinal tooth
thick, nearly obsolete; lateral tooth strong, elongate, thick,
serrate.

Length 134, height 61, diam. 50 mm.

Type locality, Lake Tanganyika.

Cameronia vynckei BourGuIGNAT, Un. and Ir., 1886, p. 81.
Cameroma vynckii SIMPSON, Syn., 1900, p. 910.

1382 PLEIODON

Phodon (Cameronia) vynckei GkRMAIN, Moll. L. Tan., 1908

p. 87, figs. 49, 50, 51.

“This species is principally characterized by its short, more
or less subtrigonal form, much developed in height, and by
its prominent, well-inflated, nearly central beaks. The dorsal
margin is distinctly curved in a direction slightly ascending ;
anterior end rounded; basal margin subconvex, slightly in-
curved in the centre; posterior end twice as long as the ante-
rior and prolonged into a beak that is almost basal. The shell
is thick, solid, heavy, quite strongly striate; epidermis a bril-
liant, deep brown; nacre roseate, slightly bluish at the mar-
gins.” (Germain).

,

PLEIODON TCIADIENSIS Germain.

“Shell large, very elongate-oblong; valves moderately in-
flated, very thick and heavy; dorsal margin slightly convex as
far as the postero-dorsal angle; ventral margin medially in-
curved, nearly parallel to the dorsal margin; anterior region
moderate, semi-elliptical; posterior region well developed,
more than twice as long as the anterior, terminating in a short
point, slightly elevated; dorsal ridge moderate, very obtuse;
beaks obtuse, much compressed, not prominent, eroded, show-
ing a beautiful, very iridescent, bluish nacre; muscular impres-
sions deep; hinge scarcely denticulated in front, strongly den-
ticulated posteriorly. Epidermis dark chestnut; lines of
growth quite strong and irregular nacre salmon-rose, re-
markably iridescent.

Length 160, height 62.5 mm. at 66 mm. from the beaks,
diam. 39 mm.” (Germain).

Type locality, Lake Tchad.

Phiodon (Cameronia) tchadiensis GERMAIN, Bull. Mus. Hist.

Nat., 1905, p. 489; Ibid, 1906, p. 60, fig. 4; Afrique Cent.

Fr., 1907, p. 578, fig. 98.

PLEIODON HARDELETI Germain.

“Shell much elongated, slightly wedge-shaped; valves quite
inflated, thick and solid; dorsal and ventral margins divergent ;
dorsal margin subconvex, slightly ascending; ventral nearly

PLEIODON 1383

straight, slightly incurved in the middle; anterior end short;
posterior end very long, almost three and one-half times as
long as the anterior, terminating in a short, oblique point;
beaks quite obtuse, much depressed; muscular impressions
deep; hinge irregularly dentate, denticulations stronger pos-
teriorly. Epidermis dark chestnut, passing into black towards
the anterior and ventral margins; lines of growth moderate
and irregular; nacre very bright rose-salmon, very iridescent.
Length 105, height 43.5 at 39 mm. from the beaks, diam. 28
mm.” (Germain).
Type locality, Lake Tchad.
Pliodon (Cameronia) hardeleti GERMAIN, Bull. Mus. Hist.
Nat., 1905, p. 489; Ibid, 1906, p. 56, fig. 2; l'Afrique Cent.
Eire 1007, 9: 1577, fis. 90.

Var. molli Germain.

“This variety differs from the type: By its more regularly
elongate oval shape; by its dorsal margin being néarly straight,
slightly ascending, and nearly parallel to the ventral margin,
(in the typical form the dorsal and ventral margins are very
divergent) ; by the less decidedly truncate posterior end, etc.

Length 105, height at 44 mm. from the beaks 38, diam. 26
mm.” (Germain).

Type locality, Lake ‘Tchad.

Pliodon (Cameronia) hardeleti var. molli GERMAIN, Bull. Mus.

Hist. Nat., 1906, p. 58, fig. 3; Afrique Cent. Fr., 1907, p.

578, fig. 100."

The following are unfigured species of Cameronia:

Cameronia anceyi Bourcuicnat, Esp. Ouk., 1885, p. 30.
Cameronia complanata BouRcuIGNAT, Un. and Ir., 1886, p. 7
Cameronia dromauxt BourRGUIGNAT, Un. and Ir., 1886, p. 84.
Cameronia guillemeti RourcuicNat, Un. and Ir., 1886, p.
Cameronia jouberti BourcuicNat, Un. and Ir., 1886, p. 88.
Cameronia lacardiana Bourcuienat, Un. and Ir., 1886, p. 78.
Cameronia marioniana BourcuIGNaT, Esp. Ouk., 1885, p. 28.
Cameronia mabilliana Bourcuicnat, Un. and Ir., 1886, p. 86.
Cameronia moineti Bourcutcnat, Un. and Ir., 1886, p. 89.

384 MONOCONDYLA‘A

Cameronia pulchella. Bourcuicnat, Un. and Ir., 1886, p. 73.

Cameroma obtusa Bourcuicnat, Un. and Ir., 1886, p. 75.

Cameronia randabeli Bourcuicnat, Un. and Ir., 1886, p. go.

Cameroma revoiliana BourcutGnat, Moll. Tan., 1885, p. 107.
All from Lake Tanganyika.

xenus MONOCONDYLAZA d@Orbigny, 1835.

Aplodon Sprx (not of Rafinesque, 1818), Test. Fluv. Bras.,

1827, pl. xxv, figs. 1, 2.

Monocondylea d’Orpicny, Guerin Mag., 1835, p. 37.
Spivoconcha Pirspry, Naut., VII, 1893, p. 30.

Shell rounded to obovate, rather solid, with a low, poste-
rior ridge, which is generally bordered by two or more dark,
radiating bands; epidermis dull olive-green to olive-brown,
cloth-like; hinge with two irregular teeth under the beak in
the left valve, and two in the right, the posterior under the
beak, the anterior in front of it and interlocking with those of
the left valve, the whole generally more or less tuberculate ;
nacre soft, silvery, with iridescent shades; anterior scars unit-
ed: posterior indistinct ; prismatic layer wide.

Animal with the marsupium occupying the whole length of
the inner branchie: gills very large, curved below, inner very
much the larger, united the whole length of the abdominal sac ;
‘palpi small, round below, attached along their upper edge;
mantle thick, greatly thickened at the edge, with a few papillz
in front of the branchial opening below; branchial opening
large, with numerous small knob-like papilla; anal opening
large, without papillze, separated completely from the bran-
chial opening by a bridge; superanal opening not closed below.

Type, Monocondylea paraguayana d’Orbigny.

In Monocondylea the teeth are imperfect, there being us-
ually a single rounded tooth in the left valve often with a pit
behind it and one tooth in the right valve, or frequently there
is a smaller one in front of it with pit between. In M. reticu-
lata the teeth are very irregular and somewhat broken up into
denticles.

MONOCONDYLA‘SA 1385

IKEY TO SPECIES OF MONOCONDYLA/A.

Shell more or less roughly, concentrically sculptured.
Surface with crenate striz. reticulata.
Surface squamose, rasp-like. jas pidea.

Shell more or less radially sculptured,

With strong radial ribs throughout. costulata.
With radial depressions in front of the posterior ridge.

guarayana.
Shell smooth or lightly concentrically striate.
Nearly orbicular. franciscana.
Obovate, green, convex. lentiformis.
Elliptical.
Solid, subtruncate at dorsal slope. corrientesensis.
Rather thin, rounded behind. mermis.

Subrhomboid or subquadrate.
Short, almost squarely truncate behind.
minuana, paraguayensis.
Long rhomboid, obliquely truncate behind. parchap pi.

Group of Monocondylea guarayana.

Shell obovate, inflated, solid, solid, often slightly produced
just behind the center of the base; beaks full, turned inward
and forward.

MONOCONDYLA!A GUARAYANA d’Orbigny.

Shell oval, inflated, very solid, inequilateral; beaks full and
elevated, somewhat pointed; dorsal outline arched; anterior
end rounded ; base line curved in front, slightly emarginate in
front of the posterior ridge; posterior ridge imperfectly dou-
ble, ending near the base of the shell in a narrow biangula-
tion; in front of it are two shallow, wide, radial depressions;
dorsal slope obliquely truncate; epidermis brown or yellow:
ish-brown; each valve has a single, rounded, subcompressed
tooth, that of the right valve largest; nacre apparently salmon.

Length 40, height 29, diam. 24 mm.

Bolivia.

1386 MONOCONDYL ABA

Monocondylea guarayana d’OrBicNy, Guer. Mag., 1835, p.
38; Voy. Am. Mer.,°1843,; p. 614,. pl. uxviit, figs. 4-———H.
and A, Apams, Gen. Rec. Moll. 11, 1857, p: 501; its pl.
cxvil, fig. 3.—CuHrENu, Man., 1859, II, p. 145, fig. 715.—
SIMPSON, Syn., 1900, p. QIO.

Margarita (Monocondylea) guarayana Lea, Syn., 1838, p. 28.

Unio guarayana HANtey, Biv. Shells, 1843, po 213, pl sexi,
fig. 14.—Sowerry, Conch. Icon., XVI, 1868, pl. xcv1, fig.
524.

Margaron (Monocondylea) guarayana Lua, Syn., 1852, p. 45;
1870, p. 73. :

This species is somewhat oval in outline, and is distinguished
by having two curved, radial depressions in each valve in front
of the posterior ridge.

MONOCONDYL2&A INERMIS (Spix).

Shell small, evenly elliptical, rather thin, slightly inequilat-
eral; beaks full and elevated, apparently having a short, deep
lunule in front of them; surface yellowish-green; nacre pur-
plish or pinkish-tinted; hinge line delicate; teeth small and
compressed.

Length 21, height 16.5 mm.

South Brazil.

Aplodon ierme Spix, Test. Fluv. Bras., 1827, p. 32, pl. xxv,
figs. I-2—von InERING, Arch. fur Nat., 1890, p. 126, pl.
ix, figs. 1-3.

Monocondylea inerme SIMPSON, Syn., 1900, p. QII.

I have never seen this species and Wagner merely mentions
it with a few words of description. The figures, however,
are good, probably taken from a young shell, and show that
it is provided with a single, somewhat compressed tooth in
each valve. The above measurements are from these figures.

MONOCONDYL.EA PARCHAPPIT d’Orbigny.

Shell singularly long rhomboid, compressed to convex, solid,
concentically striate, inequilateral; beaks prominent, rather
sharp, turned forward; dorsal outline arched; anterior end
rounded; base nearly straight; posterior end obliquely trun-

MONOCONDYLAA 1387

cate; epidermis brownish-green; nacre bluish to rose-color ;

tooth of the left valve conical, rounded, that of the right low.
Length 47, height 28, diam. 19 mm.

Argentina.

Monocondylea parchappii d’Orpicny, Guer. Mag., 1835, p. 38;
Voy. Am. Mer., 1843, p. 615, pl. Lxvii1, figs. 1-3.—Simpson,
Syn., 1900, p. QIT.

Margarita (Monocondylea) parchappu Lua, Syn., 1838, p. 28.

" Unio parchappui HANtey, Biv. Shells, 1843, p. 212, pl. xxur,
fig. 13.

Margaron (Monocondylea) parchappii Lea, Syn., 1852, p. 45;
1870, p. 73.

Monocondylea pazii Lea, Pr. Ac. N. Sci. Phila., X, 1866, p.
34; JI. Ac. N. Sci. Phila., VI, 1868, p. 273, pl. xxxv1, fig. 88;
Obs., XIT, 1860, p. 36, pl. xxxv1, fig. 88.—CLrsstn, Conch.
Cab. Ano., 1876, p. 251, pl. LXXIX, figs. 6-7.

Margaron (Monocondylea) paz Lea, Syn., 1870, p. 73.
Decidedly rhomboid in outline and much more compressed

than guarayana. Besides, it lacks the radial furrows of that

species.

MONOCONDYLA‘A PARAGUAYANA d’Orbigny.

Shell subquadrate or subrhomboid, solid, inflated, inequi-
lateral, concentrically striate: beaks full and high; dorsal line
behind them nearly straight; posterior end almost squarely
truncate ; anterior end rounded, narrowed: base curved, fullest
behind the middle; above the posterior ridge there seems to be
a couple of radial furrows; epidermis brown-green; nacre pale
greenish, brilliantly iridescent: tooth of the left valve obtuse
and nearly triangular.

Length 50, height 44, diam. 32 mm.

Rio de la Plata drainage.

Monocondylea paraguayana d’Oreicny, Guer. Mag., 1835, p.
37-SoweErsy, Conch. Man., 1839, fig. 149.—d’OrBIeny,
Voy. Am. Mer., 1843, p. 612, pl. Lxx, figs. 5-7.—CLESSIN,
Conch. Cab. Ano., 1876, p. 245, pl. Lxxvutt, figs. 1, 2.—SIMp-
SON, Syn., 1900, p. OII.

1388 MONOCONDYL ASA

Margarita (Margaritana) paraguayana LA, Syn., 1838, p. 27.
Unio paraguayana Han xy, Biv. Shells, 1843, p. 212, pl. xx1,
fig. 17.—Sowerey, Conch. Icon., XVI, 1866, pl. L1, fig. 273.
Margaron (Monocondylea) paraguayana Lea, Syn., 1852, p.

45; 1870, p. 73- !

Unio paraguayanis CxatLow and Reeve, Conch. Nom., 1845,

p. 62.

A large, solid, subquadrate species, with brilliantly iridescent
nacre, of which VW. minuana is, perhaps, but the young. There
are often two faint, green rays on the dorsal slope of each
valve.

MONOCONDYLEA MINUANA. d’Orbigny.

Shell irregularly rhomboid, convex or subinflated, solid,
concentrically striate, mequilateral; beaks quite prominent,
turned inward and forward; posterior ridge rounded; dorsal
line behind the beaks neariy straight; anterior end narrowed
and rounded; base lightly curved; posterior end obliquely
truncate; epidermis greenish; nacre pale greenish or tinted
with reddish; tooth of the left valve roughened.

Length 46, height 28, diam. 20 mm.

Rio de la Plata drainage. ,
Monocondylea minuana d’Oreicny, Guer. Mag., 1835, p. 37;

Voy. Am) Mer, 1842) p, 612) ply 1c fies. 6-10:

Margarita (Margaritana) minuana Lia, Syn., 1838, p. 28.
Margaron (Monocondylea) minuana Lea, Syn., 1852, p. 453

1870; spa 32
Unio mnuanus Haney, Biv. Shells, 1843, p. 213, pl. xxu,

fig. 18.—Sowerby, Conch. Icon., XVI, 1868, pl. xct, fig. 497.
Monocondylea paraguayana, (part), Simpson, Syn., 1900, p.

QIt.

I formerly believed that this species was the same as para-
guayana, being only the young of it. It is however more
elongated, and, perhaps, less inflated than that. The dorsal

slope is more obliquely truncated.

MONOCONDYLA‘A 1389

MOoNOCONDYL4A RETICULATA Moricand.

Shell subelliptical or subrhomboid, somewhat inflated, sub-
solid, inequilateral; beaks high and full, turned forward over
a sort of lunule; dorsal outline behind the beaks arched; pos-
terior end obliquely truncate or subtruncate ; anterior end nar-
rowed and rounded, angled above; base curved; surface hav-
ing irregular, concentric striz, which appear as if reticulated ;
epidermis cloth-like; nacre bluish-white; teeth more or less
broken up, subnodulous.

T,ength 4o, height 30, diam. 21 mm.

Brazil.

Monocondylea reticulata Mortcanp, Rev. et Mag., X, 1858,

Pp. 453, pl. xv, fig. 2--Srmpson, Syn., 1900, p. 912.
Margaron (Monocondylea) reticulata Lea, Syn., 1870, p. 72.
Margaritana reticulata Pavret, Conch. Sam., III, 1890, p. 173.
Unio reticulatus Sowerby, Conch. Icon., XVI, 1868, pl.

LXXXVI, fig. 458.

Aplodon reticulatus VON [t1ERING, Arch. fir Nat., 1893, p. 115.

Something like WV. paraguayana, but lacking the posterior
green rays and the surface is subreticulated, while in that
species it is not.

MonoconpyLaa cestuLAta Moricand.

Shell irregularly ovate, inflated, inequilateral, with full,
rounded, elevated beaks: dorsal line behind the beaks and
dorsal slope curved, a little more prominent behind the liga-
ment; anterior end somewhat narrowed, rounded ; base curved,
but emarginate behind the middle at the termination of a shal-
low, radial furrow; posterior ridge rounded, ending near the
base of the shell in a blunt, rounded point; surface with nar-
row, radiating ribs; epidermis dark olive; nacre bluish-white ;
there is a single, thick, primary tooth in each valve.

Length 34, height 22 mm.

Brazil.

Monocondylea costulata Mortcanp, Rev. et Mag. Zool., X,
1858, p. 453, pl. xv, fig. 1—Simpson, Syn., 1900, p. 912.
Umio costulatus Sowsrrsy, Conch. Icon.,. XVI, 1868, pl.

LOK Viliin Os AZO:

1390 MONOCONDYL ASA

Margaron (\Monocondylea) costulata Lea, Syn., 1870, p. 72.

This seems to differ decidedly from any form I am ac-
quainted with. The ovate outline and radial ribs are excellent
distinguishing characters.

MONOCONDYLA:A CORRIENTESENSIS d’Orbigny.

Shell irregularly short elliptical, convex, rather solid, inequi-
lateral; beaks almost compressed, slightly elevated ; dorsal out-
line arched, subangulate where it joins the obliquely truncate
or subtruncate dorsal slope; anterior end narrow, rounded;
base line much rounded; posterior ridge rounded, ending in a
point above the base line ; surface irregularly striate ; epidermis
greenish-olive with two or three feeble, green rays on the pos-
terior part; nacre bluish-white, iridescent; muscle scars im-
pressed; teeth small, stumpy, single in each valve.

Length 44, height 33, diam. 21 mm.

Argentina.

Monocondylea corrientesensis dOrpicNy, Guer. Mag., 1835,
p- 38; Voy. Am. Mer., 1843, p. 615, pl. Lxvn, figs. 8-10.—
CriEesstn, Conch. Cab. Ano., 1876, p. 246, pl. Lxxvutl, figs.
3, 4. SIMPSON, Syn., 1900, p. O12.

Margarita (Monocondylea) corrientesensis Lea, Syn., 1838.
p. 28.

Unio corrientesensis HANLEY, Biv. Shells, 1843, p. 212, pl.
xxu, fig. 15.--SoweRby, Conch. Icon., XVI, 1868, pl. xcu11,
fig. 500.

Margaron (Monocondylea) corrientesensis 1A, Syn., 1852.
P. 45; 1870; p- 73.

More elliptical than reticulata, not so much inflated, and not
having the reticulated surface of that species.

MOoNOCONDYLA:A JASPIDEA (Hupé).

Shell subtrapezoid. compressed, subequilateral, solid; beaks
moderately full and high; dorsal outline somewhat: arched,
subanguiar where it joins the obliquely truncate posterior end;
anterior end narrow, rounded; base curved; surface covered
with squamose strie giving it the appearance and roughness
of a rasp; epidermis a tender green with small angular, jasper-

MONOCONDYL#A I391

colored spots; hinge thick, having two teeth, one of which is
smaller than the other ; nacre white, pearly.

Length 20, height 15, diam. 3 mm.

Amazon.
Umo jaspidea Hupé, An. Nouv., III, 1857, p. 83, pl. xvi,

fig..2:
Margaron (Unio?) jaspideus Lua, Syn., 1870, p. 37.
Monocondylea jaspidea Simpson, Syn., 1911, p. 912.

Hupe calls this a Unio, but from his description and figure
I think it is a Monocondylea. The remarkably rough, rasp-
like surface, colored green, with small, angular jasper-colored
spots distinguish it from all other species. Hupe gives the
diameter as 3 millimeters, which may be an error as this would
make a most remarkably compressed shell. It may be that it
should have been 8 millimeters.

Group of Monocondylea franciscana.

Shell moderately inflated, lenticular, rounded, not very solid;
sometimes slightly produced at the post-basal region; beaks
rather low.

MOoONOCONDYL-EA FRANCISCANA Moricand.

Shell suborbicular, subinflated, subsolid, nearly equilateral ;
beaks full, somewhat elevated; dorsal outline very lightly
arched; dorsal slope almost squarely subtruncate ; the remain-
der of the shell nearly evenly rounded, a little fuller behind
the middle of the base; surface nearly smooth with a cloth-like,
greenish epidermis, with two or three faint, dark rays on the
posterior part; nacre bluish, somewhat iridescent ; tooth of the
left valve in front of the beak, that of the right opposite the
beak ; both are compressed and rounded.

Length 38, height 34, diam. 11 mm.

Brazil.

Unio (Monocondylea) franciscana Moricann, Mem. Nat.
soc, Hist, Nat.-Gen:, VIEL, 1837, p-30, pli m1, figs. 14-17.
Margarita (Margaritana) franciscana Lea, Syn., 1838, p. 35-
Margaron (Monocondylea) franciscana Lea, Syn., 1852, p-

45; 1870, p: 72.

1392 IELERINGELLA

Monecondylea franciscana Ciessin, Conch. Cab. Ano., 1876,
p. 251, pl. LXXIVv, figs. 4, 5—SIMPSON, Syn., 1900, p. QI2.
Aplodon franciscana von liERinc, Arch. fiir Nat., 1893, p.

115.
The shell is not very solid, and is more nearly orbicular than
that of any other species.

MOoNnoOcONDYI,44A LENTIFORMIS Lea.

Shell irreglarly obovate, short, convex, solid, inequilateral ;
beaks rather high but not very full, turned forward over a
small lunule; dorsal line behind the beaks arched; posterior
slope almost squarely truncated ; anterior end much narrowed ;
base rounded, considerably fuller behind the middle; epider-
mis dirty green; there are one or two faint rays on the pos-
terior ridge; nacre lurid purplish, iridescent behind, thicker
in front; prismatic border wide.

Length 40, height 33, diam. 17 mm.

Southern Brazil.

Monocondylea: lentiformis Lea, Pr. Ac. N. Sci. Phila., X,
1666, p:34.7 JL Ac Nascin Philasy Vij 868) p: 272, plo xexxvs
fio. 86 "Obs, 2c, 1860, p: 32. pla xxxvi fe. 66:— CrmssiNn,
Conch.-Cab: Ane:; 1876, p:. 250; pl. Lxxix, fies. 4) 5 ——Simp-
SON, Syn., 1900, p. 912.

Margaron (Monocondylea) lentiformis Lea, Syn., 1870, p. 72.

Aplodon lentiformis VON InERING, Arch. fiir Nat., 1893, p. 67.
The epidermis is badly worn off over most of the surface of

the disks in the type, and the cavity of the shell is blotched

with greenish-blue. It is a more solid, less inflated species
than franciscana, is longer and more obovate.

The following species is unknown to me:

Monocondylea tamsana DuNKER, Mal. BI., V, 1858, p. 220!

Genus IHERINGELLA Pilsbry, 1893.

Plagiodon Lea, Pr. Ac. N. Sci. Phila., VIII, 1856, p. 79.
Theringella Pitspry, Nautilus, VI1, 1893, p. 30.

Shell solid, inflated, rounded to rhomboid in outline, with a
more or less developed posterior ridge; beaks high, curved

IHTERINGELLA 1393

inward and forward, without sculpture; epidermis dull olive,
cloth-like; hinge teeth imperfectly developed, nodulous or
broken more or less into denticles, there being an irregular
tooth in the left valve under the beak, sometimes partially
bifid, and two in the right valve, with the pit between them
under the beak ; anterior muscle scars deep, more less united ;
posterior scars shallow; nacre soft, bluish-silvery, iridescent
behind.

Animal unknown.

Type, Plagiodon tsocardioides Lea.

In [heringella the hinge teeth are even more irregular than
in Monocondylea. They are more or less tuberculate or often
studded with irregular pustules and are sometimes more or
less longitudinal.

KrEY TO SPECIES OF [HERINGELLA.

Shell much inflated, rhomboid or subrhomboid.

Surface smooth. tsocardioldes.

Surface more or less cancellated. semisulcata.
Shell only moderately inflated.

Outline rounded. rotundata.

Rotund triangular. balzant.

Group of Jheringella tsocardioides.

Shell rhomboid or /socardia-shaped, with a high, distinct,
strongly curved posterior ridge; beaks decidedly full and
turned forward.

THERINGELLA ISOCARDIOIDES (Lea).

Shell smooth, subtriangular or subrhomboid, greatly inflated,
inequilateral, subsolid or rather thin; beaks very full and high,
turned forward and inward; posterior ridge well developed,
subangulate ; anterior and posterior ends almost squarely sub-
truncate; hinge line arched; base nearly straight; epidermis
dull olive; teeth imperfect, nodulous, short, the upper division
longer, double in each valve; anterior scars deep and confluent ;

1394 IHERINGELLA

dorsal scars within the beak cavities, which are deep; nacre

white and very iridescent.

Length 27, height 24, diam. 23 mm.
Rio de la Plata; Eastern Peru?

Plagiodon tsocardiodes Les, Pr. Ac. N. Sci. Phila., VIII,
1956; px 70;

Plagiodon isocardioides Lea, Obs., VI, 1857, p. 38, pl. xxxu,
he» 325: Jl Ac N. Set Phila. 1M, 1858) ps 318) pl. sexe
fig. 32—Kuster, Conch. Cab. Unio, 1862, p. 292, pl. xcvit,
figs. 8-10.

Unio isocardioides SowERBY, Conch. Icon., XVI, 1868, pl. xc,.
fig. 484.

Margaron (Plagiodon) isocardioides La&A, Syn., 1870, p. 71.

Theringella isocardiotdes SIMPSON, Syn., 1900, p. 913.

The form of this shell is much like that of Jsocardia moltk-
iana as J.ea remarks. ‘The teeth are imperfect and somewhat
granulate or dentilate.

JHERINGELLA SEMISULCATA (H. Adams).

Shell rhomboid, solid, ventricose, somewhat inequilateral ;
beaks incurved, but little elevated; posterior ridge well devel-
oped, curved, lightly pinched up, ending in a blunt point at
the base of the shell; dorsal outline almost evenly arched from
the beaks to the end of the posterior ridge; anterior end evenly
rounded; base rounded in front, incurved behind the middle;
surface rugosely concentrically striate, marked with radial
sculpture medially ; epidermis subrugose, olivaceous, blackish ;
nacre pearly white, iridescent.

Length 34, height 25, diam. 18 mm.

Fastern Peru.

Monocondylea (Plagiodon) semisulcata H. ApAms, Pr. Zool.

Soc: ond 1870, 7.376; pl. xxvi, ties:
Theringella semisuicaia StmPsoNn, Syn., 1900, p. 913.

Adams does not tell anything of the teeth of this species,
but states that he had referred a larger specimen, previously
seen, to Lea’s P. isocardioides, but that on comparing speci-

IH ERINGELLA 1395

mens obtained since, he considered the two distinct. This
species has a more elongated outline, and is decidedly sculp-
tured, while Lea’s shell is smooth.

Group of [heringella rotundata.

Shell somewhat rounded, sublenticular, posterior ridge rath-
er low.

INERINGELLA ROTUNDATA (MLousson).

Shell short elliptical, inflated, rather solid, inequilateral ;
beaks full and elevated, somewhat turned forward; posterior
ridge narrowly rounded; surface with concentric striz; epi-
dermis olivaceous-fuscous, teeth short, thick, single in each
valve, sulcate; beak cavities deep; nacre whitish, pearly ; mus-
cle scars moderate, subtriangular.

Length 52, height 42, diam. 30 mm.

South America.

Plagiodon rotundatus Mousson, Mal. Bl., XVI, 1869, p. 187.
—PFEIFFER, Nov. Conch., IV, 1876, p. 139, pl. Cxxxt1, figs.
So

Theringella retundata SIMPSON, Syn., 1900, p. 913.

The outline of the shell of this species is almost regularly
short elliptical, there being a very blunt point at the ending of
the posterior ridge. I have seen young shells in the collection
of Mr. H. FE. Sargent, which I refer to this species.

THERINGELLA BALZANt (von [hering).

Shell irregularly subtriangular, solid, subinflated, having a
much greater diameter behind the beaks, inequilateral ; beaks
full and high; anterior end narrowed, rounded; hinge line very
slightly curved, but much higher behind; posterior end ob-
liquely truncate; base rounded ; epidermis thick, interruptedly
radiate, blackish or olivaceous-fuscous ; nacre white, iridescent ;
teeth thick, transverse, compressed, double in each valve ; pris-
matic border wide.

Length &6, height 66, diam. 40 mm.

Ric Paraguay; San Paulo, Brazil.

1396 FOSSULA

Plagiodon balzani von HERING, Arch. fiir Nat., 1893, p. 69,
plicir; hiee3:
hermngella balzant SIMPSON, Syn., 1900, p. O14.

This species is more triangular in outline than rotundata,
the surface is rougher, the greatest degree of inflation is nearer
the posterior end. von Ihering states that the epidermis has
very fine, chain-like or twisted striz.

Genus FOSSULA Lea, 1870.

Fossula Lea, Syn., 1870, p. 72 (footnote).

Shell obovate, inflated, solid, with rather high beaks and a
low posterior ridge; epidermis olive-brown, somewhat smooth,
sometimes slightly raved; there is an irregular tooth in the
left valve under the beak, and behind it a cavity; in the right
valve there is a cavity under the beak, and an irregular tooth
in front of and another behind it; the teeth and cavities are
generally partly covered with brownish or amber-colored mat-
ter, and more or !ess pitted; anterior cicatrices well marked,
united; posterior faint; prismatic border wide.

Animal unknown.

Type, Monocondylea fossiculifera d@Orbigny.

Conchologically the genera Monocondylea, Iheringella and
Fossula seem to be closely related. In the latter there is a
sort of ligamental matter in the cavities between the hinge
teeth that is often more or less regularly pitted.

FOssuLA FOSSICULIFERA (d’Orbigny).

Shell obovate, short, subinflated or inflated, rather solid, in-
equilateral; beaks slightly elevated, not inflated; posterior
ridge low, subangulate, sometimes appearing like a raised cord ;
dorsal outline lightly arched; anterior end narrow, rounded ;
base well rounded to the end of the posterior ridge at or near
the median line; dorsal slope obliquely truncate or subtrun-
cate; surface with rude, irregular growth lines, sometimes with
traces of radial striz; epidermis olive to blackish, dull; left
valve with an irregular tooth under the beak or a little in
front of it with a cavity in front of and another behind the

FOSSULA 1397

tooth ; right valve with two teeth, one in front of the beak, the

other behind it; anterior scars impressed; nacre lurid, bluish

to flesh-colored ; prismatic border wide.
Length 80, height 63.5, diam. 35 mm.
Length 83, height 57, diam. 37 mm.
Parana River, South America.

Monocondylea fossiculifera d@OrwiGNy, Guer. Mag., Tesi 9B
38; Voy. Am. Mer., 1843, p. 614, pl. Lxxx, figs. 5-7.—
Ciesstn, Conch. Cab. Ano., 1876, p. 249, pl. xLxrx, figs.
Mea

Margarita (Margaritana) fossiculifera Lea, Syn., 1838, pe 28:

Umio fossiculifera HANiny, Biv. Shells, 1483, Pa 22), plexes
fig. 19.—Sowerry, Conch. Icon., XVI, 1868, pl. xcvt, fig.
521.

Margaron (Monocondylea) fossiculifera Lea, Syn., 1852, -p.
45; 1870, p. 73. ;

Fossula fossiculifera VON THErRtNc, Arch. fiir Nat., 1893, p. 64,
pl. 1m, fig. 2—Stmpson, Syn., 1900, p. 914.

Unio fossiculiferus Catiow and Rerve, Conch. Nom.. 1845,
P. 59.

Anodonta fusciculifera Part, Conch. Sam., IIT, 1800, pe u70:
The cavities or pits in the hinge of this species are often

partly filled with a sort of ligamental matter, which is decidedly

pitted. The nacre is often considerably thickened in the front
part of the shell.

Fossut.A BALZANI von Thering,

Shell solid, subinflated, irregularly. subtriangular or sub-
trapezoid, concentrically subrugose, somewhat inequilateral ;
beaks moderately elevated; hinge line sinuous, regularly cre-
nate in the middle; anterior end narrowed, subtruncate; base
curved; posterior end obliquely subtruncate, rounded where
it joins the base; epidermis fuscous-olivaceous; nacre lead-
colored, with bronzy maculations.

Length 86, height 66, diam. 40 mm.

Rio Paraguay; Rio Apae, South America.

Fossula balsani von Trertnc, Arch. fiir Nat.. 1893, p. 65, pl.

Il, fig. 1.—Srmpson, Syn., 1900, ps O14:

1398 FOSSULA

The form of this does not differ greatly from some of Lea’s
specimens of fossiculifera, but the regular crenation in the
middle of the hinge line, if constant, ought to be a good dis-
tinguishing character.

FossuLA BRAZILIENSIS von Ihering.

“This species 1s considerably smaller than /*. fossiculifera
and is distinguished from it by the smaller anterior end and
the much more inflated posterior half of the shell. The beaks
are smaller and less prominent than in that species. In the
example from the Paraguassu River, which is 42 mm. long,
33 mm. high and 22 mm. in diameter, they are situated at 13
mm. from the anterior end. The length of the hinge to
the beginning of the sinulus is 26 mm. and the distance
of the beaks from its anterior end is 8 mm. The dorsal
margin is obliquely inclined from behind and above to
the front and is slightly convex posteriorly. Posterior mar-
gin oblique above and convex below, forming a blunt angle
at about the centre. The anterior margin is regularly rounded.
Ventral margin oblique and nearly straight in front, convex
behind. The greatest height is at 13 mm. from the posterior
end. Surface smooth, with close, thread-like growth lines,
which towards the ventral margin become irregular, thicker
and further apart. Somewhat in front of the centre is a
broad, flat impression, which extends from the beaks to the
ventral margin. Behind this impression the shell is remark-
ably inflated. From the beaks to the angle in the posterior
margin is a strong elevated line, which borders the somewhat
concave dorsal area. The lunule is very small, quite indistinct.
At the anterior end of the hinge are three downward pointed
continuations of the ligament, through which the tooth-like
thickenings of the hinge. which are lacking in the right valve,
are shown. The rather thick hinge of the right valve has a
long, subobsolete, forwardly curved tooth, which fits into a lig-
ament covered cavity in the left valve, 7 mm. long. On the
closed shell, which gapes only a little in front and behind, the
beaks are 2 mm. from each other and the part of the shell

LEILA 1399

visible between them belongs to the right valve. The sinulus
is triangular, hook-shaped below and sharply pointed in front
and lies at the posterior end of the dorsal margin. ‘The um-
bonal cavity is comparatively deep. The muscular impressions
are deep. The prismatic border of the shell is 3 mm. wide at
the anterior portion of the ventral margin. The very irides-
cent nacre is pale reddish with large greenish spots.” (von
Ihering).

Type locality, Rio Paraguassu, State of Bahia, Brazil.
Fossula brasiliensis von Inertnc, Abh. Senck. Ges., XXXII,

IQTO;/p: 116, pl. 12, figs. 1a-b:

“This species is easily distinguished from F. fossiculifera
by its smaller size, less prominent teeth and the more posterior
position of the sinulus. One specimen from Machedo Por-
tella has two carinz defining the dorsal area. Two other spec-
imens from the same locality are 52 mm. long and have a well-
developed lunule, short and broad. The epidermis of these is
a dark brown or olive-brown color.

Genus I,EILA Gray, 1840.

Columba Lua (not Columba Linneus, Aves, 1758), Tr. Am.

huleSocs,, V4 1833,p.-78:

Leila Gray, Syn. Brit. Mus., 1840, p. 142.

Shell large, obovate, inflated, with a straight hinge line,
which is produced into a slight wing before and behind; the
posterior end bluntly pointed and somewhat truncate above,
with a faint posterior ridge; beaks full, smooth; epidermis
olive, generally smooth ; hinge edentulous ; beak cavities rather
shallow; dorsal scars small and numerous, running in a
straight line from behind the beaks downward and forward:
posterior muscle’ scars united, large; pallial line generally
showing a sinus.

Animal having the mantle united behind into two short, sep-
arate, contractile siphons, according to Gray.

Type, Anodonta blainvilleana Lea.

1400 LEILA

Conchologically this genus seems to be very closely related
to dnodontites, especially to the group of A. trapesialis. Some
of the shells of that genus have a slight dorsal wing in front
and behind, and traces of a pallial sinus.

LEILA BLAINVILLEANA (Lea).

Shell obovate, subinflated, bihiant, inequilateral, subsolid ;
beaks rather full, long and high; posterior ridge narrowly
rounded; above the ridge there is a wide, radial depression ;
dorsal line nearly straight, produced into a pointed wing in
front and a slopingly truncate one behind; anterior end very
narrow, much cut away below; base rounded, much fuller be-
hind the middle; posterior end bluntly pointed at or below
the median line; surface with irregular growth lines; epider-
mis dark olive, with indications of delicate, radial striz; hinge
line edentulous; ligamental patches triangular; muscle scars
shallow ; nacre flesh-colored ; pallial line with a broad, shallow
sinus behind.

Length 153, height 93, diam. 54 mm.

Peru; Brazil; south to Argentina.

Anodonta blainvilleana Lea, Tr. Am. Phil. Soc., V, 1834, p. 77,
pl. xi, fis. 357 Obs: as 34 p. 189, pl. xu, fig. 35 —Han-
LEY, Biv. ohells, 1843) ps222. (plxcciy, hess.

Margarita (Anodonta) Bacnenieane LSA, yn, 1836, sp2"535
1838, °p. 31.

Anodon blainvilleana Catiow and Reeve, Conch. Nom., 1845,
p. 66.

'Margaron (Anodonta) blainvilleana Lea, Syn., 1852, p. 52.

Leila blainvilleana H. and A. Apams, Gen. Rec. Moll., II, 1857,
p. 507; III, pl. cx1x, figs. 4, 4a—CueENu, Man., 1859, II, p.
148, fig. 730.—STMPSON, Syn., 1900, p. 915.

Columba blainvilleana CuEsstn, Conch. Cab. Ano., 1876,
252 Di LS coxvi; Nes) aes

Anodon parishti Gray, Pr. Zool. Soc. Lond., 1834, p. 57

Margarita (Anodonta) parishti Lia, Syn., 1836, p. 53 cee,
Dp. 3.

Anodonta parishti Hantey, Test. Moll., 1842, p. 222.

Margaron (Anodonta) parishii Lea, Syn., 1852, p. 52.

LEILA 1401

Leila parishii H. and A. Apams, Gen. Rec. Moll., II, 1857, p.
507.

Anodon hans SoweRwy, Conch. Icon., XVII, 1867, pl. 1v, fig. 8.
The type is a young !eft valve, which has been almost en-

tirely denuded of its epidermis. All the shells I have seen

gape widely at the anterior base and at the end of the pos-

terior ridge. The hinder end is pointed.

LEILA ESULA (d’Orbigny).

Shell irregularly obovate, somewhat inflated, rather thin, in-
equilateral ; beaks full and high; dorsal line nearly straight or
a little sinuous, ending in a sharp pointed wing in front,
scarcely winged behind; dorsal slope obliquely subtruncate,
there being but a low angle where its outline joins the hinge;
anterior end much narrowed, cut away below; base almost
evenly rounded, a little fuller behind the middle; posterior erid
widely rounded; surface yellow-green ; nacre white, iridescent ;
pallial line widely sinused behind; anterior scars complex.

Bolivia; Brazil; Paraguay.

Tridina esula dOreicny, Guerin Mag., 1835, p. 43; Voy. Am.

Mer., 1843, p. 507.

Anodonta esula JAN, Charpentier and Jan, Cat., 1837, p. 24.
Margarita (Anodonta) esula Lea, Syn., 1838, p. 32.
Margaron (Anodonta) esula Lea, Syn., 1852, p. 52.
Margaron (Columba) esula Lea, Syn., 1870, p. 86.

Leila esula Stmpson, Syn., 1900, p. 915.

Anodonta arcuata HANEY, Biv. Shells, 1843, p. 223.

Leila pulvinata Hurst, Moll. Nouv., II], 1857, p. go, pl. xx, fig:

ig

Columba pulvinata CLessin, Conch. Cab. Ano., 1876, p. 255, pl.
EEE HOS. 12.

Anodon pulvinatus Sowerpy, Conch. Icon., XVII, 1867, pl. v,
fig. 10.

Leila castelnaudi Hurt, Moll. Nouv., II, 1857, p. 91, pl. x1x,
Hoek

Anodon castelnaudi Sowrrey, Conch. Icon., XVII, 1868, pl.
Kae S579.

Columba castelnaudii Ciesstn, Conch. Cab. Ano., 1876, p. 254,
pEeExexivs figs. 1, 2:

1402 LEILA

The synonymy of the form described above seems to be
somewhat involved. d’Orbigny used the name Jridina esula
in 1835 for a species, which he credits to Jan, and states that
it equals Lea’s Anodonta blainvilleana. In the Voyage Amer-
ique Meridionale he describes this species, stating that the anal
end is rounded, a character quite different from that of Lea’s
species, but exactly like that of the Leila pulvinata of Hupe.
I have not had access to Charpentier and Jan’s catalogue, nor
am I aware that the latter described Anodonta esula prior to
1835. It would probably be better to use Hupe’s name, as he
gave good figures and a description of his species.

LILA SPIXIt (von Ihering).

Shell irregularly obovate, thin, inflated, concentrically stri-
ate, somewhat inequilateral; beaks full; hinge line straight ;
anterior end narrowed, angled above, rounded below; base
slightly cut away in front, rounded for the most part, quite
full at the middle; posterior end subtruncate above, rounded
below ; epidermis pale olive-green, with dark brown bands and
faint, dark green rays; muscle scars large; nacre bluish-white,
iridescent ; pallial line irregular, distant from the border, hav-
ing an irregular posterior sinus.

Length 84, height 59 mm.

Amazon River.

Anodon giganteus Sprx (part), Test. Bras., 1827, p. 27, pl.

XIX, fig. I (young).

Anodonta gigantea IKustrr, Conch. Cab. Ano., 1853, p. 6, pl.

I, fig. 2 (young).

Columba spixit voN InErinc, Arch. ftir Nat., 1890, p. 135, pl.

IX, fig. 4.

Leila spixii SIMpsoNn, Syn., 1900, p. 916.

Von Ihering has shown in the Archiv fur Naturgeschichte,
1890, p. 135, that the smaller of the two shells figured by Spix
as Anodon giganteus is a distinct species which he refers to
Columba and to which he gives the specific name spivi. It 1s
a smaller species than the Leila esuwla, it is not so pointed in
front as is that species or L. blainvilleana, and it is faintly
marked with rather wide rays.

ANODONTITES 1403

Genus ANODONTITES Bruguire, 1702.

Anodonittes BRUGUIERE, Journ. Hist. Nat. Paris, I, 1792, p.
rails

Patularia Swainson, Malacology, 1840, pp. 287, 381.

Glabaris Gray, Proc. Zool. Soc. Lond., 1847, p. 197.—SIMP-

SON, Syn., 1900, p. 9106.

Shell rounded to elongated, inflated, subsolid; beaks full,
smooth; epidermis smooth or cloth-like, rarely having faint
rays; hinge line straight or slightly curved, edentulous, some-
times a little sinuous, the escutcheon distinct and large; nacre
soft tinted, the prismatic border wide and well defined.

Animal with the marsupium occupying the whole of the in-
ner branchiz, which are united their entire length to the ab-
dominal sac; palpi generally semicircular or kidney-shaped ;
attached along their entire upper length, not projecting pos-
teriorly ; branchial and anal openings with or without papille,
not united into siphons in the specimens examined, separated
by a strong bridge; superanal opening not closed below.

Type, Anodontites crispatus Brug.

Section ANOGDONTITES S. Ss.

Shell rounded to elliptical; posterior ridge low or wanting.

’ Group of Anodontites patagonicus.

Shell solid, inflated, obovate, usually somewhat produced
behind the center of the base ; beaks quite full, projecting above
the hinge line; epidermis olive-brown, rather smooth, gener-
ally rayless; anterior muscle scars well defined.

Animal with the gills large, rounded below; palpi rather
large; mantle thickened at edge, and furnished with palpi in
front of the branchial opening; branchial opening large, with
numerous minute papilla ; anal opening large, with no papille.

- ANODONTITES PATAGONICUS (Lamarck).

Shell quite variable in form, usually somewhat obovate, con-
vex to subinflated, solid, inequilateral; beaks moderately full
and high; dorsal line lightly arched; anterior end more or less

1404 ANODONTITES

narrowed, rounded; base line curved or rounded, often fuller

behind the middle; dorsal slope obliquely truncate or subtrun-

cate; posterior ridge low, with usually a shallow radial groove
just above it; surface with more or less strongly developed
growth lines; epidermis brownish to olive; hinge edentulous ;
ligamental patch triangular, deep; anterior scars well marked,
posterior scars faint; nacre whitish or flesh-colored dull; pris-
matic border wide on the base.

Length 87, height 57, diam. 37 mm.

Length 81, height 59, diam. 32 mm.

Southern South America, east of the Andes.

Anodonta patagonica LAMARCK, An. sans. Vert., VI, 1819, p.
88 Ene, Meth, Ul18275 p47 plecos sie, ese
Conch. Cab. Ano., 1853, p. 50, pl. xit, fig. 2.

Margarita (Anodonta) patagonica Lr, Syn., 1836, p. 52; 1838,
Dear:

Anodon patagonica CatLow and Reeve, Conch. Nom., 1845,
p. 67:

Margaron (Anodonta) patagonica LEA, Syn., 1852, p. 51;
1870, p. 82.

Glabaris patagonicus SIMPSON, Syn., 1900, p. 916.

Anodon trapezeus Spix, Test. Fluv. Bras., 1827, p. 28, pl. xx,

fig. L-

Anodonta trapeseum d’OrpicNy, Voy. Am. Mer., 1843, pp. 6,
10.

Anodonta trapezea Kuster, Conch. Cab. Ano., 1853, p. 7, pl. 1,
fig. 3.

Glabaris trapezea VON HERING, Arch. fiir Naturg., 1893, p. 57.

Anodonta lato-marginata Lea, Tr. Am. Phil. Soc., V, 1834, p.
70, pli xi; fig. 34%: Obs: I, 1834)-p. 188, pl: xm) fig. 34——
HAN ey, Biv. Shells, 1843, p. 221, pl. xxiv, fig. 14.—CHENU,
Man., II, 1859, p. 146, fig. 724.—-CLesstn, Conch. Cab. Ano., '
1973, D-c7Opl. Xia hOSt eee.

Margarita (Anodonta) lato-marginata Lea, Syn., 1836, p. 53;
[S38, ps 30;

Margaron (Anodonta) lato-marginata Lea, Syn., 1852, p. 51;
1870, p. 82.

ANODONTITES 1405

Anodon lato-marginatus SoweRsy, Conch. Icon., XVII, 1867,

pla ives 3:

Anodon. lati-margiata CatLtow and Reeve, Conch. Nom.,

1845, p. 67.

Anodonta lati-marginata Srropr., Mat. Mal., Pt. 1, 1874, p.

67.

Anodonta membranacea dOrwicNy, Voy. Am. Mer., 1843, p.

GIG. pls Ixcxtx, fies 11,

Anodonta solida Kuster, Conch. Cab. Ano., 1853, p. 50, pl.

Klee hio., Te
Anodonta uruguayensis Lea, Pr. Ac. N. Sci., Phila., IV, 1860,

p92; Jl Ac. N. Sei, Phila: V,1863, p. 393, pl. xtvint, fig.

g02; Obs.) XxX 1663; p:.20, pl. xivin, fig.) 302:—CiESsIN,

Conch. Cab. Ano., 1874, p. 114, pl. xxxvuu1, figs. 1, 2—Sow-

ERBY,.Conch. Icont, XVI, 1870, pl. xxx, fig. 127.
Margaron (Anodonta) uruguayensis Lea, Syn., 1870, p. 83.
Columba uruguayensis Pavren, Conch. Sam., III, 1890, p. 188.
Anodonta sinuosa CLESsIN, Conch. Cab. Ano., 1873, p. 90, pl.

MOM oS. ls 2s
Anodonta serpentina CLEssin, Conch. Cab. Ano., 1876, p. 223,

PIER, MISS 2) 93:

I have no doubt but that Lamarck’s Anodonta patagonica
is the same as Lea’s A. lato-marginata. The description of
the former is very brief, but the figures in the Encyclopedie
Methodique, which are referred to, represent the species very
accurately. The shell is represented in the external view as
having concentric bands and certain specimens in the large
series that I have seen are thus banded.

lLea’s type of Anodonta uruguayensis, an old worn shell, is
the only one in the collection, save a few very young that are
doubtfully the same. It is a little more inflated than most
specimens that are called /ato-marginata, and may possibly be
distinct.

Var. felix (Pilsbry).

Similar in form to the type, but the epidermis is light yel-
lowish-green, painted with short, radiating, dichotomous or
simple lines, or narrow V’s of green with two green rays on

1406 ANODONTITES

the posterior slope. Interior pale pink within the pallial line;

prismatic border faint olive-buff. There are some black zig-

zags along the pallial line-or outlining the muscle scars.
Colonia, Uruguay.

Glabaris lato-marginatus Lea, var. felix Pryspry, Pr. Ac. N
Sci.. Phila.,' 1806, p: 563, pl. xxvii fies,

Glabaris patagonicus var. felix SIMPSON, Syn., 1900, p. 917.

ANODON'TITES CRASSUS (Swainson).

Shell irregularly obovate or somewhat pentagonal, scarcely
subinflated. solid, inequilateral ; beaks full and high; hinge line
lightly curved; dorsal slope strongly, obliquely truncate; an-
terior end narrowed, rounded or subtruncate, angled above;
base line nearly straight in front, very full and subangulate
behind the middle; surface with well-marked growth lines;
epidermis dark grass-green; nacre whitish with iridescent
tints; muscle scars deep.

Length 80, height 52, diam. 32 mm.

Rio de la Plata.

Anodon crassus Swainson, Zool. Ill., 1st ser., III, 1823, pl.

CLXVII.

Margarita (Anodonta) crassa La, Syn., 1836, p. 23; 1838, p-

Bo:

Anodonta crassa HANLEY, Test. Moll., 1842, p. 222.
Anodon crassa CarLow and Reeve, Conch. Nom., 1845, p. 66.
Margaron (Anodonta) crassa Les, Syn., 1852, p. 52; 1870,.

Po2
Glabaris crassus SIMPSON, Syn., 1900, p. 917.

Close to A. patagonicus, but I have never seen a specimen
of that species quite so elongated or so pentagonal as the fig-
ure represents Swainson’s shell to be. His shell is said to be
deep grass-green, while patagonicus is always more or less
brown, it has its greatest diameter well forward while that of
patagonicus is at the middle. Swainsoii gives no measure-
ments and | have given those of his figures.

Tt is claimed in the Testacea Fluviatilia that this is the same
as the Anodon giganteus of Spix, but this is certainly an error.

ANODONTITES 1407

ANODONTITES WYMANII (Lea).

Shell long obovate, rather solid, convex or subinflated, in-
equilateral ; beaks but little elevated or inflated; dorsal outline
arched ; anterior end narrowed and rounded; base rounded, a
little fuller behind the middle; dorsal slope obliquely sub-
truncate ; posterior end somewhat biangulate about at the me-
dian line ; surface irregularly, concentrically striate ; epidermis
cinnamon red to brownish; ligamental patch narrow, elon-
gated: muscle scars well marked; nacre rose-tinted, with a
brownish-red prismatic border.

Length 80, height 50, diam. 30 mm.

Uruguay River, South America.

Anodonta wymanii Lara, Pr. Ac. N. Sci. Phila., IV, 1860, Pu Ol:
Jl. Ac. N. Sci. Phila., V, 1863, p. 390, pl. xray, fig. 294; Obs.,
X, 1863, p. 26, pl. xniv, fig. 294—C1Esstn, Conch. Cab.
ANOS, 1873, pr O04, pl. XRT figs, 1-2:

Margaron (Anodonta) wymanii Laa, Syn., 1870, p. 80.

Anodon wymant Sowerny, Conch. Icon., XVII, TO7O; (pl SOGKe
fer li7.

Glabaris wymanii Stmpson, Syn., 1900, p. 917.

More elongated and more richly colored than J. patagom-
cus. It is quite richly colored within as well as without.
ANODONTITES SIRIONIS (d’Orbigny).

Shell oblong almost evenly elliptical, subsolid to rather thin,
convex or subinflated, inequilateral; beaks moderately full and
elevated; dorsal slope obliquely subtruncate; surface rather
strongly and irregularly, concentrically striate, sometimes
showing faint radiating lines of wrinkles; epidermis greenish
to brownish, scarcely shining; ligamental scars triangular ;
muscle scars shallow ; nacre bluish-green, sometimes with pur-
plish tintings.

Length 87, height 50, diam. 37 mm.

Kio dela Plata.

Anodonta sirionis d’OrpicNy, Mag. Zool., 1835, p. 40; Voy.
Am. Mer., 1843, p. 615, pl. Lxxtv, figs. 4-6: LXxx, figs. 1.4.
—Crrsstn, Conch. Cab. Ano., 1874, p. 128, pl. x11, fieswie 2:

Margarita (Anedonta) sirionis Lea, Syn., 1838, p. 31.

1408 ANODONTITES

Anodon sirionts CatLow and Reeve, Conch. Nom., 1845, p. 68.

Margaron (Anodonta) sirionis Lea, Syn., 1852, p. 51; 1870,
p. 82. :

Glabaris sirionis Simpson, Syn., 1900, p. 918.

Anodonta ferrarisun dOrprIGNy, Guer. Mag., 1835, p. 40.

Very close to 4. wvmantn, but probably different. I have
specimens before me that I refer with some doubt to this
species, which are somewhat rhomboid. It is hardly as solid
a species as wymanit; it is not so much produced in the post-
basal region; the texture is different, for instead of being
bright and warm within and without it is cold and lurid.

Var. iheringi (Clessin).

Shell slightly obovate oblong, subinflated, solid, inequilat-
eral, with well marked, concentric sculpture; beaks full and
high ; dorsal outline arched; anterior end somewhat narrowed
and rounded; posterior end subtruncate above, widely rounded
below : base line lightly rounded ; epidermis chestnut ; ligament
long, thick ; nacre whitish.

Length 61, height 39, diam. 22 mm.

Taguara del Mundo novo, Brazil.

Anodonta theringi Ciesstn, Mal. BL, V, 1882, p. 191, pl. tv.

fig. 5.
Glabarts theringi Stmpson, Syn., 1900, p. 919.

After comparing a set of what I take to be Clessin’s 4.
theringt with specimens of strionts Orb. and the descriptions
and figures of the two species I am inclined to believe that the
former is not more than a variety of the latter. Clessin states
that his shell has chestnut epidermis and white. nacre, but
there are specimens before me, in which the epidermis is olive-
colored and the nacre bluish-white.

ANODONTITES PAzII (Lea).

Shell round-obovate, subinflated, subsolid, inequilateral ;
beaks moderately full, slightly elevated; dorsal line lightly
arched; anterior end somewhat narrowed, rounded; base
rounded; dorsal slope obliquely subtruncate; surface with ir-

ANODONTITES 1409

regular growth lines ; epidermis brownish-olive or brown-tinted

violet ; ligamental patch small, triangular; muscle scars indis-

tinct; nacre violet-tinted, rich and iridescent; prismatic bor-
der wide, reddish-tinted.

Length 60, height 43, diam. 26 mm.

Length 53, height 38, diam. 26 mm.

South America.

Anodonia past Lea, Pr. Ac. N. Sci. Phila., X, 1866, p. 35;
HieAc NaScih Phila Vie 1868; p: 274, pl. xxxvi, fis: 67;
Obs., XII, 1869, p. 30, pl. xxxvi, fig. 87—CLeEssin, Conch.
Cab. Anc., 1874, p. 139, pl. xi, figs. 3, 4.

Margaron (Anodonta) pazii Lea, Syn., 1870, p. 81.

Glabaris past? StMPsoN, Syn., 1900, p. gI8.

I have before me the type, the epidermis of which has been
somewhat worn away, and another smaller and more inflated
shell, which [ refer to this with a little doubt. Lea remarks
that the nacre is the most intensely red of any Anodonta with
which he is acquainted. Indeed the whole shell is tinged with
this reddish or violet-red color, which is one of its best dis-
tinguishing characters.

ANOPDPONTITES RUBICUNDUS (Lea).

Shell suborbicular, subinflated, scarcely subsolid, slightly in-
equilateral ; beaks considerably elevated, though not very full;
dorsal line very lightly arched; dorsal slope widely and al-
most squarely truncate; anterior end a little narrowed and
with the base rounded; surface with irregular growth lines;
epidermis dark olive, with two feeble, darker rays on the pos-
terior ridge; muscle scars shallow ; ligamental patch small, tri-
angular; nacre bluish, tinted reddish and violet at the border.

Length 59, height 51, diam. 30 mm.

Length 77, height 61, diam. 36 mm.

Uruguay River, South America.

Anodonta rubicunda Lea, Pr. Ac. N. Sci. Phila., IV, 1860, p.
925 fisher N. Sci. Phila.j.V5 1863, p: 392, pl. xvi, fig. 200:
Obs., X, 1863, p. 28, pl. xiv, fig. 299.—CLessin, Conch.
Cab. Ano., 1876, p. 106, pl. xxxm, figs. 5, 6.

I41o ANODONTITES

Anodon rubrcundus Sowerby, Conch. Icon., XVII, 1870, pl.
Xxx, fig. 118.

Margaron (Anodonta) rubicunda Liza, Syn., 1870, p. 75.

Glabaris rubicundus Stmpson, Syn., 1900, p. 918.

The type of this species has the epidermis considerably
eroded. It is a shorter shell than pazii, not so solid nor richly
colored, the posterior end is widely and almost squarely trun-
cate, meeting the dorsal line nearly at a right angle, while in
pazii it is slopingly subtruncate or slightly rounded. In the
type the nacre at the border shows colored bands.
ANODONTITES ROTUNDUS (Spix).

Shell almost orbicular, a little narrower in front, subsolid,
inequilateral, subinflated; beaks elevated and full, turned in
_over a long, narrow, clean lunule; posterior end sometimes
slightly truncate, often almost evenly rounded; hinge line
curved ; surface almost smooth ; epidermis finely and delicately,
concentrically wrinkled, olive, greenish-brown or yellowish-
brown, often feebly raved and having two or three broad,
darker rays on the dorsal slope; nacre bluish, silvery, having
a narrow, outer, iridescent border, and delicately, radially stri-
ate throughout; prismatic border wide, lurid.

Length 75, height 64, diam. 38 mm.

Brazil.

Anodon rotundus Sprx, Test. Fluv. Bras., 1827, p. 28, pl. xx,
figs. 2-4.

Anodon rotunda Kuster, Conch. Cab. Ano., 1853, p. 33, pl.
vill, fig. I.

Margaron (Anodonta) rotunda Lea, Syn., 1870, p. 81.

Glabaris rotunda von Inertnc, Arch. fur Nat., 1893, p. 59.

Glabaris rotundus Stmpson, Syn., 1900, p. 918.

Anodonta cailliaudu Lra, Pr. Ac. N. Sci. Phila., [V, 1860, p.
308 ; Jl. Ac. N. Sci. Phila.s V; 1863; p. 395, pl. xiv, fig. 207 ;
Obs., X, 1863, p. 31, pl. xiv. fig. 297——CLEssin, Conch.
Cab:-Ano.; 1873.p: 105, pl. mexemphes, 30

Anodon cailliaudi Sowrrey, Conch. Icon., X VII, 1867, pl. x11,
fig. 28.

Margaron (Anodonta) cailliaudti Las, Syn., 1870, p. 81.

ANODONTITES I4il

This is probably the finest species of the genus. The figure
_and description by Spix are of a young shell, not more than 35
millimeters in length, but they perfectly fit young shells of
Lea’s Anodonta cailliaudii. It is one of the most nearly or-
bicular of the Naiades, being but slightly narrower in front,
and often not at all truncate behind. It differs from rubicun-
dus in its rounded posterior end and the color of its nacre;
from fazii in its external and internal color. ‘The radial sculp-
ture of the nacre is a good distinguishing character.

ANODONTITES SPIXII (d’Orbigny ).

Shell elliptic rhomboid, inflated, rather solid, inequilateral ;
beaks full and high; dorsal line arched ; anterior end rounded:
base rounded; posterior slope obliquely subtruncated : poste-
rior ridge rounded, ending in a blunt point.a little above the
base of the shell: surface with irregular, concentric sculpture,
some of it rather coarse, part of it fine and Wavy ; epidermis
brownish; muscle scars shallow; nacre flesh-colored, with
greenish, iridescent tints behind; pallial line with a small sinus
behind ; prismatic border well marked.

Length 93, height 68, diam. 47 mm.

Rio Parana.

Unio (Anodontes) spixti d’Orsicny, Guerin Mag., 1835, p. 39.
Glabaris spixtt Simpson, Syn., IQOO, p. 932.

In 1835, in the Guerin Magazine, d’Orbigny used the name
Unio (Anodontes) spixii d’Orbigny, and stated that it equaled
Anodon rotundus of Spix and 4. trapezeus Spix, but he gave
no description. In the Voyage Amerique Meridionale he re-
peated the same statement, but gave a brief Latin description.
This description does not agree with either 4. rotundus Spix
or 4. trapezoideus Spix, which I believe are distinct species,
but it does agree fairly with a specimen sent by d’Orbigny
to Dr. Lea, labeled by the former “Ano. spixt Orb.” While
this is close to some other forms of the group, I am inclined
to believe that it is a valid species and have used the name
apparently applied by d’Orbigny to it.

1412 ANODONTITES

ANODONTITES MEMBRANACEUS (Maton).

Shell smal!, subinflated, thin and fragile, irregularly obo-
vate, almost equilateral: hinge line straight or curved down-
ward a little medially ; anterior end narrowed, rounded; base
well rounded, fuller behind the middle; posterior end wide,
rounded, joining the dorsal edge at‘an angle where it is pro-
duced into a small wing; beaks full, rounded ; epidermis green-
ish, lighter colored at the umbonal region; nacre smooth, sub-
margaritaceous, transversely, delicately striated.

Length 24, height 17 mm.

Rio de la Plata.

Mytilus membranaceus Maron, Tr. Linn. Soc. Lond., 1811,
PigZzo; plescmivs hess Iaaere.

Margarita (Anodonta) membranacea Lea, Syn., 1836, p. 22;
1838, p. 23.

Margaron (Anodonta) membranacea Lea, Syn., 1852, p. 343
1870} ps 55:

Unio membranaceus Haniey, Test. Moll., 1842, p. 202.

Glabaris membranaceus SIMPSON, Syn., 1900, p. QT9.

Umo subtrapezius Puttipri, Zeits. fur Mal., IV, 1847, p. 96;
Abbild., III, 1848, p. 80, pl. v, fig. 3.—Kustrr, Conch. Cab.
Unio, 1862)"p: 283, pl: xevs fies 4:

Maton states that his shell is fragile and membranaceous,
that the nacre is transversely striate. I am not certain whether
he means by the last statement that it is concentrically striate,
showing the growth lines or that it is radially striate as is the
case with many species of Anodontites. It is possible that his
shell is but the young of some other well-known form, but I
know of no species of this group in which the young is fragile
and membranaceous.

ANODONTITES LEOTAUDI (Guppy).

Shell somewhat rhomboid obovate, convex, scarcely sub-
solid, inequilateral ; beaks moderately full and elevated ; dorsal
and basal outlines curved; anterior end a little narrowed,

rounded ; dorsal slope obliquely subtruncate, below which the
posterior end is rounded; surface irregularly, concentrically

ANODONTITES T1413

sculptured ; epidermis chestnut with faint vestiges of darker
rays on the dorsal slope, subshining; nacre flesh-colored or
purple-tinted, iridescent; muscle scars shallow; ligamental
patch triangular.

Length 63, height 37, diam. 20 mm.

Trinidad Island, West Indies.

Anodonta leotaudi Guppy, Ann. and Mag., XIV, 1864, p. 243.
Margaron (Anodonta) leotaudi asa, Syn., 1870, p. 83.
Glabaris leotandi Simpson, Syn., 1900, p. 920.

At the time of publishing the Synopsis I had never seen
this species, and as it had not been figured I was unable to
give any idea as to its relationships. Recently Mr. William
Moss, of Ashton-under-Syne, England, has donated an au-
thentic specimen from Trinidad to the National Museum.
This shell is somewhat worn, having been taken dead, but it
is in condition to give a fair idea of the characters of the
species. I place it with some hesitation in the group of 4.
patagonicus. It scarcely gapes either in front or behind.

Group of Anodontites brevis.

Shell rhomboid, swollen, with full, high beaks and a pinched-
up posterior ridge.

ANODONTITES BREVIS (Sowerby).

Shell rhomboid, inflated, solid, rather short, somewhat in-
equilateral; beaks full and elevated; posterior ridge angled,
pinched up; hinge line nearly straight; posterior end slopingly
rounded; anterior end rounded, cut away slightly below; base
curved; epidermis blackish-brown, sinuously striated; nacre
orange with a thick border.

Length 66, height 43.5 mm.

La Plata, S. America.

Anodon brevis Sow:rsy, Conch. Icon., XVII, 1870, pls xx

fig. 124.

Glabaris brevis Stmpson, Syn., 1900, p. 932.

I have never seen this species and know nothing whatever

about it excepting from Sowerby’s figure and very brief de-

1414 ANODONTITES

scription. Certain specimens of Strophitus edentulus answer
very well to this figure and description, excepting the some-
what pinched-up posterior ridge, which may not be correctly
drawn. I know of no South American Naiad at all like it and
I would not be surprised if it was a rather unusual specimen
of the species to which I have compared it.

Group of Anedontites crispatus.

Shell elliptical obovate, slightly produced at the posterior
base, and straight or very feebly incurved in front of it; epi-
dermis fuscous or tawny, cloth-like behind, somewhat rayed
by more or less incised lines in front, where it is wrinkled like
dried paint, the wrinkles often being looped; nacre lurid, blu-
ish, somewhat iridescent.

Animal having gills of thin, semi-transparent texture, with
wide, vertical, light-colored ridges, the whole beautifully retic-
ulated under a glass, inner wider, united throughout to the
abdominal sac; palpi rather small, semicircular, attached along
their entire upper border; mantle thin, very thick on the bor-
der ; branchial opening with short, fleshy palpi; anal and super-
anal openings united, but separated from the branchial open-
ing by a strong bridge.

ANODONTITES CRISPATUS Bruguiere.

Shell long rhomboid or long obovate, thin or scarcely sub-
solid, convex, inequilateral; beaks not full or greatly elevated ;
posterior ridge full, rounded or faintly biangulate; anterior
end narrowed and rounded; dorsal outline nearly straight ;
posterior end sometimes obliquely subtruncate above, some-
times almost evenly rounded, occasionally biangulate below ;
base nearly straight; in front of the posterior ridge there is
sometimes a broad, shallow, radial depression; surface with
radial sulcations and concentric growth lines, which are broken
into loops at the radial grooves; epidermis greenish-yellow or
tawny ; nacre blue; muscle scars shallow.

Length 53, height 27.5, diam. 17 mm.

Widely distributed in tropical South America.

ANODONTITES I415

Anodontites crispata Brucuterr, Jl. d’Hist. Nat., I, 1792, p.
E31.

Anodonta crispata Lamarck, An. sans Vert., VI, 1819, p. 86.

Margarita (Anodonta) crispata Liza, Syn., 1836, p. 48; 1838,
Be 20:

Anodon crispata Catiow and Reeve, Conch. Nom., 1845, p. 66.

AMargaron (Anodonta) crispata Lea, Syn., 1852, p. 47; 1870,
Pp. 75.

Glabaris crispatus SIMPSON, Syn., I900, p. 910.

? Anodonta crispa LAMARCK, Enc. Meth., H, 1827, p. 147, pl.
CcIL, fig. 3.

Anodonta puberula Gouin, U. S. Expl. Ex., XII, 1852, p. 434,
figs. 548, 548a, 548).

Anodon reticulatus SoweRBy, Conch. Icon., XVII, 1867, pl. x,
fig. 27.

Margaron (Anodonta) reticulata Lua, Syn., 1870, p. 80.

Anodonta reticulata Pavret, Conch. Sam., IIT, 1890, p. 184.
Specimens, which are before me labeled Anodonta crispata

Lam., agree fairly well with Lamarck’s description and the

figures in the Encyclopedie Methodique, and with Gould’s

type of A. puberula. It is a small species and varies much in

the degree of its sculpture.

ANODONTITES CHEEZIANUS (Sowerby).

Shell almost evenly long elliptical, inflated, solid, dull olive,
with irregular growth lines and delicate radial lines on the
front half ; beaks only moderately elevated, flesh-colored ; dor-
sal outline lightly arched; dorsal slope obliquely truncate;
anterior end narrowed, rounded; base very slightly incurved |
medially ; posterior ridge full, rounded, ending in a rounded
point at the base of the shell; surface striate and subrugose ;
epidermis yellowish-green ; nacre bluish-white.

Length 48, height 27 mm.

Anodon cheeziana Sowrrny, Conch. Icon., XVII, 1867, pl. xv,

fig. 52.

Glabaris cheeziana SIMPSON, Syn., 1900, p. 932.

Only a brief description is given for this species and no

locality is assigned. In most characters it agrees with 4. cris-

1416 ANODONTITES

patus. but, according to the description, it is a solider, more
inflated form, and is perhaps a little darker colored. I fee:
sure that it is an Anodontites belonging to the crispatus group.

ANODONTITES PHILIPPIANUS (Simpson).

Shell decidedly trapezoid, scarcely subsolid, rather com-
pressed; inequilateral; beaks moderately full and elevated;
dorsal outline lightly arched; dorsal slope obliquely truncate ;
anterior end narrowed, rounded; base very slightly incurved
medially ; posterior ridge full, rounded, ending in a rounded
point at the base of the shell; surface striate and subrugose ;
epidermis yellowish-green ; nacre bluish-white.

Length 53, height 32, diam. 18 mm.

Ucayali River, Peru.

Anodonta subsinuata Puiiieet, Mal. Bl., XVI, 1869, p. 41.—

PrerrrEer, Nov. Conch., III, 1869, p. 487, pl. cv, figs. 7, 8.
Glabaris philippianus SIMPSON, Syn., 1900, p. 9I9.

According to the outline figure giving a dorsal view of this
-shell it is compressed along the middle. The statement that
the surface is rough and wrinkled would seem to show that
it belonged in this group. ‘The species is more rhomboid in
outline than A. crispatus and is apparently more greenish in
color. |

The name subsinuata, applied to this by Philippi, will have
to be placed in the synonymy, as Sowerby used it previously
for an Anodontites which he placed in Anodonta.

ANODONTITES NAPOENSIS (Lea).

Shell irregularly elliptical, oblong, solid, convex, inequilat-
eral; dorsal outline strongly and almost evenly curved from the
narrowed anterior end to the end of the posterior ridge; base
line but slightly curved; surface having irregular growth lines ;
epidermis marked with radial rows of fine, zigzag wrinkles,
almost black at the border, lighter colored at the umbonal re-
gion; muscle scars deep, the anterior ones large; nacre lurid
greenish.

Length 62, height 32, diam. 19 mm.

River Napo, Ecuador.

ANODONTITES 1417

Anodonta napoensis Lea, Pr. Ac. N. Sci. Phila., XII, 1868, p.
162; Jl. Ac. N. Sci. Phila., VI, 1868, p. 324, pl. nam, fig. 127;
Obs., XII, 1869, p. 84, pl. 1, fig. 137W—CrxEsstn, Conch.
Cab. Ano., 1873, p. 116, pl. xxx1v, figs. 3. 4.

Margaron (Anodonta) napoensis Lea, Syn., 1870, p. 8o.

Glabaris napoensis Simpson, Syn., 1900, p. 920.

The figured type of this species is a single right valve in the
collection of the National Museum and is a singular shell. It
is very solid, very dark, and most peculiarly and delicately
sculptured. The dorsal outline is much more strongly curved
than is that of the base. The hinge has been ground away but
it is apparently edentulous. T,ea has other shells, which he
refers to this species, which I think are something else.

ANODONTITES TORTILIS (Lea).

Shell subrhomboid, convex, scarcely subsolid, inequilateral ;
beaks only moderately full and elevated; anterior end some-
what narrowed, rounded; dorsal outline arched; dorsal slope
obliquely truncated; base curved, often quite full behind the
middle; surface with irregular growth lines; epidermis much
wrinkled and looped, the loopings often disposed in a radial
manner; that of the posterior end usually concentrically lam-
ellose ; greenish-yellow or yellowish-green, often dull and dirty
colored; nacre bluish, sometimes a little lurid; muscle scars
shallow.

Length 70, height 47, diam. 25 mm.

Cartagena, Colombia; British Guiana; Isthmus of. Darien:
Nicaragua ; Costa Rica.

Anodonta tortilis Lra, Tr. Am. Phil. Soc., X, 1852, p. 291, pl.
MeV es 4 Obs) ValG52a E47 apl. XX VIEL sfie. 4
Cressin, Conch. Cab. Ano., 1875, p. 166, pl. Lv, figs. 7, 8.

Margaron (Anodonta) tortilis Lea, Syn., 1852, p. 47; 1870, p.
75:

Anodon tortilis Sowrrry, Conch. Icon., XVII, 1870, pl. xxxvu,
fig. 154.

Glabaris tortilis Simpson, Syn., 1900, p. 920.

1418 ANODONTITES

Anodonto luteola Lea, Pr. Ac. N. Sci. Phila., II, 1858, p. 118;
jl. Ave: WSer-sBhila., TV; 1860; 2207," pl) nm, heey
Obs., VII, 1860, p. 85, pl. xii, fig. 147—CrEssin, Conch.
Cab, Atio.; 1874, p: 122; pl xmxyir fies la

Margaron (Anodonta) luteola Liza, Syn., 1870, p. 83.

Anodon luteolus Sowersy, Conch. Icon., XVII, 1870, pl.
XK: fey es2

Glabaris luteolus Stmpson, Syn., 1900, p. 920.

Anodon schomburgianus SOWERRY, Conch. Icon., XVII, 1870,
pl. xxx1v, fig. 137.

Glabaris schomburgianus StMPSON, Syn., 1900, p. 920.

Anodonta schomburgkiana Cursstn, Conch. Cab. Ano., 1876,
P= 235, (pl x xvin fis. As
The type of Anodonta tortilis is a young shell somewhat

eroded and greenish-tinted at the umbonal region. That of

A. luteola is a nearly adult shell without any of the green color

at the umboes and unworn. ‘The examination of additional

material since writing the Synopsis has convinced me that the
two are identical. The species is shorter in proportion to its

height than crispatus or philippianus. I believe now that A.

schomburgianus is only a yellowish variety of the above. The

ridge which Sowerby figures and mentions on the posterior
slope is sometimes present in A. tortilis.

ANODONTITES STREBELIL (Lea. )

Sheil irregularly obovate, subcompressed, thin, inequilateral ;
beaks moderately developed; posterior ridge rounded; dorsal
line lightly arched; anterior end narrowed, rounded; base
curved, fuller behind the middle; dorsal slope obliquely trun-
cate; surface with delicate growth lines; epidermis with fine,
loop-like wrinkles arranged in radial rows, shining, yellowish-
green with very numerous, faint, green rays; nacre deep blue,
slightly lurid, with feeble, radial sculpture; muscle scars shal-
low.

Length 40, height 23, diam. 13 mm.

Mexico.

ANODONTITES 1419

Anodonta strebelu Lea, Pr. Ac. N. Sci. Phila., XX, 1868, p.
150; Jl. Ac. N. Sci. Phila., VII, 1868, p. 322, pl. x1, fi 135 5
Obs; XLT: 1869; p. 82) ple ii te: 135.—CLESSIN, Conch.
Cab. Ano., 1874, p. 138, pl. xm, figs. 5, 6.

Margaron (Anodonta) strebelii Lea, Syn., 1870, p. 79.

Glabaris strebelti Simpson, Syn., 1900, p. 920.

This species was founded on a single, evidently young spec-
imen, whose soft parts Dr. Lea examined. Both shell and
anatomy go to show that it is an Anodontites and not an Ano-
donta. The shell is shining and appears rather dark, probably
on account of the dark nacre.

ANODONTIVES CYLINDRACEUS (Lea).

Shell long obovate or rhomboid, scarcely subsolid, convex,
inequilateral ; dorsal outline lightly curved, base nearly straight :
anterior end narrowed and rounded; posterior end obliquely
subtruncate above, rounded below; beaks rather low; surface
with irregular growth lines; epidermis with faint, loop-like
wrinkles arranged in radiating rows, scarcely wrinkled behind
the middle of the shell, tawny green with delicate, faint, darker
rays, somewhat shining; nacre bluish, violet-tinted and richly
iridescent.

Length 40, height 20, diam. 12 mm.

Length 57, height 32, diam. 19 mm.

Medellin River, Mexico.

Margarita (Anodonta) cylindracea Lea, Syn., 1836, p. 54;
1838, p. 32.

Anodonta cylindracea Lea, Tr. Am. Phil. Soc., VI, 1838, p.
45, pl xin, dig. 40 ;/Obs.; 11,1838; p: 45; pl. x11, fiss.4o-—
Cressin, Conch. Cab. Ano., 1874, p. 161, pl. 1111, figs. 5, 6.
—FiscHEr and Crosse, Miss. Sci., II, 1894, p. 528—von
Martens, Biol. Cent. Amer., Moll., 1900, p. 535.

Anodon cylindracea SowErpny, Conch. Icon., XVII, 1869, pl.
XXIV, fig. 93.

Margaron (Anodonta) cylindracea La, Syn., 1852, p. 51;
1870, p. 82.

Glabaris cylindraceus Stmpson, Syn., 1900, p. 920.

1420 ANODONTITES

I have only seen a single shell of this, the one whose meas-
urements are first given, and this was presented to Dr. Lea
by Dr. Burroughs. According to Dr. Lea it is a thin shell but
the figure shows it to be somewhat solid. It is a more elon-
gate and more decidedly rhomboid species than the nearly
related A. strebelit.

Fischer and Crosse, (I. c.), separate the forms figured by
Sowerby in the Conchologia Iconica as var. subarcuatula. But
von Martens, (1. c.), remarks that “there is no reason to give
it a distinct name.”’

ANODONTITES LIMNOICUS (d’Orbigny).

Shell slightly obovate, subrhomboid, convex or subinflated,
rather thin, inequilateral ; beaks moderately full, and elevated ;
dorsal outline lightly curved; anterior end narrowed, rounded,
sometimes cut away a little below; base rounded, sometimes
a little fuller behind the middle; dorsal slope obliquely trun-
cate ; posterior ridge rounded or faintly biangulate, ending at
or below the median line, often in a feeble biangulation; epi-
dermis greenish or brownish, often banded, sometimes with a
dark ray or two on the posterior end, smooth; nacre purplish.

Length 55, height 30, diam. 22 mm.

Length 60, height 35, diam. 20 mm.

Patagonia, north to the Amazon; west to Bolivia.

Anodonta limnoica @OrbiGcNy, Guer. Mag., 1835, p. 40; Voy.
Am. Mer., 1843, p. 610, pl. LX x1x, figs. I-3—CrLEssin, Conch.
Cab: Ano) 1874;"p) 120, pit xu, figs. 34

Anodon limnoica Catriow and Reeve, Conch. Nom., 1845, p.
67.

Margarita (Anodonta) limnoica Lea, Syn., 1838, p. 30.

Margaron (Anodonta) limnoica Lea, Syn., 1852, p. 50; 1870,
Pp. 79.

Glabaris limnoicus SIMPSON, Syn., 1900, p. 921.

Anodonta lymnoica Cuenu, Ill. Conch., 1858, pl. 11, figs. 1,
1a; 10.

Anodonta puelchana d’Oricny, Guer. Mag., 1835, p. 40; Voy.
Am. Mer., 1843, p. 620, pl. LXxxrx, figs. 7-9.—CHENU, IIL.
Conch., 1858, pl. 11, figs. 7, 7a.—CLessin, Conch. Cab. Ano.,
1874, p- 130, pl xii figs. 5, 6.

ANODONTITES 1421

Margaron (Anodonta) puelchana LEA, Syn., 1852, p. 51; 1870,
p. 81.

Glaberis puelchanus SIMPSON, Syn., 1900, p. 921.

Anodontites puelchanus Pirspry, Princeton Univ. Exp., III,
IQII, p. 100.

Anodonta obtusula Hurt, Moll. Nouv., III, 1857, p. 87, pl.
Xvi, fig. 3.—Criessin, Conch. Cab. Ano., 1875, p. 214, pl.
BVI, fe= 12:

Anodon obtusula Sowrrsy, Conch. Icon., XVII, 1868, pl. xx,
fig, 81.

Margaron (Anodonta) obtusula Lea, Syn., 1870, p. 79.

Glabaris obtusula von JueRtNc, Arch. ftir Nat., 1893, p. 119.
Since writing the Synopsis I have seen a set of shells, which

shows considerable variation, and seems to stand partly be-

tween the 4. limnoicus and A. puelchanus of dOrbigny. The

figures of the two show but little real difference, the latter being

a little more inflated in the ventral region and not so distinctly

banded as the former.

ANODONTITES LUCcIDUS (d’Orbigny).

Shell oblong, subrhomboid, subinflated, thin, with a yellow-
green epidermis, which is smooth and shining and is marked
more or less with broken rays on the anterior part and entire
ones on the posterior part; beaks high, rather sharp; dorsal
and basal lines curved, the latter more so; anterior end round-
ed; dorsal slope obliquely truncate; posterior ridge somewhat
double, ending in a feeble biangulation; nacre blue with dark,
zigzag markings.

Length 50, height 25, diam. 15 mm.

Uruguay.

Anodonta lucida d’Orsicny, Guer. Mag., 1835, p. 40; Voy. Am.
Mer., 1843, p. 620, pl. LXxrx, fig. 4-6—CuENU, Ill. Conch.,
1858, pl. 111, figs. 6, 6a, 6b—CtLEssin, Conch. Cab. Ano.,
1875, p. 208, pl. LxIx, figs. 4, 5.

Margaron (Anodonta) lucida Lua, Syn., 1852, p. 51; 1870, p.
82.

Glabaris lucidus Stupson, Syn., 1900, p. 921.

1422 ANODONTITES

This differs from limnoicus by its higher beaks, the system
of rays broken and entire and by the zigzag, internal markings,
which appear to be somewhat like those often seen in 4. trape-

_sialis and its allies.

ANODONTITES INCARUM (Philippi).

Shell almost evenly long elliptical subinflated, subsolid,
somewhat inequilateral ; beaks considerably elevated ; posterior
ridge well developed, rounded, with a radial groove above it;
hinge line lightly arched; anterior end rounded; base rounded,
sometimes a little fuller behind the middle; posterior end ob-
liquely subtruncate above, narrowly rounded below; surface
irregularly and regularly striate; epidermis greenish; nacre
flesh-color or salmon-tinted.

Length 52, height 31, diam. 19 mm.

Peru
Anodonta incarum Puiiiert, Mal. Bl, XVI, 1869, p. 40.—

PFEIFFER, Nov. Conch., ITI, 1860, p. 488, pl. cv, figs. 9-11.
Glabaris incarum SIMPSON, Syn., 1900, p. 921.

The shell is elliptical or very slightly subrhomboid, while
that of 4. philippianus, to which it is allied, is decidedly rhom-
boid or trapezoid.

ANODONTITES HOLTONIS (Lea).

Shell oblong, somewhat rhomboid, thin, subinflated, inequi-
lateral; beaks full and elevated ; anterior end narrowed, round-
ed above, cut away below; dorsal and base lines nearly straight ;
posterior end obliquely truncate above, rounded below ; surface
with irregular growth lines; epidermis with widely spaced,
radial rows of loop-like wrinkles, dirty greenish, with several
broad, feeble, dark rays behind, subshining ; nacre blue, slight-
ly iridescent behind; muscle scars shallow.

Length 68, height 34, diam. 23 mm.

Colombia.

Anodonta holtonis Lea, Pr. Ac. N. Sci. Phila., I, 1857, p. 85;
Th Ac. Ni Sci; -Phila., Ill, 1857..p.0 3G) plecx, fig. ans
Obs., VI, 1847, p. 36, pl. xxxu, fig. 31.—Cressin, Conch.
Cab. Ano., 1874, p. 149, pl. 1, figs. 5, 6.

ANODONTITES 1423

Anodon holtonis Sowrrsy, Conch. Icon., XVII, 1870, pl.

XXXVI, fig. 147.

Margaron (Anodonta) holtonis Laa, Syn., L870; p. 70:
Glabarts holtonis Simpson, Syn., 1900, p. 921.

A thin, oblong, somewhat rhomboid, subinflated species
with a dirty green epidermis. ‘he beaks are higher than are
those of cvlindraceus and the shell is thinner and only rayed
behind.

Group of .dnodontites inequivalvis.

Shell elliptical, moderately solid and inflated, with a low
posterior ridge, slightly produced behind near the base and
truncated above the posterior slope; beaks full, smooth ; lig-
ament imbedded in a sort of groove, which extends to the an-
terior point of the shell; epidermis slightly roughened, often
cloth-like, and showing the rest periods, having faint, radiating
lines; nacre bluish, soft, but not brilliant.

Animal unknown.

ANODONTITES INASQUIVALVIS (Lea).

Shell small, slightly inequivaive, inequilateral, subelliptical
or subrhomboid, convex, scarcely subsolid ; anterior end round-
ed, sometimes slightly cut away below; dorsal and basal re-
gions rounded; posterior end obliquely subtruncate above;
surface with irregular growth lines ; epidermis having concen-
tric, delicate folds, which are more or less looped, the loops
arranged in radial rows, greenish, tawny or straw-color,
sometimes faintly rayed; nacre bluish, greenish-blue or flesh-
color, bright and iridescent.

Length 42, height 28, diam. 17 mm.

Length 35, height 24, diam. 15 mm.

Lake Nicaragua; Mexico.

Anodonta inequivalvis LeA, Pr. Ac. N. Sci. Phila., XII, 1868,
Puosc jb wcy Ni: Sci. Phila. Vil at S86s: p.202,' pl; Kurt, fig.
108 -2@bs., 2H. 1860, p. 52) ple xpi; fig. 108=—CLEssIN,
ConchCaby Amo: 18745 pale). pl. xnv, figs. 7, 8.

Margaron (Anodonta) inequivalzts Lea, Syn., 1870, p. 83.

Glabaris inequivalvis StMPson, Syn., 1900, p. 922.

1424 ANODONTITES

Anodonta lenticularis Lua, Pr. Ac. N. Sci. Phila., XII, 1868,
p. 9535 JE Ac AN, Sct. -Phila:, V1) i668, p 200; sal pala ation
1625 (Obs); «215 1809; «p: 350, pl x thes 162 —=Crescine
Conch. Cab-Ano.;: 1874, p. 134, ple xn digs: 5,6:

Margaron (Anodonta) lenticularis Lea, Syn., 1870, p. 81.

Anodonta inequivalvis lenticularis VON MARTENS, Biol. Cent.
Amer., Moll., 1900, p. 534.

Anodon glabrus SowERBy, Conch. Icon., XVII, 1870, pl. xxv,
fig. 97.

Anodon montezianus SowERBY, Conch. Icon., XVII, 1870, pl.
XXXVI, fig. 145.

Anodonta viridana Curssin, Conch. Cab. Ano., 1876, p. 226,
pl. ExXXv, He
A large number of specimens of this species are before me

and they show a considerable amount of variation in form and

color. In the type the left valve is a little higher than the right,
but this character is not constant. I do not think that Lea’s

Anodonta lenticularis, the type of which is before me, differs

even varietally.

ANODONTITES GRANADENSIS (Lea).

Shell elliptic rhomboid, convex, inequilateral, scarcely sub-
solid, the outline being almost evenly elliptical except that the
dorsal slope is somewhat obliquely truncated; posterior ridge
full, rounded; epidermis concentrically striate, slightly wrink-
led and looped, deep green with a straw-colored area at the
base of the shell in front of the posterior ridge, and occasion-
ally two or three posterior rays; nacre blue, purplish or flesh-
colored, iridescent.

Length 36, height 22, diam. 14 mm.

Lake Nicaragua, Centrat America.

Anodonta granadensis Lea, Pr. Ac. N. Sci. Phila., XII, 1868,
p. 96; Jl. Ac. N. Sci. Phila., VI, 1868, p. 288, pl. xu, fig.
100; Obs., XII, 1869, p. 48, pl. xii, fig. 100—CLESsIN,
Conch. ‘Cab.Ano.,; 1874,-p: 134; 7pl. XLiv. hes. 3) /4-

Margaron (Anodonta) granadensis Lia, Syn., 1870, p. 81.

Glabaris granadensis SIMPSON, Syn., 1900, p. 922.

ANODONTITES T425

Anodonta mequivalzis granadensis VON Martens, Biol. Cent.

Amer., Moll., 1900, p. 535.

Probably only a variety of imequivalvis but rather more elon-
gate in outline, more delicate and having generally, though
not always, a pale flush at the base of the shell in front of the
posterior ridge. Sometimes this buff color is extended around
the outer edge of the shell as a band.

ANODONTITES DEPEXUS (von Martens).

“Shell solid, ovate-rhomboid, rather convex, sculptured with
light, radiating grooves and concentric, frilled striz, oliva-
ceous ; beaks not prominent; shortly rounded in front; dorsal
margin straight, slightly ascending; postero-dorsal angle ob-
tuse; ventral margin somewhat curved; posterior end subros-
trate, oblique above, rounded below; nacre pale bluish, very
iridescent towards the margin, edge of margin black ; sinulus
triangular, anterior margin almost perpendicular.

Length 67, height 41.5, ale 45, diam. 24 mm. Vertices in
T-3 long.

Length 64, height 39.5, ale 45, diam. 23.5 mm. Vertices in
1-3 long.

Length 46, height 20, alz 31, diam. 16 mm. Vertices in 1-3
long.’ (von Martens).

Type locality, Paso Antonio, Rio Michatoya, W. Guatemala.
Anodonta depeva vON Martens, Biol. Cent. Am., Moll., 1900.

py 535, Plex figs: 3) 30-c:

“Three specimens of nearly equal size and a younger one are
before me, all having shallow furrows radiating from the sum-
mits towards the ventral margin, which cut the concentric
strie of growth and cause them to become more or less frilled ;
in the fore and hinder parts of the shell these furrows are not
to be seen, and in the hinder part, at a determined line, they
disappear and the concentric lines become simple, more crowd-
ed, and somewhat membranaceous and projecting, the appear-
ance here being more dull and dirty, contrasting with the some-
what shining olivaceous color of the middle and fore parts.
This peculiarity is visible in all four examples, but in a some-
what different degree ; whether it is due to the structure of the

1426 ANODONTITES

periostracum, or caused by the fore and middle parts of the
length being more worn than the hinder part, it is impossible
to tell. I know of no other Anodonta or Glabaris with similar
structure; the general form and solidity of the shell, as well
as the well-marked, dull, (lustreless), marginal zone, prove
that it belongs to the South American group of Anodonta late-
marginata Lea.”

This species may be only a form of inequivalvis, from which
it seems to differ mostly in its larger size and the greater so-
lidity of its shell.

ANODONTITES TEHUANTEPECENSIS (Crosse and Fischer).

“Shell inequilateral, oval, slightly inflated, quite solid, cov-
ered with a greenish-brown epidermis, without rays, with fine,
concentric striae, which become sublamellose posteriorly and
near the ventral margin; anterior side curved; posterior side
obliquely and obtusely subtruncate; ventral margin regularly
curved; dorsal margin nearly straight, slightly ascending be-
hind the beaks, which are small and eroded; dorsal slope some-
what compressed and obscurely bounded by an obliquely de-
scending depression. Nacre bluish-white and iridescent; ad-
ductor muscular impressions superficial. Ligament narrow.

Length 56, height 37, diam. 19.5 mm.” (Crosse and Fisch-
er).

Type locality, Cacoprieto, Isthmus of Tehuantepec, State
of Oajaca, Mexico.

Anodonta tehuantepecensis Crossr and Fiscuer, Jl. Con.,
XLI, 1893, p. 32.—Fiscuer and Crosse, Miss. Sci., II, 1894,
p. 526, pl. Lxx, figs. I-Ia.

Glabaris tehuantepecensis SIMPSON, Syn., 1900, p. 933.

“We have seen only a single specimen of this species, which
is distinguished from its allied forms by its regularly oval
shape and its rather solid shell.”

ANODONTITES TRAUTWINIANUS (Lea).

Shell elliptic rhomboid, scarcely subsolid, convex or subin-
flated, inequilateral; beaks moderately full and elevated; pos-
terior ridge rounded, ending in a blunt point near the base of

ANODONTITES 1427

the shell; dorsal and ventral outlines rounded; anterior end
round; dorsal slope obliquely truncate; surface with irregular
growth lines; epidermis dull, somewhat cloth-like, often with
faint, radial, thread-like lines, greenish or brownish, occasion-
ally with yellowish bands; nacre flesh-color, or bluish-tinted,
bright and iridescent; muscle scars faint.
Length 78, height 45, diam. 28 mm.
Cartagena, Colombia.
Anodonta trautwiniana Lea, Tr. Am. Phil. Soc., X, 1852, p.
2 pli XENI, 1S. As; Obs, V, 1852; p. 43, ple xxvi, figs 48.
Margaron (Anodonta) trautwiniana Lea, Syn., 1870, p. 81.
Anodon trautwinianus Sowerby, Conch. Icon., XVII, 1870,
pl. xxx, fig: 134.
Margaron (Anodonta) troutwiniana LEA, Syn., 1852, p. 51.
Glabaris trautwinianus SIMPSON, Syn., 1900, p. 922.
Anodonta troutwiniana, CLessin, Conch. Cab. Ano., 1874, p.
LEZ pl. SKKVE Mess, 2:
? Anodon ovatus SWAINSON, Ex. Conch., 1841, pl. XxxvI.
? Anodonta carthagena ——, Who? Where?
This species seems to be almost equally related to this group,
to that of crispatus and that of trapesialis.

ANODONTITES MONTEZUMA (Lea).

Shell almost regularly short elliptical, convex, inequilateral ;
thin; beaks full but not greatly elevated; anterior end a little
narrowed, rounded, slightly cut away below; dorsal and basal
lines rounded, the latter full just behind the middle; posterior
end rounded, very slightly produced about on the median line;
epidermis rough, yellow and green; anterior scars distinct;
posterior scars confluent ; nacre white and iridescent.

Length 42, height 29, diam. 13 mm.

Central America.

Anodonta montezuma Léa, Pr. Am. Phil. Soc., II, 1841, p. 31;
Tr. Am. Phil. Soc., 1842, p. 240, pl. xxtt, fig. 55; Obs., ITI,
1842, p. 78, pl. xxut, fig. 55.—C Lessin, Conch. Cab. Ano.,
1970; p> 220; pl. Lxxil, figs: 7, 8.

Margaron (Anodonta) montezuma Lea, Syn., 1852, p. 51;
1870, p. 82.

Glabaris montezuma SIMPSON, Syn., 1900, p. 923.

1428 ANODONTITES

This may be a true Anodonta related to A. exilior. I have
never seen it and the description is rather brief, while the fig-
ures give no characters by which I can decide. It is very
shghtly obovate, thin, with a rough yellow and green epider-
mis.

Group of Anodontites trapesialis.

Shell large, inflated, elliptical, narrower in front, with full,
rather prominent beaks, a slight wing on the post-dorsal part,
and sometimes a small one in front of the beaks; gaping de-
cidedly in front and slightly behind; epidermis smooth, gener-
ally uniform olive-green; hinge line straight or slightly sin-
uous; escutcheon large and conspicuous; nacre bluish-silvery,
sometimes marked with parallel, wavy dark lines.

Animal with the marsupium filling the inner branchie ; gills
large, inner the larger; palpi very large, reniform ; mantle thin,
with a wide, thickened edge: branchial opening small, plicate,
but not crenulate or papillose; anal opening large, smooth,
separated from the branchial by a strong bridge.

ANODONTITES TRAPESIALIS (lamarck).

Sheil large, subinflated, rather thin, irregularly obovate or
subtrapezoid, inequilateral:; beaks large, full and elevated;
hinge line nearly straight, usually slightly arched ; anterior end
narrowed, rounded, subangulate above, often slightly cut
away below; base line rounded, frequently fuller just behind
the middle; posterior end obliquely truncate above, rounded
or drawn out to a blunt point at or below the median line; sur-
face with light growth lines: epidermis yellowish-green, green-
ish-tawny to ashy-green, darker and often broadly, faintly
rayed on the dorsal slope, sometimes feebly rayed on the disk ;
dull or subshining; nacre bluish to flesh-color, generally iri-
descent behind: pallial line often having a faint, posterior
sinus; muscle scars shallow.

Length 145, height 82, diam. 53 mm.

Length 120, height 72, diam. 46 mm.

Tropical South America from Brazil and Peru southward.
Anodonta trapesialis L,AMARCK, An. sans. Vert., VI, 18109, p.

87.

Tridina trapesialis d@’OrticNy, Guer. Mag., 1835, p. 43.

ANODONTITES 1429

Glabaris trapesialis Pu,spry, Pr. Ac. N. Sci. Phila., 1896, p.
503.—SIMPSON, Syn., 1G00, p. 923.

Anodonta trapeziahs BLAtNvintEe, Man. de Mal. et Conch.,
1825, p. 538, fig..1.—-Desnaves, Enc. Meth., II, 1827, p.
147, pl. ccv, fig. 1—Wyarr, Man. Conch., 1838, p. 68, pl.
xJ, fig. 3—Kuster, Conch. Cab. Ano., 1853, p. 31, pl. vu,
fig. 4.—Ciessin, Conch. Cab. Ano., 1876, p. 235, pl. Lxxvul,
fig. 5.

Anodon trapezialis Croucu, Ill. Int. Lam., 1827, p. 16, pl. 1x,
he. 7:

Margarita (Anodonta) trapezialis Lea, Syn., 1836, p. 53; 1838;
Boeke

Margaron (Anodonta) trapezialis Lea, Syn., 1852, p. 52; 1870,
p. 82.

Columba trapezialis Pret, Conch. Sam., III, 1890, p. 188.

Anodon giganteus Spix (part), Test. Fluv. Bras., 1827, p. 27,
Plas sMeeK a1OR Le.

Anodon gigantea Sowerny, Conch. Icon., XVII, 1867, pl. vi,
fig. 18.

Anodonta gigantea VON Martens, Mal. Bl. XV, 1868, p. 196.

Columba gigantea Paitrr,, Conch. Sam., III, 1890, p. 188.

? Anodon penicillatus Grav, Pr. Zool. Soc. Lond., 1834, p. 57.

Anodonta penicillata H. and A. ApAms, Gen. Rec. Moll., IT,
1S57, ps 503.

Anodon susanne Gray in Griffith, Cuv., XII, 1834, pl. xxiv,
fig. 1—Sowersy, Conch. Icon., X VII, 1867, pl. 1x, fig. 21.

Anodonta susanne Pmtet,, Conch. Sam., III, 1890, p. 185.

Anodon cicona Gout, Pr. Bost. Soc. Nat. Hist., [V, 1851, p-
Q2.

Anodon blainvilleana Sowrrry, Conch. Icon., XVIT, 1867, pl.
Vij ties 2.

A fine, abundant, widely distributed and very variable spe-
cies. The figure in the Encyclopedie Methodique is from a
shell with evenly rounded lines, the posterior end being rather
squarely truncate above and widely rounded below. The base
shows no traces of angulation behind the middle. The anterior
base of the shell usually gapes widely and there is a slight gape
at the edge of the dorsal slope.

1430 ANODONTITES

Var. anserinus (Spix).

Shell elongated, considerably narrowed in front, full and
often subangulate behind the middle of the base.

Anodon anserinus Spix, Test. Fluv. Bras., 1827, p. 29, pl.
XVII, figs. 1, 2.—SowerBy, Conch. Icon., XVII, 1870, pl.
RK, ie T25.

Anodon anserina CatLow and Reeve, Conch. Nom., 1845, p.
66.

Margarita (Anodonta) anserina Lea, Syn., 1838, p. 31.

Anodonta anserina CuENu, Man., 1859, II, p. 146.—CLESSIN,
Conch. Cab. Ano., 1873, p. 80, pl. xx, fig. I.

Margaron (Anodonta) anserina Lea, Syn., 1852, p. 52; 1870,
p. 83.

Glabaris trapezialis var. anserinus SIMPSON, Syn., 1900, p. 924.
This form, which is quite common, varies imperceptibly

into the type.

Var. exoticus (Lamarck).

Shell much elongated, narrowed in front; base often in-
curved in front of the middle, full behind the middle; hinge
line somewhat sinuous.

Anodonta exoticus LAMARCK, An. sans Vert., VI, 1819, p. 87.
—Dr1essert, Rec. Coq., Lam., 1841, pl. x11, fig. 1—CHENU,
Til. Conch., 1858, pl. 111, fig. 2—-Cressin, Conch. Cab. Ano.,
1875, P. 179; plo Uva, fies. 15-2:

Anodon exotica CatLow and REEvr, Conch. Nom., 1845, p. 66.

Columba exotica Patri, Conch. Sam., III, 1890, p. 188.

Glabaris trapestalis var. exoticus SIMPSON, Syn., 1900, p. 924.
The hinge line is arched in the posterior half and sags in

_the middle of the front half.

Var. scriptus (Sowerby).

Shell elongated, generally irregularly obovate; base full be-
hind the middle, often a little incurved in front of the middle;
epidermis chestnut; nacre with a number of dark V-shaped
and zigzag markings.

Length 162, height 88 mm.

ANODONTITES I43I

Anodon scriptus Sowrrsy, Conch. Icon., XVII, 1867, pl. tv,
fig. 9.

Glabaris trapesialis var. scriptus SIMPSON, Syn., 1900, p. 924.

Anodon subsinuatus SoweRpy, Conch. Icon., XVII, 1867, pl.
vil, fig. 14.

Anodon areolatus Sowrersy, Conch. Icon., XVII, 1867, pl. x,
fig. 28.

Anodonta bahiensis Kuster, Conch. Cab. Ano., 1873, p. 94, pl.
MO he = 2:

Glabaris bahiensis von IneERtNG, Arch. fiir Naturg., 1893, p.
115.
Varies to forms with the ordinary colored epidermis, and to

those, which almost want the dark internal markings.

Var. rioplatensis (Sowerby).

Shell short, decidedly pentagonal; epidermis pale olive-

brown with a band near the border.
Length 110, height 73 mm.

Anodon rioplatensis SowreRvy, Conch. Icon., XVII, 1870, pl.
VIS es LOL.

Anodonta rioplatensis Cinssin, Conch. Cab. Ano., 1875, p. 217,
plaLxcvetne 3°

Glabaris trapesialis var. rioplatensis Simpson, Syn., 1900, p.
925:

? Anodon ciconia Sowrersy, Conch. Icon., XVII, 1870, pl.
XXIX, fig. Lisa.

Var. moretonianus (Sowerby ).

Anodon moretonianus SOWERBY, Conch. Icon., XVI, 1867, pl.

ix, fie 20:

Glabaris trapezialis var. moretonianus SIMPSON, Syn., 1900, p.

Q25.

Shell narrow, thick, oblong, anterior side very short, round-
ed; posterior side long, acuminated, with a narrow, distinct
keel above the terminal angle, expanded into a three-cornered
wing above the keel.

Perhaps a good variety.

Length 68, height 38 mm.

1432 ANODONTITES

Var. cygneformis (Pilsbry).

Shell irregularly long obovate, rather delicate and thin, not
inflated ; epidermis greenish or olive-green.

Length 136, height 68, diam. 37 mm.

Glabaris trapesialis var. cygneformus Piuspry, Pr. Ac. N. Sci.
Phila., 1896, p. 563, pl. Xxv1, fig. 4, 5.—S1mpson, Syn., 1900,
p- 925.

The posterior end is drawn out and bluntly pointed.
ANODONTITES RADIATUS (Spix).

Shell irregularly oblong, thin and fragile, compressed, pel-
lucid, inequilateral; dorsal outline straight; anterior end nar-
rowed and rounded; base lightly curved in front, very full
behind the middle, the outline curving up to a blunt point at
the posterior end above the median line ; dorsal slope obliquely
truncate; beaks full, slightly elevated; surface densely, con-
centrically striate; epidermis glaucous-green with broad, reg-
ular, faint, darker rays; nacre bluish.

Length 65, height 33 mm.

Brazil. f
Anodon radiatus Spix, Test. Fluv. Bras., 1827, p. 31, pl. xxi

fies

Margarita (4nodonta) radiata Lea, Syn., 1836, p. 51.

Anodon radiata CatLow and Reeve, Conch. Nom., 1845, p. 67.

Margaron (Anodonta) radiatus Lea, Syn., 1870, p. 83.

Glabaris radiata von InERING, Arch. fiir Nat., 1893, p. 115.

Glabaris radiatus SIMPSON, Syn., 1900, p. 925.

y

The shell figured is evidently quite young, and Wagner
states that the margins are membranous. It may be only the
young of a variety of A. trapesialis, but it is remarkably full
at the base behind the middle, and I have never seen any shells
of that species so rayed.

ANODONTITES SIMPSONIANUS (Pilsbry).

Shell subelliptical or slightly obovate, subinflated or in-
flated, solid, inequilateral; beaks long, full and elevated: pos-
terior ridge well developed, rounded, ending in a blunt point

ANODONTITES 1433

on the median line; hinge line lightly arched behind, nearly
straight in front; anterior end narrow, rounded, angled above;
base line curved, a little fuller behind the middle; dorsal slope
obliquely subtruncate ; surface with irregular, concentric sculp-
ture; epidermis greenish-brown, subshining’; nacre flesh-color,
often with letter-like or zigzag, dark markings; muscle scars
impressed; pallial line remote from the border. The valves
gape widely along the anterior part and slightly behind.

Length 138, height 80, diam. 60 mm.

Rio de la Plata.
Glabaris simpsonianus Pitspry, Pr. Ac. N. Sci. Phila., 1896,

p: 564, pl. xxvir, fig. 13.—SIMPSON, Syn., 1900, p. 925.

A remarkably solid, inflated species, which has a nearly
evenly elliptical outline. The epidermis is more brownish than
in most specimens of A. trapesialis.

ANODONTITES StNuOsUS (Lamarck).

Shell trapezoid, inflated, thin, inequilateral, hinge line de-
cidedly sinuous, being arched behind the beaks and incurved
in front of them; anterior end narrowed, rounded below,
sharply angled above’ base straight to considerably incurved
medially; posterior end wide, obliquely subtruncate above,
rounded below ; beaks full and elevated ; surface having irregu-
lar growth lines; epidermis olive-green, sometimes slightly
rayed; nacre whitish or bluish-white, iridescent.

Length 85, height 53 mm.

Length 08, height 56, diam. 39 mm.

Brazil.

Anodonta sinuosa LAMARCK, An. sans Vert., VI, 1819, p. 87.—
DESHAYES, ‘Enc. Meth., II, 1827, p. 147, pl. cciu, fig. 2.—
Haney, Biv. Shells, 1843, p. 224, pl. xxv, fig. 16.

Margarita (Anodonta) sinuosa Lea, Syn., 1836, p. 54; 1838,
Ds 32:

Anodon sinuosa Catiow and Reeve, Conch. Nom., 1845, p. 68.

Margaron (Anodonta) sinuosa Lea, Syn., 1852, p. 53; 1870,
pot

Anodon sinuosus SowrErRBy, Conch. Icon., XVIT, 1867, pl. viii,
fig. 15.

1434 ANODONTITES

Anodon sinuosis Swanson, Ex. Conch., 2d ed., 1841, p. 20,

ple xvi:

Glabaris sinuosus SIMPSON, Syn., 1900, p. 925.

The hinge line in this species is decidedly sinuous and in
some cases the lunule passes back under the beaks. As in the
other species of the group, the anterior base gapes. It may be
only a variety of trapesialis.

ANODONTITES GRIJALVA: (Morelet).

Shell very large, solid, very much inflated, inequilateral, ir-
regularly elliptical; beaks enormously large, full and high;
hinge line arched behind, nearly straight or lightly incurved
in front; anterior end narrowed, rounded, subangulate above;
base rounded, full behind the middle; posterior end rounded,
slightly more prominent on the median line; surface with
rude, unequal, concentric striz; epidermis brownish-black ;
nacre flesh-colored; muscle scars shallow.

Length 161, height 100, diam. 95 mm.

Tabasco, Mexico.

Anodonta grijalu@ Moretet, Jl. de Conch., XX XI, 1884, p. 12.
—Fiscuer and Crosse, Miss. Sci., I, 1894, p. 532, pl. LX1x,
figs. 1, La.

Glabaris grijalv@ SIMPSON, Syn., 1900, p. 926.

Anodonta grijoloe P.airet, Conch. Sam., IIT, 1890, p. 180.
This species, which is apparently related rather closely to 4.

trapesialis, is greatly inflated, solid, has a dark epidermis and

higher, larger beaks than Lamarck’s shell has.

ANODONTITES GLAUCUS (Valenciennes).

Shell varying from long elliptical to somewhat short obo-
vate, scarcely subsolid, not very inequilateral ; subinflated, gap-
ing at the anterior base and slightly behind; beaks moderately
full and elevated, slightly wrinkled at the tips; hinge line arch-
ed behind the beaks, straight or a very little incurved in front
of them; anterior end rounded, usually subangulate above;
base rounded or lightly curved, often fuller behind the middle ;
dorsal slope obliquely truncate or subtruncate; posterior end

ANODONTITES 1435

pointed about on the median line; surface with delicate, often

faint, concentric striz; epidermis varying from ashy-green or

vellowish-green to brownish, sometimes feebly rayed and
banded; nacre bluish to flesh-color, brilliant, often slightly
rayed.

Length 103, height 60, diam. 37 mm.

Length 90, height 60, diam. 37 mm.

Length 95, height 56.5, diam. 34 mm.

Length 104, height 56, diam. 35 mm.

Length 112, height 68, diam. 38 mm.

Mexico; South to Peru and Brazil.

Anodonta glauca VALENCIENNES, Rec. Obs. Zool., II, 1833, p.
236, pl. L, fig. 2—DrLEssErt, Rec. Coq. Lam., 1841, pl. x11,
fig. 3—CrxEssin, Conch. Cab. Ano., 1876, p. 222, pl. Lxx1,
fig. 1—FiscHer and Crosse, Miss. Sci., IT, 1894, p. 533, pl.
EXDX SSA t,he:

Margarita (Anodonta) glauca Lea, Syn., 1836, p. 51; 1838,
p- 30.

Anodon glauca Catiow and RrEEve, Conch. Nom., 1845, p. 67.

Margaron (Anedonta) glauca Lea, Syn., 1852, p. 50; 1870,
p. 8o.

Monocondylea glauca H. and A. Anams, Gen. Rec. Moll., IT,
LO57, ps SOL

Glabaris glaucus Simpson, Syn., 1900, p. 926.

Anodonta burroughiana CHENU (part). Ill. Conch., 1858, pl.
ifke
This is apparently a widely distributed and very variable

species. It varies from long elliptical to a rather short obovate

form and there is considerable difference in the degree of in-
flation and the color of the epidermis. I cannot separate spec-
imens before me, from Colombia, South America, from this
species, as they agree essentially with shells in the Stearns Col-
lection from Mazatlan, Mexico. Lea has a young shell in his
collection from Brazil, which he has labeled “Anodonta glau-
ca Valen.,” which is probably the same. The species is gen-
erally of finer texture, is smoother externally and has a more
brilliant nacre than 4. trapesialis, to which it is closely allied.

1436 ANODONTITES

Var. sinaloensis (Crosse and Fischer).

Subcompressed, epidermis shining, thin, pale olivaceous-fus-
cous, scarcely radiate; nacre pale salmon-rose with white bor-
der.

Length 106, height 52, diam. 36 mm.

Rio Presidio, Sinaloa, Mexico.

Anodonta glauca var. simaloensis Crosse and Fiscuer, Jl. de
Conch., XX XI, 1883, p. 219.

Glabaris glaucus var. sinaloensis SIMPSON, Syn., 1900, p. 926.

Anodon glaucus Sowerey, Conch. Icon., XVII, 1870, pl. xxvit,
fig. 105.

Anodonta ciconia CARPENTER, Maz. Shells, 1857, p. 117.—
FIscHER and Crosse, Miss. Sci., II, 1894, p. 534, pl. LX XVII,
figs. 2-2a.—-von Martens, Biol. Cent. Amer., Moll., rgoo,
pe. 530, plaxis, fig. A
Possibly worthy of a varietal name. There is a single valve

from “New Granada” contributed by Gibbon, in the Lea Col-

lection, which agrees pretty closely with the description of

Crosse and Fischer.

ANODONTITES UMBONATUS (Simpson).

Shell irregularly long rhomboid, inflated, somewhat inequi-
lateral; thin; beaks enormously large, full and high; hinge line
lightly curved: anterior end rounded, angled above; base
slightly incurved in the middle; posterior end obliquely trun-
cate above, squarely truncate below; posterior ridge widely,
faintly double; surface with strong growth lines; epidermis
mud-colored; nacre white.

Length (of figure) 146, height 90 mm.

Locality unknown.

Anodon ciconia SowERby (part), Conch. Icon., XVII, 1870,

ple xxix ie: 15:

Glabaris wmbonatus SIMPSON, Syn., 1900, p. 926.

Sowerby has given two figures of what he calls Anodon
ciconia Gould. One of these is probably a young 4. trapest-
alis, the other is from a large shell of a totally different species.

ANODONTITES 1437

This seems to be, perhaps, more closely related to 4. forbesian-
us than anything else, but is more rhomboid, more inflated,
has much larger and more prominent beaks and different epi-
dermis.

ANODONTITES BRIDGESH (Lea).

Shell oblong, subelliptical, scarcely subinflated, somewhat
inequilateral, rather thin; beaks moderately full, but little ele-
vated ; hinge line almost straight, very slightly arched ; anterior
end rounded, almost as wide as the posterior end, subangulate
above; base incurved medially in adult or old shells; posterior
end rounded, a little drawn out on the median line; surface
with irregular growth lines; epidermis dull greenish or brown-
ish-green, darker on the dorsal slope, occasionally faintly
rayed; nacre brilliant silvery and iridescent, bluish, greenish
or flesh-colored, sometimes salmon-tinted within the cavities,
often faintly radially sculptured.

Length 132, height 68, diam. 42 mm.

Nicaragua ; Honduras.

Anodonta bridgesii Lea, Pr. Ac. N. Sci. Phila., XII, 1868, p.
95: JI. Ac. N. Sci. Phila., VI, 1868, p. 291, pl. xia, fig. 104;
Obs., XII, 1869, p. 51, pl. xm, fig. 104.—C1essin, Conch.
Cab. Ano., 1874, p. 136, pl. LXv, figs. I, 2.

Margaron (Anodonta) bridgesti Lea, Syn., 1870, p. SI.

Glabaris bridgesii Stimpson, Syn., 1900, p. 926.

More elongated than wmbonatvs and almost evenly rounded
behind. ‘he beaks are very much lower than in that species.
By an error the artist has made the type of Lea’s species bian-
gulate behind. ‘The shell is almost evenly rounded. It is more
elongated than 4. forbesianus, is scarcely narrowed in front,
and is not truncate behind as that species 1

YD

ANODON'ITES JEWETTIANUS (Lea).

Shell long rhomboid, inflated, thin to subsolid, slightly in-
equilateral ; beaks full and elevated; hinge line lightly arched,
sometimes a little sinuate; anterior end more or less cut away
below, rounded above and angular where it joins the hinge

1438 ANODONTITES

line; base straight or curved; posterior end obliquely truncate
above, rounded below; surface sculptured with fine, even
growth lines; epidermis ashy-brownish or ashy-greenish, dark-
er on the posterior end and sometimes at the anterior end;
nacre greenish-bluish or flesh-colored, sometimes salmon in the
cavities.

Length 108, height 62, diam. 45 mm.

Lake Nicaragua.

Anodonta jewettiana laa, Pr. Ac. N. Sci. Phila., XII, 1868,
p. 95.

Glabaris jewittianus SIMPSON, Syn., 1900, p. 927.

Anodonta jewetin Lea, Jl. Ac. N. Sci. Phila., VI, 1860, p. 280,
pl. xu, fig. ror; Obs., XIT, 1860; p: 40, pl. xin, te, 101. —
Cressin, Conch. Cab.-Ano:, 1874; p. 135) pl. xiv, hes. 2 2:

Margaron (Anodonta) jewettii LxA, Syn., 1870, p. 81.

A very large series of shells of this species is before me, in-
cluding the type. which is more strongly cut away at the an-
terior base than is the case in most specimens. As a rule the
shells are more inflated then those of G. bridgesii, are
more regularly rhomboid, and are paler in color, but there are
intermediates, which approach both forms. ‘The close, deli-
cate, concentric sculpture seen in the type is not absolutely
constant. Like the other species of the group the shell gapes
at the anterior base and is slightly open behind. I have seen
a few shells with faint, radial sculpture.

ANODONTITES FORBESIANUS (Lea).

Shell trapezoid, somewhat inflated, subsolid, slightly inequi-
lateral; beaks rather full and high; hinge line lightly arched ;
anterior end narrowed, rounded, angled above; base nearly
straight or lightly curved; posterior end almost squarely trun-
cated; surface with feeble, concentric strive; epidermis pale
brown, sometimes tinted with green and banded with burnt
brown, dark on the dorsal slope, shining; nacre bluish-white ;
muscle scars somewhat impressed.

Length 116, height 70, diam. 50 mm.

Uruguay ; Peru.

ANODONTITES 1439

Anodonta forbesiana Lea, Pr. Ac. N. Sci. Phila., IV, 1860, p.
o2 Ki AceN. Sei. Phila: V> 1863; p. 393, pl. xivi1, fig. 303;
Obs., X, 1863, p. 29, pl. xivi1, fig. 301.—CLEssin, Conch.
CabeAno:,, 1673, p- 105, pl. xxxiv, figs: 152:

Anodon forbesianus SowrRpvy, Conch. Icon., XVII, 1870, pl.
OES, ties 10,

Margaron (Anodonta) forbesiana Lea, Syn., 1870, p. 81.

Glabaris forbesianus SIMPSON, Syn., 1900, p. 927.

More trapezoidal than wmbonatits ; the base is not so straight;
the epidermis is brownish, with faint, dark bands, instead of
mud colored, and it is more squarely truncate behind. It
gapes slightly behind, and widely at the anterior base.

ANODONTITES MORICANDII (Lea).

Shell long trapezoid, scarcely inflated, rather thin, gaping
at the front, the anterior base and the hinder end, ’inequi-
lateral; beaks moderately elevated and inflated; hinge line
straight or slightly incurved, developed into a low wing be-
hind; anterior end rounded, narrowed a little and cut away
somewhat below; base curved, straight or even a little in-
curved medially ; posterior end with a long, oblique truncation
above, narrowly rounded below; surface with uneven, concen-
tric sculpture, the ridges sometimes disposed to be granulous ;
epidermis shining, pale ashy-green, darker on the dorsal slope ;
nacre bright bluish, silvery and iridescent ; muscle scars shal-
low.

Length 117, height 70, diam. 35 mm.

Brazil.

Anodonta moricandu Lra, Pr. Ac. N. Sci. Phila., IV, 1860; p.
Gor ailme: Ne Sem Phila. Vo 1863.p. 366) pl xaaix tes 203°;
Obs., X, 1863, p. 32, pl. xL1x, fig. 303Cressin, Conch. Cab.
AMOLRIS7A, Ps Lid, pl. XX XVIiPes. 3. A.

Anodon moricandi Sowrrsy. Conch. Icon., XVII, 1870, pl-
XK figs, 126.

Margaron (Anodonta) moricandu Lea, Syn., 1870, p. 81.

Glabaris moricandii VON THERING, Arch. fiir Nat., 1893, p. 115-
—SIMPSON, Syn. 1900, p. 927.

1440 ANODONTITES

? Anodon exoticus SowrRsy, Conch. Icon., XVII, 1867, pl.
RVI, fist 7.
Anodonta angustata CLessin, Conch. Cab. Ano., 1876, p. 226,
pl Umea: tes.16,7-
Anodonta hertwigtt von InERING, Arch. fiir Nat., 1890, p. 150,
ple ass, hee:
Glabaris hertwigit SIMPSON, Syn., 1900, p. 925.
fine series of this species is now before me and a careful
study of it convinces me that: von Ihering’s Anodonta hert-
wigu is the same. He gives a very rough outline figure of his
species, in which the ventral region is incurved medially, and
refers to the figure and description of A. anserina in the New
Conchylien Cabinet. In the figure in that work the base of the
shell is considerably produced medially, but I am now convinced
that it is the same as Lea’s moricandii. A dorsal view of this
shell shows the sides to be flattened and nearly parallel.

Group of Anodontites georgine.

Shell subsolid, obovate, with a decided, curved posterior
ridge, and a smaller one above it, the space between the ridges
a shallow groove.

ANODONTITES GEORGIN.E (Gray).

Shell irregularly obovate, solid, inequilateral; beaks not
much elevated or inflated; posterior ridge high, sharply an-
gled, ending in a point about on the median line; above it
there seems to be a low, radial ridge; dorsal outline arched ;
anterior end narrowed, rounded; base subangularly produced
behind the middle; epidermis thick, olive-colored ; nacre varie-
gated purple and red.

length (of figure) 62.5, height 37 mm.

Rivers of Paraguay.

Anodonta georgine Gray, Griff. Cuvier., XII, 1834, pl. x1x.
Glabaris georgine SIMPSON, Syn., 1900, p. 927.

A species, which seems to differ very decidedly from all
others by having a sharp, high posterior ridge. No measure-
ments, and only the briefest description are given, this con-
sisting of a few words in the index.

ANODONTITES 1441

Group of Anodontites trigonus.

Shell long, elliptical, solid, inflated, produced at posterior
base, with a smooth, shining epidermis; nacre very bright.

ANODONTITES TRIGONUS (Spix).

Shell somewhat pentagonal, solid, subinflated, inequilateral ;
beaks moderately elevated ; hinge line slightly arched ; anterior
end narrowed, rounded or subtruncate; posterior ridge well
developed, rounded, ending in a blunt point about on the me-
dian line; dorsal slope obliquely truncate ; base produced about
at the middle where it is subangulate; epidermis pale to dark
olive, somewhat sericeous, showing darlk rest marks ; nacre blu-
ish, iridescent ; muscle scars well marked.

Length 48, height 30, diam. 20 mm.

Brazil ; Ecuador; Peru; Bolivia.

Anodon trigonus Sprx, Test. Fluv. Bras., 1827, p. 20, pl. xxi,

fig. 2.

Margarita (Anodonta) trigona Lea, Syn., 1836, p. 51; 1838,

D230:

Anodon trigona Cattow and Reeve, Conch. Nom., 1845, p. 68.
Anodonta trigona Haney, Test. Moll., 1842, p. 218.—Kus-

ip Conch CabsAno:, 1853,p.0, pl. it, fics 5:

Margaron (Anodonta) trigona Lea, Syn., 1852, p. 50; 1870,

Pp. 75:

Glabaris trigonus SIMPSON, Syn., 1900, p. 928.

Anodon chiquetana d’Orpicny, Guer. Mag., 1835, p. 41.
Anodonta chiquetana Paret,, Conch. Sam., III, 1890, p. 177.
Anodonta castelnaudi Hurt, Moll. Nouv., II, 1857, p. 88, pl.

XVII, fig. 4. °
Anodonta subrostrata Puttiprt, Mal. Bl, XVI, 1869, p. 39.—

PFEIFFER, Nov. Conch., III, 1869, p. 486, pl. cv, figs. 1-3.
Anodonta ucayalensis Paitieri, Mal. Bl., XVI, 1869, p. 40.—

PFEIFFER, Nov. Conch., III, 1860, p. 486, pl. cv, figs. 4-6.

There is a shell in the Lea Collection bearing the name Ano-
donta trigona Spix, that is a little higher in proportion to
length, and lighter colored than the figure of 4. trigonus given

1442 ANODONTITES

by Spix, but it agrees well in other characters. It may possi-
bly be entitled to specific rank. It may be given the varietal
name oi pallescens.

ANODONTITES AMAZONENSIS (Lea).

Shell elongated, subinflated, solid, inequilateral, subrhom-
boid; beaks moderately full and elevated, elongated ; posterior
ridge rounded, but having about three radial, thread-like ribs ;
hinge line lightly arched; base straight or a little incurved me-
dially ; anterior end evenly rounded ; posterior end with a long,
oblique subtruncation above, somewhat biangulate below; sur-
face strongly and irregularly. concentrically sculptured; epi-
dermis very dark olive with shadings of green, lighter at the
‘beaks ; nacre brilliant purple-rose; muscle scars impressed.

Length 81, height 37, diam. 25 mm.

Amazon.

Anodonta amazonensis Lr, Pr. Ac. N. Sci. Phila., IV, 1860, p.
895 Jl Ac. Ne Sci.Phila. V, 1863; p 305. pl. xivis figs0o=
Obs., X, 1863, p. 31, pl. xvi, fig. 300.—CLEssIn, Conch.
Cab. Anos, 18745. p:.LLO> ple Mek Vien.

Anodon amazonensis SowERBy, Conch. Icon., XVII, 1870, pl.
XR, fet 120.

Margaron (Anodonta) amazonensis Lea, Syn., 1870, p. 82.

Glabaris amagonensis SIMPSON, Syn., 1900, p. 928.
lea states that several specimens of Anodonta amazonensis

were submitted to him by Mr. Wheatley. There is only the

type, a slightly broken shell, in the Lea Collection. The group
to which it belongs is a very puzzling one, and although I have
had the opportunity to examine a good deal of material be-
longing to it, but little of it at all closely agrees with the fig-
ures or descriptions. ‘There seems to be an almost complete
connection between amazonensis and mortonianus, though the
former is typically very much more elongated than the latter.

ANODONTITES WEDDELLIT (Hupé).

Shell rather solid, subinflated, somewhat elongated, elliptic-
rhomboid, inequilateral; beaks full and high; dorsal and basal
lines curved ; anterior end a little narrowed, rounded ; posterior

ANODONTITES 1443

end obliquely truncate above, meeting the dorsal line with an

angle, rounded below ; surface with rather strong growth lines ;

epidermis dark brown; nacre white in the cavities, iridescent
or green at the borders.

Length 66, height 35, diam. 22 mm.

Brazil.

Anodonta weddellu Hurt, Moll. Nouv., III, 1857, p. 87, pl.
XVu, fig. 5.—Cressin, Conch. Cab. Ano., 1876, p. 214; pl.
LCV Pe NS Gi

Anodon weddellii Sowersy, Conch. Icon., XVII, 1868, plex,
fig. 80.

Margaron (Anodonta) weddellii Lea, Syn., 1870, p. 79.

Glabaris weddellii Simpson, Syn., 1900, p. 928.

Shorter in proportion to height, and not so cylindrical as
A, amazonensis.

ANODONTITES ELONGATUS (Swainson).

Shell much elongated, solid, subinflated, inequilateral, sub-
rhomboid when adult, long ovate when young; beaks rather
full and high; hinge line lightly arched, the curve extending
almost evenly to the post-basal point of the shell: anterior end
evenly rounded; base nearly straight, in old shells sometimes
a little incurved: surface with delicate growth lines, sometimes
with very faint indications of radial sculpture; epidermis rich
reddish-brown, shining; nacre brilliant, flesh-colored or pale
rose, richly iridescent; anterior scars impressed; posterior
scars large. distinct.

Length 74, height 36, diam. 25 mm.

Brazil.

Anodon elongatus Swainson, Zool. Il., rst Ser., ITI, 1823, pl.
CLXXVI.

Margarita (Anodonta) elongata Lea, Syn., 1836, p. 53; 1838,
Pp- 32.

Anodonta elongata HANtEy, Test. Moll., 1842, p. 223%

Anodon elongata CatLow and Reeve, Conch. Nom., 1845, p.
66.

Glabaris clongatus StMpson, Syn., 1900, p. 928.

1444 ANODONTITES

Anodonta solidula Drvitie and Hurt, Rev. et Mag. Zool.,
1850, p. 644, pl. xvi, fig..2—Hups, Moll. Nouv., III, 1857,
p. 88, pl. xvim, fig. 2—Crusstn, Conch. Cab. Ano., 1876, p.
22%, pl. LxxmT fie= 2)

Margaron (Anodonta) solidula Lea, Syn., 1852, p. 53; 1870,
p. 83.

Anodon solidula Sowrersy, Conch. Icon., XVII, 1869, pl. xxi,
fig. OI.

Anodonta wheatleyi Lxs, Tr. Am. Phil. Soc., X, 1852, p. 287,
pl. xxvieig.4o5°Obs:, V, 1852) p. 43) pk Saavy fies 4o—
Cressin, Conch. Cab. Ano., 1874, p. 113, pl. xxxv1, figs. 3, 4.

Margaron (Anodonta) wheatleyi Lea, Syn., 1852, p. 51; 1870,
p32:

Anodon amethystus SowrERny, Conch. Icon., XVII, 1860, pl.
XXIV, figs. 95, OS5a, 950.

Anodonta amethysta Ciessin, Conch. Cab. Ano., 1875, p. 180,
plyrx fies 2.

Anodon dactylus SowERsy, Conch. Icon., XVII, 1867, pl. xix,
fig. 75.

Anodonta dactylus Ciessin, Conch. Cab., 1875, p. 175, pl. Lv,
fig. 3.

Margaron (Anodonta) dactylus Lea, Syn., 1870, p. 8o.

Lea’s Anodonta wheatleyi absolutely agrees with the figure
of .4. elongatus in Swainson’s Zoological Hlustrations. Viewed
from above the shell is decidedly wedge-shaped behind the
umbonal region. It is a beautiful species.

ANODONTITES LINGULATUS (Hupé).

Shell long elliptical, very solid, inequilateral, convex or sub-
inflated; beaks moderately full and elevated; posterior ridge
well developed, subangulate, arched; dorsal and basal lines
rounded; anterior end narrowed, evenly rounded; posterior
end with a short, oblique truncation above the decided point
at the end of the posterior ridge; surface with strong, concen-
tric strize; epidermis greenish with brown bands or brownish-
black ; nacre white, iridescent at the border.

Length 97, height 50.5 mm.

Paraguay.

ANODONTITES 1445

Anodonta lingulata Hurt, Moll. Nouv., III, 1857, p. 80, pl.
VIN. W——Cimssin,Conch.iCab; Ano., 1875, p. 215, pl.
Lp Alaa a vee

Anodon lingulata Sowrrpy, Conch. Icon., XVII, 1869, pl.
RONG sls OO:

Margaron (Anodonta) lingulata La, Syn., 1870, p. 70.

Glabaris lingulata von Titertnc, Arch. fiir Nat., 1893, p. 110.

Glabaris lingulatus Simpson, Syn., 1900, p. 920.

A fine, solid, almost regularly elliptical species. Hupe has
evidently given erroneous measurements, for he says “Long.,
100; haut., 92; épaiss., 40 mill.”

The shell seems to be more ponderous and more evenly ellip-
tical than any of the related forms.

ANODONTITES MORTONIANUS (Lea).

Shell long rhomboid or subelliptical, rather solid, inequilat-
eral, subinflated; beaks slightly prominent; posterior ridge
somewhat double, sometimes with two or three slight, radial
ridges and depressions ; dorsal and basal outlines more or less
curved, the latter full behind the middle; anterior end round-
ed, occasionally subangulate above; dorsal slope obliquely
truncate; surface rather finely, concentrically sculptured; epi-
dermis olive-brown to blackish; nacre whitish or flesh-colored,
iridescent.

Length 77, height 41.5, diam. 30 mm.

Length 70, height 41.5, diam. 26 mm.

Length 79, height 39.5, diam. 26.5 mm.

Parana River, South America.

Anodonta mertoniana Lea, Tr. Am. Phil. Soc., V, 1834, p. 80,
pl. x11, fig. 37; Obs., I, 1834, p. 192, pl. x1, fig. 37.—CLEs-
Suny. Conch) Cabs Anos ' 1874) pas i, ply XiVan. nes. 5,0.

Margarita (Anodonta) mortoniana Lea, Syn., 1838, p. 30.

Anodon mortoniana Catiow and Rerve, Conch. Nom., 1845,

p. 67.
Margaron (Anodonta) mortoniana Lea, Syn., 1852, p. 150;
1870, p. 8o.

Glabaris morionianus Stmpson, Syn., 1900, p. 920.

1446 ANODONTITES

The type of this, according to Dr. Lea, is in the Academy
of Natural Sciences at Philadelphia. Several specimens are
before me, which probably belong with this species, some of
them of the !,ea Collection and labeled Anodonta mortoniana
by Lea himself. They show more or less transition towards
A. amazonensis.

ANODONTITES LONGINUS (Spix).

“Shell transverse, oblong, almost three times as long as
high, anterior end rounded and narrow; posterior end dilated,
very obliquely truncated; solid, but not heavy; pellucid; pos-
terior region obliquely angulated, transversely sulcate. Dorsal
margin very long, compressed, elevated. and angulated pos-
teriorly, obtusely angulate anteriorly; beaks somewhat prom-
inent, depressed. Margins acute. Hinge terminating in a
small sinulus. Epidermis brownish-green. Interior of shell
smooth, pearly, bluish.

Length 4.7, height 1.7 in.” (Spr).

Type locality, Japura and Solimoes rivers, Brazil.

Anodon longinus Spx, Test. Fluv. Bras., 1827, p. 29, pl. xxu,

fig. I.

Mycetopus longinus CLessin, Conch. Cab. Ano., 1875, p. 202.

Glabaris longinus SIMPSON, Syn., 1900, p. 9290.

Iridina tongina LA, Syn., 1836, p. 57.

Anodonta longina Kustrr, Conch. Cab. Ano., 1853, p. 7, pl. 11,
fies.

Mycetopoda longina von InertINc, Abh. Senckenb. Ges.,

MXIT, 19750,)ps 110:

ANODONTITES HIDALGOI (Germain).

“Shell of medium size, elongate-subquadrangular, somewhat
inflated, slightly gaping at both ends, terminating posteriorly
in a short beak, situated very low; dorsal margin nearly
straight, ascending, quite rapidly inflected from the postero-
dorsal angle to the beak in a slightly curved line ; ventral mar-
gin scarcely subconvex, very slightly incurved, almost paral-
lel to the dorsal margin; anterior region short, rounded, cut

ANOLDONTITES 1447

away at the base; posterior region two and one-half times as
long as the anterior, very slightly narrowed, subtruncate ; beaks
eroded, showing a lead-colored, very iridescent nacre, rounded,
slightly compressed and quite prominent; dorsal ridge narrow
towards the beaks. becoming obsolete towards the posterior
region; ligament brilliant deep chestnut-color, quite strong.
14 mm. long; hinge very slightly curved, scarcely thickened;
anterior muscular impressions subelliptical, quite deep; pos-
terior very faint; pallial almost none. Shell thick, solid, com-
paratively heavy, with quite fine, concentric striz : epidermis
a brilliant chestnut-brown, becoming rusty posteriorly ; nacre
greenish-blue, very iridescent.

Length 44-45, height 27-26, at the beaks 16-15, diam. 17.25-
17 mm.” (Germain).

Type locality, Ecuador.

Anodonta (Glabaris) hidalgoi Germain, Bull. Mus. Hist. Nats

1908, p. 64.

ANODONTITES DULCIS (von Thering).

“Shell elongate, oval, of medium size, gaping considerably
at both ends, not very thin, quite inflated, with a shining sur-
face. Anterior end rounded, narrower than the posterior end,
which is broader and regularly rounded with the inconspicu-
ous point above the middle. Beaks quite inflated, broad, ap-
proximate, and much eroded. The vertical profile is elongate
heart-shaped. The horizontal profile shows the greatest diam-
eter at about the middle of the length, from which point it
evenly diminishes towards the posterior end, whereas anterior-
ly it very slowly decreases as far as the beaks, beyond which
it rapidly slopes to the anterior region. The rounded anterior
margin forms a distinct angle with the dorsal margin and
curves regularly into the evenly rounded ventral margin. ‘The
dorsal margin is straight in front, slightly curved behind and
passes gradually into the posterior margin. The dorsal area
is broad, low, slightly abrupt; the lunule is linear and very
small. The ligament is long, ending in a triangular sinulus,
the anterior edge of which is the shorter and almost vertical

1448 ANODONTITES

or slightly oblique. Epidermis olive-green, lighter on the pos-
terior portion and dark brown anteriorly. Nacre iridescent
blue. The prismatic margin is narrow. Impressions of the
posterior adductors are under and partly behind the sinulus;
those of the anterior adductors are very small. The sculpture
is peculiar. On the anterior portion are numerous radiating
striz, while the epidermis, where it remains, shows fine, radial
wrinkles, which are very short on account of being interrupted
by the lines of growth.

I have before me two single valves of almost the same
length. The length of the hinge is 48 mm. The beaks are 19
mm. from the end of the hinge, showing an umbonal index of
39.60/100.

Length 79, height 45, diam. 29 mm.” (von Jhering).

Type locality, Fazenda do Sacremento, Municipio de San
Domingos do Prata in the State Minas, and undoubtedly in
the region of the Rio Doce.

Glabaris dulcis von THertnc, Abh. Senckenb. Ges., XXXII,

IQIO, p. 132, pl. 12, figs. sa-b.

Section StyGANopon von Martens, 1900.

Styganodon von Martens, Biol. Cent. Am., Moll., 1900, p.

525:

Shell subrhomboid, with a thick, dark, rather rough, sombre-
colored epidermis, which is sometimes faintly rayed, nacre
lurid, shaded green; animal unknown.

Type, Anodonta tenebricosa Lea.

Group of Anodontites tenebricosus.
Shell elongate, slightly inflated; base incurved.

ANODONTITES TENEBRICOSUS (Lea).

Shell long rhomboid or trapezoid, somewhat inflated, rather
solid, especially when old, inequilateral ; beaks but slightly ele-
vated ; anterior end narrowed, rounded, generally more or less
cut away below; hinge line slightly arched; base straight or a
little incurved medially; posterior end somewhat obliquely

ANODONTITES 1449

truncate or subtruncate above, rounded below ; posterior ridge
full, rounded; surface rough, usually with rude, irregular
growth lines, covered with a thick, dirty olive or brown epi-
dermis, which sometimes is feebly rayed; nacre lurid, bluish
or greenish, thicker in front; muscle scars large, impressed ;
prismatic border wide.

Length 83, height 46, diam. 37 mm.

Length 80, height 48, diam. 30 mm.

Brazil, Ecuador, Peru; south to Argentina.

Anodonta tenebricosa Lma, Tr. Am. Phil. Soc., V, 1834, p. 78,
pl. x11, fig. 36; Obs., I, 1834, p. 190, pl. x1, fig. 36.—CHENU,
Man., 1850, p. 146, p. 720.

Margarita (Anodonta) tenebricosa La, Syn., 1836, p. 54;
TOS, 32:

Anodon tenebricosa SowrERBy, Conch. Icon., XVII, 1867, pl.
NI oe 4a

Margaron (Anodonta) tenebricosa Lea, Syn., 1852, p. 53;
1870, ps 83:

Glabaris tenebricosa VON InERING, Arch. fiir Nat., 1893, p. 61.

Anodon tenebricosus SOWERBY, Conch. Icon., XVII, 1870, pl.
KOT M1. 123

Glabaris tenebricosus SIMPSON, Syn., 1900, p. 930.

A rough, dull-colored, unattractive species, which, when old,
usually has the shell much eroded. ‘The border outside the
pallial line is wide, and in old specimens the pallial line is gen-
erally impressed and crenate.

ANODONTITES PASTASANUS (Clessin).

Shell rather short, rhomboid, moderately inflated, subsolid,
subrugose, lightly, undulately striate, somewhat inequilateral ;
beaks full and elevated; hinge line arched; base incurved me-
dially so that the shell is a little arcuate ; anterior end rounded ;
posterior end obliquely truncate above, rounded below ; epider-
mis dark fuscous; nacre whitish.

Length 69, height 37, diam. 26 mm.

Rio Pastasa, Ecuador.

Anodonta pastasana Criesstn, Mal. Bl. (2), I, 1879, p. 173, pl.

Ob Ai
Glabaris pastasanus SIMPSON, Syn., 1900, p. 930.

1450 ANODONTITES

A comparatively short, somewhat inflated species which has
a decidedly rhomboid outline. It is rather shorter in propor-
tion to its height than 4. tenebricosws and 1s more rhomboid
and arcuate.

ANODONTITES SGCLENIFORMIS (d’Orbigny).

Shell elongated, falcate-rhomboid, subcompressed, scarcely
subsolid, inequilateral; beaks low, subcompressed; posterior
ridge full, widely rounded; dorsal outline lightly arched; base
incurved medially; anterior end a little narrowed, rounded;
posterior end obliquely truncate above, rounded below ; epider-
mis dull, lurid, greenish-brown, sublamellous, often faintly
rayed behind; nacre very dark, lurid, with bluish, greenish and
brownish tints, iridescent ; prismatic border wide.

Length 75, height 28, diam. 15 mm.

Brazil, south into Argentina.

Anodonta soleniformis dOrpicny, Guer. Mag., 1835, p. 41;
Voy. Am. Mer., 1843. p. 617, pl. Lxxiv, figs. I, 3—CLESSIN,
Conch: ‘Cabi Anow 1873; py Tip Xxvietie TT,

Margarita (Anodonta) soleniformis Lua, Syn., 1838, p. 32.

Margaron (Anodonta) soleniformis Lea, Syn., 1852, p. 53;
1870, p. 83.

Glabaris soleniformis VON IHERING, Arch. fur Nat., 1893, p. 59.
—SIMPSON, Syn., 1900, p. 930.

Anodon solentdea SoweRey, Conch. Icon., XVII, 1867, pl.
XVII, fig. 65.

Margaron (Anodonta) solenidea Lea, Syn., 1870, p. 83.
Several specimens of this species, donated to Dr. Lea by

d’Orbigny are before me. They are a little narrower in front

than behind, and falcate, being much more elongated and
compressed than 4. tenebricosus.

ANODONTITES CLESSINI (Fischer).

Shell somewhat elongate, .subinflated, arcuate-rhomboid,
subsolid, inequilateral ; beaks moderately full; dorsal line light-
ly arched; base incurved medially; anterior end rounded or
lightly cut away below; posterior end obliquely rounded or

ANODONTITES 1451

sometimes obliquely subtruncate: anterior base gaping ; epi-
dermis concentrically lamellose, showing slight, radial fold-
ings, rough and dull, greenish-brown: nacre lurid, greenish or
bluish-green, sometimes very dark.

Length 80, height 32, diam. Ig mm.

Length 57, height 27, diam. 17 mm.

Southern Brazil; southward into Argentina.

Mycetopus plicatus Ciesstn, Mal. Bl., Y. 1882, p. 190, pl. tv,

fig. 7.

Mycetopus clessini Fiscuer, Jide Conch., XXX VII. 1890,

p. 8, footnote.

Glabaris nehringi von lHERtNc, Arch. fiir Nat., 1893, p. 60.
Glabaris clessini Stmpson, Syn., 1900, p. 930.

This species varies considerably in form, the posterior end
being either obliquely rounded or almost squarely subtruncate.
It is more elongated in proportion to its height than tenebri-
cosus or pastasanus.

Fischer changed the name plicatus to clessini because the
former name had been used by Sowerby for a species which
he (Sowerby) placed in Mycetopus. Sowerby’s shell is a
Mutela, and that of Clessin a Anodontites of the tenebricosus
group. Von Ihering applied the name nehringi to the above
after Fischer had changed it, and was evidently not aware that
the French savant had done so.

ANODONTITES BAMBOUSEARUM (Morelet).

Shell somewhat elongated, subrhomboid, slightly falcate,
subinflated, rather solid, inequilateral, with a chestnut-brown
epidermis, which is brilliant at the anterior part and sublamel-
lose at the posterior end, having a few, black rays; beaks low;
dorsal line lightly arched; anterior end rounded, a little nar-
rowed; base very slightly incurved medially ; posterior end
slopingly rounded above, more narrowly rounded below : nacre
bluish-white; muscle scars shallow.

Length 75, height 40, diam. 24 mm.

Palenque in Chiapas, Mexico.

Anodon bambousearum Moree, Test. Nov., II, 1851, p. 24.

1452 ANODONTITES

Anodonta bambousearum FiscHer and Crosse, Miss. Sci., II,
1804, P.527,pleLxur, figs: 6,160:
Glabarts bambousearum SIMPSON, Syn., 1900, p. 930.
I have never seen this species, but Fischer and Crosse give
a full description and beautiful figures of-it in the Mission
Scientifique. It is shorter in proportion to its height than 4.
soleniformis and differs from the other allied species in having
the anterior end shining.

ANODONTITES SCHROTERIANUS (Lea).

Shell elongated, subtrapezoid, convex, moderately solid, in-
equilateral; beaks elevated and sharp but not full; hinge line
curved, the curve continuing along the posterior end to near
the base: anterior end considerably narrowed; base lightly
curved or straight ; epidermis dull, thick ,dark greenish-brown,
feebly rayed on the dorsal slope, sublamellous and subreticu-
lated; nacre bluish, slightly lurid, sometimes marked with
letter-like or zigzag characters; pallial line with a small poste-
rior sinus.

Length 76, height 38. diam. 20 mm.

Amazon drainage.

Anodonta schroteriana Lea, Tr. Am. Phil. Soc., XI, 1852, p.
202.<pl, xxx, fen 55;pObss Vo tS52pa4S. ply xexicaiow 155:
—Huvpf, Moll. Nouv., II, 1857, p. 89, pl. xvi, fig. 3—
CLESSIN, (Conch: ‘Cab. Ano. 1874) p- sits ‘plo oer vat, esas woe

Margaron (Anodonta) schroteriana Lua, Syn., 1852, p. 51;
1870, p. 82.

Anodon schrotertana Sowerpy, Conch. Icon., XVII, 1868, pl.
KK io 7A.

Margaritana schroteriana Pate, Conch. Sam., III, 1890, p.
W732:

Glabaris schriterianus SIMPSON, Syn., 1900, p. 931.

The figured type is not in the Lea Collection, but two well
matched valves very closely approaching it are. The outline
is trapezoid, the shell being considerably narrowed in front.
It is not so inflated as 4. bambousearum, is narrower in front,
and the anterior part of the epidermis is not smooth.

ANODONTITES 1453

Group of Anodontites obtusus.

Shell short, inflated, thin, feebly rayed, rays often broken ;
base rather full.

ANODONTITES OBTUSUS (Spx).

Shell rather short, somewhat obovate, scarcely inflated, thin
to subsolid, inequilateral; beaks moderately elevated; dorsal
outline arched; anterior end narrowed, rounded; base nearly
straight ; posterior end widely rounded or almost squarely sub-
truncate ; epidermis somewhat concentrically plicate, sometimes
with inconspicuous, radial plications, greenish-olive, lurid, of-
ten with feeble, wavy or broken rays, especially on the dorsal
slope; nacre bluish and greenish-tinted, lurid; muscle scars
shallow.

Length 60, height 40, diam. 25 mm.

3razil; Paraguay.

Anodon obtusus Spix, Test. Fluv. Bras., 1827, p. 30, pl. xx1,

fig. 3.

Margarita (Anodonta) obtusa Lua, Syn., 1836, p. 52; 1838, P.

Zune
Anodonta obtusa Potiez and Micuaup, Gall. Moll., 1844, p.

144, pl. Lv, fig. 3—Kuster, Conch. Cab. Ano., 1853, p. 8,

pl. 1, figs. 3, 4—Muscrave, Phot. Conch., 1863, pl. 1, fig. 7.

—CrEsstn, Conch. Cab. Ano., 1875, p. 170, pl. LVI, figs. I, 2.
Margaron (Anodonta) obtusa Lea, Syn., 1852, p. 51; 1870,

Deo2:

Anodon obtusa Sowrrey, Conch. Icon., XVII, 1867, pl. xu,

fig. 30.

Glabaris obtusus SIMPSON, Syn., 1900, p. 931.
Anodonta VALENCIENNES, Coq. Mar. Biv., 1827°, pl. XLVIII,

figs. 3a, D.

A short, rather thin, subinflated, obovate species.

Var. juparanus (von Thering).

“The specimens described come from the Lagoa Juparana.
They differ-from the typical form only in the hind end, the
rounded, low extremity of which is separated from the oblique

1454 ANODON'TITES

posterior margin by a shallow excavation. Three diverging
ridges extend from the beaks to the hinder end, the upper of
which forms the projecting angle, which I have mentioned.
The largest specimen has a length of 52 and a height of 36
mm. But | have already received this variety from Mucury,
represented by considerably larger and thicker specimens, of
which the largest has a length of 60 mm.” (von Ihering).

Glabaris obtusa juparana Von IHERING, Abh. Senckenb. Ges.,

XXXL, AIO p13 1.

ANODONTITES LITURATUS (Spix).

Shell rather small, obovate, somewhat inflated, subsolid, in-
equilateral; beaks full and high; dorsal and basal outlines
slightly curved; anterior end narrowed and rounded; poste-
rior end almost evenly rounded, slightly fuller below; surface
of the shell greenish, with numerous radial spots or broken
rays of darker color; nacre iridescent, purplish-tinted.

Length 42, height 28 mm.

Brazil.

Anodon obtusus var. b. lituratum Spix, Test. Fluv. Bras., 1827.

Da BO, qple, Socio, ioe
Anodonta litturata Hurt, Moll. Nouv., 1857, p. 87, pl. xvu.,

fig. 4.

Anodon liturata Sowerby, Conch. Icon., XVII, 1868, pl. xx,

fig. 78.

Glabaris lituratus SIMPSON, Syn., 1900, p. 931.

Probably a valid species, though Dr. Lea believed it to be
the same as A. obtusus. It seems to be a smaller species, is
more inflated and solider than obtusus. The epidermis differs
in being green, and having, for the most part, broken rays.
According to Hupe’s figure the nacre is purplish.

Section VIRGULA Simpson, 1900.

Virgula SiMTSON, Syn., 1900, p. 931.

Shell subsolid to solid, moderately inflated, greatly elon-
gated, straight or falcate, rounded in front, sharply pointed
at the posterior base, where the high, sharply defined posterior

ANODONTITES 1455

ridge ends and above which it is somewhat obliquely truncated ;
beaks not high; epidermis green to olive; nacre brilliant, bluish
or purplish, iridescent, rayed with very fine, indistinct ridges ;
posterior end with a slight sinus.

Type, Anodon ensiformis Spix.

ANODONTITES ENSIFORMIS (Spix).

Shell very greatly elongated, subsolid, convex, inequilateral,
wider in front, drawn out to a slender point behind, more or
less arcuate when adult: beaks but little elevated; posterior
ridge well developed, sometimes pinched up into a rather nar-
row, rounded ridge, ending at the base of the shell in a de-
cided point; anterior end evenly rounded; hinge line lightly
arched, joining the long oblique dorsal slope at a low angle;
surface with strong, irregular growth lines and inconspicuous,
radial threads; epidermis dark, greenish-brown, scarcely shin-
ing; nacre brilliant, bluish, bordered and tinted with green,
richly iridescent; anterior scars well marked; posterior scars
shallow.

Length 106, height 27, diam. 15 mm.

Length 97, height 25, diam. 15 mm.

Tropical South America.

Anodon ensiformis Spix, Test. Fluv. Bras., 1827, p. 31, pl.
XXIV, figs. 1, 2—SowerBy, Conch. Icon., XVII, 1867, pl.
Xo Meee ae

Iridina ensiformis Lea, Syn., 1836, p. 57.

Anodonta ensiformis d’OrRBICNY, Voy. Am. Mer., 1843, p. 618,
pl. LXxIx, fig. 10.—Kuster, Conch. Cab. Ano., 1853, p. 8,
Dist iowi2.—— Cou Man 1850; lls p. 146. fie. .7on

Margarita (Anodonta) ensiformis Lia, Syn., 1838, p. 32.

Margaron (Anodonta) ensiformis Lea, Syn., 1852, p. 51; 1870,
p. 82.

Glabaris ensiformis SIMPson, Syn., 1900, p. 932.

An excessively elongated and peculiar species, with daz-
zlingly brilliant, iridescent nacre.

1456 ANODON TITES

ANODONTITES FALSUS (Simpson).

Shell much elongated, scarcely faleate, somewhat rhomboid,
scarcely subsolid, subcompressed, very inequilateral ; beaks low
and not inflated; posterior ridge well developed, rounded, end-
ing in a blunt point at the base of the shell; dorsal and basal
lines parallel; anterior end rounded: posterior end obliquely
rounded ; epidermis somewhat concentrically wrinkled, smooth-
er on the dorsal slope, with faint, radial markings in front,
dull ashy-brownish or greenish-brown, with inconspicuous rays
on the dorsal slope; nacre bluish, dull purplish in the cavities,
iridescent.

Length 77, height 21.5, diam. 1 mm.

Yuruari River, a branch of the Orinoco.

Glabaris falsus SIMPSON, Syn., 1900, p. 932.

This species stands between A. ensiformis and A. solenifor-
mus, though I should think it considerably nearer to the for-
mer. It differs from that in having the dorsal and ventral
outlines parallel, in having the posterior end obliquely rounded
from above instead of being drawn out to a slender point, in
being duller colored exteriorly and internally. A. ensiformis
sometimes shows very feeble rays behind.

The following are unfigured or unidentified species of Ano-
dontites :

Anodon porcifer Gray, Pr. Zool. Soc. Lond., 1834, p. 58.
Paraguay.

Anodonta nicaragua Puitiprt, Zeits. fur Mal., V, 1848, p. 130.
—von Martens, Biol. Cent. Am., Moll., 1900, p. 536.
Nicaragua.

Von Martens, (1. c.), believes this to be the same as JA.
bridgesti I,ea, in which case it would have priority.

Anodonta aperta RAFINESQUE, Atl. Jl. No. 4, 1832, p. 134.

-arana River, South America.

Anodonta atrovirens Pui.iprt, Zeits. fur Mal., V, 1848, p. 130.
—von Martens, Biol. Cent. Am., Moll., 1900, p. 534.—
SIMPSON, Syn., 1900, p. 933.

MYCETOPODA 1457

Von Martens, (1. c.), considers this to be the same as A.
mequevalzis Lea. If correct, it would have priority.
Anodonta carinata DunKeER, Mal. BIL., V, 1858, p. 225.

Colombia.

Anodonta cornea Puutprt, Zeits. fur Mal., V, 1848, p. 130.—
von Martens, Biol. Cent. Amer., Moll.,.1900, p. 535.
Nicaragua.

Von Martens, (1. c.), states that this species resembles A.
mequivalvis Lea, but, on account of certain discrepancies, he
“dare not identify it with Lea’s species.”

Anodonta giullaini H. and A. ApAmMs, Gen. Rec. Moll., II,
Lon jap 5025 credited to: Necluz:

Anodonta paphos Ra¥inesqur, Atl. Jl. and Friend., 1832, p.
134.

Parana River.

Anodon pictus SwAINSoN, Ex. Conch., 2d ed., 1841, p. 139.

Anodonta wallisi Mousson, Mal. Bl., XVI, 1869, p. 188.

Anodonta bergi VON THERING.

Where?

Genus MYCE TOPODA d’Orbigny, 1835.

x

Mycetopoda d@Orricny, Guer. Mag., 1835, p. 41.
Mycetopus dOrpicny, Voy. Am. Mer., 1847, p. 600.

Shell thin, elongated, truncate above behind, with a low,
posterior ridge and rather flat, smooth or slightly concentric-
ally wrinkled beaks ; epidermis smooth, shining, pale greenish-
yellow or brownish, rayless; hinge line long, straight, edentu-
lous or showing faint traces of denticles under a glass beneath
the nacre; nacre soft, bluish-white and iridescent ; muscular
impressions faint, irregular, the smaller anterior scar above
the larger one; beak cavities shallow.

Animal having very long gills, the inner much the larger,
united to the abdominal sac throughout their whole length:
palpi large, round below, projecting very slightly behind, and
attached along the whole length of the straight upper border ;
mantle very thin, slightly thickened at the edges; branchial
opening closed below into a short, papillose siphon, and sep-

1458 MYCETOPODA

arated from the nearly smooth anal opening by a strong
bridge; superanal opening not closed below; foot very long,
developed at the lower end into a sort of head or button.

Type, Mycetopoda soleniformis d’Orbigny.

So named by its author in the Guerin Magazine, but after-
wards changed by him to Mycetopus in the Voyage Amerique
Meridionale. The genus has been made the type of a separate
family by Gray, and was so acknowledged by Gill, Pelseneer
and cthers, but it does not seem to me to be separable from
the Mutelide.

The genus Mycetopoda is a well-characterized group con-
taining a few South American forms, all of which have elon-
gated, delicate shells and a foot capable of great extension
and are, no doubt, without exception, burrowers. Although
the shells of Solenaia closely resemble those of this group and
the species of that genus undoubtedly burrow, I have every
reason to doubt that there is any close relationship between
them. The shells of Solenaia are of different texture and they
show a ruder growth than do those of Mycetopoda. Such
vestigial teeth as the former have are distinctly schizodont,
while those of W/ycetopoda, when at all developed, are taxo-
dont.

I do not feel at all sure that the different so-called species
siliquosa, occidentalis, staudingeri, subsinuata, pygme@ea and
hupeana are anything more than variations of one widespread,
abundant and variable form. I have material before me,
which differs somewhat from any of the above, but I do not
feel justified in bestowing on it either specific or varietal
names.

Group of Mvycetopoda siliquosa.

Beaks in front of the center of the shell; anterior end evenly
rounded ; basal lines nearly straight ; posterior ridge quite low.
Animal with the characters of the genus.

MYCETOPODA SILIQUOSA (Spix).

Shell somewhat elongated, thin, inequilateral, scarcely in-
flated, gaping at the anterior base, subtrapezoid; beaks but
moderately full; posterior ridge well-developed, usually rather

MYCETOPODA 1459

narrowly rounded, ending in a blunt point at the base of the
shell; hinge line straight; base line straight or slightly in-
flated medially; anterior end narrowed and rounded; poste-
rior end decidedly obliquely truncate; surface with irregular
growth lines, often with inconspicuous radial sculpture; epi-
dermis ashy-green, often flushed with brown, shining; nacre
bluish-white.

Length roo, height 37, diam. 18.5 mm.

Length 115. height 39, diam. 20 mm.

3olivia, Brazil: south into Argentina.

Anodon siliquosus Spix, Test. Fluv. Bras., 1827, p. 30, pl.
RMT; fig: 2.

Mycetopus siiquosus H. and A. ApAms, Gen. Rec. Moll., II,
1857, p. 505; III, pl. cxviit, fig. 1—Sowexrsy, Conch. Icon.,
XVI, 1868, pl. 1, fig. 2; 11, fig. 2a—CtiEssin, Conch. Cab.
ANGI S75) D5 200) PE EXVIN, Meso 2-4= LXTX, fig. 1

Platiris (Mycetopus) siliquosus Lea, Syn., 1852, p. 56; 1870,
p. 90.

Platiris (Iridina) siliquosa Lea, Syn., 1836, p. 56; 1838, p. 34.

Anodonta siliquosa Kuster, Conch. Cab. Ano., 1853, p. 35, pl.
vill, fig. 3.

Mycetopoda siliquosa CHENU, Ill. .Conch., 1858, pl. 1, figs. 2,
2a, 2b, 2c—SIMPSON, Syn., 1900, p. 934.

? Anodonta legumen von Marrens, S. B. Nat. Fr., 1888, p. 65.

Glabaris legumen SIMPSON, Syn., T1900, p. 932.

Mycetopoda legumen von IHERING, Abh. Senckenb. Ges.,
KOO Sone). pant20:

Mycetopus clessini VON IlnERING, Arch. f. Naturg., 1893, p. 57.

Mycetopoda clessini von Tureinc, Abh. Senckenb. Ges.,
DOGAS Th AIO O:, ps N20:

This seems to be a variable form approaching closely in
some cases to VM. occidentalis, but is less inflated, more elon-
gated, has a straight hinge line and is more obliquely truncate
posteriorly. It is quite probable that it runs into MW. subsin-
uata. The clessini of von Thering is the same as Sowerby’s
figure of siliquosa on pl. 11, fig. 2a.

1460 MYCETOPODA

Var. staudingeri (von Thering).

More decidedly obliquely truncate behind and more nearly
straight on the base than typical siliquosa.

Upper Amazon in Ecuador and Peru.

Mycetopus staudingeri VON IttERinc, Arch. fir Naturg., 1890,

Pa 13i diss. Ales:

Mycetopoda staudingeri StmPson, Syn., 1900, p. 934.—VON

THERING, Abh. Senckenb. Ges., XXXII, 1910, p. 121.

Von Ihering, (1. c. 1910, p. 121), says-in regard to this
form: ‘The strong elevation of the dorsal margin, especially
behind the sinulus, as well as the post-sinual posterior adduc-
tor scars, are characteristic of this species. It is restricted in
its distribution to the region of the Upper Amazon, whence I
have it from Huallaga and Huagamba. The specimen “B,”
which I figured, has a length of 103 and a diameter of 21 mm.
The height in the middle of the shell is 36 and at the posterior
angle of the dorsal margin 43 mm.

The variety from Ecuador, which I mentioned in my orig-
inal description, (p. 130), is decidedly larger. It reaches a
length of 142 mm., but the largest specimen that I have ex-
amined is apparently, judging from the muscular impressions,
not fully grown. Moreover this Ecuador form has the anterior
end lower and the posterior end much more elongate ; I, there-
fore, distinguish it as var. equitorialis var. n. It was cited
by Clessin, Mal. BL, N. F., I, 1879, p. 174, from Ecuador as
M. siliquosus Orb. from specimens collected by Higgins.”

MyYCETOPODA ORBIGNY! von Thering.

“Of this species, which d’Orbigny confused with A/. sil-
iquosa, | have examined a specimen from Bolivia received
from d’Orbigny. I have scarcely anything to add to the de-
scription and figure of d’Orbigny, except that the position of
the posterior muscular impressions is praesinual. This species
differs trom M. siliquosa in its considerable size and much
longer posterior region. The latter does not really exceed 80
mi. in length and has the anterior end much smaller than this
species. The adductor scar is decidedly preesinual. On the

MYCETOPODA 1461

dorsal area are two or three broad, radiating ridges. The
specimen from Piricacaba is only 73 mm. long and yet, accord-
ing to the muscular impressions, fully grown. Compared with
it, M. orbignyi reaches double the size, even to 140 mm. in
length. According to d’Orbigny, this species lives both in
Bolivia and the Rio de la Plata.” (von Ihering).
Mycetopoda siliquosus @Ornicny, Guer. Mag., 1835, p. 41.
Mycetopus siliquosus d’Orvicny, Voy. Am. Mer. Moll., 1843,
p. 601, pl. LXvit.
Mvcetopoda siliquosa, (part), Simpson, Syn., 1900, p. 934.
Mycetopoda orbignyt von IneRtNG, Abh. Senckenb. Ges...
ROOM 1910, ps 120,

MyYcETOPODA OCCIDENTALIS Clessin.

Shell somewhat elongate, subtrapezoid, subinflated, thin,
shining, brownish-green ; beaks rather full; dorsal line straight
behind the beaks, incurved in front of them; anterior end nar-
rowed, rounded, subangulate above; base line curved a little;
posterior end wide, rounded, subangulate above and below;
nacre bluish-white.

Length 96, height 44, diam. 23 mm.

Rio Patasa,. Ecuador.

Mvcetopoda occidentalis Ciesstn, Mal. I, Bl. 1, 1879, p. 174,

pl. x1, figs. 2, 3—S1Mpson, Syn., 1900, p. 934.

This species has a somewhat trapezoid shell and is unusually
high in proportion to its length. The anterior end is consid-
erably narrowed; the posterior end is wide, and though al-
most evenly rounded is bluntly angled above and below, a
character not found in any other species that I know of.

MYCETOPODA SUBSINUATA (Sowerby).

Shell elongated, irregularly obovate, inflated, thin, gaping
in front, inequilateral; beaks only moderately elevated; hinge
line straight behind the beaks, slightly incurved in front of
them; anterior end evenly rounded, narrowed; base full at
and behind the middle, subsinuate anteriorly; posterior end

1462 MYCETOPODA

slopingly rounded above, more narrowly rounded below; epi-

dermis smooth, olive-colored.

Length 121, height 40 mm.

Sogota; Colombia; Ecuador.

Mycetopus subsinuatus SoweRBy, Conch. Icon., XVI, 1868, pl.
Iv, fig. 10—Cressin, Conch. Cab. Ano., 1875, p. 205, pl:
LXVII, fig. 3—-von Martens, Biol. Cent. Am., Moll., 1got,
p. 540, pl. x11, fig. 5-54.

Mycetopoda subsinuata SIMPSON, Syn., 1900, p. 934.

I have seen specimens of what I believe to be M. siliquosa
that approach this somewhat, but none which equal it in the
elongated inflation from in front of the middle of the base to
near its hinder end.

MyYcETOPODA PYGMEA (Spix).

Shell much elongated, delicate, thin, convex, narrowed in
front, wider behind, gaping at the anterior base; beaks low;
dorsal line straight ; base slightly fuller in the middle; anterior
end rounded, narrowed; posterior end slopingly rounded
above, narrowly rounded below: surface with faint growth
lines; epidermis smooth and shining in front, roughened and
reticulated on the dorsal slope, pale amber-color, sometimes
tinted green; nacre bluish, very delicately, radially sculptured,
iridescent.

Length 73, height 22, diam. 12 mm.

Brazil; northward to Nicaragua.

Anodon siliquosus var. b, pygmeum Srix, Test. Fluv. Bras.,
10277, Pp. BO, Dig wie ties. eras

Mvycetopus pygmeus Sowerby, Conch. Icon., XVI, 1868, pl.
I1, fig. 4.—Cresstn, Conch. Cab. Ano., 1875, p. 207, pl. Lxx,
fig.3:

Platiris (Mycetopus) pygmeus Lua, Syn., 1870, p. 90.

Mycetopoda pygmea SIMPSON, Syn., 1900, p. 934.

Mycetopus weddellu Hurt, Moll. Nouv., III, 1857, p. 93, pl.
xx, fig. 2—Sowerpy, Conch. Icon., XVI, 1868, pl. 11, fig. 5.
-—Cresstn, Conch. Cab. Ano., 1875, p. 203, pl. Lxvi, fig. 6.

MYCETOPODA 1463

Mycetopoda weddelli von IHErinc, Abh. Senckenb. Ges.,

XXXII, 1910, p. 119.

An exceedingly thin, delicate species, which sometimes has
a form much like specimens of 17. siliquosa, but it is always
smaller and more fragile. The finely reticulate epidermis on
the dorsal slope is a good distinguishing character. Von Iher-
ing believes this to be the young of M. siliquosa, but it differs
in the character of the epidermis, texture and form from young
siliquosa that I have seen.

Von Ihering, (1. c.), considers weddellii specifically distinct
from pygmea.

MyYcETOPODA HUPEANA (Clessin).

Shell small, thin, subtrapezoid, somewhat inequilateral ;
greenish-tinted or olive-green ; beaks full, moderately elevated ;
hinge line straight ; anterior end narrowed, rounded, cut away
below ; base line nearly straight, a little fuller behind the mid-
dle; posterior end almost squarely subtruncate.

Length 54, height 21 mm.

Brazil.

Mycetopus pygmaeus Hurt, Moll. Nouv., III, 1857, p. 93, pl.

RG lO 2:

Mycetopus hupeanus Ciesstn, Conch. Cab. Ano., 1875, p. 206,

pli xvi, fie. 15.

Mycetopoda hupeana Simpson, Syn., 1900, p. 935.—VON I[HER-

ING, AbDh. Senck. Ges., XXXII, 1910, p: 110:

This may be only a variety of siliquosa, but the beaks are
more central than in any specimens of that species I have seen.
It is higher in proportion to its length than MW. pygmea, and
less inequilateral.

Von Thering, (1. c.), refers Sowerby’s figure of MW. pyvgmea,
(pl. ur, fig. 4), to this species.

MycrropopaA BAHIA von [hering.

“A fragile, transparent shell, which gapes comparatively

little in front. The diameter increases rapidly from the ante-

rior margin as far as the beaks, then gradually to the middle
of the shell, whence it gradually slopes to the hinder end.

1464 MYCETOPODA

Dorsal margin straight: antero-dorsal angle sharp; postero-
dorsal angle rounded. The ventral margin is convex, sloping
to the last third of the shel!, whence it gradually ascends. The
anterior end is regularly rounded, with a low, rounded extrem-
ity. A broad fold, widening posteriorly, extends from the
beaks to the hinder end. Beaks low, scarcely rising above the
hinge, and situated at 23 mm. from the anterior end or at
30/100 of the length. ‘The sinulus is shallow, bordered in
front by a short, oblique line and gradually disappearing to-
wards the end of the dorsal margin. The form of the sinulus
militates against the theory that the specimen is a very young
one, yet the slight depth of the muscular impressions would
indicate that it is not fully grown. The shell is exceptionally
thin, so much so that it is possible to read the underlying label
through its substance. The posterior adductor scars are sub-
sinual and even presinual. Epidermis pale green, darker to-
wards the ventral margin and with radiating rays on the an-
terior half. Nacre lively iridescent, with fine, radiating rays.
The prismatic border is only 1 mm. in front, but at the hinder
end becomes from 6 to 8 mm. wide.

Length 78, height in the middle 26, behind 27 mm., which
is from 33/100 to 34/100 of the length, diam. 15.5 mm.’’ (von:
Ihering).

Type locality, Rio Sao Francisco, Villa Nova, State of Bahia.
Mvycetopoda bahia von IHERING, Abh. Senck. Ges., XXXII,

IQIO, p. 122, pl. 12, figs. 3a-b.

“This species stands near to 7. hupeana, but differs in hav-
ing the portion of the dorsal margin behind the beaks much
longer, which explains the lenger form of the shell and the
more anterior position of the beaks.”

MyYcETOPODA PUNCTATA (Preston).

“Shell elongate, thin, covered with a pale olive periostra-
cum, and exteriorly sculptured with faint striz radiating from
the umboes; umboes inconspicuous; anterior end rounded,

gaping ; posterior end produced, acuminate below ; dorsal mar-
gin straight; ventral margin slightly convex; interior of shell

MYCETOPODA 1465

nacreous, marked throughout with very fine, radiating, punc-
tate striz.

Length 72, height 21.5 mm.” (Preston).

Type locality, Rio Chenchi, U. S. Colombia.

Mycetopus punctatus Preston, Ann. Mag. Nat. Hist., (8), III,

LOOOs P5134 plas, te. /S:

Mycetopoda bunctata VON THERING, Abh. Senck. Ges., XXXII,

TOLO,) Ps 122:

Von Ihering, (1. c.), remarks: “This species stands very
close to VW. krausei, but differs from it by the more anteriorly
situated and less inflated beaks, which do not rise above the
dorsal margin, while in krause’ the elevation is conspicuous.
The punctate, radial striz on the interior of the shell, which,
according to Preston, characterize the species, are not visible
in MZ. krauset.”

MyYCETopvpopA KRAUSEI von Thering.

“Shell thin, moderately large, quite elongate, gaping rather
widely in the anterior half. The greatest diameter is about
in the middle of the shell, from which it slopes gradually to
the posterior margin, and anteriorly as far as the beaks, from
which point it slopes more rapidly to the anterior margin.
The beaks are flat, small, slightly prominent and are situated
at 21 mm. from the anterior end, being 1-4 of the length. An-
terior end regularly rounded; the hinder end tongue-shaped,
pointed, with the point below the middle of the shell. The
dorsal margin is straight and:meets the anterior margin at a
sharp angle; the ventral margin is curved, oblique in front and
extending posteriorly to the height of the sinulus, whence it
gradually ascends to the hinder end. An obtuse, broad ridge
extends from the beaks towards the hinder end. Above this
two or three shallow furrows extend posteriorly. Epidermis
bright olive-green, becoming brownish towards the ventral
margin, with feeble, radiating rays. Muscular impressions
weak, the posterior adductor ‘scars extend anteriorly to the
middle of the sinulus or even a little further. The sinulus is
small, not deep and triangular. The prismatic border is nar-

1466 MYCETOPODA

row and broadens out only towards the hinder end, where it
becomes 3 mm. wide. Nacre blue and red, iridescent, except
under the hinge where it is a vellowish-brown.
Length 85, height 25 mm. or 29/100 of the length.” (von
Ihering ).
Type locality, Rio Araguaya, Wha do Bananal.
Mycetopoda krausci von [HERING, Abh. Senck. Ges., XXXII,
[910, Pp! 12s pl. 12: he. 2e-p:

Group of Mycetopoda ventricosa.

Shell rather short and high, subrhomboid with a strong an-
gle at the anterior upper point, cut away below in front,
slightly sinuous on the base, narrower behind; strongly trun-
cate on posterior slope; posterior ridge wide and lightly
curved; hinge line curved.

Myceropropa VENTRICOSA d’Orbigny.

Shell somewhat elongated, rhomboid, thin, subinflated, yel-
lowish-brown, very inequilateral; beaks somewhat elevated;
dorsal and ventral lines nearly straight and parallel, the latter
slightly incurved; anterior end angled above, rounded and cut
away below; posterior end obliquely truncate above, bluntly
pointed below the median line, rounded below; nacre flesh-
colored.

Tjength 112, height 42, diam. 21 mm.

Bolivia.

Mycetopoda ventricosa d’Orsicny, Voy. Am. Mer., 1843, p.
602, p!. LXxu, figs. 1-3.—SoweErsy, Conch. Icon., XVI, 1868,
pl. uu, fig. 8-—CLEssin, Conch. Cab. Ano., 1875, p. 202, pl.
LXIX, figs. 2, 3.— SIMPSON, Syn., 1900, p. 935.

Platiris (Mycetopus) ventricosus LEA, Syn., 1852, p. 56; 1870,
This differs from the other species in being very inequilat-

eral. The dorsal and ventral outlines are nearly straight and

parallel; the general outline is decidedly rhomboid.

MYCETOPODA 1467

Group of Mycetopoda soleniformis.

Shell large, rounded in front, but somewhat truncated on
the lower anterior part: base line evenly incurved; posterior
ridge well developed, curved, truncate on posterior slope;
beaks central.

Animal that of the genus.

Myceropops SOLENIFORMIS d’Orbigny.

Shell large, elongated, rhomboid, almost exactly equilateral,
subinflated, brown-green; beaks but little elevated; hinge line
straight ; base line somewhat sinuous, being incurved at and
behind the middle; anterior end produced near the dorsal
line, cut away decidedly below; posterior end obliquely sub-
truncate, somewhat biangulate below, ending in a point at its
base; posterior ridge double, the lower one high and sharp;
surface with strong growth lines, with radial lines in the mid-
dle: nacre blue.

Length 224, height 56, diam. 30 mm.

Bolivia ; Peru.

Mycetopoda soleniformis @Orxbicny, Guer. Mag., 1835, p. 41.
—CuHENU, Ill. Conch., 1858, pl. 1, figs. 1, 1a, 1b—SIMPSON,
Syn., 1900, p. 935.

Platiris (Mycetopus) soleniformts Lua, Syn., 1838, p. 34; 1852,
psOr 15705p2 00:

Mycetopus soleniformis Reeve, Conch. Syst., I, 1841, p. 125,
pl. xciv—d’Orsicny, Voy. Am. Mer., 1843, p. 601, pl. LXvI.
—H. and A. Apams, Gen. Rec. Moll., II, 1857, p. 505; III,
pl. exvim, figs. 2a, 2b——CHENu, Man., 1859, II, p. 147, fig.
72° —Rrerve, Elements of Conch., I], 1860, pl. xxxtr, fig.
181a, b—Sowerpy, Conch. Icon., XVI, 1868, pl. 1, fig. 1.—
€ressin. Conch. Cab. Ano. 1875, p. 201, pl. Lxviri, fig. 1.

Mycetopus solenoides Sowrrey, Conch. Man., 1839, fig. 151.
A magnificent species, the largest and finest of the genus.

The location of the beaks almost midway between the anterior

and posterior ends, and the high, sharp, double posterior ridge

are characters that separate it decidedly from all other species.

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ADDENDA et CORRIGENDA.

Page to1, To the synonymy of Lampsilis lienosa add:
Furvama (Micromya) lienosa Ortmann, Ann. Car. Mus.,
MELT O12, Pp. 240.

Page 180, Dele the last six lines. They will be found on page
281.

Page 230, J,ine 16 from top read calimatorum.

Page 289, Lines 1 and 7 from the top, read grandensis.

Page 348, Line 11 from top read shefferianus.

Page 402, To synonymy of Alasmidonta add:

Alasmodon Swainson, Tr. on Mal. 1840, p. 382.

Page 573, To the synonymy of Unio batavus add:

Unio steventianus Drovurr, Unionide Russ., 1881, p. 14;
Supp. Un. Serbie, 1884, pls. 1, 11.

Page 583, To Unio monceti add:

Var. ruber Germain.
“Typical in form; shell of a magnificent, brilliant red;

nacre bright rose-salmon, very iridescent.’ (Germain.)
Type locality, Fintebe, Lake Victoria-Nyanza.

Unio monceti var. rubra GERMAIN, Bull. Mus. Hist. Nat.,
1906, p. 306.

Page 630, To the svnonymy of Unio jayensis add:

Unio leonensis “B. H. Wricut’ Simpson, Pr. U. S. Nat.
Mus: DEVE S602, p. 410; pl, rxim, figs. 2, 4.

Page 730, Dele last five lines and first eight lines on page 731.
See p. 1142.

Page 732, Dele line 4 from top.

Page 779, To synonymy of Pleurobema nix add:

? Unio placidus Kuster, Conch. Cab., Unio, 1861, p. 262, pl.
EXXXVIND, Ne. 2.
Page 988, To the synonymy of Vodularia bonneaudi add:
Jnio bonneaudi HANtKY and THEosALp, Conch. Ind., 1876,
pa 22n pl xvi, ties. 5. (6:

Page 1068, Physunio friersoni. While this work was going
through the press, Mr. L. S. Frierson called my attention
to what had been overlooked in compiling the Synopsis,
viz., that the name of wvelaris for a Unio was used by Han-
ley in 1856. Sowerby’s name for this species must, there-
fore, be changed and I propose that of friersoni in its
place.

1470 ADDENDA ET CORRIGENDA

Page 1166, To the synonymy of Lamellidens marginalis add:

Unio marginalis anodontina HANLEY and THEOBALD, Conch.,
ind,1876, p06, pl. XI fis. 7,

Unio zonatus DrsHAYEs, Enc. Meth., IT, 1827, p. 587.

Unio marginalis sonata HANLKY and THroparp, Conch. Ind ,
1976, )p: 20, pl: XLiv, fig. 2:

Lamellidens marginalis zonatus Preston, Rec. Ind. Mus.,
Vil; Tor2ip: 305:

Preston, (1. c.), considers the latter form worthy of varietal
rank.

Page 1170, Lamellidens burmanus. ‘The name pulcher having
been previously used in Unio by Lea, I change the name
as above.

Page 1175, To the synonymy of Lamellidens generosus add:

Unio generosus angustior HANLEY and THEOBALD, Conch.
Inds; 1876," p22; pl: xivis fis.

Page 1313, To the svnonymy of Spatha add:

Mitriodon RocHEBRUNE, Bull. Mus. Hist: Nat., 1904, p. 461.

Page 1362, To the synonymy of Mutela plicata add:

Mutela plicata CiEsstn, Conch. Cab., Ano., 1873, p. 195, pl.
1B, Gaon AKERS Mesa 2¥

Page 1378, After line 5 from the top add:

The following are unfigured species of Pleiodon:

Pleiodon diolibanus BourcuicNnat, Moll. Egypt et Ab., 1879,
Pp. 47.

Pleiodon elongatus Bourcuicnar, Moll. Egypt et Ab., 1879,
D. 47.

Pleiodon Ictourneaurianus Bourcuicnat, Moll. Egypt et
AD. 1870; pags.

Page 1401, To the synonymy of Leila esula add:

Anodonta gigantea Kuster, Conch. Cab., Ano., 1853, p. 6,
Plies afion ae
Page 1405, Dele lines 7 and 8 from the top.
Page 1460. Line 13 from bottom read @quatorialis.

Date of publication, August 1, 1914.

CIN DEX

Abacoides (Unio). Hald. ......... 343 /®gyptiacus (Unio) Han. ........ 1020?
Abacus (Margaron) Lea ........ 810 YD TIES Vie) eo Seene pon meeaddc 1021
Abacus (Pleurobema) Ijea ....... 810 “Eneolus (Pseudodon) Drouet....1089
Abacus (Unio) Elialdseyseeeie ss ae 810 VE TIETIS m CWMLO)) Panicle: o.ceiee scltee 1021
Mbadianus) (Unio), Bst, Soce.c.e: 1042 Afquatus (Margaron) Lea........ 642
Abbevillensis (Margaron) Lea.... 653 EGuatisas(WmniG), Leaky aee.cccisne 642
Abbevillensis (Unio) Lea......... 653 /Equatoria (Nodularia) Morel. ...1032
Abbreviatus (Unio) West. ....... 961 Afquatorius (Unio) Morel. ...... 1032
Aberrans (Margaron) Ijea........ 655 Afquitoria (Nodularia) Simp. ....1032
Pbernanse (Winio) lea essen eee. 655 JD etbkey CLOfahtoy)! NEG samesagessenc yc 180
Aberti (Cyprogenia) Con. ,...... 328 -Eruginosa (Nephronaias) Morel. 275
Aberti lamarckiana (Cyprogenia) -Eruginosus (Nephronaias) Simp. 276
Teale spas SAS ee eee 329 “Eruginosus (Unio) Morel. ...... 276
Aberti (Margaron) Lea. ......... 32 Afsopus (Margarita) Lea....:.... 806
/Aloxescinl ACUfarien)), (Cosas Son oousabeees 32 “tsopus (Matrearon) Dea. .s..... 807
Ablatuse (Unio): Wea seme. cee ee 675 “Esopus (Pleurobema) Green..... 806
Abnormis (Unio) Morel. ........ 1063 Esophus (Plethobasus) Ort. .../ 807
Abortivus (Unio) Heude......... 935 ALSOpUSis (Unio)en Greenienien tees ok 806
Mpruptuse. (Unio) weSay:. snes Lee: 77 Asthiopitormis) (Unie) Thi iyi... . 1312
Joie (AUF OY). ICloL, Sehooases dede 558 7Rthiops, ‘(Diplodon) Lea:.....-. 1247
Abyssinica (Nodularia) Simp. ... 582 féthiops (Margaron) ILea:....... 1247
Abyssinicus (Unio) Marts. ...... 582 Ethiops piricicabana (Diplodon)
Acrorhyncha (Lanceolaria) Haas. 957 Shin (= gina Puen MEE me cece 1248
Acrorhyncha (Nodularia) Marts. . 956 “Ethiops piracicabanus (Diplodon)
Acrorhynchus (Unio) Marts. .... 957 II sein, sites cuss eicag a oe ato eS te 1247
Actephilus’ (Unio) Bet. ..:...... 533 Ethiops piracicabana (Unio) Ih. .1248
Acuens (Pleurobema) Lea........ 746 SE thiopss (Unio), Beason. aaseeeen: 1247
Norns (WWhano)y" Ie Saanoceny cage 746 iAMferula | GParreysta)). leans. ac 1134
Acuminatus (Nodularia) Simp. ... 580 Afernulas (Wmio)n leas anteeretiee oe 1134
Acuminatus (Unio) H. Ads. ..... 579 Aferulus. (Margaron) Lea..°..... 1134
Acuticosta (Castalia) Hupé....... 1199 AUiGaaIkes. (Usa) MLeelo San oases - 1134
/emteonin, Stim, “Goocacaedousn hac 1139 AHimissG@eampsilis)) “Simps sss 68
Acutirostris (Diplodon) Ijea..... 1276 Affinits (Margaron) Dea.......... 68
Acutirostris (Margaron) Tea..... 1277 Achinisy (Uias0)) weleude. sass alee 92
Acutirostris (Unio) Lea......... 1276 Auissancy (Uist) Gene a tasaeen eee 68
Acutissimus (Margarita) Tea..... 251 Ausohanew (Uap e » Syouie ya eee ponies 50, 62
Acutissimus (Margaron) Lea..... 252 Africanus (Margaron) Dea ....... 576
Acutissimus (Medionidus) Lea.... 251 Mtricanus sy CWmio) sh eas aeceroee sak 576
Acutissimms) (G@Wnio)e- Lea.e...caci- 251 Agricolarum (Anodon) Heude.... 404
Adansoni (Spatha) Jouss. ....... 1325 Agricolarum (Anodonta) Pet. ... 404
Adansoni (Spathella) Jouss. ..... 1326 Aheneus (Margaron) Lea........ 605
Admirabilis (Cameronia) Bgt. ...1379 Aheneus (Unio) Lea.........-..- 604
/Egyptiaca (Nodularia) Caill, > eer lOLO Alabamensis (Lampsilis) Con. ... 185
/Egyptiaca (Unio) Caill. ........ 1020 Alabamensis (Margaritana) Lea:. 352

Menon Conpangey Madciot

(Uno) Eathen Wyrereea, /§

1472

Alabamensis (Margaron) Lea nae 352
Alabamensis (Strophitus) Tea.... 351
Alabamensis (Unio) Con. ....... 185
Alabamensis (Unio) Sow. ....... 352
Alasmid ortae Saya cis cles ie nies ese 492
Masmodon) Swe siesisns oe ceils 1469
Alasmodontar Sayanieroeiese a sushi caters 492
Alasmodontina (Complanaria)

Stump! “asl ele aietcleeteinte atelate error 483
Alasmodontinus (Unio) Pet. .... 483
Alata i(BurtonialgeAmceuscic csc 1356
Alatay (WEiyriaNieSOweeletet teste celeron 1220
Alata® (@lanipsilis) msavaee cise bine 162
Alata’ |\Giyminadta)igSwaec. cis cele nt 163
Alata (Metaptera) Stimp. ....... 163
Alata <CMiutela)! Wealienccns.uemist 1356
Alata poulsoni (Lampsilis) Con. , 164
Mlata (Nivel ato timers ciersiesinte 163
AlatamGMy scans waetstelaerieletstel eters 163
AMatan@blatinis) meanest ees 1356
Alatas (Gerop tera) nO ntsc 163
Alata simpsoni (Mutela) Marts. .1357
Mata iS patira) Lean m-iteystarcirctecks 1356
Alata ((Symphynota) Tease. e.ee 163
Ailata "CUinio) Wamanrckilnascescisie 163
Alatis a@vampsilis) eSimps eee eis 163
Alatus (Margarita) Lea.......... 163
‘Alatus \(Margaron) Wear cece. cee 163
Alatus poulsoni (Lampsilis) Simp. 164
Alatus) ((Prisodon))2 SOw: jc eerie e 1220
Alatus, (Unio) Savers sielclerversieve 163
Aleroni (Unto) Ca ieee Vee eisrete 541, 572
Alexandri (Umni10)) Kobe ........«. S41
Alfertants) | GUm10)) gab Sta vraictetsreie I192

Alienigena (Lampsilis) C. & F. .. 178
Alienigenus (Lampsilis) Simp. ... 178
. Alienigenus (Unio) C. & F. ..... 178

Aligera (Lepidodesma) Simp. ,... 239
Aliger (Lepidodesma) Hde. ,.... 238
Alluaudi (Mutela) Ger. .......... 1366
Alluaudi (Parreysia) Dautz. .....1141
Alluaudi (Unio) Dautz. ......... 1142
Alta Celeurobémia)! Simpy sneer 771
Altiris) (Glampsilis) \Gons jews eee 45
Altiise(Marcartta)) i wWoeanssetisie cise 45
Altiis @Wargcaron)) Wea sass. 6 so 45
AMUN (CULO) (Corts Gososocousoocc 45
Altilisy @Umyo)i MRvieh ee cietele..te-aeleiere 56
Altum (Pleurobema) Con. ....... 771
Altus ((Miargaron) leans cieicieteicie 771
Altits) (GUinto)mContemmmericeci + -tcieiee Bay
Amabile (Pleurobema) Lea....... 794
Amabilis (Margaron) Tyea........ 194
Amabilis iGUnio}) elyeattecistae eller 794

INDEX

Amazonensis (Anodon) Sow. ,....
Amazonensis (Anodonta) Lea..... 1442
Amazonensis (Anodontites) Lea...1442

Amazonensis (Glabaris) Simp. .. 1442
Amazonensis (Margaron) [Lea.....1442
Ambifaria (Nodularia) Marts. ,..1036
Ambifarius (Unio) Marts. ....... 1037
Ambigua (Alasmodonta) Say..... 325
Ambiguaw (Castalia), Blige -ecidels 1203
Ambigiua, (Castalia) Wamtic.o--cee 1196
Ambigua (Castalia) Sow. ..1198, 1201
Ambigua (Hemilastena) Say...... 325
Ambigua (Margaritana) Kust. ... 325
Ambigua (Mya) Wood........... 1199
Ambigiia (Unio) Deshsinrict.lei ree 1196
Ambiguus (Tetraplodon) Ih. ,....1198
Ambiguus (Tetraplodon) Simp. ,..

SAO oA OU AdsoUdod jade ooo 1197, 1198
Ambiguus (Tetraplodon) Sow., ,..1195
TawaMonfeabioey (OkshCoy) Ihe “Ganagooso 1198
Ambiguus (Unio)! Phila cue circ 1298
Ambiguus (Unio) Sow. .......... 1196
AsablamodonwRatan seniecineieceiecotete SIr
Amethysta (Anodonta) Cless. ....1444
Amethystus (Anodon) Sow. ...... 1444
Ammnicus =(@Untio))) SROSS:) Getielels el eheie 571
Ameena ((lampsilis)) Weal joa. scams 122
Amecenus (Lampsilis) Simp. ...... 122
Amcenus (Miagaron) Tea ..::.... 122
/Naneanites (What) JBGEY So ea akaons 122
Amphichenus (Lampsilis) Fr. ... 186
Amphichenus (Lampsilis) Simp. . 186
Amphichenus (Unio) Fr. ....... 186
Amplusst@Uinio)) ey eayserim ceetiateniet 656
Ampullaceus (Diplodon) Lea ....1230
Ampullaceus (Margaron) Lea ....1230
Ampullaceus (Unio) Wea ...5.... 1230
Amyedalonatasy Hyak, Capertee: 306
Amygdalonajas Ortmann ........ 306

Amygdalum (Lampsilis) Lea +++» 140
Amygdalum (Margaron) Lea .... 140

Amygdalum (Unio) Lea 2s... 140
Anataria (Spatha), Jickie. ose eect 1350
Anaticulus (Margaron) Tea ..... 759
Anaticultis! @Unio)) Wea. se. cc 759
Anatina (Anodon) ©. & R...:.... 367
Anatina (Anodonta) Drap. ...... 367
Anatinus (Anodon) Sow. ........ 437
Anatinus @Anodon)“Durt. =....... 367
Anatinus (Mytilus) Linn. ....... 367
Anceps (Nodularia) Desh. ....... 984
Anceps \(Oxynaia) i blaas 2). «em 984
Anceps: (Unio) Desh... 3... 984
Anceyi (Brassea)' Ger, ..0...05. 1372
Anceya (Brazzea)l Both fete 1372

INDEX

Anceyi (Cameronia) Bgt. ....... 1383
Anceyi (Grandidieria) Bet. ...... 1055
Anceyi Oloncetia)) Bete cielo 1345
Anceyi (Spatha) Bet. ...... 1331, 1345
Ancyrensis louisei (Unio) Kob. .. 732
Ancyrensis (Unio) Kob. ........ 732
Andersonensis (Unio) Lea ...... 742

Andersoniana (Nodularia) Prest. . 979

Andersonianus (Unio) Nev. ..... 979
Andrewse (Quadrula) Marsh .... 895
Andrewsit (Quadrula) Marsh .... 895
Aneasi (Anodonta) cet cere cstere 1307
Angasi (Margaritana) Pet. ...... 1307
Marais (WUirwo)) SOs oss choosoccs 1307
Angoniensis (Unio) Prest. ....... 72
Angulata (Anodon) C. & R. ..... 464
Angulata (Anodonta) Lea ....... 464
Angulata’ (Gonidea)) Dea ........ 464
Angulata haroldiana (Gonidea)
IDE Men remote ect iOrer aa ecicieencrciet 466
Angulata (Margarita) Lea ....... 464.
Angulata (Margaron) Lea ....... 464
Angulata subangulata (Anodonta)
Fllemips Mavs seus eee. rays eieyerensis seiee 466
Amgulata ‘subangulata (Gonidea)
lelSsuho acoomashdoeus aoe OODeD 465
Angulata (Mya) Wood .......... 1213
Angulatus (Anodon) Sow. ....... 464
Angulatus (Margarita) Lea ...... 1213
Angusta subflava (Mya) Schrot. .. 532
JWwoeiey (Uistio)), ILEKS 5 5a5qaeq000 731
Angustata (Anodonta) Cless. ....1440
Angustata curta (Mutela) Ger. ...1354
Anigtistatay @ltidina)) eSOwsueeiele oleic 1353
Angustata (Mutela) Jick. ........ 1354
Angustata ponderosa (Mutela)
(COR Mamoru cdoe con Onincicrcs cori 1354
Angustatus (Margarita) Lea ..... 678
Angustatus (Margaron) Lea ..... 678
Angustatus) (Unio)! Weal ...0.>..- 678
Annandalei (Parreysia) Prest. I122
Annulatus (Anodon) Sow. ...... 349
J\noeloya, OMG Gonads onoeopece 358
ANNs) ILI “eogindooogoodoooboS 358
PANO CONtAMIV Al, fete icisis sisislste: ePelsysie) oiots 1453
Anodontzformis (Microdontia)
InIGES ao\nagobsoogoonoo so popaOnS 1010

Anodonteformis (Nodularia) T.-C. toro
Anocdonteformis (Unio) T.-C. ...1010
AMO C Ont eSun Clivesarels clevehsiscctelcisisolersie 358
Anodontina ((Unio)) Lam. ..:....- 1167
Anodontinus (Unio) Kust. ...... 1167
Anodontinum(Pseudodon)Roch. ..1103
Anodontites) SEiEtiei irc ss iclcjereics overs 1403

1473

Anodontoides floridensis (Iampsil-

SS) MAU Calemecrere aishniace eta beielateretotienate gt
Anodontoides (Lampsilis) Bak. .. 92
Anodontoides (Lampsilis) Lea .. 90
Anodontoides (Margarita) Lea... 91
Anodontoides (Margaron) Lea .. 91
Anodontoides’ Simp. ............. 466
Anodontoides (Unio) Lea ....... 90
Anodontoides (Unio) Rve. ...... 92
AnModOntOpSis™ Ol pees «sera ciecielele > 466
Anserina (Anodon) C. & R. ..... 1430
Anserina (Anodonta) Chenu ..... 1430
Anserina (Margarita) Lea ....... 1430
Anserina (Margaron) Lea ....... 1430
Anserinus (Anodon) Spix ....... 1430
Anserirostris (Anodonta) Kust. ...365
Anthonyi (Margaron) [ea ...... 612
And nopnal (Uimioy) JOC Gaooooonoos 612
Antiniloticus (Unio) Bgt. ....... 1192
Antiochianus. (Unio)! Wocs 2.2.2... 549
Antrosa (Amblema) Raf, ........ Wie
Aperta (Anodonta) Raf. ........ 1456

Apicellatum(Ptychorhynchus)Hde. 1147
Apicellatus(Ptychorhynchus)Simp. 1147

Apicellatus (Unio) Hde. ........ 1147
Apicina, (eampsilis)) Weal een<-. 112
Apicinus (Lampsilis) Simp. ...... 112
Apicinus (Margaron) Lea ....... II2
APICinUsSCUMIO) Wy eawatereelelcieistelclets DIZ
Apiculata (Quadrula) Say ....... 846
Apiculatus asper (Unio) Pet. ... 841
Apiculatus (Margarita) Lea ...... 847
Apiculatus (Margaron) Lea ...... 847
‘Apiculatus: @Unto)) Says Saaee-cleel 846
Mplatuss @Diplodon)) Rveses).1.- 1. 1259
Aplattisy GWUni1O) Oo RVieM astcverels sercle 1260
plod om SPU cre sic oheleteloneleleterelenerers 1384
MES NECESN Sooonbonoyo to 000000 223

Appressa (Pleurobema) Simp. 748, 749
Appressum (Pleurobema) Lea .... 747

Appressus) s@Wainio)) Weal cree sicicrs ler 748
Apprimus (Diplodon) Simp. ..... 1231
Apprimus (Margaron) Lea ...... 1231
JNoyosahoohetse ((Uhebkop) IE Ba olo Hoga aod 1231
Approxima (Jampsilis) Lea ..... 68
Approximans (Spatha) Prest. S1ag2
Approximus (Lampsilis) Simp. ... 68
Approximus (Margaron) Lea .... 68
Approximuss (Unio), Weal... o.. 68
Aquilus) @(Miargaron)! Lea ...:.... 664
ENG alts GWm10))) yak cnierck cists crete 664
Nradeew@Wnio)) Philitisrceileieeies 533
Araneosa (Nodularia) Roch ..... 1045
Araneosam¢Zaitia)» ROCs ‘i.% << eeree 1045

Aratus(Miargaron)). Wea s.ce..s- 716

1474 INDEX
Aratus (Unio) Con. Peeper ys et 605 Argenteum pannosum (Pleurobema)
Aratus (Unio) Meeamasen. ss te 716 Simp. ase eee tee ote 799
Araucana (Unio) Hupé ......:... 1257 Argentea (Pleurobema) Simp. .... 799
Araucanus (Margaron) Lea ...... 1257 Argenteum (Pleurobema) Lea ... 798
Araucantis, (Unio) Pals 25. 2 1257 Argenteus (Margaron) Lea ...... 799
Arceformis (Anodon) Hde. ..... 415 Argenteus (Strophitus) Con. ..... 468
Arceformis (Anodonta) Hde. .... 417 Argenteus (Unio) Weal o.s2.2. 2. 799
Arceformis flavotincta (Anodonta) Argenteus CUnio} Sows, pee ewees 748
IMiarctS..* 2h Seton rcteteee orci te ic lve) aoe 417 Argyratus (Dampsilis) Raf. ..... 200
Arceformis (Margarita) Lea .... 13 Arietina (Chelidonopsis) Roch. 1368
Arceformis (Margaron) Lea .... 13 Arietina (Chelidonura) Roch. 1368
Arceformis (Truncilla) Lea ..... 12 Arkansasensis (Anodonta) Lea ... 347
Arczeformis, (Winio)iea >. .0.. 2 13 Arkansasensis (Lampsilis) Lea ... 129
Archer ((Ouvladrula)mebire ssc. eee 861 Arkansasensis (Margaron) Lea .. 347
Arcrdens: Simp seme eres «scree ele 475 Arkansasensis (Strophitus) Con. 348
Arcidopsis@ipitupwaae secs... ose IIQI Arkansasensis (Unio) Tea ....... 130
Arconaiay Cont maeeeicneee. cer eine 1187 Avkarnsia-©) vQeeWwsaee ote Rene 477
Arctatus (Margarita) Tea ......-. 645 Arnoldina| lann. 40. eeeee ce eae Sos
Arctatus. (Marzaronm)i yea gcse 645 Armatus (Mycetopus) Hde. ...... 460
Arctatus tortivus (Unio) Lea .... 645 Arquatius- Uno) s Come ycmasiaciacte 96
Axetatuss (Uso) yiGonr secs. ste ot 644 Arthropteromm siROChee se sien seein 1374
Azctatus) GUinto) Mem, feasciee soe 598 Aveo Wiehe I pacaducaeadgas= 311
Arctior, (Margarita) wean scien Roy Ns) (Uperko))) lslenok, Goosowacuoodos 1192
Arctior (Margaron)) Wea .......-. 598 Askewi (Quadrula) Marsh ...... 869
Arctior (Unio) sileea mee eieiereetoe 598 Askewi (Unio) Marsh ........... 870
Arcuata (Alasmodon) Gld. ....... 516 Aspatharia iB ets wiieens scree 13477
Arcuata (Alasmodonta) Bar. ..... 516 Aisnere(Manganita) i laeaine. emits 841
Arcuata (Anodonta) Caill. ...... 1336 Asper (Margaron)) Weale. a. 55-2 eu 841
Arcuata (Anodonta) Han. ....... 1401 Asper (Quadrula) Simp. ....321, 841
Arcata nGliidina) ten ce Wine ease 1336 HMjorae (UUhotKonY WheRG aagdweudnolos 840-
Arcuata (Margarita) Lea <....:.. 1336 Aspera (Quadrula) Lea .......... 840
Arcuata (Margaritana) Kust. .... 516 Asperatus (Margaron) Lea ...... 851
Arcuata (Margaron) Lea ........ 1336 asperatus CUnio)) Wea ees. occ 851
Arcuata (Mya) Faton ........... 516 Asperrimus (Margarita) Lea .... 842
Axcuatay (Spatha)etCarll error 1336 Asperrimus (Margaron) Lea .... 842
Arcuatus (Mycetopus) Fisch. .... 460 Asperrimus i(Unio) Tea‘. ......- 842
Arcula (Alasmidonta) Lea ....... 508 Asperula (Nodularia) Lea ....... 989
Arcula (Alasmodonta) Con. ...... 509 Asperula (Oxynaia) Haas ....... 989
Arcula (Baphia) H. & A. Ads. .. 509 Asperulus (Margaron) Lea ...... 989
Arcula (Margaritana) Lea ....... 509 Asperulus (Unio) Weare “sh Serene! 989
Arcula (Margaron) Lea ......:.. 509 Astierianus (Unio) Dup. ......-. 555
ArculayCUnio)) bat, ere steneieilete ate Soo) Aten (Unto) alvemunncmeiere ceo cdee 167
Arcus (Margarita) Dea, 2225... BOOM me Ate @Umio) Nils: sister era eee 570
Arcus .@Miargaron))Hyedy ces. ne ees OOo wAter (Unio) Ivesse eet anaemic: 555
Arcus (Unio) mContasmtieniecteradecnic 5909 AtraadUnio)) Deshten. oaser sc 167, 570
Ardusianus (Unio) M.-T. ....... 541 Atinatay (Ui10)) «Swe tiserctsec re aie e 182
Arealis (Anodonta) Kust. ........ 365 Atratus (Diplodon) Simp. ....... 1267
Arelatensis (Anodonta) Dup. .... 364 Atratus (Diplodon) Sow. ........ 1261
Aremprosthus (Unio) Loc. ...... 548 Atratus (Unio) Han 2. sc... .05- 182
Areolatus (Anodon) Sow. ....... 1431 Atratis) (Umion oO cites 1-11 1262
Areolatus (Anodon) Sw. ........ 347 Atrocostatus (Margaron) Lea .... 817
Areolatus (Anodonta) Fer. ...... 347 Atrocostatus @Wnio). Léa >...s--- 817
Argentea (Anodonta) Lea ....... 468 Atrocostatus (Unio) Rve. ........ 826
Argentea (Margaron) Lea ....... 468 <Atrocostatus (Unio) Sow. ....... 82r
Argentea pannosa (Pleurobema) Atromarginatus (Margaron) Lea . 605
SIMD s+ ke eee arereuste scoreteberee he be avo 799 Atromarginatus (Plectomerus) Con. 605,

INDEX

Atromarginatus (Unio) Tea ..... 605
Atropurpureum (Alasmodon) Raf. 510
Atroviolacea (Obliquaria) Raf. ... 731
Atrovirens (Anodonta) Phil. .363, 1456

Atrovirens) (Unio) ‘Ross. .......... 570
Attenuata (Anodonta) Held ..... 363
Attenuata (Obliquaria) Raf. ..... 731
Attenwatus. GUinio)) Beal... a... - 698
Aubreyi (Anodon) Hde. ......... 405
Aubreyi (Anodonta) Pet. ....... 405
Aucklandicus (Unio) Sow. ...... 1291
Aucklandica (Unio) Gray ........ 1291
Aucklandicus (Margaron) Lea ...1291
Aurata (Anodonta) Kust. ...... 402
Auratus (Margarita) Lea ....:... 1257
Auratus @Mangarom)) Weay.e.-o-s 1257
JxoeEynoe! (Ofartoyy) GEE os sea aeo oe 1268
Lveiengney ((Ufaky) 12th, Kogooeoeoass 1257
Noha, (UUinkOd) JRnOs Sone anadoas 1259
Auiratus (Unio)! Sows wives ses see 1260
Aurea (Margaritana) Pet. ...... 1085
Avtieey ((Orrcinalkyy) Wee: Geaqa-ocas 861
Aureus (Anodonta)! Pate cn. ose 437
Aureus (Diplodon) Simp. ........ 1268
Aureus (Margaron)) Tjea ......... 861
Aureus (Pseudodon) Hde. ....... 1085
Aureusm (Unio)! seas meso ues 861
Auricularius (Unio) Speng. ...... 518
PN UIC Ok cles OULU miatcier tye tral earn ictal ae 1137
Aurorea. (Parreysia) Hde. .....<. 1138
AtiroreusiaG@Unio)is Hides cmc cide cs 1138
Australis (Diplodou) Lam. .....1297
Australis (Hyridella) Sw. ....... 1298
Australis (Lampsilis) Simp. ..... 94
Australis legrandi (Diplodon) Pett.1298
Australis (Margarita) Lea ....... 1298
Australis (Margaron) Lea ....... 1298
Avistralisie Wma) pelkdarmes erase cee 1297
FARIS tial Se UOim1O) mUStw cere ore 1297
AERIS (UfaKe)) Ieee, Saeyoasaoc 1297
Ava (Monocondylea) Theob. 1098
Ava (Pseudodon) Theob. ....... 1098
Avellana (Pleurobema) Simp. .... 778
Averillig (Unio) By He Ws J... 138
Avery (Margaron)) ea .....-<0- 259
Averyi (Nephronaias) Lea ...... 258
Aa (Use) IUCEY Ga genOpoOe OOOO D 259
Avicularia (Hyria) Guer. ....... 1221
Avicularis: (@aiyria)® Tams 5... ies 1221
Avicularis .(Wnio) Desh. ..:..... 1221

Avicularis var. b. (Hyria) Lam. ..r1219

Avonensis (Anodon) Turt. ...... 362
Avonensis (Anodonta) M.-T. .... 362
Avonensis (Mytilus) Mont. ...... 362
Avoensis (Mytilus) Turt. ....... 362
Asiacuss @WUnio)s Woe. . 2. te. n 548

1475
Aztecorum chapalanus (Nephro-
MAtTAS)MeeVa ESI sc sverenl eon ake here 270
Aztecotum chapalanus(Unio) Marts. 271
Aztecorum (Lampsilis) Simp. .... 270
Aztecorum (Margaron) Lea ..... 270
Aztecorum (Nephronaias) Phil. .. 269
Aztecorum soledadensis (Unio)
Mila sitis oa Weve sieuslavatocsis oaitiohtia series es 271

Aztecorum strebeli (Unio) Marts. 256

LWA rexosrien (Uinroy yoy Hage docaac 270
Babensis) (Unio) Kob.......---5- 559
Babylonica (Pseudodontopsis) Kob. 443
Badium (Alasmodon) Raf. ...... 511
Badiuss (Unio)e Kok), ..sascceseue 572
Bagdadensis (Margaron) Lea 1023
Bagdadensis (Nodularia) Bet. 1023
Bagdadensis (Unio) Bet. ..:..... 1023
Bahia (Mycetopoda) Ih. ........ 1463
Bahiensis (Anodonta) Kust. :.... 1431
Bahiensis*(Glabaris) Ih. ......... 1431
Baris (Spathal) hi Adse neem ore 1350
Bairdianus (Margaron) Lea ..... 149
Bairdiants) (Unio) eea sas ekenines 149
Bakeri (Parreysia) H. Ads. 1125
Bakeries (Unro)m Ey eAdss nena sce. 1125
bakeries W200) miviartSasereet eee 1127
Bakoyi (Nodularia) Roch. ....... 1044
Bakoyis@Unio)= Rocha manent 1044
Baldwinensis (Margaron) Lea ... 654
Baldwinensis (Unio) Lea ....... 654
Baletonicus, (Unio); Kust os... ose 533
Balonnensis (Unio) Con. ........ 1298
iBpalzani((Possula)” The tees. aoe 1397
Balzani (Iheringella) Ih. ........ 1395
Balzani Gelaciodon) lhe srs ceieks 1396

Bamboursearum (Anodon) Morel. 1451
Bambousearum (Anodonta) F.&C. 1452
Bambousearum (Anodontites)

Morel.
Bambousearum (Glabaris) Simp. .1452
Bandini (Unio) Kust.

a a A 571
Bandini @Unio)) Ross; ws... ...- 540
Bangoranensis (Nodularia) Ger. ..1039
Bangoranensis (Unio) Ger. ...... 1040
Baphia He andeA. Ads. .osee0..-- S11
Bap hicemeeuschisen eerie 511
ehdorie, Jakinme. soonkonobonooeae 223
IBarhatamcow amit Sore erae 223
Barnesiana (Pleurobema) Simp. .. 754
Barnesianum (Pleurobema) Lea .. 754
Barnesianus (Margarita) Lea .... 754
Barnesianus (Margaron) Lea .... 754
Barnesianus, @Unio)) Wea ..2...... 754
Baro (Tetraplodon) Ih. .:....... 1198
Batrandiy CWUnio)) Dups 22.2... 555

Barrattii (Margaron) Lea ....... 661

1476 INDEX

Barratt. ((Wntom) ean oc. «ier > 666 Berlandiery 1@Unto) @veamose.eeoe 172
Barrotty (Unio) sPretiw: cis cies. ai 6 sie 661 Beroeuss (Wie) mcobie.. -/seeeeeee 559
Barrotti@Unio) (Retin. <i. ci 661 Bertilloniana (Spatha) Prest. ....1334
Basalisi (Unio) lgeamenk ss. «<1 =e 657 Beskeanus (Diplodon) Dunk. ....1238
seen, (Ney) IMI, ike IR. aoepoecc 560 Beskeanus (Margaron) Lea ..... 1238
Batava) ((Mysca)) Durt... osc. 569 Beskeanus (Unio)! Dunk: Gs... 22. 1238
Batava|GUmio)) amber ia. ater 560 Bhamoensis (Parreysia) Simp. ..1112
Batavi i@Wmto) miNOssaeieaer... serene 570 Bhamoensis (Parreysia) Theob. ..1111
Batavus (Margarita) Wea ........ 570 Bialataw@Barbala)aiChentaese cs ee 225
Batavus (Margaron) Lea ........ 570 Bidlata (Elyriopsis) Simpy ....0% 207
ipehichabey (QU patko)) Nil, te RE boos oo 568 Bialata (Symphynota) Tea ...... 225
Batavus requieni (Unio) Ross. ... 573 Bialata (Unio)) Hanley §.......... 225
Baumann (Spathaye eur, ©. /ci1--1ere 1333 Bialatus (Hyriopsis) Simp. ...... 208
Baykiniatus) CUnio) (at. .......6 825 aeveMnbicy | (Uke) IOS Aasbooano 225
Bazini (Quadrula) Hde. ........ 928 Biangularis (Lampsilis) Lea .... 59
Bazinin@Unio)mEidesse nee 928 Biangularis (Unio) Lea ........ 59
Beadleiana (Quadrula) Lea ...... 869 Biangulata (Anodon) Sow. ...... 465
Beadleianus (Elliptio) Ort. ...... 869 Biangulata (Anodonta) Cless. ... 465
Beadleianus (Margaron) Lea .... 869 Biangulatus (Lampsilis) Simp. .. 59
Beadleianus (Unio) Lea ......... 869 Biangulatus (Margaron) Lea .... 59
Bealei (Anodonta) Lea .......... 426 Biangulatis, (Winio)) seal nacessaes 59
Bealei (Margaron) Lea ...... 150, 427 Bi-celatusis (Unio) Rives cietesice 103
Bealer (@Unio)m eae 12 on eee 149 Breolora (Uinta) Rates marsierncieeteletctte 731
Beauchampii (Quadrula) Marsh .. 895 Bicristata (Microcondylea) Strub.
Beauforti (Cristadens) Bav. ..... BUS © — COM ONC Ororohg Dr OOOO COA C.0 U0 1099
Beanforti (Unio) Bayes seeeeoenee 1157 3icristatus (Pseudodon) Strub. ..1099
Beaverensis (Margaron) Lea .... 656 3iemarginata (Truncilla) Lea ... 28
Beaverensis (Unio) Lea ......... 656 Biemarginatus (Margaron) Lea .. 29
Beccarianus (Unio) T.-C. ....... 1152 Biemarginatus (Unio) Tea ...... 29
Beccarianus i@Vargus)) T-Gy Sac. . II51 Biesiana (Parreysia) Hde. ...... 11390
Bednalli (@Unio)euhate sanoeeeeeeier 1298 Biesiana (Pseudobaphia Haas ...1139
Bellamyi (Nodularia) Jouss. ....1026 Biesianus (Unio) Hde. ......... 1139
Bellamyi (Pharaonia) Jouss. ....102 Bigbyense (Pleurobema) Lea .... 756
Bellamyi (Spatha) Jouss. ....... 1318 Bigbyensis (Pleurobema) Simp. .. 756
Bellua (Anodonta) Morel. ....... 227 +Bigbyensis (Margaron) Lea .... 756
Bellua) €ristaria)) Worel 2-1 226 Bigbyensis (Unio) Lea ......... 756
Bellulusm(CUnio) Gear asec eta 740 Bigerrensis (Unio) Mill. ........ 555
Benedictensis (Anodon) Sow. .... 424 sisibba Gon odon))) Meld erat renvare 404
Benedictensis (Anodonta) Dekay .. 424 Bigibba (Anodonta) Paet. ...... 404
Benedictensis (Margarita) Lea ... 424 Bigorrensis (Unio) Loc. ........ 555
Benedictensis (Margaron) Tea) .. 424 3ilineata (Symphynota) Lea ....1167
Benedictensis (Symphynota) Lea . 424 Bilineatus (Margarita) Lea ..... 1167
Benedictii (Anodonta) Latch. .... 424 Bilineatus (Margaron) Lea..... 1167
Renedicti! (Marearon) tlediea. sn 424 Bilineatus (Unio) Han. a Ratearane 1167
Bengalensis (Anodon) Sow. ..... 1071 Bilirata (Lanceolaria) Haas ..... 954
a ; Bilirata (Nodularia) Marts. ..... 953
3engalensis (Anodonta) Cless. ...1071 Se ; 3

: ‘ sillotianus | @Unio))) (Ghar) anes 1130
Bengalensis (Margarita) Lea ..... 1071 : :

; Biloba (Epilobasma) Raf. ...... 731
Bengalensis (Margaron) Lea ....1071 Re #

P Bre Nrateinslsy Ms¥borhoy Wa gis otoandoeoods 1097
Bengalensis (Unio) Dea ........ 1071 Binnevin COipledos)atiean eee oes 1267
Bensoni (Margaron) Lea ....... 459 Binneyi (Margaron) Lea ........ 1268
Bensonianus (Mycetopus) Pet. .. 459 Binneyi (Unio) Lea ............ 1268
Bergi (Anodonta) hy .--...-.. 1457 Binominata (Imampsilis) Simp. ... 42
Beringiana (Anodonta) Midd. .... 373 3inominatus (Lampsilis) Simp. .. 43
3erlandieri (Iampsilis) Lea ...... 172 honovrhagnesy (Obabyay)) Maly (a MIR S45 aac 1120

Berlandieri (Margaron) Lea. .... 172 Ibs sonia (Ufo) Wet “Ggeoues coc al Gre

INDEX 1477

Bissellianus (Margaron) Lea .... 714
Bissellianus) (@Unio)!) Gea f.-..3-. 714
Bitlisensis (Unio) Kob. ........ 732
Biwe (Nodularia) Kob. ......... 967
Bin) Unto) MKObS Eye. scr. abade Oe7
Blainvilleana (Anodon) C. and R. 1400
Blainvilleana (Anodon) Sow. .1429
Blainvilleana (Anodonta) Lea ....1400
Blainvilleana (Columba) Cless. ..1400
Blamvalleana (Cveila) Weal faa. 1400
Blainvilleana (Margarita) Lea .1400
Blainvilleana (Margaron) Lea ..1400

Blaisei (Quadrula) D. and H. F. . 922.

Blanchianus

@Unio)) Kobs. 222... 559
Blandianus (Margaron) Tea .... 848
iBilandianuse@Omto)) 5 Leal) kyo er. cers 848
Blandingianus (Margarita) Lea .. 713
Blandingianus (Margaron) Lea .. 713
Blandingianus (Unio) Lea ...... 713
Blatchleyi (Ijampsilis) Dan. ..... 190
Blauverensis (Unio) Pet. ....... 656

Bloyetts¢Spatha)y Martsy “rte ec 1328
Bloyeti (Spathella) Bet..
Beettgeri (Nodularia) Neum. .... 965
Boettgert CUnio)) Neum. =........ 965

Bohmi (Nodularia) Marts. ...... 1036
Bohmi= Unio) Miantsis Gireess-1- sh 1036
Toul Urano)” (Cill Se dotesecacacr 861
Bonelli CWnio)s HROSSs * teeloi oi) -tt 10 451
Bonellii (Anodon) Sow. ........ 451

Bonellii (Baphia) H. and A. Ads. 451

Bonellii (Leguminaia) West. .... 452
Bonellii (Margarita) Lea ....... 451
Bonellii (Margaritana) Kust. .... 451
Bonellit (Margaron) Lea ........ 451

Bonellii (Microcondylea) Cless. .. 451
Bonellii (Microcondylus) Drouet ..452

Bonneaudi (Margaron) Lea ..... 989
Bonneaudi (Nodularia) Eyd. .... 988
Bonneaudi (Unio) H. & T. 1469
Bonneaudi (Unio) Eyd. ........ 988
Bonplandy! G@Unto)) Viale peryetes 1 'oue 1275
Borealis (Lampsilis) Gray ...... 63
Borealis: GWinto))ies Giayaencs crises 64
Borellii (Nodularia) Anc. ...... 1035
Lyemmabhiy MObariey) Vasnes gob amo eeoe. 1035
Borneensis (Cristadens) Iss. 1155
Borneensis (Ctenodesma) Simp. II55
BorneensiseucUnio)), Ussi riser TI55
Borneensis (Virgus) Haas ...... 1155
Bourguignati (Brazzea) Bet. ...1372
Bourguignati (Burtonia) Bgt. .... 206
Bourguignati (Cameronia) Bgt. ..1380
Bourguignati (Chambardia) ..... 1350

3ourguignati (Grandidieria) Joub. 1060
Bourguignati (Leguminaia) Loc. 447

Bourguignati (Mutela) Bet. ..... 1358
Bourguignati (Mutela) Sm. ..... 1358
Bourguignati (Pharaonia) Roch. .1020
Bourguignati (VPleiodon) B. ....1380
Bourguignati (Pseudospatha) Bgt. 206
Bourguignati smithi (Mutela)

WIENS. cacdmougooneboodeccoducn 1356
Bourguignati (Spatha) Bet. 1327
Bourguignati (Spathella) Bet. 1327
Bourguignati truncata (Mutela)

Wiehe uncle oomamtG comin onmcre On 1358
Bourguignati (Unio) Land. ..1020

Bourguignatianus (Margaron) Lea 543

Bourguignatianus (Unio) Lea .. 543
Bournianum (Pleurobema) Lea .. 740
Bournianus (Margaron) Lea .... 741
Bournianus Pleurobema) Simp. .. 741
Bourntanus, (Unio) Wear 2). -.0.6 - 741
Boydianus (Margaron) Lea .... 65
Boydianuss (Unio)! Weal se sinracceryers 65
Boykiniana (Quadrula) Lea .... 82
Boykinianus (Margaron) Lea .... 825
Boykinianus (Plectomerus) Con. .. 825
Boykinianus (Unio) Lea ........ 824.
Bozasi (Leptospatha) R. & G. 1329
IBOZASTnGSpatiaa) im Recon Ganeteicrsrertele 1328
Bozasi (Spathella) R. & G. ...... 1329
Bracteata (Lampsilis) Gld. ...... 73
Bracteatus (Lampsilis) Simp. ... 74
Bracteatus (Margaron) Lea .... 74
Bracteatusi @Unio)eiGldey ere jterers 74
Brandti (Anodonta) Drouet .... 437
Brandtii (Nodularia) Kob. ...... 970
Brandi, (CUmio)! Kobe eeyeyrer.) 101° 971
Braziliensis (Fossula) Ih. ........ 1398
Brazosensis (Margaron) Lea .... 818
Brazosensis (Unio) Lea ........ 818
levee. I8fents satanic cooo6 gona clo 1371
Breve (Pleurobema) Tea ........ 800
Breve subellipticum (Pleurobema)
Slits soaeoouadetoooradddoo0b0KC 8o1
Brevialismn (Uin10)) yeu Crsmmrcrcieteteyeseter se 803
iBrevialisy @Wn10))s amen crerereitetels ich 554
Brevialis, CUnio)) (SoOwiee cmv ce veel 299
Brevicula (Lampsilis) Call ...... 57
Breviculus brittsi (lampsilis)
Slits ogachueacebaspoon sou eutnd 58
Breviculus (jampsilis) Simp. .... 58
iBreviculussGUnio)h Calls): ictecc. 58
Brevidens (Margarita) Lea ...... 8
Brevidens (Margaron) Lea ...... 8
Brevidens (Truncilla) Lea ...... 7
Brevidens) (Unio), Weal <3. oe. er. 7
Brevirostris (Unio) Kust. ...... 573
Brevis (Anodon) Sow, .......... 1413

Brevis (Anodontites) Sow.

1478 INDEX
Brevis: (Glabarnis)@ simp) 2.2... 1413 Bulbasus, (GUmio)s Weal oe... eh se 782
Brevis (Pleurobema) Simp. .... 801 Bullata (Obliquaria) Raf. ...... 731
Brevis subelliptica (Pleurobema) Bullatus prasinus (Unio) Pet. .. 849
SIMA) Seve ee miele esate wee 8o1 Bullatus schoolecraftensis (Unio)
Brevis subilliptica (Pleurobema) Pt. sien ie eine ereerer ae eee 851
SUEDE erchetere irae srevepsianeratelesecaerana eter 801 sullatwus; aC Uinio) cs Contmet tre 849
Brevis. (Unio). wljeay gees © « «aceite 8or Bullella“Simp.ss 2s nine 508
Bractt (Unio) Wanutza s.r 719 Bulloides (Diplodon) Tea ...... 1286
Bridgesii (Anodonta) Lea ...... 1437 Bulloides (Margaron) JTjea ...... 1286
Bridgesii (Anodontites) Lea ..... 1437 Bulloides (Unio), Weaw esse. ee 1286
Bridgesii (Glabaris) Simp. ....... 1437 Bulloideus Simpson ..... SGesinds 1286
Bridgesii (Margaron) Lea ...... 1437 3urkensis (Margaron) Lea ...... 674
Bridotx ((Brazzacanespt. « orien 1374 sybhg Canicresy (CWGcbre)) IPs. Bas caaac a 674
sridouxi (Burtonia) Bet. ...... 205 Burmana (Parreysia) Blan. 1120
Bridouxi (Cameronia) Bet. 1379 3urmanus (J,amellidens) Simp.
Bridouxi (Moncetia) Bet. ...... TSAO apes avevars"eraieus (o,ollesegencnekaienetohey ays 1170, 1470
Bridouxi iGMutela)e Bet) sa..enee 1353 Burmanus (Parreysia) Simp. 1120
Bridouxi (Pliodon) Ger. .:.... 1379 Burmanus, ICUnio)e. Bianeee sci. 1120
sridouxt IGlimo)s Both... ce eres II92 Burroughianus (Anodon) Sow. 1071
Brimleya (Unio) i Ss cbse Wits ieee 805 Burroughiana (Anodonta) Chenu.1435
Brimleyi (Pleurobema) S. H. Wr. 805 Burroughiana (Anodonta) [ea 1071
srittsi (Cyampsilis) simp: fone. os 58 Burroughiana (Margaron) Lea 1071
Broti (Parreysia) Desh. <:..... 1131 Burroughianus (Diplodon) Lea 1271
Brot. (GUmio) im Deshi 2-year II3II Burroughianus (Margarita) Lea ..1271
Broti (Unionella) Maas. “o.72..- 1131 Burroughianus (Margaron) Lea ..1271
Browniana (Hyria) Sow. ...... 1223 Burroughianus (Unio) Lea 1271
Browniana (Margaron) Lea ....122 Bursa-pastoris (Quadrula) B. H.
Browniana (Triquetra) H. & A. DWV ines al vavsksicvcia cbatetaleuee nie havaree rarer avele 890
7 2\c (ee EOE ICO DEES ORION OCS 122 3ursa-pastoris (Unio) B. H. Wr. 890
3rownianus (Margarita) Lea ....122 3urtchianus (Unio) S. H. Wr. 637
Brownianus (Prisodon) Tea ....1222 3urtoni (Grandidieria) Woodw. 1052
Brownianus (Unio) Lea ...... 122 Burtoni insignis (Grandidieria)
Brownii (Diplodon) Lea ...... 1240 Bete ieee oi eideatins scucaaiceaeetetn ey tedaeiete 1053
Brownii (Margaron) Lea ........ I241 Burtoni insignis (Unio) Marts. 1054
Browns) ).GUmi0)) ) lease reieeieiere 1241 Burtoni (Margaron) Tea ....... 1053

Bruguierianus (Margaron) Lea .. 563
Bruguierianus (Unio) Bgt. .... 563
Brumbyana (Pleurobema) Simp. . 785
Brumbyanum (Pleurobema) Lea .. 784

Brumbyanus (Margaron) Lea .. 785
Brumbyanus (Unio) Tea ...... 784
Brumleyanus (Unio) [Lea ....... 784
Brumpti (Leptospatha) R. & G. 1329
Brumpt: (Spatha)y Rey cceGe neo 132
Brumpti (Spathella) R. & G. ....132
Buchanensis (Anodonta) Lea .... 469
Buchanensis (Margarita) Lea .... 469
Buchanensis (Margaron) Lea .... 469
3uckleyi (Margaron) [Tea ...... 628
Buckleyi orcuttii (Unio) S. H. Wr. 629
Buckley1 (Unio) Lea .........2.. 627
Buddianus (Margaron) Lea ...... 628
Buddianus (Unio) Dea .......... 628
3ulbosa (Pleurobema) Simpson .. 782
Bulbosum (Pleurobema) Lea .... 782
Sulbosus (Margaron) Lea ...... 782

Burtoni servainiana (Grandidieria)
Bet.
Burtoni servainiana (Unio) Marts. 1053

Burtoni smithi (Unio) Marts. ...1055
Burtoni sturanyi (Grandidieria)
Midrts.x An-cleraromuciatetsiohe ctor eisrere teers 1054
Burtoni sturanyi (Unio) Marts...1054
Burton s/CUmi0)) s oiiew eect else 1055
Burtoni (Unio) Woodw. ........ 1053
Buntoniay ote saci caret rereret 202
Buschiana (Monodontina) Con. 1086
Buxeus (Marearon) Wea -.5--).).. 612
Biuxeus (Unto)? Weal feteeseisc cae 612
Buxtoni (Unio) B. H. Wr. ..,. 650
Bythinicus (Unio) Kob. ........ 565
Cacao. (GMiargaron))) Wear once 867
(Gaerioy (eka) Ie) joeedeonacuc 867
Celata (Micromya) Con. ...... 34
Crelatura (Conv secrets cceycctsinsite 1019
Czlatus (Margarita) Tea ........ 35

INDEX

Celatus (Margaron) Lea ....... 35
CzxlatusmdWinio)mConi-.. «00 522ee 35
Cerulea gaudichaudii (Nodularia)

IPTESt sere on aes ceria 982
Czrulea keraudreni (Nodularia)

BreS Eaestte ste travatons toon cls arses See cots 983
Cerulea (Nodularia) Lea ........ 978
Czrulea (Nodularia) Simp. ...... 980
Ceruleus (Margarita) Lea ....... 979
Czeruleus (Margaron) Lea ....... 679
Ceruleus (Mycetopus) Hde. .... 460
Ceres (Umionmbealet cerca 979
Caffer africana (Nodularia) Simp. 575
Caffer africanus (Unio) Lea .... 576
Caffer pentheri (Unio) Stur. .... 577
CaiterG@Miargaron)) deal as scienace 575
Caffer (Nodularia) Simp. ...... 575
Caiketn Ont) nmin) ON ear iorgnee 574
Cathet (Ui) muntist ame eee ae 576
Caffer vaalensis (Nodularia) Simp. 576
Caffer vaalensis (Unio) Chap. .. 576
Canteen, Saintes gooodesadancocoeer 574
Catiram(Cateria) Conn adeecnciscs 575
Cahabensis (Quadrula) Tea ...... 858
CahabensiswGWmio)) hea ssa. eee 858
Cailliaudi (Anodon) Sow. ....... 1410
€aillaudi~GSpatha)! Marts) 2.2... 1316
Cailliaudii (Anodonta) Lea ...... 1410
Cailliaudii (Margaron) Lea ..... I410
Cailliaudi martensi (Spatha) Ger. 1323
Caipiray (Diplodon)) Ths oh... os... 1243
Gaipiras@Wmia) ee lhi ee. sens see sac 1244
Calamitarum arcuans (Nephron-

alas) Wahine Gr (Carer naarste Sie Gis oaiene 280
Calamitarum arcuans (Unio) F. &

(Cee ro.nic CE BOC oIS OO niin CEC ee 280

Calamitarum subventralis (Neph-
GOUNAIAS) wel actSn espaol ees, clevelore| “27
Calamitarum (Unio) Morel. ..... 280
Calathus (Nodularia) Bet. ...... 1044.
Galathus: (Unio)! WBetin sake scree 1044
Calceola (Alasmidonta) Simp. .. 497
Calceola (Baphia) H. & A. Ads. .. 497
Calceola (Margarita) Lea ...... 497
Caleeola (Margaritana) Kust. .. 4097
Calceola (Margaron) Lea ....... 4907
Calceolay@Unio)) Weshs. sence seis 497
Calceolus (Alasmidonta) Lea .... 496
Calceolus (Strophitus) Con. .... 497
Calceolius i@Wnio)s Wea ee. oscee 497
Caldwellii (Margaron) Lea ...... 259
Caldwellii (Nephronaias) Lea .... 259
Caldwellie@Winio)) ween... secs oe ns 259
Calendisw Unto) Rate cam. oec oer 73it

Californiensis (Anodon) Sow. .... 377

Californiensis (Anodonta) Lea... 376
Californiensis (Margaron) Lea ... 377
Caliginosus (Margaron) Lea .... tor
Caliginosus (Unio) Lea
Calimatarum (Nephronaias) Simp. 280
Calimatorum (Margaron) Lea .... 280

Calipygos (Anodonta) Kob. ..... 415
Callifera (Anodonta) Marts. ..... 437
Calliopsis) @Unio) Kob. 55.2: ....- 732
Calliscaphameowr ante eaten 1351
Callista (Grandidieria) Bgt. ..... 1059)
(Callonaiamoinypee: eraacia sete oii 1210
Callosa (Anodonta) Kust. ...... 364
Callosus (Margaron) Lea ...... 588
Callosusm (Unto): Wea 2.2). .00 0 587

Cambodiensis (Margaron) Lea ...1067
Cambodiensis (Physunio) Lea 1067
Cambodiensis (Unio) Lea ....... 1067
Cambodjensis (Margaron) Lea 1095
Cambodjensis (Monocondylza)

eto UIA onic Ami aac tres E Gomietitn: Meoees 1095

Cambodjensis (Pseudodon) Pet. ..1095
Cambojensis (Pseudodon) Morel. 215
Cambojensis (Unio) Sow. ...215, 1013

Camelopardalis (Unio) Sow. .... 85
Camelopardilis Lampsilis) Lea .. 86
Camelopardilis (Margaron) Lea .. 86
Camelopardilis (Unio) Lea ....,. 86
Camelus. (Margarita) lea ...... 335
Camelus (Margaron) Lea ....... 335
Canielus, (Unio) Wears ssenis cre 335
Gamerontan Beta syn. oie. oes 1378
Campsianus (Unio) Pet. ........ 1026
Camptodon (Margarita) Lea .... 707
Camptodon (Margaron) Lea .... 707
Camptodon (Unio) Say .......- 707
Canadensis (Margaron) Lea ..... 40
Canadensism@Unio) Wea “ssesseuss 40
Canefrianus (Lamellidens) Simp. .1176
CanthyriaweswalnSonees ace seein c 52
Capax (Lampsilis) Green ...... 47
Capasx ((Margaron)) Weal ssecocesse 47
Capax (Unio) Green .....-...... 47
Caperatus- @Dromus)) Weak ...... 343
Caperatus (Margaron) Lea ...... 343
Caperatuse @Unio) Wea Seasons. 343
Capigliolo bandini (Unio) Pet. .. 540
Capigltolom@Uinio) Kust. ae «cscs 573
Capiclolog @Winio)y (Payiiw nis... cen 540
Capillaris) @Wnio))) eae aa. acs 22
Capilluss@Unio) le Say: sc ssteinetsreleieien 34
Capitata (Cuneopsis) Hde. ...... 044
Capitatus (Cuneopsis) Simp. .... 945
Capitatusm@Uinio); Hide, S26 acess 945
Capseformis (Margarita) Lea ... 30
Capseformis (Margaron) Lea ... 20

1480 INDEX
Capseformis (Truncilla) Lea 29 Castelnaudi (Leila) Hupé ........ I140r
Capseformis (Unio) Lea ........ 30 Castelnaudi (Prisodon) Hupé ....1220
Carbonarius (Margarita) Lea 590 Castelnaudii (Columba) Cless. 1401
Carbonarius semigranosus (Unio) Castus (Margaron) Lea ...-.... 613
Peta el neice fee ekeree Ogi ee Castism (Unio) ele eal meee ates 613
Carbonarius \@Unio)ebea .. ose 590 Cataracta (Anodon) C. & R. 386
Cardiacea (Unio) (Desh: .....40. 886 Cataracta (Anodonta) Say ....... 386
Cardiacea (Unio) Guer. ........ 889 Cataracta (Unio) Desh. ......... 386:
Cardium occidens (Unio) Pt. .. 40 Cataractus (Anodon) Sow. ....... 387
Gardiruny CUnio)iaCon, 2.20 eee 40 Cataractus (Mytilus) Eaton ..... 386
Cardium ventricosus (Unio) Pet. 40 Catawbensis (Margaron) Lea 660:
Carinata (Anodonta) Dun. ...... 1457 Catawbensis (Unio) Simp. ...... 660
Carinata (Miya) Eaton ......... 80 Catillus (Unto) Conyac see 884
Carinata (Solenaia) Hde. ........ 463 Catilus (Unio) B. H. Wr. ...... 884
Carinatus (Mycetopus) Hde. 463 Caudatus (Unio) Wag. Bironens setter ete I221
Carinatus (Unio) Bar ..4..22005 80 Caudiculata (Hyriopsis) Marts. .. 218
Carinifera (Anodonta) Con. 243 Caudiculatus (Caudiculatus) Haas 218
Carinifera (Pilsbryoconcha) Con. 243 Caudiculatus (Hyriopsis) Simp. .. 218
GCarinifera(Unio) alzam-. 0) eee 652 Candiculatus Simp screenees treet. 218
Carinthiacus (Unio) Ross. ...... 571 Caudiculatus (Unio) Marts. ..... 218
Cariosa (Anodonta) Kust. ...... 364 Caveata (Quadrula) Hde. ....... 934
Cariosa (Lampsilis) Say ........ 43 Caveatuss G@Unto)i Hide: sss seee oe 934
Cariosa (Mya) Eaton .......... 44 Cellensis (Anodonta) C. Pfr. 361
Cariosa ((Wnio)i Game sesso ee 44, 506 Celiensis (Anodonta) Kob. ...... 410:
Cariosus (ampsilis) Simpson .... 44 Cellensis beringiana (Anodonta)
Cariosus (Margarita) Lea ...... aa Middl: =: sasnee ok here eee 374
Cariosus (Margaron) Lea ....... 44 Celtiformis (Cuneopsis) Hde. 946
Cartosusi @Unia)i «Sayaene eee a4 Celtiformis (Unio) biden... ee 046
Carmneus Unio) ust ee el eeee 567 Ceninas CHusconaja) mOntit een ree 874
Carolinensis (Castalia) Sow. sere LOO: Cerna (Ouadrila) Conese ee eee 873
Carilinensis (Unio) Bos. ........ 711 Cercinause@WUnro)Conwae eeeee 874
Carrei (Burtonia) Putz, ........- 204 Chaiziana (Anodon) C. & R. ..... 1320
Carrei (Mutelina) Putz. ........ 204 Chaiziana (Anodonta) Rang ..... 1319
Carrei (Pseudospatha) Putz. 204 Chaiziana (Margarita) Lea ...... 1320
Carthagena (Anodonta) ........ 1427 Chaiziana (Margaron) Lea ...... 1320
Carunculina Simpsons ).s.4.5 42008 148 Chaiziana (Spatha) Rang ........ 1319
Casablance (Margaron) Lea 1257 Chalcoensis (Anodonta) C. & 1dog is
Casablance (Unio) Pfr. ......... 1257 Chambardiase better eee 1350
Caseblance (Diplodon) Simp. 1257 Chamberlaimia Simpy sees 219
Caszeblance (Unio) Phil. ........ 1257 Championi (Nephronaias) Marts. . 262
Gastalia ps amse aan sence 1194 Championi (Unio) Marts. ........ 262
GastalrellasSimps sea eee renin: 1208 Chantrei (Anodonta) Bet. ....... 437
Castalina’® Wiha cy saa eee 1204 Chantrei (Leguminaia) Loc. ..... 446
Castanea (Anodon) Hde. ........ 404 Chantrei (Pseudodon) Toc. ...... 450
Castanea (Anodonta) Pet. ...... 404 Chantreyi (Monocondylea) Pet.. 446
Castanea, (Obovaria) Tea ...-...- 200, Chantr (Unto) octane seen 548
Castanea (Quadrula) Simp. ...... 877. Chapalensis (Anodonta) C. & F... 381
Castaneus (Margarita) Lea ...... 301 Chaperi (Pseudodon) de M. ..... 1095
Castaneus (Margaron) Tea ...... 301 Chaperi (Pseudodus) de M. ..... 1095
Castaneusia@Umio)iiweaw ence ace 301 Charbonnieri (Brazzea) Bet. ....1374
Castanedsa (Umno) meats i cies steiters 731 Charbonnieri (Cameronia) Bet. ..138r
Castelnaudi (Anodon) Sow. ....:. 1401 Charbonnieri (Nodularia) Bet. ..1024
Castelnaudi (Anodonta) Hupé ....1441 Charbonnieri (Pliodon) Ger. ..... 1381
Castelnaui (Harmandia) Haas - 1051 Charbonnieri (Unio) Bet. ....... 102
Castelneaui (Harmandia) Roch. ..1050 Charlottensis (Margaron) Lea ... 484
Castelnaudi (Hyria) Hupé ...... 1220 Charlottensis (Symphynota) Lea . 484

INDEX

Charlottensis (Unio) Lea ....... 484
Charonm(@Unio)e rests). 556 eee ee 725
Charpentieri (Anodonta) Kust. .. 365
Charruana (Unio) d’Orb. ........ 1243
Charruanus (Diplodon) d’Orb. 1243
Charruanus (Margarita) Lea ..... 1243
Charruanus (Margaron) Lea ..... 1243
Charruanus) @Wnio)l Sows) .sossc.. 1243

Chathemensis (Margaron) Lea ... 662

Chathamensis (Unio) Lea ....... 662
Chattanoogaense (Pleurobema)
LEN we AS Sirti eae cates te ae 760
Chattanooogaensis (Margaron)
Lee Ten Octet Oe Spa BRA ete 760
Chattanoogaensis (Pleurobema)
SIND aay ed a Cee 760

Chattanoogaensis (Unio) Lea .... 760
Chaudhurii (Nodularia) Prest. ... 988
Cheeziana (Anodon) Sow.

wctaterete 1415
Cheezianus (Anodontites) Sow. 1415
Cheeziana (Glabaris) Simp. ...... 1415

Chefneuxi (Grandidieria) N. & A. 1061

ChelidonuramiRoch eae 1367
Ghelidonopsist Ance cea saeceeeeeee 1367
Cheniana (Anodon) Hde. ........ 404
Cheniana (Anodonta) Pet. ...... 404

Chickasawhensis (Margaron) Lea. 866
Chickasawhensis (Quadrula) Lea.. 866

Chickasawhensis (Unio) Lea...... 866
Childreni (Diplodon) Gray ...... 1269
Childreni (Margarita) Lea ....... 1269
Childreniy (Unio) Gray... «1402 1269
Childrenr(@Unio)) Hans -2..0..-.. 61
Chilensis (Diplodon) Gray ....... 1257
Chilensis) (Unio) (Gray ..2..0-... 1257
Chiloénsis (Diplodon) Kust. ..... 1264
Chiloénsis (Unio) Kust. ......... 1264
Chinensis (Acuticosta) Haas ....1140
Chinensis (Anodonta) Kust., 231, 1072
Chinensis (Anodonta) Pet. ...... 437
Chinensis levis (Acuticosta) Haas

AC BD OOR OB ord SSOHIEE oO ARIE II4I
Chinensis levis (Parreysia) Hde. .1141
Chinensis (Margaron) Lea ...... 1140
Chinensis (Parreysia Tea ........ 1139
Chinensis squamosa (Acuticosta)

IIE AGE dence. obi OOCEDSaN pea nice ae 1140
Chinensis Squamosa (Parreysia)

Eerie ee. Nita as Ore 1140
Chinensis squammosus (Parreysia)

SHLD. .ciciatia renee ataner era t ete t IT140
Chinensis! (Unio) yea i...5.-2-.. 1140
Chipolaensis (Unio) Walk. ...... 638
Chiquetana (Anodon) d’Orb. 1441
Chiquetana (Anodonta) Pet. 1441

Chivoti (Nodularia) Ger.

1481
ChivotiGUinio)) (Gers 4 -asoe. sen oe 10390
Chiosism(Unio) Rate waseceec sence 731
Choziensis (Unio) Prest. ........ 726
Chun (QWargaron) Wea ......... 877
Chunii nasuta (Quadrula) Simp... 877
Chun ((@uadrula)) Wea 2.5... .:c. 876
Chunwi(inio)ieweayese see aense: 877

Churchilliana (Pseudodontopsis)
Kob.
Churchillianus (Pseudodon) West. 443

Churchillianus (Unio) Bet. ...... 443
Churchillianus (Unio) Sow. ..... 443
Cicatricoides (Unio) Fr. ........ 808

Cicatricosa (Pleurobema) Simp. .. 808
Cicatricosum (Pleurobema) Say.. 807
Cicatricosus ((Wnio)! Sayev.ssacee 808
Cicatricosus varicosus (Unio) Pet. 808
Ciconia (Anodon) Sow. ....1431, 1436

Ciconia (Anodonta) Carp. ....... 1436
Ciconia (Anodonta) Gld. ........ 1429
CiconiusmG@Unio) ir Kobyeemiss ecco 547
Cicunmi@Marcaron lear serait 711
Cicur (Unio) Migeame see 711
Cilicia (Anodonta) Kob. ........ 371
Cincinnatiensis (Margaron) Lea.. 26
Cincinnatiensis (Unio) Lea ...... 26

Cinerescens (Toxolasma) Raf. ... 731
Cinnamomicus (Margaron) Lea .. 779

Cinnamomicus (Unio) Lea ...... 779
Cinnamominus (Unio) Sow. ..... 779
Circulus (Margarita) Tea ....... 292
Circulus (Margaron) Lea ........ 292
Circulus (Obovaria) Lea ........ 291
Cizcults! ((Wnio)) Wealasee acne 292
Circumactus’ (Unio) Lea ........ 753
CirratusyCWnio)) eas a case neces 657
Cistelliformis (Margaron) Lea ... 641
Cistelliformis (Unio) Lea ........ 641
Claibornensis (Iampsilis) Lea ... 70
Claibornensis (Margarita) Lea ... 70
Claibornensis (Margaron) Lea ... 70
Claibornensis (Unio) Lea ....... 70
Clappertoni (Anodonta) Koen. 1315
Clarkiana (Lampsilis) Lea ....... 53
Clarkianus (Lampsilis) Simp. .... 54
Clarkianus (Margaron) Lea ...... 54
@larkianusw@Uinto))) lean y-.5 seo crese 54
Clava (Pleurobema) Lam. ....... 735
(Cleve! (Uitte) barn Geka eoncecacc 736
Clavuss@Marearita)) Weal. sa. .ceee 736
Clavius @Marcaron). Weal o-yancee 736
Clavatsw GUimio) aRVes acters <veveete crete 736
Clessini (Anodontites) Fisch. 1450
G@lessini (Glabaris) Simp: ........ 1451
Clessini (Mycetopoda) Ih......... 1459
Clessini (Mycetopus) Fisch. ..... 1451

1482

Clessini (Mycetopus) Ih.
Cliffordiana (Obliquaria) Raf.
Clinchense (Pleurobema) Lea ....
Clinchensis (Margaron) Lea
Clinchensis (Unio) Lea
Clintonense (Ptychobranchus)
Simp.
Clintonensis (Ptychobranchus)
Simp.
Clione Gist.
Coarctata (Anodonta) Ant.
Coarctata (Anodonta) P. & M. ...
Coarctata (Unio) Tam.
Coccinea magnalacustris
rula) Simp.
Coccinae paupercula (Quadrula)
Simp.
Coccinea (Quadrula) Con.
Coccineum (Pleurobema) Ort.
Coccineus (Margarita) Lea
Coccineus (Margaron) Lea
Coccineus (Unio) Con.
Cochlearis (Anodon) Sow.
Cocoduensis (Unio) Rve.
Ceelestis (Iridina) Lea
Ceelestis (Mutela) Cless.
Ceelestis (Platiris) Lea
€Cornata (CAnodon) Gldis..2 232...
Cognata (Anodonta) Gld.
Cognata (Plagiola) Lea
Cognatus (Margaron) Lea
Cognatus (Unio) Lea
Colchaguensis (Unio) Phil.
Colletopterum Bet.
Collina (Alasmidonta) Con. ......
Collinus (Margaron) Lea
Collinus) (CUmio)) (Consieeaeectereeie cle
Coloradoensis (Lampsilis) Lea
Coloradoensis (Margaron) Lea ...
Coloradoensis (Unio) Tea
Coloratus (Unio) Charp.
Columba Lea
Columbensis (Margaritana) Lea ..
Columbensis (Margaron) Lea
Columbensis (Unio) Lea
Columbiensis (Unio) Pet.
Compacta (Truncilla) Lea
Compactus (Margaron) Lea
Compactus (Unio) Lea
Compertum (Pleurobema) Fr.
Compertus (Unio) Fr.
Complanaria Sw.
Complanata (Alasmodonta) Bar.
Complanata (Anodonta) Ross.
Complanata (Baphia) H. &
Ads,

(Quad-

A.

ee a?

INDEX
1459 Complanata (Cameronia) Bet. ...1383
731 Complanata (Complanaria) Con... 491
743 Complanata curta (Mutelina) Ger. 1344
744 Complanata curta (Spatha) Ger. ..1344
744 Complanata (Hyria) Hupé ....... 1219
Complanata katherine (Symphy-
335 MOta)\, Weak.) ferercrsheremuetotaha rage alensoke 492
Complanata (Margarita) Lea - 491
336 Complanata (Margaritana) Calk. . 491
223 Complanata (Margaritana) West. 517
.381 Complanata (Mutelina) Jouss. ...1344
363 Gomplanata (Mya) Dill. ......... 652
652 Complanata (Mya) Eaton ....... 491
Complanata (Spatha) Jouss. ..... 1343
884 Complanata (Symphynota) Bar. 490
Camplanata (Unio) Desh. ....... 652
884 Complanata (Unio) Han. ........ 401
883 Complanatus (Alasmodon) Sow. 491
883 Complanatus (Anodon) Sow. 368
- 883 Complanatus (Elliptio) Ort. ..... 652
883 Complanatus jejunus (Unio) Lea.. 658
883 Complanatus (Margarita) Lea 652
437. Complanatus (Margaron) Lea .... 652
100 Complanatus (Prisodon) Hupé ...1219
1360 Complanatus quadrilaterus (Unio)
1360 Way (efi seveleis Si OS Ere OS OF eee 659
1360 Complanatus (Unio) Dill. ....... 651
376 Complanatus (Unio) Midd. ...... 517
376 Compressa (Alasmodonta) Mke. 451
310 Compressa (Complanaria) Con. 482
311 Compressa (Margaron) Tea ...... 242
311 Compressa (Microcondylea) Pet. 482
1258 Compressa (Monocondylea) Lea .. 242
438 Compressa plebia (Symphynota) C.
501 isting aa Seon Ofacs Gea orc. © 483
501 Compressa plebius (Symphynota)
50x S) heh eA te sor waraee bo 2 483
164. Compressa (Pseudodon) Con. 242
165 Compressa ((Spatha))e Basta ace 242
165 Compressa (Spatha) Marts. ..... 1103
587 Compressa (Symphynota) Lea 481
1399 Compressissimus (Margaron) Lea. 334
354 Compressissimus (Unio) Lea 334
710 Compressus (Complanaria) Ag. 483
709 Compressus (Margarita) Lea 482
710 Compressus plebius (Unio) C. B.
9 1. Canta ae ahi Son Obie om ae 483
9 Compressus (Unio) Con. ........ 482
9 Compressus (Unio) Hde: ......... II50
8090 Comptts (Unio) MDT Gaolime ct. t)-1-16 1182
809 Computata (Nephronaias) C. & F. 257
480 Computatus (Unio) C. & F. .... 258
491 Conasaugenses (Pleurobema) Lea 800
367 Conasaugensis (Pleurobema) Simp. 800
Conasaugensis (Unio) Lea ...... 800
491 Concavus (Margaron) Lea ...... I4l

INDEX 1483
Goncavius «@Uinio)e dear ware cere ioe 141 Contontam (bly tia) SOW. .e.c.s.5 +06 1188
Concestator (Lampsilis) Lea ..... 102 Contorta (Margaron) Tea ....... 1188
Concestator (Margaron) Lea .... 102 Contortal/Ciriquetra)! Wea, ....2.... «. 1188
Concestator @Winio)) Wea vo... ae. 102 Contortus conjugens (Unio) Hde. 1190
Concolor (Margaron) Lea ...... 785 Contortus muticus (Unio) Hde. ..1189
ConcolorsiGWinto) i MWeave or. stcietsre se» 785 Contorttis; @Uni10)) Hides oo. 5. 3:5). 3. 1188
Confertus (Margarita) Lea ...... 639 Contractus (Margaron) [ea ..... 654
Confertus (Margaron) Lea ...... 639 Contractausm@Uinio): Weal onics5 5 ste 654
Contertusi:@Unto)! Weal aos... 638 Contradensmbiaas: | 6 acistsieccieicteleics © ove 1006
Confragosa (Alasmodonta) Say .. 476 Contradens (Contradens) Haas...1005
Confragosa (Baphia) H. & A. Contradens (Margarita) Lea ..... 1005
IN SaeatetayePtereecarslee Se Sea isvel stereo! 476 Contradens (Margaron) Lea ..... 1005
Confragosa (Margarita) Lea ..... 476 Contradens (Nodularia) Lea ..... 1005
Confragosa (Margaritana) Calk. . 476 Contradens (Unio) Lea ........ 1005
Confragosa (Margaron) Lea ..... 476 Contraria (Lampsilis) Con. ...... 69
Confragosa (Unio) Desh. ..:..... 476 Contraniisy (Unio) (Gone j.52 4.6 «5 69
Confragosus (Arcidens) Say ..... 475 Contrarius (Lampsilis) Simp. .... 69
Confragosus (Unio) Sow. ....... 476 ContmtusCUnio)) Tes sev. sere 934
Confusa ‘(Anodon)) Hides 0... 0... 405 Conuss (Unio) PSpengss sacs. 532, 731
Confusa (Anodonta) Pet. ....... 405 Cooperiana (Anodonta) Pet. ..... 399
Congareus (Margarita) Lea ..... 616 Cooperiana (Quadrula) Lea ..... 852
Congareus (Margaron) Lea ..... 616 Cooperianus (Margarita) Lea .... 852
Congarxus GUinio)) Weare aca- ec. 616 Cooperianus’ (Margaron) Lea .... 853
Conjugans (Tritogonia) B. H. Wr. 322 Cooperianus (Plethobasus) Ort. .. 853
Conjugans (Unio) B. H. Wr. .... 323 Cooperianus, ‘CUnio)) Leal < ...2)..:. 852
Conjungens (Arconaia) Hde. 1190 Copanensis (Nephronaias) Marts.. 267
Connasaugensis (Margaritana) Coperm CMarcaron)! Weare ccts sly, «16 106
ICE eds BEE o Ooo BoA Cree Cth 351 Copete CUO) mea ecm erencrchctors ope isis 106
Connasaugensis (Margaron) Lea . 351 Conm@Niarscanita)eleeay er prercreiciersvcrere 766
Connasaugeensis (Strophitus) Lea Cone (Miargaron)) Meares crclcctcraerenctats 766
t AOR OCLcnnY San onon ho aoarcd Ainge ue Cor «(Bleurobema): "Cont .-).. 2 30. FOS
Connasaughensis (Unio) Sow. .... 351 Cora(Umio) Con 72s aecacete ssc 766
Connesaughensis (Margaritana) Conbetm (Unto) Deschs ijgas- c.0ctsi 1172
Glessh Siatottoctorraclecierel eet rors sls 351 Corbicula (Grandidieria) Bet. ....1058
Conradianus (Margaron) Lea .... 248 Corbiculiformis (Unio) Kob. .... 559
Conradianus (Unio) B. H. Wr. .. 248 Corbis @\farearon)) lea" saaeneen II1Ig
Conradicus (Margarita) Lea ..... 247 Corbisy, GBarreysia) lan? osae sens. 1119
Conradicus (Margaron) Lea ..... 247 Gorbish@Winro))) evan. sale siieiceerers eve III9Q
Conradicus (Medionidus) Lea..... 247 Cordata (Castalia) H. & A. Ads. 1199
Conradicus) (Unio) Wear a... ce. 247 Cordatal (Castalia) (Strobs ees 1196
Conraditis’ Unio) Con: ......... 248 Cordata “(@bevaria)iO Rak Sse. 302
Consanguineus (Margaron) Lea.. 759 Cordatus (Tetraplodon) H. & A.
Consanguineus (Unio) Lea ...... 759 NUS tar eo rerer teen: Sic crtera te eete sre srereromaters 1199
Consentaneus (Unio) Ross. ...... 571 Gordatius) GUinto))* Cons) o. a. ccs 882
Consobrinus (Lamellidens) Lea...1171 Corder @Unio)- iden semmerecc cee 946
Consobrinus (Margaron) Lea ....1171 Coreana (Quadrula) Marts. ...... O14
Consobrinus (Unio) H. & T. 1171 Coreanus (Unio) Marts... 22... 914
Consobrinus’, (Unio)! Wea ia 1171 Coriaceus (Diplodon) Dun. ...... 1269
Conspicuus .GUnito)) Wea) tii. 66 Conaceusy Unio): Dunl fs7.:<.s.c120 1269
Constricta (ampsilis) Con. ..... III Contam GWimto) PR Vier ia cerccie clove hele 593
Constrictus (I,ampsilis) Simp. ... 111 Cornea (Anodonta) Phil. ....437, 1457
Constrictus (Margaron) Lea ..... IIt ConmreolawiGSpatha)) Roch y sisjecreyeies 1318
Constrictus (Unio) Conrad ...... III Gomes CUrti0)” TWea® sieccwierere: store 657
Contiguus (Margaron) Lea ...... 103 Cortutas (Miya) Eaton s.csc5 <2 200 331
Contiguus, CUiio) Weat ...5..... 103 Cornuta (Theliderma) Sw. ....... 331
Continentalis (Nodularia) Haas..: 972 Cornutus (Margarita) Lea ....... 331
Contorta GBurtonia) Bets .2..... 205 Cornutus (Margaron) Lea ....... 331

1484 INDEX
Cornutis (Unto) Bars Yreeteicieten- «<1 331 Corvus, ((Margaron)) Weave cencwies 610
Cornuum-lunze cinnamomea (Goya (QeiaMo)) WOE Ss onesdgabeoons 610
(Onadiula) lidesseeeme enc - <1 936 Costata (Alasmidonta) Raf. ...... 489
Cornuum-lune cinnamomeus Costata (Alasmodonta) Say ..... 489
(Oksackanikn)y Sires Sesdoccoupdes 936 Costata (Amblema) Raf. ........ 731
Cornuum-lunae (Quadrula) Hde. . 935 Costata (Complanaria) Con. ..... 489
Cornuum-lune (Unio) Hde. .... 935 Costata (Symphynota) Raf. ...... 488
Corpulenta (Anodon) Sow. ...... 430 Costatus (Plectomerus) Con. .... S821
Corpulenta (Anodonta) Coop. .... 430 Costatusm@Unio) Conse eee 821
Corpulenta (Margaron) Lea ..... 431 Costulata (Margaron) Lea ....... 1390
Correyana (Margaritana) Pet. ... 474 Costulata (Monocondylea) Moric. 1389
Corrianus (Lamellidens) Lea 11714 Costulatus, @Unio)) "Sows sens sce 1389
Corrianus (Margarita) Lea ...... 1175 Couchiana (Quadrula) Lea ...... 842
Corrianus (Margaron) Lea....... 1175 Couchianus (Margaron) Lea...... 843
Corrianus (Unio) Kust. ......... 979 Couchtanus) @Unio)) sbeaw se e erie 843
Gorrianus) GUintonme eames lisse 1175 Coulbois: (CBrazzea)) Bet 22: o.. .- 1373
Corrianus (Unio) Sow. .......... 1168 Coulboisi (Cameronia) Bgt. ...... 1379
Corrientesensis (Margarita) Lea..1390 Coulboist, (@Wnio) Bete ae eee 1024
Corrientesensis (Margaron) Lea..1390 Couperiana (Anodonta) Lea ..... 398
Corrientesensis (Monocondylza) Couperiana (Margaron) Lea ..... 399
GEO; “Aaoooc ooo oadaduvcapoudS 1390 Courquinianus (Unio) Bgt. ...... 541
Corrientesensis (Unio) Han. ..... 1390 Cowperiana (Anodonta) l[Lea..... 399
Corrugata (Alasmodon) DeKay... 507 Coyensis (Gyampsilis)) Pils)e- ee el 196
Corsugata (Celynia) Waal, verecierrayer 1212 Crapulus (Margaron) Lea ....... 766
Corrugata levirostris (Parreysia) Crapulus) (CUnio) year eam ems ase 766
1B Sa ga Rr ale Die Sine SRO ROO ES 1107 Crassa=(Anodon) ii @issaRe seis 1406
Corrugata (Margaron) Lea ...... 1213 Grassay (Anodonta) scans sasesen oe 1406
Corrugata (Mya) Mull. ......... 1106). (Crassa) (Dalliella) Simpy faceee 1077
Corrugata nagpoorensis (Parreysia) Crassa (Cibbosula) Wood ....... 942
Wey sme reseasicretersine wclehere rats iotetesoe eles 1108 CrassaGWlarcarita) Wea secre 1406
Corrugata (Parreysia) Mull. ..... I105 Crassa (Margaritana) Retz....... 518
Corrugata (Spatha) Dautz........ 1348 €rassa (Margaron) Lea ......... 1406
Corrugata (Triquetra) H. & A. Crassas (Miya) Batons es acieteciere cl 80
/NICRMAS RAs Ocae CoO OOO UE OO 1213 Grassa i@Viya) Wioods eeeceesceos 942
Corrugata (Unio) Blain. ........ 1213 Crassa (Simpsonella) Drouet..... 1077
Corrugata (Unio) Lam. ......... 1106 Crassidens (EFilliptio) Ort. ....... 607
Corrugata (Unio) Mand. ........ 571 Crassidens (Margarita) Lea ...... 607
Corrugatus levirostris (Unio) H. Crassidens (Margaron) Lea ...... 607
a Cie Pee ae Sst Perc rare aOTnTS Oteee 1108 Crassidens (Unio) ijams et ccc 606
Corrugatus (Margarita) Lea ..... II06 Grassidens @Un10) mSoun sees 81
Corrugatus (Margaron) Lea ..... 1106 Crassidens var. a (Plectomerus)
Corrugatus _nagpoorensis (Unio) Cons oases a deisis eres byeisiacenelereens 831
13 an heen aS. rela dota Gat aa eer oko eC 1108 Crassidens var. a (Unio) Lam.’... 831
Corsugatus: (CUnio)) Retz) er... 1106 Crassidens incrassatus (Unio) Lea 608
Coruscus diazensis (Unio) S. H. Crassissimus (Margarita) Lea..... 516
Nia Aine aan 6 Sco dose naaS 632 Crassissimus (Unio) Han. ....... 519
Coruscus fryanus (Unio) B. H. Crassitestaoimps mares 236
AWWirsw terete ston sicre neuen aebeesietcPelovens) ss4se 632 Grassus «GAnodon) sows aemiiiemiccie 1406
Coruscus fryanus (Unio) Simp. .. 633 Crassus (Anodontites) Sw. ...... 1406
Coruscus (Margaron) Lea ....... 632 Crassus batavus (Unio) Jor. ..... 570
Coruscus (Unio) Glid. ........... 631 Grassus )CGlabaris) soiipas ele e oie 1406
Corvinus (Margaron) Lea ....... 160 Crassus (Margarita) ibeas ee seer 80
‘ornare (Uherka)) IUCKEl 5 Wo GoeouoEoo 160 G@rassus ((Marearoen)) Weae. «oer 518
Corvunculus (Lampsilis) Lea .... 158 Crassus musivus (Unio) Ort. .... 569
Corvunculus (Margaron) Lea .... 159 Crassus (Pseudodon) Drouet 1077
Corvunculus (Unio) Lea ........ TSS0) (Crassus CUn1O) miaien wrreictsy-leleleierels 815

INDEX

Merassus= CUimiO) in Cone tac istecie clues 77
Crassus, CUimo)) Beasts. si cec0.0s oc 65
1Crassus) .@Wmios INGESSss ciacicasrres er 570
SAGES (Uist) RET Gooddocoboce 555
Crassus) @Uinio))) PREtZa verse srstetsis) sone 518
(SMSSES (Wii SEGT BUotosaboonbe 80
Crassus |GWnio)! SOW. sicies ag sc 82, 607
Crebristriata (Margaron) Lea ....1082
‘Crebristriata (Monocondylzxa)
ISHII CogdeaoanodoteuoGsuc G0 1082

Crebristriata (Trigonodon) Con. .1082
Crebristriatum (Trigonodon) H.

See La Men ch wet svar ctosredchispeueleiene vote ee h a iaxane 1082
Crebristriatum peguensis (Trigon-
OGOn) EMA Scie nagesey none: sletercreyetonsye 1083

Crebristriatus curvata (Pseudodon)

NAGOS tere rats vers sit cvokere cysuecas¥erovereieheveres 1083
Crebristriatus curvatus (Pseudo-

dom POR RESts ga. cols icaoycleis eiosin seketetere 1083
‘Crebristriatus peguensis (Pseudo-

GOM))* SIMp! wow eycichsveeveretsiore eievel oh oraxs 1083
Crebristriatus (Pseudodon) Anth. ro82
‘Crebristriatus (Unio) Sow. ...... 1082
Crebrivittatus (Margaron) Lea.... 759
‘Crebrivittatus (Unio) Lea ........ 759
‘Crenodonta Schlut) ..22.6.-<4.5. 813
Crepera (Anodonta) Lea ........ 1072
‘Crepera (Dalliella) Simp. ........ 1073
Crepera (Margaron) Tea .......; 1073
‘Crepera (Simpsonella) Lea ...... 1072
‘Creperus (Anodon) Sow. ........ 1072
Creperus (Margarita) Lea ....... IIs
Creperus (Margaron) Lea ....... IIs
METED ELISE (OW 110) ely arus relists eveleiels/ere II5
Cressenus: CUnio)e lane esi cselereta ere II5
*Crispaw (Anodonta) Warm accis cis 1415
Crispata (Alasmodonta) Mouss...1086
‘Crispata (Anodon) C. & R. ...... 1415
Crispata (Anodonta) Lam. ....... 1415
‘Crispata (Anodontites) Brug. 1415
Crispata (Margarita) Lea........ 1415
sCrispata (Margaritana) Pet. ..... 1086
Crispata (Margaron)) Wea .:..... 1415
‘Crispata (Nodularia) Gld! 22. ....- 994
Crispatas-(Umio)PGldy a5. crs cristae 994
Crispatus (Anodontites) Brug. 1414
*Crispatus (Glabaris) Simp. ...... I4I5
‘Crispatus (Margaron) [Lea....... 994
RGrispatus GUO) be Ele vcr Lem srcterererers 994
‘Crispisuleata (Nodularia) Ben. IO17
Crispisuleatus (Margaron) Lea...1017
*Crispisulcatus (Unio) Ben. ...... IOI7
GristadensmSinnpay Genesco cte sae 1154
IOngindih Snitink Sasoomoureeccsoon 223
«Crocatus (Margaron) Lea ....... 50

«Crocatus (Unio) Lea ............ 50

Crocodilarum prestricta (Unio)

Ba SG
Crocodilarum rudis (Unio) Marts. 910
Crocodilarum (Unio) Morel.

shayatere 591
Crocodilarum semipustulata (Unio)

Heer or Oaeier eye ractata av chowicvereit cis 592
Cromwellii (Lampsilis) Lea ...... 157
Cromwellii (Margaron) Lea ..... 158
Cromyellins (Unio) eal. eens 157
Crosseana (Castalia) Hid. ....... 1204

Crosseanus (Tetraplodon) Hid. ...1203

Crossei (Contradens) Haas Sesisisiss LOOS
Crosset)|@Physunio) Di & Jolacqece 1065
Crossem (@Uinio)), DSS Jane aoe 1065
Cruda (Pleurobema) Simp. ...... 753
Crudum (Pleurobema) Lea ...... 753
Crudus (Wine) Sean ertecermicieete 753
Cryptoraoita (Spatha) Ger. ...... 1337
Cryptoradiata (Spatha) Putz. ~ 1337
Ctenodesmat-simps Aare ase 1154
Cucunrariag( Cons a-rcnace eee 1304
Cuchirertats Simpse eee eeeicn 1304
Cucumoides (Margaron) Lea .1305
Cucumoides (Unio) Tea ......... 1305
Cultelliformis (Diplodon) Con..... 1300
Cultelliformis (Margaron) Lea - 1301
Cultelliformis (Unio) Con. ...... 1301
Cultratae CAnodonta)) (Glide 212... 424
Gumberlandiay Ont) os sacs eee 522

Cumberlandianus
Cumberlandianus
Cumberlandicus

(Margarita) Tea 119
(Margaron) Lea 119
(Margaron) Lea. 119

Cumberlandicus (Unio) Tea...... 119
Cumingianus (Unio) Dun. ....... 1305
Cumingii (Anodon) Sow. ........ 1089
Cumingii (Anodonta) Lea ....:.. 1089
Cumingii (Hyriopsis) Lea ....... 210
Cumingii (Margaron) Lea...210, 1089
Cumingii (Microcondylea) Cless. r1o89
Cumingii (Monocondylea) Lea ...1089
Cumingii (Pseudodon) Lea ...... 1089
Cumingii (Pseudodus) de M. 1089
Cumiunei (Unio)! Weal eeaccene sees 210
Cuneata (@Mutela)is Prests cassie 1365
Cuneata) (Miya) Baton) 2... 066 607
Cuneata (Pleurobema) Raf. ...... 810
Cuneatuss (Unio)! Bary aise sen 607
Cuneatus) GCUnio): Ross! s.2n 20260 555
CuneatusmG@Unio) ie Sayaanes sme aoe 737
Cuneatusm (Unio) e Swe, catenhe ines 6
Cuneolus (Margaron) Lea ....... 743
Cuneolus (Pleurobema) Lea ..... 743
Cuneolus (Pleurobema) Simp. ... 744
Cuneolus, (Unio)! ‘Wea sss clcs crctens 743
@tineopsiss Simp. ion. ceriseacecioas 943
Cuneus? (@uadrula)) “Cons -.2 seen 806

1486 INDEX

CuneusmCUnto) = Galler cers eo 884
Cuneus ‘CUnio)) Conrad s5:......- 897
Cunninghami (Unio) B. H. Wr... 635
Cuprea (Obliquaria) Raf. ........ 731
Cuprinus arcuans (Unio) Marts... 280
Cuprinus coloratus (Unio) Marts. 587
Cuprinus (Diplodon) Simp. ...... 1258
Cuprinus (Margarita) Lea ....... 180
Cuprinus (Margaron) Lea ....... 180
Cuprianus nephriticus (Unio)

IIETECR SEs 6 boca. op Oe Onedot 281

Cuprinus persulcatus (Unio) Marts. 278
Cuprinus subventralis (Unio)

Marts: merc l.porcciesrentomioniocis o's svereners 281
Cuprinus tabascoensis (Unio)

Marts: : © Se kieis sie ets. © aie s)s:disjeaoae,c 282
Cuprinus! (@Uinio) Wea a...) 6 os ate 180
Cuprinus: "(Uinio) siMiarts: | coecie 280
@uratus) G\Wlargaron)eeay mace ae 665
Curatust (Unio \imleal wee ceuelciete aie: 665
Curreyana (Baphia) H. & A. Ads. 474
Curreyana (Margaritana) Lea .... 474
Curreyana (Margaron) Lea ...... 474
Curreyana (Micromya) Ag. ..... 474
Currevana (Strophitus) Con. .... 474
Garreyana “CUnio)e Sows)... <> 1-1-1 474
Curreyanus ((Unio)) Hane 21.2)... 474
Curta (Pleurobema) Simp. ....... 763
Curtum (Pleurobema) Lea....... 762
Cuntusi(@Margaron)) (eau... leciie 763
Cartas (Unio) Wea errs scree 763
Curvatus (Anodonta) Jay ....... 437
Cunvatus® (G@Uin10) Sue eae rear cere 665
Cuspidatusis(Umi10)) Wear cy.ai sie oles 665

Cuvierianus (Margaron) Lea .... 666

Cuvierianus (Unio) Tea ........-; 666
(COychobis (User) Wil Soaoaooodac 575
Cyclips (Toxolasma)) Raf. =. .-... 731
Cychips Unio) Ber we sere 77
Cyclomiuycae Simipea rier ercnctetsctarsrasiels 1278
Cygnea anatina (Anodonta) Linn. 366
Cyenea sCAnodon) M@rs ie ecictcteleciens 361
Cygnea (Anodonta) Hann. ...375, 376
Cygnea (Anodonta) Linn. ....... 359
Cygnea beringiana (Anodonta)

Fliariyas,/ ¥sc\ete ices sis rem etevessvcusisre. enotene 374

Cygnea impura (Anodonta) Hann.

Soe OC 376, 378, 380, 381, 382, 383
Cygnea (Margarita) Lea ......... 361
Cygnea (Margaron) Lea ........ 361
Cygnea piscinalis (Anodonta) Nilss. 368
Cygnea ponderosa (Anodonta) C.

1 OC PR Cn peen Rian 5.0) Sia cc SOOTHES 368
Cygnea rostrata (Anodonta) Ross. 369
Cygnea (Symphynota) Lea....... 361
Cygneus (Anodon) Turt. ........ 360

Cygneus (Anodontes) Cuv. ......
Cygneus (Mytilus) Linn. ........
Cygnoea (Anodonta) Gass.
Cylindracea (Anodon) Sow.
Cylindracea (Anodonta) Lea
Cylindracea (Margarita) Lea
Cylindracea (Margaron) Tea ...
Cylindracea subarcuatula (Ano-
onitias) ies (Gee Gs carters eareepasionne
Cylindraceus (Anodontites) Tea...
Cylindraceus (Glabaris) Simp.
Cylindrella (ampsilis) Lea .....
Cylindrellus (Lampsilis) Simp.
Cylindrellus (Margaron) Lea
Cylindrellus (Unio) Lea .........
Cylindrica (Lanceolaria) Haas ...
Gylindrical (Miya) eibaton= os
Cylindrica (Nodularia) Simp.
Cylindrica (Quadrula) Say
GylindritaeSimip: eee eee oe
Cylindrica strigillata (Quadrula)
Bee SEVS LWorciy cyl setorcsnnssnbaae toreieeciciotehe
Cylindrica sCUnito) ia Swaseesn see ee
Cylindricus (Margarita) Lea
Cylindricus (Margaron) Lea .....
Cylindricus (Orthonymus) Ag. ...
Cylindricus strigillatus (Unio) B.
IA. Witt ficitvatrese siciate aoe cre eer ole
€ylindxrreus| (Unio) Say, s.n.2- ee +r
Cyphia (Obliquaria) Raf.
(Syqojaney “(GUkervey)) (Come aoaeaneccoon
Cyphias aesopus (Unio) Pet.
Cyphius (Unio) Say
Gyprogernial JA ge Mies sae cromicee eine
Cyrenoides (Margaron) Lea
Cyrenoides (Plagiola) Phil. .....
Cycenoides (CUnto)) Phils 42225...
Cyrenopsis (Grandidieria) Bet.
Daccaensis (Parreysia) Prest.
Dactylinus (Unio) Hde.
Dactylus (Anodon) Sow. ........
Dactylus (Anodonta) Cless. .....
Dactylus (Margaron) Lea ..117,
Dactylasm@Wis0) mlyeas mere er eet
Dactylus (@Umro)) sMiorelS s.)s0.-
Dahomeyensis (Anodon) Sow.
Dahomeyensis (Anodonta) Lea .
Dahomeyensis (Margaron) Lea...
Dahomeyensis (Spatha) Lea .....
Dahurica (Margaritana) Kob.
Dahuricus (Unio) Midd.
Dakota (Anodonta) Fr.
Dalei (Anodonta) Tess: .........
Dallasiana (Anodonta) Lea ......
Dallasiana (Margaron) Lea ......
Dalli (Unio) B. H. Wr.

INDEX 1487
Malte lia Sinmtpeeeenecree crete ete 1069 Dejecta (Anodonta) Lew. ....... 384
Damralismiveachiy-ncreeer aoe ee SII Dejecta (Arnoldina) Hann. ...... 385
Damascensis (Margaron) [Lea 563 Delaportei (Araconaia) Morl. .... 211
Damascensis* (Unro) Tea ........ 563 Delaportei (Hyriopsis) C. & F. .. 211
Damnoreas GUnio)r deOrbs ss. -1.ce s 1312 Pelaponter Unto) (Ci & EY os. >. 211
Dantelise CUmio)= Gasst 9 -\-).5) 6 21ers 21 536 Delesserti (Margaron) Tea ...... 557
Daniella -GUnto) Wallaroo. < ton 1208 DelessertreCUnto)) Bet: Ll ase. 557,
Danielsii (Anodon) Sow. ........ 428 Delicatus (Margaron), Lea ....... 552
Danielsii (Anodonta) Lea ........ 427 WelicatusGUnio)) Wea eso. nae. os 552
Danielsii (Margaritana) Pet. . 428 Delodon’ (Unio) Stroby 4... 546.66 < 1227
Danielsii (Margaron) Lea ....... 428 Delodonta (Unio) Tam. .:....:.. 1227
Daniels CUnio) BS He Wr. =... - 611 Delodontus (Diplodon) Simp. ....1227
Dariensis (Anodon) Sow. ........ 394 Delodontus (Margarita) Lea...... 1227
Dariensis (Anodonta) Lea ...... 394 Delodontus (Margaron) Lea ..... 1227
Dariensis (Margaron) Lea....394, 616 Delodontus (Unio) Sow. ........ 81
DariensisCUnio)) Weal s.sa.<<ce ese 616 Delphinopterus (Unio) D. & F. .. 208
Datusy @Viargaron) bea" sossen ce. 665 Delphinulus (Lampsilis) Morel. ...193
IDEKAIG (Oho ILC eas As Gonigmonac 665 Delphinulus (Margaron) Lea ..... 194
Dautzenbergi (Contradens) Haas 1015 Delphinulus (Unio) Morel. ...... 194
Dautzenbergi (Nodularia) Morl. .1014 Delphinus (Margaron) Lea ...... 208
Dautzenbergi (Unio) Morl. ...... tors Delphinus (Metaptera) Morl. 208
Decampsiana (Nodularia) Watt. ..1026 Deéelphinus s@W@nio)) (Grins «co. 0. oe 208
Decampsianus (Unio) Watt. ..... 1026 Delphinus (Unio) Speng. ....... 731
Decisa (Pleurobema) Simp. ...... 759 Deltoidea (Alasmodonta) Bak. ... 497
Decisum (Pleurobema) Lea ..... 758 Deltoidea (Baphia) H. & A. Ads. 497
Decisus (Margarita) Lea ........ 759 Deltoidea (Margarita) Lea ..:... 497
Decisus (Margaron) Lea ........ 759 LDeltoidea (Margaritana) Lea 497
Wecisus* (Unio) Kust =. 2teess oe 797 Deltoidea (Margaron) Lea ....... 497
WecisusM@Winioy seaeen ccs seme 759 Deltoidea (Strophitus) Con. ..... 497
Declivis (Anodonta) Con. ........ 421 Weltoidea (Unto) Han: 45.2. ee. 497
Declivis geometricus (Unio) Fr. . 707 +=‘ Deltoideus (Unio) Sow. ......... 497
Declivis (Margarita) Lea ........ 708 Delumbis (ampsilis)) Cons —....- 52
Declivis (Margaron) Lea ........ 708 Welumbis (Unio) “Cony Geos. 52
Declivisi (Unio) Cons -oeek sees. 711 Delumbis (Unto) WKust... cartes 135
Wechivisei@Unto) = Saye eee cee 708 Demangei (Simpsonia) Roch. 222
Decora (Anodoen) Sow: ...-...... 421 Demararaensis (Diplodon) Simp. .1255
Decora (Anodonta) Lea ........ 421 Demararensis (Unio) Lea ....... 1255
Decora (Margarita) Lea ........ 421 Demarasensis (Unio) Pet. ..... 1255
Decora (Margaron) Lea ........ 421 Demeraraensis (Diplodon) Lea 1255
Decorata (Symphynota) Lea 486 Demeraraensis (Margaron) Lea...1255
Decoratus (Margaron) Tea ...... 486 Demeraraensis (Unio) Lea ...... 1255
Decoratuss CUnio)! Wea ae... se 486 Dembee (Nodularia) Simp. ...... 580
Decorsei persinuata (Spatha) Ger. 1340 Dembex (Unio) Rve. ............ 580
Decorsei sinuata (Spatha) Ger....1340 | Denigrata (Anodonta) Lea ...... 468
Decorser \(Spatha): (Ger. 2c... 1339 Denigrata (Margaron) Lea ...... 468
Decumbens (Margaritana) Lea... 522 Denigratus (Margaron) Lea ..... 647
Decumbens (Margaron) Lea .... 523. Denigratus (Unio) Lea ......... 647
Mecumbens (Unio) Tea ..:...... 523 Denserugata (Nodularia) Haas... 966
Wecurnvatus Unio) (Ross) <.s.ase. 571 Depauperatus (Unio) Hutton 1292
Dehiscens (Anodonta) Pet. ...... 454 Depexa (Anodonta) Marts. ...... 1425
Dehiscens (Baphia) H. & A. Ads. 454 Depexus (Anodontites) Marts. 1425
Dehiscens (Hemilastena) Ag. 454 Depressa (Ireguminaia) West. 541
Dehiscens (Margarita) Lea ...... 454.0 Wepressa CMiya) Don* /32. 22202... 538
Dehiscens (Margaritana) Cless. 454 Depressa (Obliquaria) Raf. ...... 305
Dehiscens (Margaron) Lea ...... 454 Depressa, CUinto)). (© Pir, sek ne 451
Dehtscens): @Wmio)! Say 2422.5... 454 —Depressa (Wnio) d’Orb. .....-... 1312

1488 INDEX
Wepressa WUinio)elyame eines sie. 1301 Diplodonmepic aac iter
Depressus (Margarita) Lea ...... 1298 Diplodon) @Unio))Philjes asso.
Depressus (Margaron) Lea ...... 1298 Dipsas (Anodonta) Blain. .......
Wepressus (Unio)iCons saeceee oe 1301 Dipsas’ Heach'y avec oe Cas
Depressus (Unio) Wess. 25 .5.26.. 1298 ID;EERS MOE Aa oadnontosbanseboc
Depressus (Unio), Pact: i5.05.4-- 538 Disciformis (Nodularia) Roch.
Depressus (Unio) Rve. «.........; 1298 Disciformis (Zairia) Roch. ......
Depyeis: Unio) e Cone wane eie cle 294 Discoidea (Barbala) H. & A. Ads.
Deschampsi ((Wnio)) ekoby w..u escs 732 Discoidea(Cristamayawseyea vee
Deshayesii (Wnio)) Mich. .2.....% 532 Discoidea (Dipsas) Kust. ........
Despecta (Anodon) Hde. ....... 404 Discoidea sautteri (Cristaria) Haas
Detectus (Unio) sere soe ase 808 Discoidea (Symphynota) Lea ....
Deviata (Truncilla) Rve. ........ 31 Discoideus (Margaron) Lea ......
Deviatus (Margaron) Tea ....... 2 Discoideus (Unio) Han. .:......
Deviatus. Winton) viessercce selena 2 Discoidens (Unio) Han. ........
Diavenees. scission siartanrete ere Cio 344 Discoideus CUnio) sSowlas.. sss.
Dianisotis, Rat. ime cts sateen le ee 223 Discomya se Sipser eer eeeae eee se
Diaphanusy @Unio) seats. ele 731 Discrepans (Margaron) Lea .....
Diarbekerianus (Unio) Kob. 732 Discrepans, CUnio)) Weare. cscs s
Diaurona, (Cocks eaccser chee acre 1137 Disculus (Diplodon) Tyea-........
Diazensiss@Unio) = osm elm Wieser 633 Disculus (Margaron) Lea .......
Diespiter (Nodularia) Mab. ...... 993 Disculusy (@Wnio) i alcams setae
Diespiter (Oxynaia) Mab. ....... 993 Discus connectans (Unio) Marts.
Diespiter @CUnio)) Mab. 3.30... 993 Discus (Lampsilis) Pils. ........
Dittertus) CUnio) miveaun seek ne 671 Discus (Margaron) Tea-.........
Difficilis (Margaron) Lea ....... 12 Discus panucoensis (Unio) Marts.
Ditheilis) CUnio)) Wyeaeecseiee eee 12 Discus iGUnio) ml eammeeaecetanoceee
Digenae: “seykiee fects eet area au70) Discus (Unio) Soweeeesecerhyeee
Digitata (Quadrula) Morel. ...... 822 Dispalans (Unio) B. H. Wr.
Dieitatus! (Unio) Mionels <2 .ee ce. 823 Dispansus@Unio) eae eemacie
Digitiformis (Nodularia) Sow. 968 Hallax: (Unio) eiyeawemccys ar aeieiee cre
Digitiformis (Unio) Sow. ........ 968) Dispar ((vampsilis) mlyeay seis rete cle
Dignatus assuricus (Unio) Kob. .. 546 Dispar ((Margaron)) Weal .c aes ee
Dignatus (Margaron) Lea ....... 546 Disnarel@Unio))lyeateeieem eens
Dignatus ninusi (Unio) Kob. 546 Dissimuilis| (Unio) Wea icc secs cre
Dignatus semiramidis (Unio) Kob. 546 Distans (Unio) Anth. ...........
Dignatus CUnio)leatemectees aoe 546 Distinctuss @Unio) Cancel ES pice
Dignota (Anodonta) Fer. ........ 387 Distortus; (Unio)) Beany seceee cane
Dignota (Anodonta) Raf. ........ 437 Distortus “Unto Weldey gence cele
Dilatata (Unio) me Rati see we eyperterine Gia Divaricata (Spatha), Marts. .....
Dilatatuse GWmio)) pe Sayamemn eerie 598 Divaricatus (Diplodon) Lea .....
Diminuta (Nodularia) Simp. ..... 583 Divaricatus (Margarita) Lea
DiniinutisaG@Uni1o) selyeaneerecizic ceri 583 Divaricatus (Margaron) Lea .....
Diminutus (Margaron) Lea ...... 583 Divaricatus, (Unio)! Weaema. aces
Diminiutus Wn) year aereieisere 583 Divergens (Quadrula) Ben. ......
Dimota (Nodularia) Lea ........ 1008 Divergeus’ (Unio) Bens Senccee sss
Dimotus (Contradens) Haas 1009 Diversa (Alasmidonta) Con. .....
Dimotus fischerianus (Contradens) Diversus (CUnio)) sConewee sete ae
MAS. ference acter iotanreree holsters eae Ioro Dolabella (Castalia) Sow. .......
Dimotus lugens (Contradens) Dolabelloides (Margaron) Lea
Ebaass sajcvcisdiessioustehcreciercice rie cienes IOI2 Dolabelloides (Pleurobema) Lea...
Dimotus (Margaron) [ea ....... 1009 Dolabelloides (Unio) Lea .......
Dimotus sacellus (Contradens) Dolobreformis (Lampsilis) Lea
Faas 223 ane ee ene re ee IOIL Dolobreformis (Margarita) Lea ...
Diolibanus (Pleiodon) Bet. ...... 1470 Dolobreformis (Margaron) Lea ..

Diploderma (Bariosta) Raf.

see

Dolobreformis (Unio) Lea

1045.
230

230
231
230

1283
603
603
603
603
602

INDEX
Dolobreformis (Unio) Sow. ...... 40 Droueti (spatha); (Chaps ts... 22...
Dolearis (Anodonta) Lea ....... 393 Drouetiv CUnio)) Wap. ae eee
Doliaris (Anodonta) Lea ........ 393 Dubia (Alasmodonta) Fer. .....
Dolhanse@zampsilis)) Myeay aerlerls + ve 56 Dubia (Anodonta) Bose .......
Doliaris ,(Margaron) Lea ..... 56, 393 Dibias Giridina)es@hentiy (35: -)es.ie-
IDfollievaity (AUhabto) ILC Gadoeaccoogc 56 Dubia’ CMiutela): Gmelo ..o..5..
Dolichorhynchus (Unio) T.-C. ....1167 Dubia (Mytilus) Gmel. ........
Doliolum (Anodon) Hde. ........ 414 Mishra @elatinis)) leas eo eieen ter
Doliolum (Anodonta) Hde. ...... 414 Drab aise | GUO) abitzestyerde errretete
Dolosus (Margaron) Tea ........ 167 Duclerci (Chamberlainia) Simp.
DolosusmCUnio)y Weare. aa scte ee 167 Duclerci (Simpsonia) Roch.
Dombeyana Unio)» Walesa ace oe 831 Wuclere, CUnito)! och 42.
Donaciformis (Margarita) Lea .. 309 Dugasty i(Umnio)) Miorl, Js5.. se
Donaciformis (Margaron) Lea 309 Dulcis (Anodontites) Ih. .......
Donaciformis (Plagiola) Lea 308 DualeissCGlabanis)) Who ace. ce os
Donaciformis (Unio) Lea ........ 309 Dumesleanus (Unio) Charm.
Dooleyensis (Unio) Lea ........ 662 Dunkerianus (Diplodon) Lea
D’Orbignyanus (Unio) Sow. ..... 1208 Dunkerianus (Margaron) Lea
DoreieGUnto) ob. Else awit eeteieter 634 Dunkerianus (Unio) Lea ......
Dorfeuillianus (Margarita) Lea 850 Dunlapiana (Anodonta) Lea
Dorfeuillianus (Margaron) Lea 850 Dupont: (Nodularia) Roch. .....
Dorfeuillianus (Unio) Lea ....... 850 Duponti (Parreysia) Simp. .1038,
Dorr GNodularia): Watters eciere 966 Duponti (Reneus) Jouss. ......
IDYeyrot AU iarop AW ENA “Aeoecoocednge 966 Duponti CUnio)s Beth aoccce ectes
Dorsatus (Margaron) Lea ...... 20 Duponti €Unio)) Roch, Faj5.-..-
DorsatusmGWinio) im ly eamecrracieieiercle 619 Duprei (Callonaia) Ree. .25..:.
Dorsuosus (Diplodon) Gld. ...... 1289 Duprey @Castalia) Rees wacker
Dorsuosus (Margaron) Lea ....1289 Dupret (Margaron) Dea .......
Dorsuosus (Unio) Gld. ......... 1289 Dupes CUm10)) hi Ce Rot R srs cette) ete
Douglasiez crassidens (nodularia) Dupuyi (Anodonta) R. & D.
eUiearcsit Aiisy tevsictebelleus s exer lees leis lene 963 Durieui kullethensis (Unio) Lea ..
‘Douglasiez nipponensis (Nodularia) Durieui (Margaron) Dea .......
WIESE” Tat/onmbce 6 ob he bd boo.ddan Or 961 Durieut ((Unio) Desh? 5-1
Douglasie (Nodularia) Gray ..... 959 Duttonianus (Margaron) Lea
Douglasiz shanghaiensis (Nodula- Duttonianus (Unio) Lea .......
TEN > IEE fer eiano-o ibid cao Bercie orc 961 TD ySTMOMMIA Aa. foi: see alaa-tonauelerayel olete
Douglasiz sinulata (Nodularia) Dysonii (Nephronaias) Lea .....
Nia Stems eect. cutouts een state tte ar areca on 962 Dysonii @Margaron) Dea 52.0...
‘Douglasie sinuolatus (Unio) IDK oyabbin (CO soukoy)) Mer Aasondaaaes
Mia ritsee .5 gy as is chevsheloetasere suas sia 962 Ebena (Husconaja)i Ort. si.
“Douglasiez taiwanica (Nodularia) Ebenus (Margarita) Lea .......
12a Baton cr dicnaticd acide taemearec Ob 963 Hbenus, @Miargaron)! Wea 5... 5
“Douglasie (Unio) Gray .......... 960 EHbenus' (Quadrula)) Lea) ...5.....
Moumetin Unio) eles esses Soa 732 benassi GUnio)iilyeaieeiecscraercd oretere
Downiei (Margaron) Lea ........ 685 Eearinata (Castalia) Mouss. ....
Downtei Unio); Wea. Boece « < srcte 684 Ecarinatus (Tetraplodon) Mouss.
Draparnaldy GUnio), Deshs = 3.54. 555 Edentula (Alasmodonta) Say
Dromas (Cyprogenia) Ag. ....... 341 Edentula (Anodon) C. & R.
sDromas) (@Dromus) Wea, . 5... << 341 Edentula (Anodonta) Fer. .....
Dromas (Margarita) Lea ........ 341 Edentula (Margarita) Lea .....
Dromas (Margaron) Lea ........ 341 Edentula (Margaron) [Lea .....
IDES (Ose)! WEE -Coanoaopcoos 341 Edentula (Uniopsis) Ag. ........
Dromauxi (Cameronia) Bet. ..... 1383 Edentulus (Anodon) Sow. .....
TDromanuxi@Unio) Bets cre «iss « 1024 Edentulus pavionius (Strophitus)
Dromus. (Dromus) Simp. s...... .. 342 TEEN Sonia deme ace ioaere cnt c
ID}oysky- Sry. GeoonoeeogscoooGoo 341 Edentulus (Strophitus) Say ....

-I210

. 265

- 346
- 346

1490 INDEX

Edentulus (Strophitus) Simp. .... 472
Edgarianum (Pleurobema) Lea .. 741
Edgarianus (Margaron) Lea ..... 742
Edgarianus (Pleurobema) Simp. ..742
Bdzamanus (CUnio)ielseal Use en ee 742
Edulis CAnodon) Hide: .s..<.:..- 403
Bdulis (Anodonta) Hde. ........ 403
Edwardsianus (Unio) Bgt. ...... 1127
Eftulgens (Diplodon) Lea ....... 1253
Effulgens (Margaron) Tea ...... 1254
Eftulgens. (Unio): Wea .2. 22.4.2 1253
Egyptiacus (Margarita) Lea ....1019
Egyptiacus (Margaron) Lea ..... 1020
Ehrmanni (Unio) Kob. :....«c..<< 564
EichtuCUnio)ehetes eee 826
Fightsii (Margaron) Lea ........ 826
Bightsu) (CUinio) eyea wee. eee 826
Elachista (Anodonta) Bet. ...... 365
Blectrinus (Unio)i Rye: ..22..5. 709
Elegans (Amygdalonajas) Ort. ... 307
Elegans (Margarita) Lea .......; 307
Elegans (Margaron) Lea ........ 307
Elegans (Nodularia) Roch. ...... 1032
Elegans (Plagiola) Tea «........ 307
Plesans: (Unto)! eau cena sane 307
Blegansn (Zaina) meROch meme ne 1033
Elliottii (Anodontoides) Lea .... 471
Elliottii (Margaritana) Lea ...... 471
Elliottii. (Margaron) Lea ....471, 819
Elliott (Quadrula) Wea ..2..... 819
Elliottii (Strophitus) Simp. ...... 471
IDNboydah (ANfero)) IEC Soncooccodguc 819
Ellipsaria (Obliquaria) Raf. .... 731
Billipsarius #@Unio) Saya aeeie ice 80
Ellipsiformis (ampsilis) Con. ... 128
Ellipsiformis (Unio) Con. ...... 128
Ellipsis “(Margarita) Weavseess see 299
Ellipsis (Margaron) Lea ......... 300
Ellipsis (Obovaria) Tea ........ 2909
Pllipsis: (Unio) mleeal raraetaeyerterers 299
Ellipsoideus (Unio) Toc: ........ S51
Elliptica (Anodon) Hde. :....... 403
Elliptica (Margaritana) Lea .... 472
Elliptica (Margaron) Lea ...... 472
Elliptica, (Miya) Kato ij. cer 80
BPilipticay (Unio) Rate... eeree 731
Ellipticum (Pseudodon) Con. ....1087
Ellipticus (Margaron) Lea ...... 1246
Ellipticus (Pseudodon) Con. ....1086
Ellipticus santanus (Diplodon)

line Wan 4b dloco-o5 oo ba casob ono oEaas 1247
Bllipticus c@Unio) me isatoe cece + eee 80
Kllipticus (Unio) Wag. ........ 1246
Blip tioMeiwaiens seterverersmenere- reel 527, 586

Elongaria Elaas ..5..<%- seb eeeee 1162

Elongata (Anodon) C. & R.

1443
Elongata (Anodonta) Han. ...... 1443
Elongata (Anodonta) P. & M. 363
Elongata (Brazzea) Bet. ........ 1373
Elongata (Burtonia) Bgt. ...... 205
Elongata (Damaris) Leach ...... 515
Elongata (Grandidieria) Bet. 1061
Mlongatae CElysia)) ¢Swa ese ween 1222
Blongata (Iridina) Sow. ........ 1352
Elongata (Margarita) Tea ...... 1443
Elongata (Margaritana) Lo. ..... 516
Elongata (Mutela) Pet. ......... 1352
Bicngatays(Platiris)» ven —.o4. ee 1352
Elongata (Triquetra) H. & A. Ads
PA or tok oD oetoeaaed 1222
Elongata (Unio) Good. ......... 65
Elengata (UWnio)) amie. mies ee 515
Blongata (Unio): Mich: ......0... 570
Elongatula, CUnie) C) Pitre 2s... 537
Elongatulus (Margarita) Lea .... 537
Elongatulus (Margaron) Lea 537
Hlongatulus (Unto) s'C seit fesees 536
Elongatus (Anodon) Sw. ........ 1443
Elongatus (Anodontites) Sw. 1443
Elongatus (Glabaris) Simp. ..... 1443
Elongatus (Margarita) Lea ...... 537
Elongatus (Pleiodon) Bgt. ...... 1470
Blongatus) @UWmio) iSowsresiris elie 516
Emarginata (Solenaia) Tea ...... 457
Emarginatus (Anodonta) Cless. .. 457
FEmarginatus (Margarita) Lea .... 567
Emarginatus (Margaron) Lea .... 567
Emarginatus (Mycetopus) Lea ... 457
Emarginatus (Platiris) Lea ...... 457
Emarginatus (Unio) Lea ........ 566
Embia (Anodonta) Bgt. ........ 371
Emesaensis (Margaron) Lea ..... 558
Emesaensis (Unio): Lea .......:. 558
Emesaensis (Unio) Kob. ........ 559
Emini (Nodularia) Marts. ........ 1035
Bmuoni (Unio), Martsi: see. ese see 1036
Emmonsii (Margaron) Lea ...... 6903
Emmonsin GU nro) ile eae tele 693
Eneanpa .(Plagiola)) (Simp. o.ecmeee 314
Brearpus (Miargaron) Tea <2... 314
" Bucagpuss (Unto): Igeau-eeaa einer 314
Endobranchizerissc 6 cntecsrnciee clercrcle 949
Brisidens, ihr: irs. tdctaticetonsisie see 998
Ensiformis (Anodon) Spix ...... 1455
Ensiformis (Anodonta) d’Orb. 1455
Ensiformis (Anodontites) Spix 1455
Ensiformis (Glabaris) Simp. 1455
Ensiformis (Iridina) Lea ........ 1455
Ensiformis (Margarita) Lea 1455
Ensiformis (Margaron) Lea 1455

INDEX

Episcopalis (Unio) Trist. ....... 562
Erlangeri (Nodularia) Kob. ..... 1042
Mrlangernte (Unio) Hobs ua.as sence 1042
Mroansm @\iarearon)n ieearrss ses so 676
iDacias (Curio) isIbG Baeaeogbeacs 675
Sch ati genmcsk wees a hots oie oees Svoes 340
Essoensis minor (Nodularia) Ger. 1026
Essoensis minor (Unio) Ger. ....1026
Essoensis (Nodularia) Chap. 1025
Hssoensis' (Unio)) Chap. ......-. 1025
Estabrokianus (Unio) Pet. ....... 804
Estrabrookiana (Pleurobema) Simp.
eiehols) aravsistetckerevcucyelscedererstevecisieke revere 804

Estabrookianum (Pleurobema) Lea 803
Estabrookianus (Margaron) [ea .. 804

IWstabrookianus (Unio) Lea ...... 804
Hsula (Anodonta) wWian. sec.cs.c.: 1401
Bsulali@izidina)) "d?@rby -.44-5006. 1401
Hsulaw(Weila)pdiOrby meee oene 1401
Hsula(Marcarita)idvea sess... EA OF
Hsulasi@Wareaton)» Weal ..2-...... 1401

Etowahensis (Margaritana) Con. . sro
Etowahensis (Margaritana) Lea .. 503

Hucirrus (Margaron) Dea ...... 545
Bucirnuss1dWnio)) Bete ay. tece 545
Hucyphus, (Unio) Bet accsceccs: 1020
atica Gistelimeacy nen bctiec iste cco 1351
Euphratica churchilliana (Gabillotia)
IS SESE acne eta Reverie isolone ciate iatemioe 443
Euphratica churchillanus (Gabil-
LOfia) MOimp Hmsee nesses cee 443

Euphratica (Gabillotia) Bgt. .... 442
Euphratica (Leguminaia) West. .. 443
Euphratica (Margaritana) Kob. .. 443
Euphratica (Pseudodon) Con. .... 443

Euphratica (Pseudodontopsis) Kob.
Ho eolnin HOGOe Os oe OOD Aa eee 443
Huphraticus, (Unio) Bet=........ 442
Euphymus (Unio) Charm. ...... 1130
EKurhynchus (Unio) Kust. ........ 1254
Europae (Anodonta) Leach .... 364
any mia’ yRatsieen cscs re woes aoe 60
Eurysellina (Nodularia) Pall. 1022
Eurysellinus (Unio) Pall. ........ 1022
EKuscaphys (Anodon) Hde. ...... 413
Euscaphys (Anodonta) Hde. .... 413
Evanescens (Unio) Mouss. ...... 1167
Evansi (Diplodon) Ad. & Ang. 1303
Evansi (Margaritana) Pet. ...... 1304
Evansi (Margaron) Lea ......... 1304
Evansi (Unio) Ad. & Ang. 1304
Evitatus (Margaron) Lea ...... 979
iHwitatus (Unio) Lea .......... 979
Exactus (Margaron) JIE Si.G6n0 654
Hxactiuse (Unio) eas cos.es. css 654
ap XACUEUS C(UMIO)s Gea) sjs\esciesre ee 698

I4gI
Exanthematicus (lLamellidens)
Simp Waniaceles dh Soe aoe 1169
Exanthematicus (Pressidens) Haas
999 3'6.0,.20s5)9 ovata aed Ge ODIO Crore Bie I169
Exanthematicus (Unio) Kust. 1169
Eyxasperata (Hyria) Sow. ...... 1213
Excavata (Lampsilis) Lea ...... 41
Excavatus (Lampsilis) Simpassenee 42
Excavatus (Margaron) Lea ...... 42
Wxcavatus: (Unio): Wea. sos8. 2... 42
Bxeultusy, (Unio)| (Con!) e.s4.0.58: 705

Excurvata (Anodonta) De Kay .. 392
Exiguus (Margaron) Lea

sielsiereete 137
Bxiguns (Unio): Wea \....2..2 288 137
Eyxilior (Anodonta) Lea ........ 381
EH xilis-(Anodon) '@., & Ri :2...... 242
Exalise (@Anodon)) Sow. -jse ees cos 390
Exilis (Anodonta) Lea .......... 241
Bpaliss (Margarita) Wea os.) 500. 241
Exilis (Margaron) Lea ...... 242, 1006
Exilis (Monocondylea) Pet. ..... 242
Exilis (Monocondylus) Morel. -1078
Exilis (Pilsbryoconcha) Lea .... 241
Exilis (Pseudodon) Morel. ....... 1098
lepalbiCe (Ui) IDibie Ago. gale el 1006
Eximia (Anodonta) Bet. ........ 439
Eximia (Brazzea) Bet. ......... 1372

Eximium (Colletopterum) Bet. .2 439

Eximius (Margaron) Lea ...... 1067
Eximius (Physunio) Lea ........ 1067
Bxaimius (Unio) Wea, ?..5452080.. 1067
ISS Moles YA oA bowed taco do I
Exolescens (Margaron) Lea .. 1185
Exolescens (Trapezoideus) Gld. 1185
Hxolescens: (Unio) Gld. 2.222... 1185
Exotica (Anodon) C. & R. ...... 1430
Exotica (Anodonta) Blain. ...... 1352
Exotica (Columba) Pet. ........ 1430
B<oticas (inidina)ei@hilde asso een 1377
HxOticay «Cliidina)) slvaml ieee 1352
Exotica (Mutela) Lam. ......... 1352
Hxoticaa(@Platiris) leas sm 44s 1352
Exotica ((Pliodon)) Ger: ..5.-:.5-. 1352
Exoticus (Anodon) Sow. ........ 1440
Exoticus (Anodonta) Tam. ...... 1430
Exoticus (Pleiodon) Pet. ........ 1352
Expansus (Diplodon) Kust. ..... 1231
Expansus (Unio)) Kust. ......... 1232
Explicata (Lampsilis) Morel. 2322 175
Fyxplicatus (Lampsilis) Simp. 176, 177
Explicatus (Unio) Morel. ...... 176
Exphicatism (Wino) ci. 6's a. sen5 175

Expressa (Anodonta) Marts. .... 243
Expressa (Pilsbryoconcha) Marts. 242
Extensus (Margaron) Lea
Extensus (Unio) Lea

1492

Exulcerata (Anodonta) Por. .... 363
Faba. (Margarita) Lea .......... 1243
Faba (Margaron) Lea .......... 1243
Babai@Umio) di@rbs eeesae ace 1243
Fabaceus (Margaron) Lea ...... 106
Fabaceus (Unio) Tea .......... 106
Fabagina (Parreysia) Desh. 1130
iabagina, \(Umio)) "Desh. -.. 4055, 1131
Fabagina (Unionella) Haas ...... 1131
Fabalis (Eurynia) Ort. ........ 34
Fabalis (Margarita) Lea ........ 34
Fabalis (Margaron) Lea ........ 34
Fabalis (Micromya) Lea ........ 33
Rabalis= Unio) maleate 34
Fabula (Baphia) H. & A. Ads. .. 474
Babula |(Margarita)) Wears seeoe 473
Fabula (Margaron) Lea ........ 474
Fabula (Micromya) Ag. ........ 474
Rabulaye@Pecias) mel earee ree 473
Fabula (Strophitus) Con.-........ 474
Kabula, (@Unio)) Han ee eee eee eoe 474
Faidherbi (Reneus) Jouss. ...... 1027
Falcata (Alasmodon) Gld. ...... 516
Faleata (Solenaia) Higg. ...... 458
Faleatus (Mycetopus) Higg. .... 458
Haleatus) ((Platizis) eaveaee scene. 458
ipalecatus (Unto) eS OWwaeee Nera 516
Falemeensis (Mutela) Ger. ...... 1362
Falemeensis (Mutelina) Ger, 1362
Falemeensis (Mitriodon) Roch. 1343

Fallaciosa (Lampsilis) Simp. .... 92
Fallaciosus (ampsilis) Smith .... 93

Fallaciosus (Unio) Simp. ...... 715
Ballax (Margarom)) Wea Js: se.e.5. 103
Hallax (Unto) mlvea. seen ee eee 103
Falsus (Anodontites) Simp. ...... 1456
Falsus (Glabaris) Simp. ........ 1456
Famelicus (Margaron) Tea ...... I251
Bamelicusm (Unio) mi Gldaueeeen eae 1251
Fantozatiana (Anodon) Hde. ..... 405
Fantozatiana (Anodonta) Pet. .... 405
asciatay | G@Winio) mates oe 731
Basciatus (Unio) aaSayseenae eae ner 80
Fasciola (Lampsilis) Raf. ........ 200
Fasciolaris (Obliquaria) Raf. .... ABI
Basciolarisis (WUmio) Ganka nasser 334
Hasctolis) (Unio)! «Conte. see eeaee 126
Basciolus) (Unio)e Hen ies. e eee 40
Aion (Wha) See sonkonccoc 56
Fassinans (Margaron) Lea ...... 798
Fassinans (Pleurobema) Lea ..... 797
Fassinans rhomboidea (Pleurobema)
SUMP. ‘cicero Rea AL eee 798
Fassinans rhomboideum (Pleuro-
Pema)" Simpe aaeeeenelonrte tae 798
Fassinans (Unio)s ea Jos5-s5n0 798

INDEX

Batuas|(vampsilis) leat eee 116
Fatuus (Lampsilis) Simp. ...... 117
Fatuus (Margaron) Lea ........ 117
Batuus) (Unio) beameneeee nee see 117

Favidens assamensis (Parreysia)

IPRDESE, Liciavatcaee ied eee III
Favidens marcens (Unio) Ben. I11O
Favidens (Margaron) Tea ...... IIIo
Favidens (Parreysia) Ben. ...... 1109

Favidens pinax (Parreysia) Ben. 1111
Favidens pinax (Unio) H. & T. ..1111
Favidens plagiosoma (Parreysia)

Ben: = hyatetstetors sts Oe ba CRE CO ITIr
Favidens plagiosoma (Unio)

Ie Mei ated DO RA tories ee tg IrIt
Favidens tripartita (Parreysia) Lea

Be OI css RS AISI Bxni a ake III0

Favidens trirostris (Parreysia)

MUSH 4 faite ee Ae ste eteees IIIO
Bavidensi@Wnio)m Benue senna IIIO

Favosa (Pleurobema) Simp. .... 790

Favosum (Pleurobema) Lea .... 789
Favosus (Margaron) Lea ........ 790
Havosuse« Unio)» dy eames 790
laceo: (ekindaaep) WS(C5 sooodoocsd 1116
Bex Unio)» MGs ae eee 1117
Feddeni (Parreysia) Theob. ..... IIIZ
Feddeni (Unio) Theob. ......%.. III4
Fellmani (Margaron) Lea ...... 555
Felilmant. (Unio)! =Desh) 22-2 + ees 555
Feminalis (Anodon) Gld. ........ 464
Feminalis (Anodonta) Gld. ...... 464
Fenouilii (Anodon) Hde. ........ 408
Fenouilii (Anodonta). Hde. ...... 407
Ferrarisii (Anodonta) d’Orb. 1408
Hernissi (Wnio)) Marsh eicteares 633
Ferruginea (Anodonta) Lea .... 468
Ferruginea (Margaron) Lea .... 468
Ferussaciana (Anodon) Fer. ...... 467
Ferussaciana (Anodonta) Fer. ... 347

Ferussaciana (Anodonta) Lea .... 467
Ferussaciana (Anodontoides) Lea 467
Ferussaciana (Margarita) Lea .. 468
Ferussaciana (Margaron) Lea ... 468
Ferussacianus (Anodontoides) Bak 468
Ferussacianus buchanensis (Anodon-

toides) earn Seasick eaters 469
Ferussacianus (Margaron) Lea .. 561
Ferussacianus modestus (Anodon-

TOLAES) F SIMIp Merete eteterehake eerelcherhale 471
Ferussacianus subcylindraceus (Ano-

dontoides)) Simp. “see sess eeielee 469
Ferussacianus (Unio) Lea ...... 561
Eibrosa “(@Quadrula) Hide: 2-2. 5. 918
Fubrosus @Umio)) Hide; 3.7.2.5 Wee hOTO:

Fibuloides (Margaron) Lea ...... 772

INDEX

Fibulordes! @Unto)) Wea... 0... 0. 772
Filippiana (Anodon) Hde. ...... 405
Filipiana (Anodonta) Pet. ...... 405
Eimbriata, (yampsilis)) Fir 5.3... 177
Fimbriata (Paraptera) Ort. .... 178
Firmus beettgeri (Diplodon) Ih. .1234
Firmus beettgeri (Unio) Th. ......1234
Hirmus) |) @Diplodon)i Wea. <2... 1233
Firmus (Margaron)) Ijea~........ 1233
Birmis\GwW nto) meleeay )-tscle\ ice ae 1233
Fiscallianus (Unio) Klec. ........ 535
Fischeriana (Nodularia) Morl. ..1009
Fischerianus (Unio) Morl. ...... 1009
Fisherianus (Margarita) Tea 692
Fisherianus (Margaron) Lea 693
Pishertanus: (GUinio)) Teal ..4..... 692
Fissidens (Nodularia) Simp. 584
Bissidens= = GWUnio))) IBGtts "sn. ocnle c 584
lavas @Anodon)ieAmtines syessec)s sisters 3890
Flava (Anodonta) B. H. Wr. 389
Mlavan (Obligtaria)) Rafs s.s..... 731
Flavescens (Margaron) T,ea 339

Flavescens (Ptychobranchus) Simp.

OPE OO ct IoC or IO HE SId eR OCIA 339
Flavescens (Unio) ea .......:.. 339
Flavidulum (Pleurobema) Tea .. 781
Flavidulus (Margaron) Tea ...... 781
Flavidulus (Pleurobema) Simp. .. 781
Mlavidulus Unie): Wea 2so...0...- 781
Hlavidusis(GUniol: Wea a... s.60e 749
Flavus rubiginosus (Unio) Pet. .. 873
IMenCY (Oks) (Come = oognodnonnos 873
Flexicosus (Unio) Neum. ...... 721
Flexuoso (Dysnomia) Ag. ........ 19
Flexuosa (Obliquaria) Raf. .... 731
Flexuosa (Quadrula) Simp. ...... 887
Blexuosusm(Wnio)) Con! Sa.<ec. sc. 19
Flexus (Toxolasma) Raf. ........ 731
Florentina (Truncilla) Lea ...... 30
Floreritinus (Margaron) Lea .... 31
Hlorentinuss (Unio veal eae 31
Florida (Anodon) Hde. ©......... 405
Florida (Anodonta) Pet. ........ 405
Floridensis (Margaron) Tea ..... QI
Floridensis (Unio) Tea ........ QI
Floridensis (Unio) S. H. Wr. 138
Flucki (Nephronaias) Bart. ...... 266
Fluctigera (Nodularia) Lea ...... 991
Fluctiger (Margaron) Lea ...... 992
Fluctiger (Nodularia) Lea ...... 992
Hluctiger a@Unio)) eal s.jaccrcss 992
Fluminea (Anodon) Hde. ........ 414
Fluminea (Anodonta) Hde. ..... 414
Fluviatilis (Anodon) Gld. ....... 387
Fluviatilis (Anodonta) Bosc 387
Fluviatilis (Margarita) Lea ...... 387

Fluviatilis (Margaron) Lea
Fluviatilis (Mytilus) Dill.
Fluviatilis (Unio) Green
Flyensis (Diplodon) ‘T.-C.
Flyensis (Unio) T.-C.
Foai (Burtonia) Mab.
Fokkesi (Unio) Dun.
Foliacea (Unio) Gld.

Foliaceus comptus (‘Trapezoideus)

1D (ea Ae
Foliaceus (Trapezoideus) Gld.

zoideus) Haas

Foliaceus (Margaron) Lea ...

ap airitesre
Foliaceus zayleiwanensis (Trape-

Foliaceus zayleymanensis (Trape-

zoideus) Prest.
Foliaceus (Unio) H.
Foliata (Truncilla) Hild.
Foliatus (Margarita) Lea
Foliatus (Margaron) Tea
Foliatus (Unio) Hild.
Folliculatus (Margarita) Lea
Folliculatus (Margaron) Lea
Folliculatus (Unio) Lea
Foncki (Unio) Phil.
Fontaineana (Unio) d’Orb.
Fontainiana (Unio) d’Orb.

rod hos Hoi

Brant caevekenet ate 1258

..1280

Fontainianus deceptus (Diplodon)

Simp.

ILS Ra GPa ea oriirkoe ea eke
Fontainianus (Margaron) Lea
Fontainianus (Unio) Han. ....

Fontanus (Unio) Con.
Fontinalis (Unio) Raf.
Footei (Arcidopsis) ‘Theob.
Footei (Unio) ‘Theob.
Footiana (Anodon) Sow.
Footiana (Anodonta) Lea
Footiana (Margaron) Tea
Forbesiana (Anodonta) Lea

Forbesiana (Margaron) Lea 610,

Forbesianus (Anodon) Sow.

Forbesianus (Anodontites) Lea
Forbesianus (Glabaris) Simp
Forbesianus (Unio) Tea ......

Foremanianum (Ptychobranchus)

Lea

Foremanianus (Margaron) [Lea
Foremanianus (Ptychobranchus)

Simp
Foremanianus (Unio) Lea
Formosus (Unio) Lea
Forseali (Unio) Parr.
Forsheyi (Margaron) Lea

Fontainianus (Diplodon) d’Orb. ..
Fontainianus gratus (Diplodon)

1494

Horsheyi (Quadrula) ea... 2... 844
Borsheyre (Unio)! Mean. so cccien 845
Fossiculifera (Fossula) d’Orb. 1396
Fossiculifera (Margarita) Lea ....1307
Fossiculifera (Margaron) Lea 1397
Fossiculifera (Monocondylza)

LR @) rh ies Weesveceasyyorasty of stose ethos acide 1307
Fossiculifera (Unio) Han. ...... 1397
Fossiculiferus (Unio) C. & R. ....1397
Bossulay Wyeast. acer one venient 1396
Fouladougouensis (Nodularia)

JOUSS: *. cy aMietnfaciebeicr acca erator 1030
Fouladougouensis (Reneus) Jouss. 1031
Fourtaut ((Spatha)) Palle, cc ei 1332
Fourtaui (Spathella) Pall. ...... 1333
Bountaws (Unio) mealies. eee 579
Fragilis (Anodon) C. & R. ..... 389
Fragilis (Anodonta) Fitz. ...... 437
Fragilis (Anodonta) Lam. ...... 3890
Fragilis gracilis (Unio) Pet. 182
Fragilis. (Lasmonus) Raf. ...... 731
Fragilis (Margarita) Lea ........ 389
Fragilis (Margaritana) Kust. 1086
Fragilis (Margaron) Tea ...... 389
Fragilis (Metaptera) Con. ...... 182
Fragilis (Microcondylea) Pet. ..1086
Fragilis (Symphynota) Fer. ...... 182
Pragilis (Unio) News ueeceee cece 1182
Bra oils GWT o) malaizieeomiciere elke 731
Braciliss (@Unio) Mm Sows telesecee 1257
lonarerilbis “(Usent))) “Sits, “ES ooagconebe 182
Fragosa (Quadrula) €on. .«.:... 843
Bragosa i @Uinto) ii CurSemRas sissies 844
Fragosus (Margarita) Lea ...... 844
Fragosus (Margaron) Lea ...... 844
Bragosus) (Unio) im Conmiareseeniecooe 844
Franciscana (Aplodon) Th. ..... 1392
Franciscana (Margarita) Lea 1391
Franciscana (Margaron) Lea 1391
Franciscana (Monocondylea)

IMDOTIC. < xctsaievoiess arkenuaeven eis elms 1391
Franciscana (Unio) Moric. ...... 1391
Fraternus (Margaron) Lea ...... 614
Braternuus) CUnic)mlWweame sn ececien 614
Frenzellii (Diplodon) Ih. ...... 1264
Brenzellir <@Umio)) Why a. ae 1265
Friersoni (Physunio) Simp. 1068, 1469
Friersoni (Quadrula) B. H. Wr. . 879
Friersoni (Unio) B. H. Wr. . 879
Priersoniay Ontyeus ss sek iceiente 200
Friniana (Anodon) Hde. ........ 403
Fruhstorferi (Lanceolaria) Dautz. 953
Frihstorferi (Nodularia) Dautz. .. 952
Fruhstorferi (Unio) Dautz. ...... 953
Fryanus (Unio) B. H. Wr. . 632
Fucatus (Margaron) Lea ........ 86

INDEX

Fucatus (Mytilus) Dill.
Fucatus (Unio) Lea
Fulgens (lI,ampsilis)
Fulgidus (Margaron) Lea
Fulgidus (Unio) Lea
Fuliginosus (Margaron) Tea
Fuliginosus (Unio) Lea
Buligo (GUnta) Rw esr aes seen
Fulmineus (Unio) Phil.
Fulvaster (Contradens) Haas ....
Fulvaster (Hyriopsis) D. & C.

Fulvaster (Nodularia) Simp.

Bulvaster ((Umio)) DL & GCG. 2.2.5.
Fulvus (Margarita) Lea .......
Fulvus (Margaron) Lea ........
Bulyasis CUnto) alt can sate eee
Ici (Urano: Ika bao saneSase
Fumatus (Margaron) lea ......
Kumatus: Unio) lyed winceccicicticc
Buncki) ((Uinto)iee ts ase eens
Funebralis (Diplodon) Lea ......
Funebralis (Margaron) [Lea

Bunebrals, iGUinio)) wlwea ae aseaee
Fureatum (Diplodon) Spix

Furva (Pleurobema) Simp.

Furvum (Pleurobema) Con.
benmesy (Ubsey) (Cert 4555 5556she+
Fusca (Anodon) Hde.
Fuscatus (Margaron) Lea
Fuscatus (Unio) Lea
Fusciculifera (Anodonta) Pet.
Husconaial sOlmpseisaeeeeies wistels
Kusconaja as Oxtaeenuseeine esac nne
Fusculus (Unio) Ross.
Gabbianus (Margaron) Lea
Gabbianus (Unio) Lea
Gabbianus (Unio) Marts. ........
Gabillotia Serv.
Gabonensis (Margaron) Tea
Gabonensis (Nodularia) Kust.
Gabonensis (Unio) Kust.
Gaditana (Mya) Schreib.
Gaillardi (Nodularia) Ger.
Gaillardi (Unio) Ger.
Gaillardoti (Nodularia) Pall.
Galilei (Unio) Loc.
Gallandi (Anodonta) Bet.
Gancinensis (Spatha) Simp. ......
Ganciniensis Spatha) Roch.
Gangrenosus (Unio) Schmidt .
Garbei (Diplodon) Ih.
Gargatte (Unio) Phil.
Gafgotte (Unio) Ross.
Gassiesi (Diplodon) Kust.
Gassiesi (Unio) Kust.
Gastonensis (Margaron) Lea

INDEX

Gastonensis (Unio) Lea
Gaudichaudi (Margaron) Lea .... 982

Gaudichaudi (Nodularia) Eyd. .. 982
Gaudichaudi (Unio) Eyd. ...... 982
“Geavi (Nodularia) Ger. ........ 1033
MGeayire CUn10) i GELsn es visieletevercls)s is shots 1033
Geddingsianus (Margaron) Lea .. €40
Geddingsianus (Unio) Lea ...... 639
Geminus (Margaron) Lea ....... 686
Gemiunus, CUmio))lgeall seine. oe cisiel 685
Generosus angustior (Unio) H. &

AIRS We are eb cape dee, eralterePeeranclie le cieyaiie)'sttsp ats 1470
Generosus (Lamellidens) Gld. ....1175
Generosus (Margaron) Lea II75
Generosus (Unio) Gld. .......... 1175
Genezarethanus (Unio) Loc. .... 551
Genthii (Margaron) Tea ........ III
Gente Unreal -eictoetstesctere III
‘Gentiliana (Barbala) Hde. ...... 232
Gentiliana (Cristaria) Hde. .... 232
Gentilianus (Cristaria) Hde. .... 233
Genuinus (Margaron) [Lea ..... 103
‘Genuinus? CUnio))— Wea... sec. «os 103
Geometricus (Unio) Tea ........ 707

Georgiana (Alasmidonta) Lea ... 503
Georgiana (Margaritana) Lea .... 504
Georgiana (Margaron) Lea ...... 504
Georgiana (Pleurobema) Simp. .. 793
Georgianum (Pleurobema) Lea .. 792
Georgianus (Margaron) [Lea .... 793

Georgianus (Unio) Tea ......... 793
Georgina) (Unio) Wam. .. oc. oo 652
Georgine (Anodonta) Gray ..... 1440
Georgine (Anodontites) Gray 1440
‘Georgine (Glabaris) Simp. ...... 1440
Gerbidoni “@Unio)— Bydé - jo.....- 979
Gereti” (GUnto))Prest) os. cccc sone 727
Gerhardtii (Lampsilis) Lea ..... 54
Gerhardtii (Margaron) Lea .:... 54
Gerhardtite GWnr1o)imleay ec sm mcielecre 54
Germana (Lampsilis) Lea ....... 154
Germanus (Lampsilis) Simp. .... 155
Germanus (Margaron) Tea ..... 155
Germanus) GUinio)) Wearicnscec4- 155
‘Gerrardi (Nodularia) Marts. 1022
Gerrardi (GUnio)) sMarts) sass. 1023
Gesnerii (Anodon) Sow. ........ 393
‘Gesnerii (Anodonta) Lea ...... 393
Gesnerii (Margaritana) Lea .... 355
Gesnerii (Margaron) Lea ....355, 303
Gesnerii (Strophitus) Lea ...... 354
Gesneri@Unio)) Wea << crcjccle sss ors 663
“Gessneri (Anodonta) Pet. ....... 393
Gessnerii (Margaritana) Pet. .... 355
SGremrvanht (CQUpmto) Me Ce ee enaces ccc 1167
“Gibba (Anodon) Sow. ......... 402

1495
Gibba (Anodonta) Cless. ........ 403
Gibbam(Marcaromn) Leay ac ccs cick 403
Gibberai@Margarita)) Teas cee. sn 796
Gibber (Margaron) Lea ........ 796
Gibber (Pleurobema) Simp. ..... 796
Gibber (Unio), Ts ae reyancnetatete a1 craves 796
Gibberum (Pleurobema) Lea .... 796

Gibbesianus (Margaron) Lea ... 681
Gibbesianus (Unio) Lea ........ 681
Gibbosa (Amblema) Raf. ...... 731
Gibbosa (Anodon) C. & R. ..... 397
Gibbosa (Anodonta) Say ........ 397
Gibbosa (Anodonta) Simp. ..... 399
Gibbosa dunlapiana (Anodonta)

LEASE ue OE nS UCLA ICICI TOR ene 398
Gibbosa (Dysnomia) Ag. ........ 2
Gibbosa (Margarita) Lea ........ 397
Gibbosa (Margaron) Lea ........ 398
Gibbosay (Mya), atone = me co. - 598
Gibbasilam Simpy jcteraeiercoe eusrsteierete 941
Gibbosus (Anodon) Sow. ........ 398

Gibbosus arcus (Unio) Con. .... 599
Gibbosus armathwaitensis (Unio)

Be. EA a Wiieaik 6, nirststralle Joveveielisueuciersvereces 599
Gibbosus delicatus (Unio) Simp. . 600
Gibbosus (Elliptio) ‘Ort: ......... 598
Gibbosus (Margarita) Tea ...... 598
Gibbosus (Margaron) Tea ...... 598

Gibbosus perobliquus (Unio) Con. ..15
Gibbosus perplexus (Unio) Pet. .. 2
Gibbosus subgibbosus (Unio) Lea 599

Gibbosus)CWmnio) Bares cc 597
Gibbosus. @Uinio) ers mc cise sisiels 25
Gibbum (Anodon) Ben. ......... 402
Gibbus:. GUinio) Speng.) «ce. ecw I1g2

Gigantea (Anodon) Sow. ....421, 1429
Gigantea (Anodonta) Kust. 1402, 1470

Gigantea (Anodonta) Lea ...... 420
Gigantea (Anodonta) Marts. 1429
Gigantea (Cameronia) Bet. ...... 1379
Gigantea (Columba) Pet. ....... 1429
Gigantea (Margarita) Lea ...... 420
Gigantea (Margaron) Lea ...... 421
Giganteus (Anodon) Sow. ...... 421
Giganteus (Anodon) Spix ..1402, 1429
Giganteus (Unio) Lea ........... 815
Gigas (Complanaria) Sow. ...... 491
Gigas (Megadomus) Sw. ........ 491
GicaspadUinto)is Sowers etek. 319
Giraudi (Cameronia) Bet. ...... 1381
Giraudi (Grandidieria) Bet. ..... 1059
Giraud; (@Pleiodon) Bet. ........ 1380
Giraud) @eliodon)! ‘Ger > sec cnc 1381
Giullaini (Anodonta) H. & A. Ads. ..

Se RTST iS usar nna da consis Sho charset eicks 1457
Glabarisy (Grays fis) sucvs. & sree roseyenexeus oe 1403

1496

Glaber (Margarita) Lea ......... 119
Glaber €Margaron)) Wea <-...... 119
Gilabers (@Uinio) Wear secre wee 119
Glabra, (Anodonta) stab) <...0606 363
Glabrata sGWinno) dame) focrave le nucre rel 652

Glabratus: (Unio) “Sows ss-. ec. 495

Glabrus (Anodon) Sow. ........ 1422
Gladiator (Nodularia) Ancey .... 991
Gladiator (Unio) Ancey .....-.- 991
Gladiolus (Lanceolaria) Hde. .... 955
Gladiolus (Nodularia) Hde. ...... 955
Gladiolus’ (Unio), Hides ons... minie 995
Glandacea (Quadrula) Lea ...... 900
Glandaceus (Margaron) Lea ..... 900
Glandaceus, (Unio) leea wae. siete tert 900
Glandulosa (Anodon) Anth. ..... - 3890
Glandulosa (Anodonta) B. H. Wr. 3890
GlansaGE unynia))) *Ontes este 154
Glans? @vampsilis) Wear. <. .iecere 153
Glans; (Margarita); Wears. recier 154
Glans(GWilarcaron))) Te Gaaterc.tetenretere 154
Glans @Uinio) ele ealerrreiciettetereetor 154
Glauca (CAnodon)/ (Ge GyRew. esc 1435
Glanca (Anodonta) Val. .....°.. 1435
Glauca (Margarita)! Wear. -rtetere 1435
Glauca’ @Wargaron)! Weal 22)... 1435
Glauca (Monocondylea) H. &

AS AS ae del setaerercuheraa tanta 1435
Glauca sinaloensis (Anodonta)

( CAEN oan ARIE REID ELA Oe ORICA 0 GCOS 1436
Glaucinus: ((Unito)) Por. Sle eerie 571
Glaucus (Anodon) Sow. ........ 1436
Glaucus (Anodontites) Val. ...... 1434
Glaucus (Glabaris) Simp. ...... 1435
Glaucus sinaloensis (Anodontites)

Ge Be seeistatercic ciel s cloleftes ertetote 1436
Glaucus sinaloensis (Glabaris)

Simp: ais's cloteretoherspetexers «icetetaeets eke 1435
Glebulas\ Cont fa-crmeeie aise 286
Glebulus (Unio) Say ..5.......- 288
Glenelgensis (Diplodon) Denn. 1290
Glenelgensis (Unio) Denn. ...... 1290
Globata’ (@uadrula)) Weave. ane 8090
Globatus® CWnto)T yeay cieteter sions het eters 8909
Globosa (Anodon) Sow. ........ 432
Globosa (Anodonta) Lea ........ 432
Globosa (Margarita) Tea ....47, 432
Globosa (Margaron) Lea ........ 433
Globosa (Symphynota) Lea ...... 47
Globosula (Anodon) Hde. ...... 413
Globosula (Anodonta) Hde. °.... 413
Globosus (Margarita) Lea ...... 47
Globosus> (Umno) lan 2) miclererel 47
Goascoranensis (Margaron) Lea .. 264
Goascoranensis (Nephronaias) Lea.. 264

Goascoranensis (Unio) Tea ...... 264

INDEX

Goliath (Hyriopsis) Rolle: ...... 210.
Gonidea Conrady oe eres neletleratere 463
Gontieri (Margaron) Lea ........ 568
Gontient (Unio) Bet) eee 568:
Gottschei (Quadrula) Marts. .... 931
Gottschei (Unio) Marts. ........ 932
Gouldianus (Unio) Ward ........ 884
Gould Glampsilis) “Wear sence 168
Gouldii (Margaron) Dea-........ 168
Gould! 1GUinio)! Svea ae 168

Gowhattenensis (Parreysia) Simp. 1129

Gowhattensis (Parreysia) Theob. .1121
Gowhattensis (Unio) Theob. ry Ai
Gowlattensis (Unio) Pzt. ....... 1121
Gracilentus (Margaron) Lea .... 679
Gracilentus” @Unio)) Wea" Ses. er 679
Gracilior® @Yampsilis)) Gea“. a.eee 135
Gracilior (Margaron)! Weal ifsc. 136:
Gracihor (Unio) Wvea so. ae 136
Gracilis (Anodon) Sow. ...... 182, 242
Gracilis (Anodonta) Tea ........ 1075,
Gracilis (Dalliella) Simp. ........- 1075
Gracilis ‘@lyriopsis) Haas) -2..- 209:
Graciliss Gyampsilus) Bane] sete 181
Gracilis' @Miarcanxita) Wea erie 182
Gracilis (Margaron) Lea ....182, 1075
Gracilis (Metaptera) Stimp. .... 182

Gracilis (Microndylea) Strub. 1163
Graciliss @Miya) Eaton jee eerie 182
Gracilis) (Paxaptera)) Ontawcreteterte 182
Gracilis (Rectidens) Strub. ...... 1163
Gracilis' (Simpsonella) Lea... ..: 1075
Gracilis (Symphynota) Lea ...... 182
Gracilis Unio) y Bareencterrecireeterrs 182
Gracillimus (Unio) Rolle ...... 952
Gracillior Unio)! Wear sean. ee 136:
Graellsianus: (Unio) Bgt. ........ 541
Graeter1 "CUnio) KobS 22 >5.sree: 559°
Granadensis (Anodonta) Lea 1424
Granadensis (Glabaris) Simp. ....1424

Granadensis (Margaron) Lea 717, 1424

Granadensis (Unio) Wea <..-2e- Fe
Grandensis (Unio) Con. ........ 289
Grandidens (Margaron) Tea .... 921
Grandidens (Unio)! “Weal s-. ..e 921
Grandidiert ((Uni0)" “Bets ae. eer To27
Grandidieria® “(Bet Seneca 1051
Grandidieriana (Burtonia) Bgt. .. 206
Grandis (Anodon) Sow. ........ 419
Grandis (Anodonta) Say <2... 418°
Grandis (Anodonta) Simp. ...... 42
Grandis benedictensis (Anodonta)

Tea’ to iihis cls cyoialetasats censlateueteta che abebets 423

Grandis footiana (Anodonta) Lea 422
Grandis gigantea (Anodonta) Lea 420
Grandis leonensis (Anodonta) Tea 423:

IND

(Grandis, Gvaneanitay eilyear trv crete 419
Grandis’ (Margarom) dea J... 0... 419
Granifera pusilla (Quadrula) Simp. 906
Granifera (Quadrula) Dea ...... 905
Graniferus (Margarita) Lea ..... 905
Graniferus (Margaron) Lea ...... 906
Graniientus, Unio) s ea c-i-iecvs 1-1 905
Granosas CWimr1o) EG esrerersicietererener 1251
Granosus (Diplodon) Brug. ...... 1250
Granosus (Margarita) Lea ...... 1251
Granosus (Margaron) Lea ...... 1251
Granosus: (GWinio)i Eanes te. ccrcs oer 1251
Granosus (Unio) Schum. ........ 554
Grantianus, (Unio) Beto so... 1126
Granulatis- (Unio) Wea... 3.5... 155
Granulatus (Margaron) Lea 155
Granulatus (Truncilla) Raf. ..... 2
Granulatts) Unio) Weal srreeyerstr- 155
Granulifer: (Unio) Ret. ye. «= 1253
Granuliferus (Diplodon) Dun. ..1253
Granuliferus (Unio) Dun. ...... 1253
Granulosa (Grandidieria) Bgt. ..1058
Gratiosa CNodularia)) Phill... -.. 993
Gratiosus (Margaron) [Lea ...... 004
Gratiosus! CUnio)) Bethe eeere er 583
(Geypogus (Wha) Ii Aosqocpocs 994
Grateloupiana (Anodonta) Gass. .. 363
Grateloupiana (Pseudanodonta)

FS tS Mm ENAG cl ooreh oe hcveparcNoltend fevatekazste role 363
Gratus (Diplodon) Simp. ........ 1282
Gratus a@Miarzaron))) Weay ecm. «1 1282
Gratises@Winio)) mals ae icusvecstoxarsteera tele 1282
Gravida (Grandidieria) Bet. 1056
Gravidus (lampsilis) Roch. ..... 1063
Gravidus (Margaron) Lea ...... 1063
Gravidus (Physunio) Lea ....... 1063
(Gieeniahogy ((Uhasto)) UGE! Vonosudodgon 1063
Gravis ((Miyai) i Wi Ode ere crear-re lel 80
Gravisa@ Uinta) ye eceterratcleetsleletelerar-lcre 81
Grayana (Lanceolaria) Haas ..... 952
Grayana (Nodularia). Lea ...... 951
Grayanus (Margarita) Lea ...... 952
Grayanus (Margaron) Lea ...... 952
Grayaniis “GUnio) sy Iseaecisj-e)-ra1-1-) <1 952
Grayanus (Unio) Schrenck ...... 9059
Grayar s@Unio))) (Griththi is. = ces 952
Greefianus (Diplodon) Simp. ....1236
Greeffeanus (Diplodon) Th. ...... 1236
Greeffeanus (Unio): Th. ....:..... 1236
Grelloisianus (Unio) Bgt. ....... 550
Greeni (Margarita) Lea ........ 339
Greeni (@Margaron)) Dea ...:..... 339
Greeni (Ptychobranchus) Con. 338
Greenies @Winto) ei Comy oe. Aelereisiele ss 339
Griffthianus (Margarita) Lea .... 653
Griffthianus (Margaron) Lea 653

EX 1497
Grifithianus (Unio) Lea ........ 653
Grijalve (Anodonta) Morel. ....1434
Grijalve (Anodontites) Morel. ..1434
Grijalve (Glabaris) Simp. ...... 1434
Grijoloz (Anodonta) Pet. ........ 1434
Groenlandica (Unio) Mérch ..... 1166
Gruneriana (Anodonta) Cless. .... 231
(Cerner (AUhoke)) Is Soooadouscas 1312
Guaraniana (Unio) d’Orb. ....... 1274
Guarayana (Margarita) Lea ..... 1386
Guarayana (Margaron) Lea ..... 1386
Guarayana (Monocondylez)

GOD. Momo ce beeen te ieeereioa cree 1385
Guarayana (Unio) Hian. .......<. 1386
Guatemalanus (Unio) Marts. 264

Guatemalensis (Quadrula) Simp... 909
Gubernaculum (Unio) Rve. ...... 26
Guillaini (Anodonta) (Rec. ...... 1179
Guillaini (Iamellidens) Rec. 1179
Guillaini 7(Spatha)) (Gers Syn-ee se. 1179
Guillemeti (Cameronia) Bgt. ..... 1383
Guillemeti CUnto)) Bet. sonscacce- 1192
Gundlachi (Nephronaias) Dun.... 274
Gundlachis@Unito)mDunissias cee 275
Gundlachi (Unio). Sow. ......... 273
Guppyi (Cristadens) Smith ...... 1156
Guppyi (Ctenodesma) Simp. ..... 1156
Guppy1 (€Unio) Smith .......... 1156
Habetatus (Margaron) Lea ...... 874
Haconensis (Anodonta) Th. ...... 410
Haconensis (Nodularia) Ih. ..... 970
aconensis» (Unio) ih. .2-2.. eee 970
Hageni (Contradens) Haas ..... 1008
Hageni (Microndylea) Strub. ...1008
Hageni (Nodularia) Strub. ...... 1008
Magenis (Umio)e Stubs see ee 1009
Hagleri (Pleurobema) Fr. ....... 776
lnlevelkeay ((lUfatio)) lds nononocoeqasoe 776
Hagner (Unio) Simp. «2. sees. 1009
Hainesiana (Chamberlainia) Lea .. 219
Hainesianus (Margaron) Lea .... 219
Hainesianus (Unio) Lea ......... 219
Haleiana (Lampsilis) Lea ....... 152
Haleianus (Lampsilis) Simp. 153
Haleianus (Margaron) Lea ...... 153
Haletanuss (Unto) sljeaniee eee 153
Hallenbeckii (Anodonta) Lea .... 392

Hallenbeckii (Margaron) Lea 393, 662

Hallenbeckii (Unio) Lea ........ 662
idalepensis (@Umio)! Kobe's. .2.0- 559
amyanus (Unio): (Bet. .s.ccns ee 1192
Wanleyana «(Castalia) Sow.’ ...:.. 1196
Hanleyana (Pleurobema) Simp. 781
Hanleyanum (Pleurobema) Lea... 780
Hanleyanus (Margaron) Lea 781
Hanleyanus (Unio) Lea.......... 781

1498 INDEX

Hardeleti (Pleiodon) Ger. ....... 1382 Henryana (Margaron) Lea ...... 397
Hardeleti (Phiodon) Ger. ........ 1383 Henryiana (Anodonta) Lea ..... 397
Hardeleti molli (Pleiodon) Ger...1383 Hepaticus (Margaron) Lea ...... 642
Hardeleti molli (Pliodon) Ger. 1383 Hiepaticus <GUnio)y Gea eecseks see 642
Hargeri (Mutela) Smith ......... 1357 Herculea (Anodonta) Midd. ..... 228
Harlandi (Anodon) Hde. ........ 412 Herculea @Barbala) Pet. ¢.:...-- 228
Harlandi (Anodonta) Bi &) Ads... 412 Herculea (Cristaria) Midd. ...... 227
Harmandi (Monocondylea) Pet. 1084 Herculeus (Anodon) Sow. ....... 229
Harmandi (Pseudodon) C. & F. ..1084 Idéres (Unio) eiNeum~= usm ete ee 723
idarmandia Roch! sa aqsneeere seo 1049 Hermosus, (Unio) Bet, oo. cee 1132
Harperi (Pleurobema) B. H. Wr. 782 MHerodes (Unio) Kob. ........... 551
Harper (GU nto) iB. ebb. Wi niente 783 Heros (Crenodonta) Ort. .......: 826

Harpethensis (Anodon) Sow. .... 421
Harpethensis (Anodonta) Lea .... 421
Harpethensis (Margaron) Tea ... 421
Hartmaniana (Pleurobema) Simp. 772

Hartmanianum (Pleurobema) Lea 772
Hartmanianus (Margaron) Lea... 772
Martmantanus (Unio) ea ....... 772
Hartmanni (Spatha) Marts. ...... 1327
Hartwrighti (Diplodon) Th. ..... 1311
Hartwrighti (Unio) B. H. Wr.... 618
Mastatus, <@Uintoye Weal gence erclactoees 662
Hautteceeuri edwardsiana (Nodu-
dATIA) “SOLMDL) vovesieiecieietersroreewarelcee Ti27.
Hauttecceuri edwardsiana (Parrey-
Sia) Betsy cycler dewesetstsvereborsteponsreuc 1127
Hautteceeuri (Nodularia) Simp. 1126
Hauttecceuri (Parreysia) Bgt. ....1126
Hautteccsurt (Unio), Bets 2 .42<e- 1126
Haysiana (Scalenaria) Ag. ....... 17
Maysiana Ciruncilla)) Gea ss. ccc 16
Haysianus (Margarita) Lea ...... 17
Haysianus (Margaron) Lea ...... 17
Maysianus @Unio)) Wea 42... 17
Hazelhurstianus (Margaron) Lea. 649
Hazelhurstianus (Unio) Lea ..... 648
Hiebes: (GMiargaron) Wea 2 .scee es 711
iiebes (Unio)! Wea aaa.eecem ese Bat
Hebetata (Quadrula) Con. ...... 874
Mebetatus (Unto)! (Con. sacnee ee 874
Hedeja ((Oxynatia)® Mabe iis ceimemies 991
Heermannii (Margaron) Lea .... 173
Heermannii (Unio) Lea ......... 173
Hpeldr (CUnio)) Korstis ae. lacie cet cle 573
Heldii (Anodonta) Kust. ........ 1072
Helvetica (Anodonta) Bet. ...... 365
Hembeli (Magaritana) Con. ..... 523
Hembeli (Margaron) Lea ....... 523)
Hembeli) (Unio) MGont 6.5 cease ase 523
Hlemidons Swe, trees asic eine 496
Hemilastena). Age) tage’ ovaieic sis.<.05¢ blars 323
Hemiodon Sw: ” sisesidiees «(ile theese 496
Hemiodonta Sweeties cewis we one 496
Henryana (Anodon) Sow. ....... 397
Henryana (Anodonta) Lea ...... 306

Heros dombeyana (Quadrula) Van. 831
Heros multiplicatus (Unio) Pet... 826

Heros. (@uadiula)Sayeneeeeie nese 825
Eteros i i@Uinio): skarsteaeer erent 815
Heros (CUnio) Sayer ancien cose 826
Hertwigii (Anodonta) Th. ....... 1440
Hertwigii (Glabaris) Simp. ...... 1440
Heterodon (Alasmidonta) Lea ... 499
Heterodon (Margarita) Tea ...... 500
Heterodon (Margaron) Tea ..... 500
Heterodon), \CUnio) wea vaacaes cies 500
FMeteEro Pence. pa. feieciawie cre stato eta -otereeene I
Heudei (Anodonta) Neum. ...... 416
Heudei (Cuneopsis) Hde. ....... 945
leuder (GWinmio))) Hides xv. 2 cies cee 946
Heudeloti (Mitriodon) Roch.....: 1343
Hians (Alasmodon) Raf. ......... SIL
Hians (Alasmodonta) Fer. ....... 490
vans! a@Anodom ie So war csrersenrs sei ore I40r
labtop ((UisheDy WIG Ss Seceeaa oo 5 495
Hildalgoi (Anodonta) Ger. ...... 1447
Hidalgoi (Anodontites) Ger. ..... 1446
Higginsii grandis (lampsilis)

SUMP SF laseyotedseaclersts auspasantswuererersyoes 78
Higginsii (Lampsilis) Lea ....... 78
Hig¢einsi . (Unio) » Bearta. cerepecie 78
dldrethia (Unio) sDellek 2 sctecrne 454
Hildrethiana (Baphia) H. & A.

7G CMTC Oe CO NG Bea mec ee Hic 326
Hildrethiana (Margaritana) B. H.

SW irish, bans cease ucichovolete ces iapeme ne rat ots eysnepels 326

Hildrethiana (Strophitus) Con. ....325
Hildrethianus (Margarita) Lea .. 325
Hildrethianus (Margaron) Lea ... 325

Hildrethianus (Unio) Lea ....... 325
Binkley? 1@Uinio)) Bisw els a Witten ciciers 618
Hippopeus (Margaron) Lea ..... 816
Hippopeus (Unio) ea.........- 816
Hirasei (Nodularia) Haas ....... 973
Hirundo (Chelidonura) Roch. ....1369
Hirundo (Chelidonopsis) Marts...1368
Hirundo (Spatha) Marts. ........ 1369
HAispanus) (Unio) OROSS. 2 =e sca ecic 541
Hjalmarsoni (Nephronaias) Dun. 263

INDEX

Hjalmarsoni (Unio) Dun.
Hochstetteri (Unio) Dun.
Hockingensis (Anodonta) Call ... 437
Holstonense (Pleurobema) Lea... 739
Holstonensis (Margaron) Lea .... 739
Holstonensis (Pleurobema) Simp. 739
Holstonensis (Unio) Lea ........ 739
Holstonia (Alasmidonta) Lea .... 502
Holstonia (Baphia) H. & A. Ads. 503

Holstonia (Margarita) Lea ...... 502
Holstonia (Margaritana) Lea .... 502
Holstonia (Margaron) [ea ...... 502
Holstonia (Strophitus) Con. ..... 502
Holstoniana (Margaritana) Kust.. 503
Holstonianus (Unio) Han. ....... 503
Holtonis (Anodonta) Lea ....... 1422
Holtonis (Anodontites) Lea ..... 1422
Holtonis (Glabaris) Simp. ....... 1423
Holtonis (Margaron) Lea ....... 1423
LOMO GEN AC Ke isles cvcsieievanisial a sierersievs 358
Homsensis (Margaron) Lea ...... 560
Elomsensis (GUnio)) Leal ..../555.. 559

Hopetonensis (Margarita) Lea.... 669
Hopetonensis (Margaron) Lea ... 669

Hopetonensis (Unio) Lea ....... 668
Frorda = (Anodom)) Glda Ge .isisjcleleie se 396
Hordeum (Anodon) Sow. ........ 389
Hordeum (Anodonta) Pet. ...... 396
Horei (Grandidieria) Bgt. ....... 1035
Horei (Nodularia) EK. A. Smith.. 1034
ivorei- GUnto)) is A.) Sim seis ciel - 1035

Houghtonensis (Anodonta) Curr. . 423
Houngdaranicus (Unio) T.-C. ....1116
Housatonica (Anodonta) Lins. ... 392
Housei (Margaron) Lea ..:....... 213
Housei (Unio) Lea
Houstonensis (Margaron) Lea .... 860
Houstonensis (Quadrula) Lea .... 859

Houstonensis (Unio) Lea ....... 860
Huapensis (Diplodon) Bart....... 1265
EL Te tis GUi10) We eitey veienenalstsrehaletslelolers 544
lao (Usa TOY Soconouacdaad 560
Humerosus (Margaron) [Lea ..... 656
Hinmerosuss CUnito)) Wea saci. <1 656
Humilis (Margaron) Lea ........ 979
EitiamibisekGUn1o) elyear e.jartersiacieiscere 979
Hunanensis (Parreysia) Haas....
EKGs aiepaneassslions (sys vee levsiaueteyone 934, 1143
Hupeana (Mycetopoda) Cless. ...1463
Hupeanus (Mycetopus) Cless. ...1463
Hyalinus (Margaron) Lea ....... 485
lahyaibiaeey (QUbobto)) wIU CEN SompanouboD 485
Hydiana.(Gampsilis); Lea <2... 5. 66
Hydianus (Lampsilis) Simp. ..... 67
Hydianus (Margarita) Lea ...... 67
Hydianus (Margaron) Lea ..... =) 67,

1499
Ebydianus @Unio)) Kust. 0200s... 62
Hydianus (Unio) Lea .........5.. 67
Hygapanus (Nodularia) Simp. ... 585
Hygapanus (Unio) B6tt. ........ 585
Myla, (Onto) -COrb. ..c.e. 2. 1274
Hyleus -(Diplodon) d’Orb. ...... 1274
Hylaeus (Margaron) Lea ........ 1274
Hylaeus (Unio) Sow. ........... 1274
Hyperamblius (Unio) Kob. ..... 732
Ray tlds AI0t-e ralrcvos cus evelel telnieveteteleletetelel.s I2I1
IBhiechiey Syren odnogosobaoc00GD 1223
lehasents Sac dunpoomooudooponcc an 949
lanamchley Shien Boose aongpoocoodds 1288
Hypsiprimnus (Parreysia) Marts. 1136
Hypsiprimnus (Unio) Marts. ....1136
EIR OpPSIS GOT wle cite yore ofelolni-Vat sas 207
Tanthanius, Unio)! “ehiiy sys. -slere 1261
ieterinus) CUnio)) Cons se. os cnc. 664
Icterinus (Unio) Simp. ........-- 666
iG (GUIS) jc BXe og gogbouton ool. 1193
TIdrina (Anodonta) Spin. ........ 364
IGisovaeqs lly MIG CacoopmooodoDoKK 1392
Iheringi (Anodonta) Cless. ...... 1408
Theringi (Glabaris) Simp. ........ 1408
Theringi (Diplodon) Cless. ...... 1272
iherinet CUn10)) Simply ats ejelei siete! = ele 1273
Therinei (Unio)! BS Ee Wires sinc). 623
Elgiie CUimi1O)) hs Olas teenies elsiclsieiefeielave 1193
Imbecillis (Anodon) Sow. .....-. 306
Imbecillis (Anodonta) Say ...... 395
Imbecillis (Margaron) Lea ...... 306
Imbricata (Anodon) Anth. ....... 423
Imbricata (Anodonta) B. H. Wr. 423
Imbricata (Plagiola) Morch. ..... 313
TImbricatus (Unio) Morch ....... 314
Imperialis (Unio) Morel. ....... 219
Implicata (Anodonta) Say ....... 301
Implicata (Margaron) [ea ....... 391
Impressa (Alasmodonta) Anth. .. 504
Impura (Anodonta) Say ......... 383
Inequalis (Nodularia) Roch. 1012
Inequalis (Oxynaia) Haas ...... 1013
Inequalis (Unio) Roch. .......... 1013
Inequivalvis (Anodonta) Lea 1423

Inequivalvis (Anodontites) Lea .142
Inequivalvis (Glabaris) Lea ..... 1423
Inequivalvis granadensis (Ano-
Glouey) INET smoebagdocoocoade 1425
Inzquivalvis lenticularis (Ano
oloyete)). WENCH Uooh ocbobococon 1424
Inequivalvis (Margaron) Lea ....1423
Inangulata (Cristaria) Haas ..... 234
Incarnata (Grandidieria) Bet. 1061
Incarum (Anodonta) Phil. ...... 1422
Incarum (Anodontites) Phil. 1422
Incarum (Glabaris) Simp. ....... 1422

1500

Incertay (CAnodon)mi@. eso. ete 306
Incerta, ,CAnodonta)) Weal re. 3.2 396
incerta (Marearita) Wea. .c.ce6 3906
Incertus (Anodon) Sow. ........ 396

Incertus (Ptychorhynchus) Simp. 1150
Incrassata (Anodonta) Loc. ..... 362

Incrassatus (Margaron) [Lea ..... 608
Incrassatus (Mytilus) Shep. ..... 362
Iinerassatas Unto) Ieear mimic. 608
Eneunvyiis CUmio)) Wyea merersiie -s)erevsts = 555
Indecora (Anodon) Hde. ....... 405
Indecora (Anodonta) Pet. ....... 405
Imdefinilus: (CUmio)) Wea aamics «eter 656
Indefinitus (Margaron) Lea ..... 656
Indéfinitus (Unio) Wea oo. 5.2... 4. 656
Indicus (Margaron) Lea ....... 1118
Isotobiorets (UUbao)) Stones soonnanhoode 1118
Ineptus (Margaron) Tea ........ 71
Ineptus, @WUnto)) Weal enw vac «scteclere 711
Inerme (Aplodon) Spix ......... 1386
Inerme (Monocondylea) Simp. ..1386
Inermis (Monocondylea) Spix. ..1387
iniata, (Anodonta) elvateencwiseciciier 437
intlatal ((Castalia)ind’ Orbe rere clshare 1196
inflata ‘(yampsilis) Wea 25... onc 184
Inflata (Metaptera) Con. ........ 185
Inatae (Miya ator ecisiciielsre sien 61
Inflata (Symphynota) Lea ;:..... 185
Infatus @Viarearita) Wea en oe 185
Inflatus (Margaron) Lea ........ 185
livousienrbtsy (lUlren(s))) IREIS Soshdgnoaosnoc 61
ibebiehbey (QUkaekep) (CON Soon goagdason 185
Infrarostatus (Unio) Schep. ..... 218
Infiucata C@nadriula)) wears cerelle 864
Infucatus (Margarita) Lea ...... 864
Infucatus=@Miarcaron) Wear cece 864
Rafucatus @Unio)! Gonsr en siete 864
Tntulgens CUmio) iy Wea. . tel leiee 657
Entuscus) (Um10) sp lyeaers ote eerste 657
Ingallsiana (Nodularia) Lea ..... 999
Ingallsiana (Oxynaia) Haas ..... 1000
Ingallsianus (Margaron) Lea 1000
Ingallsianus’ (Unio) Weal -.-.n se 1000
Innest @Spatha) -Pallary eerie ce 1320
Inornata (Anodon) Anth. ....... 422
Inornata (Anodonta) Kust. ...... 365
Inornata (Nodularia) Lea ....... 986
Tnornatus (Margaron) Lea ...... 987
Tnornatus (Physunio) Haas .:... 987
Ibncraennoey. (AUheroy)) ICE Soodsdonce 987
Imornatus= (Unto) Rye hs o.0..3 989
Inoscularis (Anodon) Gld. ....... 1088
Inoscularis (Margaritana) Pet. 1088
Inoscularis (Margaron) fjea ..... 1088
Inoscularis (Pseudodon) Gld. 1088
Insignis (Grandidieria) Bgt. ..... 1053

INDEX

Insitatus CUnio)) Bo He Wire... > 671
Insolidus’ (CUmio)2 Weal an «6 scien. 486
Instructa (Pleurobema) Simp. .... 773
Instructum (Pleurobema) Lea ... 773
Instructus (Margaron) Lea ..... 773
Instquctus. CUmnia)malgeay errs cree 773
JInsularis (Dalliella) Simp. ....... 1076
Insularis (Pressidens) Haas ,....1076
Insularis (Pseudodon) Drouet ...1076
Insularis (Simpsonella) Drouet...1076
Insulsus (Margaron) Tea ....... 641
Tnsulsis Unione Wea ascetics crete 640
Intercedens (Margaron) Lea ..... 103
Intercedens (Unto) Tea --...5... 103
Intermedia (Anodon) C. & R. .... 362
Intermedia (Anodonta) Lam. .... 362
Intermedia (Quadrula) Con; ..... 837
Intermedius (Anodon) Ken. ..... 362
Intermedius (Margaron) Con. .... 838
Intermedius (Unio) Con. ........ 838
Intermerata (Anodon) Hde. ..... 405
Intermerata (Anodonta) Pet. .... 405
Interruptus (Margarita) Lea ..... 84
Interruptus (Margaron) Lea ..... 84
interruptus! (Unio) Cons a... a6... 8
interruptus’ (Unio), Wea Jo. .c. 84
Interraptus’ CWUnito)) “Say? <n... 831
Interventum (Pleurobema) Lea .. 761
Interventus (Margaron) Lea .... 761
Interventus (Pleurobema) Simp. . 761
Interventus (Unio) Tea ......... 761
Ibn cieha) (AUiaoy) ILGEL Eoacooecaoe 670
Inusitatus (Margaron) Lea ...... 671
Inventstus (Unio)! Leavy o.ciecietrer 663
IhyScnergy ISIE Shoobonmocosd06 971
Involuta (Nodularia) Ben. ...... 1004
IbayAostbuel (Bier) Soni Sadococdacc 1004
Involutus (Margaron) Lea ....... 1004
involutus: Unio)! Bent cect.) 1004
Tridella~ (Briersonia)) (Oxrts @...- 201
Iridella (EZampsilis) PP. & Bo ...:) 201
iridescens, Unto) (Cons --ecne eee 731
itaGhines bah) Stommao poanaode ona 1351
Iridinea (Solenaia) Hde. ........ 460
Iridineus (Mycetopus) Hde. .... 461
Iirisans (Anodon)) Amth> sc. e cc: 389

Irisans (Anodonta) B. H. Wr. ... 389

lems) (Cathay): Ohne soganecooeooc II5
Iris GWampsilis)) sy eawrererctere triste It4
ibnG. (@iieneeiauen) ILCEY Shossodaacdc II5
[ris GMiargaromi) ey eal yeiey-netsalet=a)e/e'~ IIS
Tints CWinio)) ole eae apheterorteretensretsiatsie ys II5
Irrasa (Pleurobema) Simp.-...... 771
Irrasum (Pleurobema) Lea ...... 770
Irrasus (Mlarezaron)) ea =... 35... obi pit
TenaswsS yew 10) pele cate eretetetelotsintoteis 771

INDEX

Jrregularis (Anodon) Hde. ....... 403
Irregularis (Anodonta) Pet. .... 403
irrorata, (Cyprogenia) Wea... 1... 326
Irrorata pusilla (Cyprogenia)

SURILD veh ic ebeessforekcten oteke ete sera kel eek 328
Irrorata (Theliderma) Sw. -:...... 327
TrrorataGWUinio)) Desh) a. .ice son 327
incoratussi@Margantta)) Weave). cr 327
Irroratus (Margaron) Tea ....... 327
Irroratus @Wnio)e lea a...) cee ele 32
Irwinensis (Unio) Tea .......... 657

Isocardioides (Iheringella) Lea. ..1393
Isocardioides (Margaron) Tea....1304
Isocardioides (Plagiodon) Lea....1394

Isocardioides (Unio) Sow. ....... 1394
Isocardiodes (Plagiodon) Lea ....1394
Jacksoniana (Obovaria) Fr. ..... 301
Jacksonianus \@Uinio) pir a. itn 301
Wacobens /GUnio) MPhils nse aces 1262
Jacquemini CUnio)> Dup. ........,. 572
Jacula q(Oxynaia) seElaas s.r sc 978
Vaculus eC Umio) Rocha nae Samii 978
Jamesianus (Margaron) Lea ..... 706
Jamesianus’ CUnio)) Weaie << cocci 706
Japanensis jokohamensis (Nodu-

IER SEW ie Wel tae een mci h ata pe cio Geo 969
Japanensis (Margaron) Lea ...... 969
Japanensis (Nodularia) Lea ...... 969
Japanensis (Unio) Kob. ......... 970
Jiapanensise(Wnio)) Wea o.fysacese 969
Japonica (Anodonta) Marts. ..... 410
Jaspidea (Monocondyza) Hupe ..1390
Jaspidea@Uinio)in Ewpe ) aye sei eaic 1391
Jaspideus (Margaron) Lea ...... 1391
Jiaubertin (Unio) o0ck asec oe 551
ayvanay CAnod om) Sows. cle cee eleto ene 242
Javanus (@Margaron)) Wea. nn... 1006
eKebercss (CUhrG)) IbGEL Ge doue aoboe 1006
Jiayanuss(Marcaron)) eleal sess wi 630
Jayanus) (Unio) Be Ei Wiase « aces 630
Vayensis) (GEliptio) (Ort cea... cc. « 630
Jayensis (Margarita) Dea .::.... 629
Jiayensis’ (Margaron)) Wea ..:.5-.. 629
Wayensisn CWO) pele caw erctern vwloloverersier= 629
Jeffreysianus (Diplodon) Tea 1299
Jeftreysianus) (Unio) Gea... 2.6: 1299
Fequnus! (Margarita): Weal <). s..<1- 659
Jejunus; iCMiargaron)) Wea, 2h. sic. 659
Nejunus- @Unio), Weal. acest asics 659
Jenkinsianus (ITamellidens) Ben. .1176
Jenkinsianus (Unio) Ben. ....... 1177
Jewettiana (Anodonta) Lea ...... 1438
Jewettianus (Anodontites) Lea 1437
Jewettianus (Glabaris) Simp. 1438
Jewettii (Anodonta) Lea ........ 1438
Jewettii (Margaron) Lea ....712, 1438

I501
NiewettriaCWinto)) seas eis sc, oicke ocrebe 712
Jickeli (Nodularia) Simp. ....... 579
Hickel’ (Unto) Simp: te... «2. stseste 579
Johannis (Margaron) [Lea ....... 780
Johannis (Pleurobema) Lea ..... 779
Johanniss@Umi1o)iiljeaie smtecircieieels =: 780
Johnstoni (Pseudavicula) Smith..1190
Johnston’ tCWnio)> Smith) fesq.s.c4 IIQI
Jokohamensis (Unio) Ih. ........ 970
Voy (Usa) IO “Aooosodocnoose 556
Jones @Viarcaron)) Wea i.e. esos 120
onesie CUnio) is ean 4 ts sepsescrete 120
Jordanicus (Margaron) Lea ...... 550
Jioxdanicuss (Wino), Bets a5 access 550
Jioreti~GAnodoti); Eide. .j.).0..% 6 a ene 403
Jiosseti, (Cameronia)) Bet... se 1379
JosSSetin(GUinvo) RIB St wer cis leleekae 1193
Jouberti (Burtonia) Bet. ........- 204
Jouberti (Cameronia) Bet. ...... 1383
Jouberti GVMloncetia) Bet. ... 3.5. 1345
Joubertiei(tutela) Bete ap aciete se 1355
Joubert @Winio): eBigtiy ciesiasseisrene 1193
Jioubini. (C@Miutela)i (Ger, 22ncio.. nace 1363
Joubini (Mutelina) Ger. ......... 1364
Jourdyi (Anodonta) Morl. ....... 408
Jourdys (@Brazzea)) Betsd..- > sno. 1374
Jourdyi corrugata (Nodularia) D.

(cai a [eel Dak on are cn oat ee Sree 999
Jourdyi corrugata (Unio) D. &

1 Gs De neo ener E OOOO Sree e 999
Jourdyi (Nodularia) Morl. ....... 998
Vourdya \G@s<ynata)r Elaasi "seein 999
Jourdyi ponderosa (Nodularia) D.

(accyal a Lig Dee Roo Ors certs rare 999
Jourdyi ponderosa (Unio) D. & H.

ee arvisste. tus apaeccencntedsnr cae Saye refiner et 999
Jourdyi CUnio)) Mork, Seneecausta- 999
JMRORHTS Stith pauacpocaccouuncde 357
Juliani (Nodularia) Rang ........ 1044
Wialtanay ((Uii10)) vai 27 eyerstercteraeke ser 3 1044
Juruanus (Tetraplodon) Ih. ...... II1Q7
Kallethensis (Unio) Pet. ........ 564
Kamerunensis (Spatha) Walk. 1349
Katherinas (Umio)_ Tea ......... 492
Keinerianus (Margaron) Lea .... 852
Keinerianus: (Unio) Wea .t....02. 852
Kelletti (Anodon) Sow. ......... 242
Kennerlyi ,(Anodon) Sow. ....... 375
Kennerlyi (Anodonta) Lea ....... 374
Kennerlyi (Margaron) Tea ...... 375
Kennicottii (Anodonta) Lea .... 435
Kennicottii (Anodonta) Simp. ... 436
Kennicottii (Margaron) Lea ..... 435
Keraudreni (Margaron) Lea ..... 983
Keraudreni (Nodularia) Eyd. .... 983
Keraudreni (Unio) Byd. ......... 983

1502

Kienerianus (Margaron) Lea .... 852
Kingi (Medionidus) B. H. Wr. .. 250
1Gasker) (Use) 18% Isl \ioe So gdcode 251
Kirki liederi (Spatha) Marts......1324
ismay (Shieuiseny wee ak aancecors 1324
Karki sCSpathella)) “Ane: *<c\c%'.- <'s 1324
Karki @Margaron)) [yeas ... 0... - 1133
Karki (Parreysta)) (yea) "rc ie ae 1133
Berek GU mio) sis atin acdercatatactelare teas 1133

Kirklandiana (Lampsilis) S.H.Wr. 126
Kirklandianus (lampsilis) Simp... 127
Kirklandianus (Unio) Han. ..... 8o1
Kirklandianus (Unio) B. H. Wr. 127
Kirtlandiana (Fusconaja) Ort. ... 801
Kirtlandiana minor (Quadrula)

SH psa eee ote enter eeeetere 802
Kirtlandiana (Quadrula) Lea .... 891
Kirtlandianus (Margarita) Lea .. 891
Kirtlandianus (Margaron) Lea ....8o1

Kirtlandianus (Unio) Lea ....... 8o1
Kasonis) oC Unio) * Sob ae eyeie oleic 547
Kleiniana (Quadrula) Lea ....... 865
Kleinianus (Margaron) Lea ..... 865
Kleimianus’ (Unio) Wusts hoc «ner 838
KMeinranus: CUnro)) gear See. e cee 865
Kobelti (Anodonta) Th. ......... 410
Kobeltt (Unto) Neum.°..2.....2. 724
iKobelte (Unio)? Rolleys 2c. scenes 551
Keehleri (Nodularia) Ger. ....... 1040
iKcehleriaGUni1o) i Gerenciterneisret ear 1041
Koseretzi (Unio) Cless. ......... 1312
Kouangensis (Quadrula) Simp. .. 923
Krausei (Mycetopoda) Ih. ....... 1465
Kraussii (Margaron) Lea ....... 1209
GEC (Uhaktoy)) IWEEY Bisnooooadoos 1209
Ksibianus (Unio) Mouss. ........ 556
Kullethensis (Margaron) Lea .... 564
Kullethensis (Unio) Tea ........ 564
Kullinthensis (Unio) Paet. ...... 564

Kunenensis (Nodularia) Simp. ... 586

Kunenensis (Unio) Mouss. ...... 586
Kuweikensis (Unio) Kob. ....... 732
Labacensis (Unio) Ross. ........ 570
Lachrymosa lunulata (Quadrula)
Sith” gupoosb oon copcdocoo odode 322
Lachrymosa (Quadrula) Lea .... 841

Lachrymosus (Margarita) Lea .. 842
Lachrymosus (Margaron) Lea ... 842

Lachrymosus (Unio) Lea ........ 842
Lacoini chudeaui (Nodularia) Ger. 1029
Lacoini chudeaui (Unio) Ger. ....1029
Lacoini (Nodularia) Ger. ........ 1028
Lacoiniy GUnio) Ger) eave +. einecters 1028
Tacteolus (Diplodon) Lea ....... 1226
TLacteolus (Unio) Wea ci ont ee 1227
Lacustris (Anodon) Sow. ........ 389

~ INDEX

Lacustris (Anodonta) Lea ....... 38m
Lacustris (Margaron) Lea ....... 389
Lacustris (Spatha) Simp. ........ 1330
Lavicatus Unio)! Say siete. 293
Ty2eviOStRis: “SUMP. + fey erereetereseie wie aiv els 1308
Lzvirostris (Unio) Ben. ......... 1107
Levis @€lanceolaria) Haas: ....:..:. 954
Levis (Nodularia) Marts. ....... 954
Levis (Ptychorhynchus) Haas ...1146
Levissima (lampsilis) Lea ...... 183
Lzvissima (Proptera) Ort. ...... 184
Lzvissima (Unio) Desh: ......:. 183:
Levissimus (Lampsilis) Simp. ... 184
Lzvissimus (Margarita) Lea ..... 184
Levissimus (Margaron) Lea ..... 184
Levissimus (Symphynota) Lea .. 183
Levissimus (Unio) Con. ........ 184
Lamarckianus (Margaron) Lea ., 32¢
Wamarckianus «(Unio)) Lea... . <1 329
Lamellatus (Lamellidens) Lea .. 1172
Lamellatus (Margarita) Lea ..... 1173
Lamellatus (Margaron) Lea ..... L733:
Lamellatus (Unio) H. & T. ..... 215
Tamellatus: (Unio)) Lea ....2.5.; 1173
Lamellatus (Unio) Sow. ........ 1175
amellidens) Simipe. | wie tel- el ole -tiere 1900

Laminata (Anodonta) Roch. ..... 437
Lamphorhamphus
Lampreyanus (Margaron) Lea ... 940

Lampreyanus (Schistodesmus) B.

& AUS so dg beets whe eee 940
Lampreyanus (Shistodesmus)Simp. 940
Lampreyanus (Unio) B. & Ads. .. 940
Mamprotula, Simp. | eis) sere iol cta cists Q1s
PampsiisiRaia criss. eters 35
Lananensis (Fusconaja) Ort. .... 871
Lananensis (Quadrula) Fr. ...... 870
WanceolariaiACony tes eceieee eee 951
Lanceolata (Arconaia) Lea ...... 1188
WanceolatayCELyria)eWea aa. ler 1188
Lanceolata (Triquetra) Tea ..... 1188
Tanceolata (Unio) Desh. ....... 689
Lanceolatus (Margarita) Lea .... 689
Lanceolatus (Margaron) Lea ..... 689
Lanceolatus (Unio) Bea <.).4- ole 689
Landanensis (Unio) Schep. ...... 1032
Landbeckt. (Unio) Phill ic... 5. - 1262
Landeaui (Cameronia) Bet. ..... 1380
Landeaui (Pleiodon) Bgt. ....... 1379

Languilati (Lepidodesma) Hde. .. 237
Languilati (Lepidodisma) Simp. . 238
Languilati (Unio) Hde.
Languillati aligerus (Unio) Hde.. 239
Laoensis (Margaritanopsis) Haas. 521
Laosensis (Anodonta) Fisch. .... 380
Laosensis (Margaritana) Lea .... 520

INDEX

Laosensis (Margaron) Lea ...... 520
Wacsensis, (Unio)! Weal. ae oer 520
Papidosus (Unio) obs 7 ier. oo 603
Papilluse(@Wnio). Saye - ssistece sis sere 34
JTardelianus (Unio) Pec. ......+. 536
Largillierti (Lampsilis) Phil. ..... 194
Largillierti (Unio) Phil. ........ 194
Lasmabrachys (Unio) Raf........ 731
Wasmigonar cat wcmud aarerccierehe hotels 488
WastenaGRatap teercrercisvele elec ns ararcttve 452
ata iC Anodow) MM SOWel aoe cle cers ol 454
Bata) (Anodonta) “Rati -wa.m..0.% 0 © 454
atanGleastenaye-Rate on crabreats.c create 453
Rata GSeptodea) (Cont 2 jose. s oe. 454
Watecostatus’ (Unio) Tea io.c.-s.s 821
Lateralis (Obliquaria) Raf. ...... 731
WatialatanChvnia) le SOweun).icierceatete 1214
Laticeps (Nodularia) Marts. .. 1007
Taticeps (Unio). Marts. ......... 1008
Laticostasus (Margaron) Lea .... 821
Laticostatus (Margaron) Lea .... 821

Laticostatus (Unio) H. & A. Ads. 821
Lati-marginata (Anodon) C. & R. 1405
Lati-marginata (Anodonta) Strob. 1405

Latiquadrata (Castalia) Sow. .- 1199
Watiradiatus (CUnio)» Con: -s......- 84
atissisaal eWn1@)) Ratoc celereieiersrerete 06
Eatissimius \GUnto)) “Sows silcee oe 2 40
Lato-marginata (Anodon) Sow. ..1405

Lato-marginata (Anodonta) Lea..1404
Lato-marginata (Margarita) Lea.1404
Lato-marginata (Margaron) Lea..1404

Lato-Marginatus felix (Glabaris)

US Bae rarest too.craraslevciens ie anclevstetes ce iets 1406
Watus, (Marganon))) Weal aoc cic scree 667
ILANTS, (UIE): (Cort, os oopoconopnes 454
Wats GUinto) med tricicisaet-) <ctaetere 667
Lauta (Anodonta) Marts. ....... 408
Lauta rostrata (Anodonta) Kob. . 4009

Lauta tumens (Anodonta) Haas.. 409
Lautus tumens (Anodontites) Haas 410
Lavigeriei (Cameronia) Ger. ..... 1381
Lavigeriana (Cameronia) Bet. 1381
Lavigerina (Brazzea) Bet. ...... 1374
Lavigerina (Burtonia) Bet. ...... 204
Lavigerina (Cameronia) Simp. 1381
Lavigerina (Moncetia) Bgt. ..... 1346
Lnavigerina (Mutela) Bet. ....... 1367
Waviverina (Spatha), Beth. ances 1346
Wavagerinus: (Unio) Bet. 222... .: 1193
Wawa CUO) mlyeae ance ceeie ce esc here 740
Lawleyanus (Unio) Gent. ....... 533
Layardii (Margaron) Lea ....... 1173
Bayacdimmcunio)r Wea o«selistcc cle cers 1173
Lazarus (Margaron) Dea ........ 684
Bazanash Wao); sear tmeis ces siemree 683

1503;
azartise (Unto) 2 SOwe mc cc sieisielere 590
Leai cinnamomeus (Unio) Gred. .. 936
eat (Diplodon) Simp. <.:)..130%. <1. 1241
Leai leleci (Quadrula) Hde. ..... 930
Beaslelecie CUnio)) Bet. «sii» ole of 930
Leai ponderosa (Quadrula) D. &
1S oe Sie disco bao bo cio cocoate 931
Peai(Ouadrula)) Gray, 2212 esol = 929
Leai truncatula (Quadrula) Neum. 930
Leai truncatula (Unio) Neum.... 931
eae CWinio) Gray) Pieces sesiee elects 929
ieeaur- @Margarita)® Wea) isis) <steret- 929
Wea (GMargaron) Wear nn... -«.6 ce. 6290
Wea e@blatinis) spl Gals aresiaclere= ce relers 1377
Leaii (Pleiodon) H. & A. Ads. 1377
Lechaptoisi (Nodularia) Anc. ....1037
Lechaptoisi. (Unio) Anc. ......... 1037
Lecontianus (Margarita) Lea .... 687
Lecontianus (Margaron) Lea 687
econtianus (Unio) Wear... esis 686
Ledoulexiana (Nodularia) Char. .. 982
Ledoulexianus. (Unio) Char. ..... 982
Iba iWrete)) debhes pe oomecuoancecc 929
Weorandin GW) mikebtey vere cfetelolsieier= 1299
Legumen (Anodonta) Marts. 1459
Legumen (Glabaris) Simp. ...... 1459
Legumen (Mutelina) Roch. ...... 1360
Legumen (Mycetopoda) Ih. ..... 1459
Wepuminata (Cony wesecceeecc ce sec 444
Rehman CUnto) Ss. HeoWirm so... 636
Leib ‘@Miargaron)) Ijea 5.5.....- 206
Weibpire (Ohbovaria): Wear ce 1 tele 206
Weibit adWUnio)i Gea sey. cisecerstorere 206°
Wetlary Gray Hara csvavetelemtsleroretetetsietete 1399
Peron eCWnr1o)) Bens cre oelcicle cheters 979
lifaton pore IRE) sadégonaoacooenos 1154
elect (Unio) = Eidey seeoeeoee ces 930
Lemeslei (Anodonta) Morel. ..... 244

Lemeslei
Lemsleyi
Le Mutel Ad.
Lenior (Margaron) [Lea
Lenior (Truncilla) Lea
Lenior (Unio) Lea
Lenis (Unio) Con.
Lenis (Unio) Lea
Lens depygis (Obovaria) Con.
Lens
Lens
Lens
Lens

(Margarita) Lea
(Margaron) [ea
(Obovaria) Tea

Lens parva (Obovaria) Simp. ..

Lens Simp.
Lens (Unio) Lea
Lenticulare (Pleurobema) Lea
Lenticularis (Anodonta) Lea

elongata (Obovaria) Simp...

(Pilsbryoconcha) Morel. 244
(Pilsbryoconcha) Simp.. 244

an 204

1504

Lenticularis (Margaron) Lea .1424
Benticularism (Unio) eas eer ccc. 791
Lentiformis (Aplodon) Th. ....... 1392
Lentiformis (Margaron) Lea .1392

Lentiformis (Monocondylea) Lea 1392
Leonensis (Anodonta) Lea ...... 423
Leonensis (Margaron) [ea ...... 423
Leonensis (Unio) B. H. Wr. ....1469
Leopoldvillensis (Parreysia) Putz. 1124
-Leopoldvillensis (Pseudospatha)

SHIP! She iaeanah Watenchney oars reste ec siete 204
Leopoldvillensis (Unio) Putz. ....112
Leotandi (Glabaris) Simp. ....... 1413
Leotaudi (Anodonta) Gup. ...... 1413
Leotaudi (Anodontites) Gup. ....1412
Leotaudi (Margaron) Lea ....... 1413
Lepidior .<Diplodon) ‘Tea :.is.-... 1255
Lepidior (Margaron) Bea ........ 1256
Wepidodesma = Simpy aces ie etane 237
Hepidus (Marearon)) "Wea i225... 140
Mepidus Unio) Gilde see aeleee 140
Kepidusi GUnio) i seaw econ enieenciee 1256
Meprosus (Unio), Mules) s..- sce ee 96
Ibo (Syeeideey) Ise oogocaodas as 1319
Leptodea (Rafinesque) Con. ..... 452
Leptodon (Lampsilis) Raf. ...... 188
Leptodon (Leptodea) Con. ...... 189
Leptodon (Symphynota) Fer. .... 189
Weptodoz@Unio) le Rataeespeieaciee ce 189
Weptospatia wR ye cowie seieeisicotestere 1313
Hesleyi ((Margaron)) Wea men. cee 745
Lesleyi (Pleurobema) Tea ....... 744
Wesley (Unio) meas 745
Lessoni (Diplodon) Kust. ....... 1296
Tessoni @Uinio)s Kauste eimcters cletaeiers 1297

_ Lesueurianus (Margaron) Lea .... 894
Lesueurianus “GUnio)) Wea a.ccee 894
Letourneuxi (Anodonta) Bet.

causes sostorciolel Merete lata terete maces 372, 439
Letourneuxi (Colletopterum) Bgt. 438
Letourneuxi (Unio)) Bet. ........< 541
Wetourneuxs | CUnio) kobe circle 556
Letourneuxiana (Chambardia) ...1350

Letourneauxiana (Pleiodon) Bet. 1470

Wevigatam GWaio) mekvcisuetstcteretsierersiene 731
iLfexaisin (CeWavoreloya)) Sto coasoaases 420
Lewisii (Anodonta) Tea ...... cietert 20)
Lewisii (Margaron) Lea ..... 420, 766
Lewisit (Truncilla) Walk. ....... 20
IG ewasitenG@Winia) meleeamectterrerecteteeiee 766
I7hotelleriana (Mutela) Prest. ..1364
Liebmanni (Margaron) [Lea ..... 625
Liébmannia (Unio)m hile ste certeei ee 625
Liederi (Nodularia) Marts. ...... 1037

INDEX

iedert (Unto) Meartsweme ree ace 1038
Liedtkei (Quadrula) Rolle ....... 921
Wrenosa es Gaiiny nia) ie Ont sess eer 1469
Tienosa (Lampsilis) Con. ....... 100

Lienosa unicostata (Iampsilis) B.
Elin Wits Acetate nae eee IOI
Lienosus constrictus (Unio) Con. 111

Lienosus (lampsilis) Simp. ...... IOL
Lienosus (Margarita) Lea ........ IOI
Lienosus (Margaron) Lea ....... IOL
Lienosus unicostatus (lI,ampsilis)

Shiiniohe yaa GoD OOO OMe ato e Gon 102
Eaenosus,) (Unio)hCon: )asaeneese ae IOI
Ligamentina gibba (lLampsilis)

SUMP! | sssreusletebeseis aateievets mishonenenst lees 82
Ligamentina (Iampsilis) Lam. ... 79

Ligamentina (Nephronajas) Ort... 80
Ligamentina nigrescens(Lampsilis)

Suhy “Gaocoperose aGuccodamn deo 82
Ligamentina (Unio) Lam. ....... 80
Ligamentinus gibbus (Lampsilis)

Simpit*s. ceeek ecto eo aees oie 82

Ligamentinus (Lampsilis) Bak. .. 80
Ligamentinus (Margaron) Lea ... 80

Ligamentinus (Unio) Kust. ..... 80
Wigatus i@Uni0) = Wea anise eee 656
Ligulan@Unio)s Mogwss- saeco 1193
Lima, Nodularia) ‘Simp: 22 .4..c0% 1018
Lima siliguriensis (Nodularia)

PEesthy lac8 Bogor ea sceemeeee 1018
Limatulus (Margaron) Lea ..... 640
Eimatalus: @Uinio)\ Cons ene. 640
Limensis (Unio)! Kust.7.oasaccn 1262
Wy imamieea yA Oli) vore\epelicievslencverersiatevere 358, 527
Lininoica (Anodon) C. & R. ....1420
Limnoica (Anodonta) d’Orb. 1420
Limnoica (Margarita) Lea ...... 1420
imnoica, (Miargaron)) Wears... 1420
Limnoicus (Anodontites) d’Orb...1420
Limnoicus (Glabaris) Simp. ...... 1420
Limosa (Anodon) Hde. ......... 412
Limosa (Anodonta) Pt. ........ 412
Limosuss (Unio)! Ikobsyrscrierteietersiete 535
ibis (Obmo) ly INMS Sosoceso55s noo
Lincecumii (Margaron) Lea ..... 818
Lincecumii (Unio) Lea ......... 818
Emececur, (Unio) (Pet. eee ee 818
Lindsleyi (Margaron) Tea ....... 85
Tandsleyi) (@Unio)i wean ele. t2 = 85
Tjimeata CAnodon)) Elders =. <.cc. ste 403
Lineata (Anodonta) Pet. ....... 403
Tineata (Unto) Viale Joes os ox 65
Lineatus (Margaron) Tea ....... 43
ineatts a GUnio)melyeamenari. eine 43
Lineolata (Obliquaria) Raf. ..... 731

INDEX

Lineolata (Plagiola) Ag. ......... 305
lesterol, (Uinte)) Seay goasooanmoc 3:05
Rineolatus, @Wnio)y (Const sire 305
Lingueformis (Anodonta) Morel. 240
Lingueformis (Margaron) Lea

SCHIP oO CED OLE IO aero De 120, 240
Lingueformis (Pilsbryoconcha)

Wow, Guoasvoch soo pasecocgaddacue stl
Lingueformis (Unio) Lea ....... 120
Lingulata (Anodon) Sow. ....... 1445
Lingulata (Anodonta) Hupé ..... 1445
Pinewlata.GlabaLis)) la scsi) ve 1445
Eingulata (Margaron) Lea .....- 1445
Lingulatus (Anodontites) Hupé...1444
Lingulatus (Glabaris) Simp. ..... 1445
Lingulatus (Rectidens) D. & C. ..1159
Eimeulatis;, (Unio)y Dac |G eta... 1160
Jjinneana (Anodonta) Tea ...... 431
Tinneana (Margaron) Lea ....... 432
J,inneanus (Anodon) Sow. ....... 432
Wita (Pleurobema) Simp: °....... 792
Lithophagus (Unio) Zieg. ....... 98tr
Litoralis (Margarita) Lea ....... 554
itoralis) (NMiascaron)) led =a. acec. 554
Waitoralisi@wWnto)m Ga eity sos ceiciess 519

Litoralis umbonatus (Unio) Ross. 554
Littoralis acarranicus (Unio) Kob. 554
Littoralis minor (Unio) Ross. 554, 572
Littoralis pianensis (Unio) Kob. . 554

Wittocalisw (Wma) Warners ea craete © 553
Litturata (Anodonta) Hupé ...... 1454
Litum (Pleurobema) Lea ....... 792
Pitucata, .“Anodon)) Sbya ese e cle 1454
Lituratus (Anodontites) Spix ....1454
Lituratus (Glabaris) Simp. ...... 1454
leginneS. (Winey) IWEeY Boo dusudcoccnds 792
Wividam(CAnodon)eilides) j-\1actecesiere 404
Wividay @Anodonta) eet weiss sic 404
ividami@sampsilis)ieoimpseieic scien 174
Lividus (Lampsilis) Simp. ...... 175

Livingstonensis (Burtonia) Bet. .. 205
Livingstonensis (Margaron) Lea.. 670
Livingstonensis (Pseudospatha)

[Baa Gakyicatee DOHC DD SO OdDs Hc 205
Livingstonensis (Unio) Lea ..... 669
Livingstoni (Pseudospatha) Ger... 205
WobatasiG@Unio)! hile So0- «1. Hoo GO
Wocandi (Gabillotia) “Ser 1. 4-1. «1 441
Locardi (Ieguminaria) Simp. .... 449
Locardiana (Cameronia) Bet. 1383
ocardiana (Chambardia)! <.....- 1350
Locardiana (Grandidieria) Bet. 1056
Locellus (Diplodon) Tea ........ 1239
Locellus @Miargaron)) Lea ....... 1239
Wocelltism@Unio)) heavy es...) 516 « 1239

Longina (Anodonta) Kust. ...... 1445

1505
ongina Ciridinay ea 2.5 .......- 1446
Longina (Mycetopoda) Ih. ...... 1446
Longinus (Anodon) Simp. ...... 1446
Longinus (Anodontites) Spix ....1446
honginus “@Glabaris)) Spix 9 ....2.- 1446
Longinus (Mycetopus) Cless. 1446
Longirostris (Unio) Ross. ....... 534
Longitudinatus (Unio) Ant. ..... 1193
LE crorexcey (Cahsviop) dao Go aaamocoeac 1258
Loomisi (Pseudodon) Simp. ..... IIOL
orter | CUnto) pekKobs acche scleistiors 551
Worte tin GWinto) yl OCA lence cilereterele 548
Lourdeli (Nodularia) Simp. ..... 581
Lourdeli smithi (Unio) Ger. ..... 581
Fe OuUnde lies (nto) mes Stee ssceteie ce ecto 581
ourdels” (Unio) “Smith)i os. sa... 581
Lucasi (Anodonta) Desh. ....370, 372
Mucasir (Margaron) Lea o..2.%..- 371
Gucida (Anodon)) “Hides a... a. ee 4II
Lucidia (Anodonta) d’Orb. ...... 1421
Lucida. (Anodonta) Hde. ........ 4II
ucidas (Margaron)) Weal seeaeceee 1421
Lucidus (Anodontites) d’Orb. ~L4A2T
ucidus; (Glabaris)) Simp) ses... 1421
Lucidus (Margaron) Tea ........ 641
Bucidusm@Unio). Wea fae caceiesss 641
Ludovicianum (Diplodon) Roch.. .1187
Ludovicianus (Trapezoideus)

ROC he crkocntersne nee sacar se 1186
Lugens (Nodularia) D. & C. + Tora
iugens (Unto) aie Ca a eee 1012
Lugubris (Anodonta) Say ....... 437
Lusubris (Margarita) éa a.505 52 639
Gugubris. (Margaron) Lea s..5... 639
Puactbris GWmn10) ast. coca sie secre 655
Bucubris “CWmio) lear ac) ./-mcererereis)- 639
Gugubris: @Unio)) Say .e.acce.- 167
Gunwlatius; Unio) mM ecatt ssc cie 22
Lunulifer (Margaron) Lea ...... 550
Wanwliter GUnio Bets, acces dere 550
Luridus (Margaron) Lea ........ 602
Ibyenearickees (Whar) JOG Aon ocadeasds 601
Lurulenta (Anodonta) Morel. .... 434
Lusitana (Anodonta) Morel. ...... 363
Teutense Gulati o)milseau a nereiisicioiie ets IL07
Luteola (Anodonta) Lea ........ 1418
Luteola @lampsilis), Wams 2.2... - 60
Wuteola (Margaron)!) Weal) janes 1418
Luteola rosacea (Lampsilis) DeKay 62
eiteolagcWmio))melyanny sen siyeiereicter 61
Luteolus (Anodon) Sow. ........ 1418
Luteolus (Glabaris) Simp. ....... 1418
Luteolus (Lampsilis) Simp. ...... 61
Wuteolus’ (Margarita): Wea ....... 61
Euateolus @Margaron) Lea ....... 61

1506 INDEX
Luteolus rosaceus (Lampsilis) Magnifica (Margarita) Tea ..... 402

SUND Ha eter re aa had Pte esis owt 62 Magnifica (Margaron) Lea ...... 402
ute qhismGUnio ll eoOwe class < acces 81 Magnifica (Symphynota) Lea .... 402
Luteus (Margaron) Lea ......<.. 1107 Magnificus (Unio) Sow. ......... 231
Wuateus sCUnia): ease scene mdas 1107 Mainwaringi (Lamellidens) Prest. 1172
Lutulentus (Diplodon) Gld. ..... 1301 Mainwaringi (Unio) Nev. ...... 1172
Lutulentus (Margaron) Lea ..... 1302 Maitenguensis (Spatha) Stur. ....1330
Eutulentus (Unio) Gid. ....:..2. 1302 Malgachensis (Unio) Ger. ........ 719
Luxata (Anodonta) Kust. ....... 364 Mialtzani) (Unio): “Kast. 9... ee 533
Muxurians CUnio)pikasts «a siec.ccier 573 Manca «CUnto)mlsamanmee ane anaes 532
Euynesi: CUnito) Wocsien men sire 558 Mancas (Unto) Mills oer ae coe onic 572
Lycicus. (Unto) pRollet {62.46 556 Mancus, GUnio)) Drouet).. +... 532
Lyonii (Margaron) Lea ......... 755 Mancus.GWinio)Dups ices acer 572
Lyonii (Pleurobema) Lea ....... 755 Mandarinus (Unio) Morel. ...... 993
yoni, sCUnio) leaner rere tee 755 Mandelayana (Parreysia) Theob. .1112
Lymmniunri@Okenise saya avnriaree 527, 529 Mandelayensis (Unio) Theob. ....1112
Lymnoica (Anodonta) Chenu ....1420 Mandinguorum (Unio) Roch. .... 584
Mabillei frasi (Mutelina) Ger.....1361 Manhoti (Pseudodon) Con. ...... 1097
Mabillei gaillardi (Mutelina) Ger. 1362 Mansuyi (Quadrula) D. & H. F. 932
Mabillei mamounensis (Spatha) Manubius (Margaron) Lea ...... 707

Ger: 12 cee do see ee 1325 Manubius (Unto) Gid. 2.2 20.5503 707
Mabillei (Mutelina) Ger. ........ 1361 Manubrius \(Unia))) Batts sieve atrsicte 707
Mabillei (Spatha) Jouss. ........ 1324 Miarcens i@Winro))) Tisiecie Deas ein.ciarcievete II1I0
Mabilli frasi (Mutela) Ger. ...... 1361 Mardinensis chantrei (Jeguminaia)
Mabilli gailliardi (Mutela) Ger....1361 EOG: SVatcat es eo eter antatotctene stetens 446
Mabilli (Mutela) Roch. ......... 1360 Mardinensis (Leguminaia) Lea .. 445
Mabilli (Mutelina) Roch. ....... 1361 Mardinensis (Margaritana) Cless. 446
Mabilli (Pseudodon) Roch. ...... 1103 Mardinensis (Margaron) Lea .... 446
Mabilliana (Cameronia) Bet. . -1383 Mardinensis (Monocondylea) Lea 446
Maccarthyanus (Unio) Bet. ...... 542 Mardinensis naegelei (Ieguminaia)
Maccarthyanus (Unio) Kob. ..... 556 WOhz Ch RE eee 446.
Macer (Margaron) Lea ......... 667 Mardinensis (Unio) Lea ..,..... 564
Macers (Winio))aweamesces cence 667, “Margaritana Schtmt. “eics cys lee 511
Macilenta (Anodonta) Morel. .... 363 WikieiuninGes so5ecanoondancan5s 512
Macilentus (Unio) Ben. ......... 985 Margaritanopsis Haas .......... 521
Macmurtrei (Margarita) Lea ....1377 Margaritifer minor (Unio) Ross. . 515
Macmurtrei (Pleidon) Con. ..... 1377 Margaritifer (Unio) Kust. ....... 515
Macnielii (Nephronaias) Lea .... 260 Margaritifera (Alasmodonta) Con. 515
Miacnieln “@Uinio)) heal rate steieecter 260 Margaritifera (Baphia) H. & A.
Maconensis (Margaron) Lea ..... GoG: VaysAcins ss. eee ah eran Ma zie
Maconensis (Unio) Lea ......... 606 Margaritifera (Baphie) Meusch. . 514
Macrodon (Margaron) Lea ...... 310 Margaritifera faleata (Margaritana)
Macrodon (Plagiola) Lea ....... 309 Dalle guctsyctentsec eet ec crer Metoratetete iy
Macrodon (Unio) Tea ss... esses 319 Margaritifera (Margarita) Lea .. 515
miei Ae (Unie) PRES ecic Les Margaritifera (Margaritana) Linn. 513
Macula (Mytilus) Shep. renee ee es 362 Margarinterd. (Marsaconveries aun ars
Maculata (Pleurobema) Simp. ... 738 ae Mean dine inser
Maculatum (Pleurobema) Con. .. 737 Margaritifera ¢ ase eee

- Margaritifera (Unio) Drap. ..... 514

Maculatus (Margarita) Lea ..... 738 ae d Wn -
Maculatus (Margaron) Lea ...... 738 Margaritiferum aoe) bien
Maculatus (Unio) Con. <2 222-406 738 Margaritiferus (Alasmodon) cs 225
Madagascariensis (Unio) Sgan. 1193 Margaritiferus (Margaritana) West.
Magnifica (Anodonta) Cless. ..... Ae PMG ode bo AS ODN AGOP GOO TO OBGB OR. 515
Magnifica (Anodon) Sow. .....-. 402 Margaritiferus (Unio) Retz. ..... 515
Magnifica (Anodonta) Chenu.... 402 Marginalis anodontina (Unio) H.
Magnifica (Burtonia) Bgt. ...... 204 Co Do By ia etarakare/wteye: Sietekos ener aoe takeilets 1470

INDEX

Marginalis candaharica (Unio)

H. (ce gall WAR A ost es a See eee 1168
Marginalis candaharicus (Lamelli-

GENS) PE Rca Arai ers eee 1168
Marginalis consobrinus (Iamelli-

dens) aiPReStee ce Anes ee II7I

Marginalis corriana (Unio) H. &
PUNE Se Pe heveys Grai cis paren ene eka eee: 1169
Marginalis corrianus (Lamellidens)
[RreStrte eae wien Oe oy aS tyr ls II7E
Marginalis cylindrica (Unio) H. &

DUR CBOE One ns AORN hho Eee 1169
Marginalis cylindricus (Iamelli-

ens) ors hele 0 es ap ee 1168
Marginalis exanthematicus (lLamelli-

dens) x sustse rie- seer ne yee 1169
Marginalis generosus (Lamelli-

dens)» Prestquduattan seen sara II75
Marginalis hanleyi (Lamellidens)

SUIT Sage p UR eee a ee 1169
Marginalis jenkinsianus (I,amelli-

den's) Presta hictk| Sees 1177
Marginalis lamellatus (Lamelli-

dens) SeRTeS tie. hes eee ee 1173
Marginalis (Lamellidens) Lam. 1166
Marginalis (Margarita) Lea 1167
Marginalis (Margaron) Lea ...... 1167
Marginalis obesa (Unio) H. & T. 1168
Marginalis obesus (Lamellidens)

115 Bes acer 1 Rats epee gas a ae a aT a 1168
Marginalis sawaddyensis (I,amilli-

dens) sPrests 18 res aoe eee 1169
Marginalis scutum (Lamellidens)

PROS te ote 4 since eee Rta, Sees T1774

Marginalis sublamellatus (Iamelli-
dens) Prest.
Marginalis thwaitesi (Lamellidens)
Prest.

DD OOTY neh Pea eee Ee II7I
Marginalis tricolor (Lamellidens)

REIS Pipe eT Me enn yer n co ti 1168
Marginalis tricolor (Unio) H. &

ROME «Tone nha Ras ee exo eg sites 1168
Marginalis (Unio) Lam. ........ 1167
Marginalis zonata (Unio) H. & T. 1470
Marginalis zonatus (Lamellidens)

BROS Et clase avers oo on ee 1470
Marginata (Alasmidonta) Say ... 504

Marginata (Alasmidonta) Simp. . 506
Marginata (Alasmodon) Gld. .... 506
Marginata (Alasmodonta) Says ecensps
Marginata (Anodon) Fer.

aie 347
Marginata (Anodonta) C. B. Ads. 506
Marginata (Anodonta) Say ...... 388

Marginata (Baphia) H. & A. Ads. 506
Marginata (Margarita) Lea

1507
Marginata (Margaritana) Gld. ... 506
Marginata (Margaritana) Kust. ., 505
Marginata (Margaron) Lea ...... 505

Marginata truncata (Margaritana)

BB: BH. Wr:
Marginata (Unio) Han. 506
Marginatus (Anodonta) Han. .... 388
Marginatus (Mytilus) Eaton .... 387
Marginatus (Unio) C & R. . SOG
Marginatus (Unio) Sow.

okie Gore 505
Marginis (Margaron) Tear Pane 158
Marginis (Unio): Tea ...2. ee 158
Marioniana (Cameronia) Bet. 1383
Marmoi (Spatha) Ger. .......... 1332
Marnoi (Spatha) Jick. .......... 1332
Marryattana (Anodonta) Wea see ae
Marryattana (Margaron) Wea <1. 423
Marryattanus (Anodon) Sow. .... 423
Marryattiana (Anodonta) Lea ... 422
Marshii (Unio) B. ee Wits ae 630
Martensi (Anodonta) Cless. Bobien hey,
Martensi (Castalina) 1h ol pate 4 Bint: 1205
Martensi (Diplodon) Ih. ..-..... 1266
Martensi (Spatha) Stur. ......... 13.23)
Martens (Unio)! elhs at a.e eee 1266
Martini (Mitriodon) Roch. ...... 1343
Martini (Spatha) Roch. ......... 1343
Mashone (Cafferia) Conn. ....... 579
Mashone (Unio) Prest. ..:...... 578
Masoni (Margarita) Lea ........ 613
Masoni (Margaron) Tea ........ 613
MasonieGUnio)aCont ile an en 613
Massini (Unio) Morel. .......... 1064
Matoniana (Mytilus) d’Orb. -...- 1288
Matonianus (Unio) Pet. ........ 1288
Mattixola(Umio):ie=Cou eee r0s3
Mattiroli ((Virgus) “1)-@) 995.502 II52
Mattirolii (Virgus) Haas ........ 1153
Mauritanicus (Unio) Bets! sax os 556
Mauritianus (Margaron) Lea 107t
Mauritianus (Unio) Lea ........ Io7I
Menielii (Anodon) Anth. ........ 422
Mearnsi (I,ampsilis) SKicshoy Gogo. 150

Mearnsiana (Anodonta) SIND es 385
Mecklenbergensis (Margaron) re 655
Mecklenbergensis (Unio) Lea .... 655
Medellina (Nephronaias) Lea ... 255
Medellinus (Margarita) Lea .... 256
Medellinus (Margaron) Lea .... 256
Medellinus (Nephronaias) Simp. 256

Medellinus (Unio) F. & Cy 08720
Medellinus (Unio): Tea ......... 256
Mederianus (Unio) Kust. ....... 1006

Mediastinus
Simp.

(Ptychorhynchus)

1508 INDEX

Mediastinus (Unio) Hde. ........ 1146 Merceri (Margaron)) “ea <2. 22. 646
Medicus (Unio) Kob. .......... 547 Mercer «Unio lveameneenicenne 646
Mediocris (Margaron) Lea ...... 655 Merdiger i@Umto Riviere cea 573
Medicecris (Unio) Lea .......-.. 655 Meredithii (Margaron) Lea .... 791
Medionidus Simp. ..........-+--- 245 Meredithii (Pleurobema) Lea .... 791
Medius (Margaron) Lea .......- 7690 Meredithiy (@Unio)) Wea e.cce- 791
WixchieQ EUiie)) {bE Soacacuoueos 769 Merodabensis (Unio) Kust. ....1107
Mieditise) GUmio). Rovesmmryetie ister 759 ©=Merusi«(Margaron) “ean te 613
Megadesma (Barbala) Pet. ...... 238 Menus (@Uinio) ial camera. arene ecece 612
Megadesma (Cristaria) Marts. .. 238 Migso gence snccciets<s are deo etoele letersi 326
Mie ead omUs! SWA) Geiavelele cio je pels eneuelens 480 Messageri (Protunio) Hass ...... 915
Megapterus (Unio) Morel. ...... 208 -Messageri (Quadrula) B. & D. .. 915
Melanochlorea (Anodon) Hde. .. 404 Mecsaverniea@Unto) Ba sae De ee ons
Melanochlorea (Anodonta) Pet. . 404 Metallica (Lampsilis) Say ...... 179
Melinia (Anodonta) Bet. ........ 365 Metallica ganina (Lampsilis) Pils. 180
Miia (ora): Aer Saeocsoode 65 Metallicus-(Lampsilis) Simp. .... 180
Mellea (Nephronaias) Lea ...... 285 Metallicuss (Unio) ei Sayomcces eure 180
Melleus (Margaron) Lea ....... 286 Metaneurus (Unio) Kust. ...... 835
Melleus (Nephronaias) Simp. .... 286 Metanever (Margarita) Lea .... 835
Melleus; @Winzo) in yeameecictereicleteriere 286 Mietanever ((Unio)) lan’ -....005- 835
MellingassG@Uinio) is Rzetrvses ceteris 65 Metanevra (Obliquaria) Raf. .... 835
Membranacea (Anodonta) d’Orb. 1405 Metanevra (Quadrula) Raf. ..... 834
Membranacea (Margarita) Lea ..1412 Metanevra (Unio) Sw. .......... 835
Membranacea (Margaron) Lea ..1412 Metanevra wardii (Quadrula) Lea 835
Membranacea (Unio) Han. ....1288 Metanevrus (Margaron) Lea .... 835
Membranaceus (Anodontites)Mat. 1412 Metanevrus (Unio) Con. ........ 835
Membranaceus (Glabaris) Simp. 1412 Metaplata (Truncilla) Raf. ...... 32
Membranaceus (Mytilus) Mat. ..1412 Metaptera (Metaptera) Raf, .... 163
Membranaceus (Unio) Han. ....1412 Metapteras Rate. .% oe ck sees oo 161
Membranaceus (Unio) Phil. ....1288 Metastriata (Truncilla) Con. .... 10
Menardi (Unio) Bits We crncteriemieie 1193 Metastriatus (Unio) Con. ....... 10
Mieneliki (Unio)! “Solly ermractcretne 1193 Mexicanus (Margaron) Lea ..... 588
Menkianus (Margarita) Lea .... 83 Mexicantus (Unio) Philo 2o.ce... 588
Menkianus (Margaron) [Lea .... 83 Mexicanus (Unio) Sow. ........ 603
Menkianus’ (GUnio))) Wear sonst 83 Micans (Anodon) Anth. ........ 434
Menzieni (Margaron) Lea ...... 1291 Micans (Anodonta) Anth. ....... 434
Menziesi acuta (Diplodon) Sut. ..1293 Micans (Margaron) Lea ..... 434, 636
Menziesi lucasi (Diplodon) Sut. ..1204 Micansi (Winton lyeaun anise eiciereienen 636
Menziezi acutus (Diplodon) Sut. 1293 Micelii (Unio) Kob. ............ 566
Menziezi aucklandicus (Diplodon) Michaudiana (Unio) Des M. .... 533

Gray sees eee eee eee veteetes 1291 Micheloti (Nodularia) Morl. .... 990
Menziezi depauperatus (Diplodon) Micheloti (Oxynaia) Haas ...... 991

Hut. BLT ae ee ds SIS Oa aaa 1292 Micheloti (Unio) Morl.......... 991
Menziezi (Diplodon) Gray patents 1290 Machol m@lucedsninaia) meee eel

Sian 4. sate lorena tanellcte si uae ‘ Neer agorexe 1292 Michonit (Fseudedon) Soa eee ae
Menziezi hochstetteri (Diplodon) Michonis Gite) ete poor oh oe ae

JOS i GRC oonictckore chore coat AOA Ciats oo 1292 MU Tesco seis a seo MASSE ong naga: org eae
Menziezi lucasi (Diplodon) Sut. 1293 Microcondyiis Drouet aes aay CA 444
Menziezi rugatus (Diplodon) Simp. Microdon (Nephronaias) Marts. .. 278

ETNA In, HE Sect tc 1291 Microdon (Unio) Marts. ...-.--. 279
Menziezi rugulosus (Diplodon) Micromya Ag. ..6s2s2 est ecdeee- 3

SShiehoy gedinoiocgde a5 ongodacoMSa bo 1291 Micronaias Simp. ....---++-+-+:: 714
Menziezi (Unio) Gray ........-- 1291 Micropterus (Physunio) Morel. ..1065

Menziesianus (Unio) Rve. ..... 1291 Micropterus (Unio) Morel. ...... 1066

INDEX 150g

Microsticta (Quadrula) Hde. .... 925 Modica (Pleurobema) Simp. ..... 795
Microstictis (Quadrula) Simp. .. 925 Modicella (‘T'runcilla) Lea ...... 10
Microstictus (Unio) Hde. ..... 925 Modicellus (Margaron) Lea ..... II
Mitcranayasmelt atin mare c <sete ceri 556 Modicellus(Unio)) Wea :22....... II
Millettii (Anodonta) R. & D. .... 363 Modicum (Pleurobema) Lea ..... 794
Mimus (Diplodon) Simp. ........ 1249 Modicus (Margaron) Lea ...... 795
Mingorum (Anodon) Hde. ...... 404 Miodicism (Unio) ea wenn onaoe . 795
Mingorum (Anodonta) Pet. ..... 404 Modiola (Unio) Prest. .......... 544
Minima (Anodonta) Mill. ...... 362 Modioliformis (Lampsilis) Lea .. 134
Minor (Alasmidonta) Lea ...... 498 Modioliformis (Margarita) Lea .. 135
Minor (Baphia) H. & A. Ads. .. 4098 Modioliformis (Margaron) Lea .. 135
Minor (Lampsilis) Tea ........ 145 Meellendorffi (Pressidens) Haas --1078
Minor (Margaritana) Lea ...... 498 Modioliformis (Unio) Lea ....... 135
Minor (Margaron) Lea ...... 146, 498 Mecesta (Lampsilis) Lea ......... 156
Miron s(Strophitus)) Can. “fo. . sec. 498 Meestus (Iampsilis) Sipal see 156
IMbinione TAU bako)) IDES Seamus sedo bon 146 Meestus (Margaron) Lea ........ 156
Minuana (Margarita) Lea ...... 1388 Micestus (Unig) ears eee ee 156
Minuana (Margaron) Lea ...... 1388 Moineti (Brazzea) Bet. ........ 1374
Minuana (Monocondylea) d’Orb. 1388 Moineti (Burtonia) Beth eee 203
Minuanus (Unio) Han. ........ 1388 Moineti (Cameronia) Bet. ...... 1383
Minuta (Anodon) Hde. ........ 412 Moineti (Moncetia) Bet. ...... 1345
Minuta (Anodonta) Pet. ........ 412 Moineti (Mutela) BREE ary ase 1367
Mira (Grandidieria) Bgt. ...... 1061 Moineti (Spatha)) Bet. ......... 1345
Misellus subclathratus (Trapezoi- Moinetr s¢Unio)ys Bete assc.0e yoee 1193

Metis?) suMVcintse os cpsystatyerenotas Ake ters 1183 Moline (Diplodon) Phil. ........ 1260
Misellus subclathratus (Unio) Molinazi\(@Unio))/ Phils 2.2.0.2, 0. 1260

Mi aictic® Mera woke sis f carS kere ora efond @o 1183 Molleuri (Parreysia) Morl. ..... 1137
Misellus (Trapezoideus) Morel. ..1182 | Molleuri (Unio) Morl. .......... 1137
Misellus (Unio) Morel. ........ 1183 Monceti (Parreysia) Simph eee 583
Misoolensis (Unio) Schep. ..... 1153. Monceti ruber (Unio) Ger. ...... 1469
Misoolensis (Virgus) Schep. ....1153 Monceti rubra (Unio) Ger. ...... 1469
Mississippiensis (Margaron) Lea . 100 Moncetm (Umio)r Bet, -eee eee 582
Mississippiensis (Unio) Con. .... 100 Vinncetia mires de ot eee pee 1344
Missouriense (Pleurobema) Mongolicus (Unio) Midd. ...... 517

IVIFATS ila = seat love celeretrehs srarctavors uceiat stare 801 Monieti (Spatha) Simp. ....... 1345
Missouriensis (Pleurobema) Marsh 802 Monocondylea d’Orb. ........... 1384
Mitchelli eclongatus (Unio) Simp. 623 Monocondylus Morel. .......... 1079
Mitchelli iheringi (Unio) B. H. Monodonta (Alasmodonta) Fer. .. 521

Wis, tasieisre eve ouevonevacreralemunie « Haute 622 Monodonta (Cumberlandia) Ort. 521
Mitchelliy (@Umio) Simp, |aece acc 622 Mondonta (Margaritana) Say ... 521
Mbiemroyskoyal ANN Gascoasacceccacs 1470 Monodontal saya eens occe eee 492
Moctezumensis (Lampsilis) Pils. 195 Monodonta (Unio) Saye Se ee 521
Modesta (Anodonta) Lea ....... 470 Monodontinas (Cons sae. 1079
Modesta (Margaron) Lea ...... 470 Monodontus (Margarita) Lea .... 522
Modesta @Barreysia)) Hides jj5235- 1122 Monodontus (Margaron) Gear; 617
Miodestar (Platints)) leat). se. sere 1335 Monodontus (Unio) Say ....... 522
Miodesta) (Spatha)) ea 2..-..+.5- 1335 Monreensis (Margaron) Lea ..... 617
Modestus (Anodon) Sow. ........ 470 Monroensis (Unio) Lea-......... 617
Modestus (Anodontoides) Lea .. 470 Montanus (Unio)’ Hde:........ 935
Modestus (Diplodon) Kust. ....1261 Montanus (Unio) Phil. ........ 1261
Modestus (Margarita) Lea ...... 1242 Montanus (Unio) Raf.-........ 731
Modestus (Margaron) Lea ...... 1242 Montezianus (Anodon) Sow. ....1424
Modestus (Unio) H. & A. Ads. 1242 Montezuma (Anodonta) Lea er Zy7)
Modestus (Unio) Hde. ........ 1123 Montezuma (Anodontites) Lea . 1427

Madestus) (Unio) Kust} ........ 1261 Montezuma (Glabaris) Simp. ....1427

1510
Montezuma (Margaron) Tea 1427
Monticola. (@Unio)) Hide. o......- 935
Moorenitanus (Unio) Pet. ....... 752
Mooresianus (Margaron) Lea ... 752
“Mooresianus (Unio) [Tea ...... 752
Moquinianus (Unio) Dup. ...... 572
Moreleti (Margaron) Lea-...... 542
Moreleti (Pseudodon) C. & F. 1094
"Mioreleti (@Unio)> sDeshs 1 2......,-<1 542
Moreletiana (Quadrula) Hde. .. 923
Moreletianus (Unio) Hde. ...... g2
Moretonianus (Anodon) Sow. ...1431
Moretonicus (Diplodon) Rve. 1300
Moretonicus (Unio) Rve. ...... 1300
Moricandii (Anodon) Sow. ...... 1439
Moricandii (Anodonta) Lea 1439
Moricandii (Anodontites) Lea ....1439
Moricandii (Glabaris) Ih. ...... 1439
Moricandii (Margaron) lea 1439
Miorini -(Unio) = Morele (is <siieier 592
Niorinits aGWintonn eee teeter rereteitels 1150
Mortoni (Quadrula) on. -..... 853
Miortoni i @Uinto)) MCons oie eerlciciemint: 854
Mortoniana (Anodon) C. & R. 1445
Mortoniana (Anodonta) Lea ....1445
Mortoniana (Margarita) Lea 1445
Mortoniana (Margaron) Lea 1445
Mortonianus (Anodontites) Lea 1445
Mortonianus (Glabaris) Simp. 1445
Mortonicus (Margaron) Lea 1300

Mossambicensis (Cafferia) Conn. 986
Mossambicensis (Nodularia) Marts.

Mossambicensis (Unio) Marts. .. 986
Mossulensis (Margaritana) Pet. . 543

Mossulianus (Unio) Kob. ...... 543
Mosulensis (Margaron) Lea .... 543
Mosulensis (Unio) Lea ........ 543
Mouhoti (Monocondylea) Lea ...1097
Mouhoti (Pseudodon) Lea ...... 1097
Mouhotiana (Margaron) Lea 1098

Mouhotiana (Monocondylaea) Lea 1098
Mouhotianus (Pseudodon) Morel. 1098

Mouhotianus (Unio) Sow. ...... 1098
Moulinsiana (Anodonta) Dup. .. 364
Moulinsiana (Unio) Dup. ...... 572
Moussonianus (Margaron) Lea .. 610
Moussonianus (Unio) Lea ...... 610
Mucidus (Unio) Morel. ........ 533
Mucronata (Mya) Eaton ........ 598
Mucronatus (Unio) Bar. ........ 598
Muelleri (Unio) Ross. ........-- 539

Mihlfeldiana (Lampsilis) Lea ... 121
Mihlfeldianus (I,ampsilis) Simp. 121
Mithlfeldianus (Margarita) Lea .. 121

INDEX

Mihlfeldianus (Margaron) Lea .. 121

Miuhlfeldianus (Unio) Lea ...... 121
Multicolor (Parreysia) Marts. 1129
Multicolor (Unio) Marts. ...... 1129
Multicostata (Castalia) Sow. 1203
Multidentatus (Margaron) Lea 1106

Multidentatus (Unio) Phil. 2
Multiplicatus (Margarita) Lea .. 826
Multiplicatus (Margaron) Lea .. 826
Multiplicatus (Unio) Lea
Multiradiata (Lampsilis) Lea .... 55

Multiradiatus (Lampsilis) Simp. 56
Multiradiatus (Margarita) Lea .. 56
Multiradiatus (Margaron) Lea .. 56
Multiradiatus CUmio)) Wea sy... 56
Multiradiatus (Unio) Sow. ..... 62
Multistriata (Unio) d’Orb. ...... 1251
Multistriatus (Margarita) Lea 1251
Mialtistriatis a Cmto) aslYeaginertasls 1251
Multisuleata (Castalia) Hupé 1203
Multisuleatus (Tetraplodon) Hupé
Sie paren Ses aie Ne Nira RE Ie IgE es os 1202
Mundus (Margaron) Lea ........ 739
Miindtis) \@Wmro) eae 2) ier yer 739

Murchisonianus (Margarita) Lea 960
Murchisonianus (Margaron) Lea 960
Murchisonianus (Unio) Lea .... 960
Murinum (Ptychorhynchus) Hde.
Murfnus (Unio) Hde.
Murrayense (Pleurobema) Lea .. 761
Murrayensis (Margaron) Lea .... 762
Murrayensis (Pleurobema) Simp.. 762

Murrayensis (Unio) Lea ........ 762
Musicus (Unio) Simp. ........ 569
Musivus (Unio) Speng. ......... 569
Mussolianus (Unio) Kust. ....... 542
Mutabilis (Diplodon) Tea ....... 1308
Mutabilis (Margaron) Lea ....... 1308
Miartabrlisi@Umio) ill eat racists ore creer 1308
Neatabslise @Unio)) ORwen eccentric 1306
Miutatus’ (Viargaron)? “Wea a... 1006
Mutatus (Unio) Mouss. ......... 1006
IM en CS HOO = dinigea.ciain ocwacadiocs 1351
Muteleformis chariensis (Parrey-

SIA) GGEF. tars einaee sie ei creeerel aloererte 1136
Muteleformis chariensis (Unio)

Cer a Cree retreats 1136
Muteleformis (Parreysia) Ger. 1135
Muteleformis (Unio) Ger. ...... 1135
Matelidd (si.0dc ca ceelss hidomiere ans 1313
WKS, IYZin GoocmnbcopadapoDes 1351
Mutica (Arconaia) Hde. ........ 1189
Mey aumiuinn erties AE e's 5c 358

Mweruensis (Parreysia) E.A. Sm. 1142

Mweruensis (Unio) EK. A. Sm. ...1142

INDEX

Miacetopodamd:@rba ms .ccie ascrece sie 1457
Miyicetopius sae Orpey mealies ve siecle si ciae 1457
Myersiana (Hyriopsis) Lea ...... 212
Myersianus (Hyriopsis) Simp. 212
Myersianus (Margaron) Lea 212
Myersianus (Metaptera) Morl. 212
Myersianus (Unio) Lea ......... 212
Miscam Tir hOmy aaaee dads craks 527
Miystica (Nodularia). Pall. ....... 1022
Mir sticus) Uaio)) | Palleiec cee aee ce 1022
Mytilloides (Unio) Con. ......... 766
Mytiloides (Margarita) Lea ..... 889
Mytiloides (Margaron) Lea ..... 889
Mytiloides (Pleurobema) Raf. 810
Mytiloides pyramidatus (Unio)

1 ASI REPENS Ci Eesics CueCCK RR Og NS a A 880
Mytiloides. (Unio) Desh. ........ 889
Mytiloides (Uniopsis) Sw. ....... 495
Miytiloides; (Unio)@S: & Es .....- 882
Mytiloides (Unio) Sw. .......... 898
Naegelei (Ieguminaia) Kob. 446
Wieceler (Unio) Ixobiss seein ae ce 559
Nagpoorensis (Margaron) Lea ...1108
Nagpoorensis (Unio) Lea ....... 1108
INIETE GASH ee oA ae i Oe ee 1211
IN-aniae GWini1a) milearme icicle cucitrsietete sate 554
Nankingensis (Monocondylza)

1S (Lae Eim ciacie ce tee Coe eo Cicero I100
Nankingensis (Pseudodon) Hde...1099
Nanquinensis (Monocondylza)

WP EEE e tonchonoksUauers cis Reateiere aie eek wi alee I100
Nannss-CUnio) mDinptewoane ccc ecss 573
Napeanensis (Margaron) Lea....1290
Napeanensis (Unio) Con. ....... 1290
Napoensis (Anodonta) Lea ...... 1417
Napoensis (Anodontites) Lea ....1416
Napoensis (Glabaris) Simp. 1417
Napoensis (Margaron) Lea ...... 1417
Narainporensis (lamellidens)

IPTESE. me cascask het siercici sae bapete tris teesucrane 1177
Nashvillianus (Margarita) Lea ... 99
Nashvillianus (Margaron) Lea ... 99
Nashvillianus (Unio) Lea ....... 99
Nashvilliensis (Unio) Tea ....... 99
Nasuta (€Eurynea) Ag: ........:. 98
Nasutal Cluny nian Onto siieieleieierte 98
Nasuta (Lampsilis) Say ......... 97
Nasutan (Miya) ei atomic. ect cis sete 98
Niasitam (Union lar: -)reyasrysierlers 597
MNiasutiism@Unione Weae ase 1s corns 691
Nasutulus (Margaron) Lea ...... 692
WNasutiulis (Unio) imleas <2 o<60e 691
Nasutus (Lampsilis) Simp. ...... 98
Nasutus (Margarita) DLea......... 98
Nasutus (Margaron) Lea ........ 98

I511
Nasutuss (Unio): Ag) i... ein 597
Nasutuss @Winio)) Cone. 3..... cee 2 693
Nasutuss (Unio): Say™ so2...+2sees 97
INaSHsy Simipy f,. ete ais cise ee bass 1099
Natalensis (Margaron) Lea ...... 576
Natalensis (Platiris) Lea ........ 132
Natalensis (Spatha) Tea ......... 1326
Natalessis: (@timio) Lea = anekkoses 576
Watolicus (Unio) Kast. .2). 222).20% 573
Navicella (Anodon) Hde. ....... 404
Navicella (Anodonta) Pet. ...... 404
Naviculoides (Margaron) Lea .... 680
Naviculoides (Unio) Lea ........ 680
Naviformis (Unio) Lam. ........ 834.
Navigoliformis (Margaron) Lea .. 575
Navigoliformis (Unio) Lea ...... 575
Nebulosa (Lampsilis) Con. ...... 118
Nebulosus (Lampsilis) Simp. 11g
Nebulosus (Unio) ‘Cons .s2ss.-2- 119
Negatus (Margaron) Tea ........ 875
Wesatuse CUimio)) Wea senaew see atte 875
Neglecta (Symphynota) Lea ..... 487
Neglectus (Margaron) Lea ...... 487
Neglectus ((Unio)’ Leal... 0... 22. 487
Weglectus (Unio) Sow. <..:..... 656
INehringi «(Castalina)) Dh. 7 Sessa. 1206
IWehring1 1(Glabaris): Whs nee. 1451
Neislerii (Margaron) Lea ........ 829
Neislerii (Quadrula) Lea ....... 829
Neisleria’CUnio)) Wear tees ane 829
Wephronaias "Baad C., aee sone cts 253
Nepbronajas) Ont. Vases cutscene 253
Nervosa @Unio)" Cont 2... stsae 309
Nervosa’ GUmto) (Raf. sa. soe secs 731
Necvosuss CUnto) Say. seuss «teats 309
Neusensis (Margaron) [Lea ...... 654
WNeusensis (Unio) Lea -..2....-. 654
Newcombiana (Brazzea) Bet. 1374
Newcombianus (Margaron) Lea.. 313
Newcombianus (Unio) Lea ..... 313
Newenhuisi (Unio) Simp. ....... 1148
Newtonensis (Anodon) Sow. ..... 392
Newtonensis (Anodonta) Lea .... 301
Newtonensis (Margarita) Lea .... 391
Newtoniana (Anodon) C. & R.... 392
Newtoniensis (Anodonta) ‘Trosch. 392
MGS Guin) Schemes ceoaodc 13
Ngesiana (Parreysia) Marts. -1I29
Ngesianus (Parreysia) Simp. .1130
Negesianus (Unio) Marts. ........ 1130
Nguigmiensis (Nodularia) Ger. ..1029
Nguigmiensis (Unio) Ger. ....... 1030
Nicaragua (Anodonta) Phil. ..... 1456
Nicaraguensis (Margaron) Lea .. 316
Nicaraguensis (Plagiola) Lea 316

isp)

Nicaraguensis (Unio) Lea ....... 316
Nicklianus (Unio) Kust. ........ 828
Nickliniana (@uadrula)) Wea 22... 27
Nicklinianus (Margarita) Lea .... 828
Nicklianus (Margaron) Lea ..... 828
Nicklinianus (Plectomerus) Con.. 828
Nicklimianus (Unto)) Wea .. «=... 828

Nicobarica (Alasmodonta) Morch. 235
Nicobarica (Cristaria) Morch .... 235
Nicobaricus (Mytilus) Fab.
Nicobaricus (Pseudodon) Simp... 235
Nieuwenhousi parcesculptus (Unio)
Marts.

BEERS han cis > SMES EOOR 1149
Nieuwenhuisi parcesculptum (Pty-

chorhynchus) Marts. .......... 1149
Nieuwenhuisi (Ptychorhynchus)

Scheps tae oleae cieieraetaeiie oteicteiteks 1148
Nieuwenhuisi (Schepmania) Haas 1148
Niuwenhuisi (Unio) Schep. ...... 1148
Nigellus (Margaron) Lea ........ 647
INigellus GUmnio) Wear ei cteier erie cles 646
Wieme ((Ubro)) Sete soooronnasouped 607
Nigerrima (Lampsilis) Lea ....... 113
Nigerrimus (Lampsilis) Simp. .... 114
Nigerrimus (Margaron) Lea ..... 114
Nigerrimus (Unio) Lea ......... 114
NiirEy (AU) IR, ssogencngeonocr 607
Nigricans (Anodon) Hde. ....... 403
Nigricans (Anodonta) Pet. ...... 403
Nigrinus (Margaron) Lea ....... 138
Nigrinus) @Unio)” Wea aa. oe eee eee 138
Nillsonii (Anodonta) Kust. ...... 365
Nilotica emini (Mutela) Marts. ..1355
Nilotica gerrardi (Nodularia)

Ma TESS ey sevecaicie capone ctareiore ie crecerehexele 1023
INilGtica | CLnidina) i SOwemerecctleretete 1355
Nilotica (Mutela) Sow. .......... 1354
Nilotica (Nodularia) Caill. ...... 1020
Nilotica (Nodularia) Simp. ...... 1024
INalotica: @elatinis)mlsecam cincteleretclotels 1355
Nilotica pruneri (Nodularia) Pall. 1021
INirikoy Here (LU savtoy ye (Cell aaa Sosaccac 1021
Niloticus (Margarita) Lea ....... 1021
Niloticus (Margaron) Lea ....... 1021
Niloticus (Mytilus) Wood ....... 1355
Nplate) (elses) Itsy Beg aemsoes 576
INtlotietis (Unio) SOW. -isieleisi ous eels 1252
Nilssonii (Anodonta) Kust. ...... 423
Nipponensis (Unio) Marts. ...... 961
Nisibana (Leguminaia) Kob. .... 452
INatens @Miarcarom))) Wea sericiteteie 106
Nitens' (Unio) Weatri.s)< ocievue tae 106
Nitidulas’ @Wnio) Kast, 2 ase. esi 1232
Nobilis @iritogonta)) (Conse e. . re 321
INopbilis @Winio)mGony -- eee se 321, 847

INDEX

Nocturnus (Diplodon) Lea ...... 1285
Nocturnus (Margaron) Lea ...... 1285
Noctitrnus: GUnio)) lea sens. oeee ee 1285
Nodifera (@uadrula))iGon: 22.2... 857
Nodiferus. (Unio) (Con: 7. ose ceeice 857
Nodosa’ (Miya)! ‘haton™ ann. ce ace ee 835
Nodosa (Mya) Gmel> {0.2 .-...s ee 532
Nodosus) (@Umnto)) Barn ere sere octets 835
Nodulariay (Contes ace ie-eice onerete 949
Nodulata (Obliquaria) Raf. ...... 731
Nodulatus pustulatus (Unio) Pet. 856
INodiulatussGUnio)s Sayeecie aceite 856
Nodulosa (Castalia) H. & A. Ads. 921
Nodulosa (Miya) Wood :........ 532
Nodulosa (Quadrula) Wood ..... 920
Nodulosa s(Wnio) a Dame arjccleire er 532
Nodulosus (Margarita) Lea ..... 920
Nodulosus (Margaron) Lea ...... 920
Nodulosus (Unio) Rve. .......... 929
Nodulosus’) @Unto) = Sayaeen. cee eee 849
Nodulosus: @Unio)\ = Sows secss cee 920
Noland (@Unio)! Ba He Wits eect 642
Nongyangensis (J,amellidens)

Brest: -sbntia coma ae Dam oreeiae 1178
Nopalatensis (Anodon) Sow. ..... 433
Nopalatensis (Margaron) Tea .... 433
Normandi (Anodonta) Dup. ..... 364
_Northamptonensis (Margaron) Lea 668

Northamptonensis (Unio) Lea ... 668

Notatus (Margarita) Lea ....... 119
Notatus (Margaron) Lea ....... 119
INGtatus! .CWnio)piGonses sr ree cee 124
INotatus G@Unio)) eames. neers 119

Nove-hollandiz (Diplodon) Gray 1304
Nove-hollandie (Margarita) Lea 1305
Novae-hollandiae (Margaron) Lea 1305

Nove-hollandiz (Unio) Gray -1305
Novi-eboraci (Margarita) Lea Foes

Novi-eboraci (Margaron) Lea .... 116

Novi-eboraci (Unio) Lea ........ 116
Novileonis (lampsilis) Pils. ..... 195
Nubilus (Margaron) Lea ........ 656
INGTiowihoe? WAUAaiKo)) AWE Gnaoapsanoad 656
Nucleopsis (Margaron) Lea ..... 768
Nucleopsis (Pleurobema) Con. ... 768
INucleopsis. (Unio) Cont seireecieer 768
Nucleus (Margaron) Lea ........ 995
Nucleus (Nodularia) Lea ........ 995
INtaclens , CUiniG) els ealerectateteteae1-/<l1 995
Whiieoiboogey (Ukarry)) Jame osagosege 716
Numidica (Anodonta) Bgt. ...... 371
Nuttalliana (Anodon) C. & R. .. 378
Nuttalliana (Anodonta) Lea ..... 377

Nuttalliana idahoensis (Anodonta)
Hemp.

INDEX

Nuttalliana (Margarita) Lea ..... 378
Nuttalliana (Margaron) Lea ..... 378
Nuttalliana (Nodularia) Lea ..... 1003
Nuttallianus (Margaron) Lea ....1004
Nuttallianus (Unio) Lea ......... 1004
Nts ((Marecaron)) Wea 2.4-c-sc0e- 770
Nux (Pleurobema) Tea .......-. 779
Nux (@boyaria)) Simp. +. ssaceeee 297
Nigh (CUO) IEE cooacdsooecpos 31
Nass (Unto) I Me ea nee tars leis eicre oie 779
Nux-persicus (Margaron) Dun. 960
Nux-persicus (Unio) Dun. ...... 960
INwasscen (Unio) Sows cen snc cic cee 1132
Nyassaensis (Margaron) Lea ....1132
Nyassaensis (Parreysia) Lea -1132
INyassaensis (Platiris) Lea ...... 1331
Nyassaensis (Spatha) Lea ....... 1331
Nyassaensis (Spathella) Anc. 1331 -
INivjassaensise (Unio) Weal sete 1132
Nyassaensis (Unio) Smith ....... 1134
INvassanams(opatha) mb Pty ecleccisic es 1331
Niyassanus) (Unio)! (Beta sce. ice 1132
@besa (@uadrula)s Vanes wesc 320
Obesus blandingianus (Unio) Lea 712
@Obesusi((Marearita)e dear serene 711
Obesus (Margaron) Lea ......... 711
Obesus paludicolus (Unio) Gld. .. 713
@pesiusm @Wi10) we lyeamnere sects eivicree 710
Obfuscus (Margaron) Dea ....... 136
Whiuscns .GWnio) wy ak acteteleleccistete 136
Oblatus (Margaron) Lea ........ 675
Oplatus (Unio) Melseala saree 675
Obliquan@Ekyria)) ets sedans a 1221
Obliqua (Margarita) Lea ........ 882
Obliqua(@uadzula)), am! fas anne 881
Obliqua (Quadula) Simp. ....... 881
ObliquamCUinio)eilvamipeseiseyieeree « 882
Obliguay(@Unio)) Wood! 2 o.5.+.<.5 889
Obliquaniam Ra tamer ricer ate 329
Obliquata (Obliquaria) Raf. ..... 731
@Obliquatuss (Unio) Say. <tc «1 of 15
Obliquiradiatus (Unio) Rve. ..... 65
Obliquum (Pleurobema) Ort. 882
Obliquus (Margarita) Lea ....... 882
Obliquus (Margaron) Lea ....... 882
Obliquus (Prisodon) Schum. 1221
Obliqnuse CUn1o) Contos seciee 898
Obliquus \(Unio)) Hatin seeceeeence 882
Obliquus (Unio) P. & M. ....... 2

Oblita (Anodonta) Tea ......... 468
Oblita (Margaron)- Lea ......... 468
Oblitusm@Uinro)ilseay one. eens a6 903
Oblonga (Anodonta) Mill. ...... 363
Oblongata (Mya) Wood ........ 65
Oblongus (Anodon) Sow. ....... 363

@blongewsy CUmio)mlbea nose ccueeee 660
Obnubilus (Margaron) Lea ...... 642
@bnubilus (Unio) Lea .s..0.. 4 641
@bovalis’ (@bovaria)? Raf. 222... 731
OMIA Sirah cobccoooogndsagda IIOI
@Obovaliss (Unto) (Come. -eece cls. 886
Obovalism@Unio) say: acscdtese reel 808
Obovariaee Rats. . 2... 5p hereto set 289
Obovatan (Miya) ‘Solftae.ctreretersielel> 732
Obscura i@eampsilis)) Wea Geno. ee 107
Obscurus (Lampsilis) Simp. ..... 107
Obscurus (Margarita) Tea ...... 107
Obscurus (Margaron) [Lea ....... 107
Obscurusy (Unio) Weawmr onal 107
Obturata (Anodon) Hde. ........ 405
Obtusa (Anodon) Hde. .......... 404
Obtusa (Anodon) Sow. .......... 1453
Obtusa (Anodonta) P. & M. ....1453
@Obtusae(Cameronia) (Bet. ee. ess 1384
Obtusa juparana (Glabaris) Ih. ..1454
Obtusay@arzarita)) Wealenct. sees 1453
@Obtusa GWargaron) Dea ..'.-.-.- 1453
@btusal7@Unio)) dt@rby ences 1263
Obtusula (Anodon) Sow. ........ 1421
Obtusula (Anodonta) Hupé ...... 1421
@btusulay(Glabaris)) Ths 2... cee 1421
ObtusulaGMaxearon))) Wealc eee 1421
@btuasus (Anodon) Spix 3.2.2... 1453
Obtusus (Anodontites) Spix ..... 1453
Obtusus (Diplodon) d’Orb. ...... 1262
Obtusus (Glabaris) Simp. ....... 1453
Obtusus juparanus (Anodontites)

Dbisy “eysvdyeicxeris <5 o0l'e cp oretstaletsceceuct nl ote 1453
Obtusus (Margaron) [Lea ....... 71
Obtusus. (Unio) heave eee 70
Obtusus var. b. lituratum (Ano-

GON) | MODIX) Mie pkek ete csiete sieeve 1454
@buncuse CUnio)) Weare aneeiess «oe 742
@Oceatay (Nodularia) Weayee. 1 985
@Occatus' (Margaron)) Tea .22.5..- 985
Occatuse (Winio) eel eaweiretelstereiee rete 985
Occidens (Margarita) Lea ....... 40
Occidens (Margaron) Lea ....... 40
@cerdensy @WUinto)) Weal Ge-na. cite 39
Occidentalis (Barbala) Pet. ..... 226
Occidentalis (Cristaria) Hde. .... 22
Occidentalis (Ibipsas) Hde.. ..... 226
@ccidentaliss@yampsilis)™Con. 3.8. 112
Occidentalis (Margaron) Lea ....113
Occidentalis (Mycetopoda) Cless. 1461
@ccidentalis) @Umio)) (Cont, ss ecce.s 113
Occultus (Margaron) Lea ....... 644
Occultusm (Unio)! wea wee sree see 644
Ochracea (Lampsilis) Say ....... 49
Ochracea (Margarita) Lea ....... 50

1514

Ochracea (Mya) Eaton .......... 50
Ochracea (Symphynota) Lea .... 50
Ochraceus (Lampsilis) Simp. .... 50

Ochraceus (Margaron) Lea ...... 50
Ochraceus (Unio) Say ........+. 50
Ocmulgeensis (Margaron) Lea ... 664
Ocmulgeensis (Unio) Lea ....... 663
@ilateliay Rat. Secs cicwteriete tier. = leisisie 452
Ogeecheensis (Lampsilis) Con. ... 109
Ogeecheensis (Unio) Con. ....... I¥o
Ohiensis (Metaptera) Con. ...... 184
Ohioensis (Anodonta) Raf. ...... 437
Ohioensis (Symphynota) Fer. ... 184
@Ohioensis) (GUmio) Pisayimecetr ae 184
Oleivora (Solenaia) Hde. ....... 459
Oleivorus (Mycetopus) Hde. .... 460
Olivaria (Amblema) Raf. ........ 73
Olivaria (Margaron) Tea ........ 1002
@livaria (Nodularia). Gea <ace.. ce IOOI
Olivarius (Margarita) Lea ...... 1002
Olivaritis. (Unio) by Come. «16s cleo s 300
Olivarius ¢Unio) Wl eay ee -)tl-tte 1002
Omiensis (Nodularia) Heim. .... 973
@niensis: (Unio) dleimh 4.5 o- cies 973
@paca (Anodonta) Wed) 2.10. «ie 428
@paca (Margarom)) Beal -. 55. occ 429
Opacatus. (Umi) GarGa hie tc sicker 626
@pacus (Margaron) Lea ........ 642
@pacus, Unio) ie Wea eel cierto <tarare 642
Opalescens (Mutela) Prest. ...... 1365
Opalina (Anodon) Anth. ........ 422
Opalina (Anodonta) Kust. ....... 365
@Opalinus “CUnio)) Anths i=)... =. 116
Opperti (Gabillotia) Bgt. ........ 441
Opperti (Margaritana) Pet. ..... 442
Opperti (Pseudodon) West. ...... 442
Opperti (Pseudodontopsis) Kob... 442
Opperti (Unio) Bgt. ...........- 442
(Oyeiqoe (QUhwen) (omy oeooods ogous: 44
Orbicularis (Anodon) Hde. ..... 404
Orbicularis (Anodonta) Pet. .... 404

Orbicularis (Monocondylea) Pet. 1081
Orbicularis (Monocondylus) Morel. 1081
Orbicularis (Pseudodon) Morel. ..1081
Orbiculata (Lampsilis) Hild. .... 76
Orbiculatus (Lampsilis) Simp. ... 77
Orbiculatus (Margarita) Lea .... 77
Orbiculatus (Margaron) Lea .... 77

Orbiculatus (Unio) Hild. ........ hay
Orbignyana (Unio) Hupé ....... 1208
Orbignyanus (Unio) Pet. ....... 1208
Orbignyi (Castalina) H. & D. 1208
Orbignyi (Margaron) Lea ....... 1208
Orbignyi (Mycetopoda) Ih. ...... 1460

Orbignyi (Unio) H. & D. ..,,....1208

INDEX

Orcutt ((Unio)i-s: BE Wik eee 629
Oregonensis (Anodon) Sow. ..... 376
Oregonensis (Anodonta) Lea .... 375

Oregonensis (Margarita) Lea .... 376

Oregonensis (Margaron) Lea 261, 376
Oregonensis (Nephonaias) Lea .. 261
Oregonensis (Unio) Lea ........ 261
@Orfdensis “CUnio) wobec eee 564
@Oriéns = CUinio)) Wea. bee reriteeere + one 454
Oxiens HCUmi0) Sow.) eects ecieeiae 92
Orientalis (Elongaria) Haas ..... 1162
Orientalis (Margaron) Lea ...... 1162
Orientalis (Nodularia) Simp. 1162
Orientalis (Rectidens) Lea ...... 1162
Orientalis’ CUiInio) MB gts ace ne 563
Oxientaliss (Unione Iseamene ee ceecien I162
Ornata (Pleurobema) Simp. ..... 747
Ornatum (Pleurobema) Lea ..... 746
Ornatus (Margaron) Tea ........ 747
Ornatus, (Unio) Lea, me. cec ee emis 747
@rnatuse Unio) nS welies aces eet 42
Orontesensis (Margaron) Lea .... 563
Orontesensis (Unio) Lea ........ 563
Orphaensis (Margaron) Lea ..... 564
Oxrphaensis (Unio)! Wea. msec 564
Oxrthomymins WAH weitere csr cists cls 811
Ortonii (Margaron) Lea ........ 1224
@xtonmACerisodon)! lease acicciieere 1224
OrtonisCWUnio)) Weak tees. erictesiets 1224
Osbecki (Margaron) Lea ........ 960
Osbeckig@Unio) mbhilh on aes. or 960
Oscar @Unio) MBs Eee Wire lacie. 648
Ostreata (Quadrula) Morel. ..... 906
Ostreatus (Unio) Morel. ........ 907

Othcaloogensis (Margaron) Lea .. 18
Othcaloogensis (Truncilla) Lea .. 17

Othcaloogensis (Unio) Lea ...... 18
Ouassoulouensis (Arthropteron)

Gers 1. ts dia cee ee eee 1375
Ouassouloui (Arthropteron) Roch. 1375
@Ovaliss((Miassaritan) ea wrereeeiene 539
@yalis; (Miya) > Donveerrr celeron 532
@yalis|CMiy.a) Monts hse ciee 539
Owalis. (Pseudodon)) Mork: \.. 33.0% 1092
OalismiCU mio) mins weleveceectae eee 539
Ovalis) @Un10); Dupree eee ere 572
Ovalis (\CUnio) MSowseeceieie visors 532
Ovata (Acuticosta) Haas ........ 034
Owvata’ (Aelia) eSiwaeeeeeae eee 49
Ovata, (Anodon)NGs Ga Ra seo. ose 419
@Ovata CAnodon)) ESoweews..---. 22
@vata (Anodonta) hear... .\.%. i 419
Ovata (Anodonta) Stark ........ 437
Ovatae(Castaliayiesowe ojos 1200
Ovatae Glaidinayniew. = eee eerie 1377
Ovata (Lampsilis) Say .........- 48

INDEX

Ovata (Margarita) Lea ......... 419
Ovata (Margaron) Lea ......... 419
Ovata (Microdontia) Haas ...... IOII
@yatam Give) on\ ssp: 06 5 ce 538
@yatay (Miya) atone >. ens. 49
Ovatam (Miysca)ieMuntep eae 539
Ovata (Nodularia) Haas ........ 1010
Ovatag (Platiris); iWweamessal. eee 1377
Qvatay (Pleiodon)! @on:. 5. .2....- 1377
Ovata (Quadrula) SUPA See se 933
Ovatas (Unio) yD eshte. | anon 40
Ovatag (Unio) vam so) ee ae 49
Ovatar (Unio) miValeae ee ae 44
Ovatus (Anodon) Sw. .......... 1427
Ovatus (Lampsilis) Syhoa, eo doodae 48
Ovatus (Margarita) Lea ........ 48
Qvatus' (Margaron)i Lea ......... 48
Ovatus ornatus @Unio)) “Cons 2 42

Ovatus pachyodon (Pleiodon) Bet. 1377
Ovatus pachyodon (Pliodon) Ger. 1378

Ovatus (Pleiodon) Sw. .......... 1376
Ovatus) (Bliodon)sn@ers yao: 1377
Ovatus (Tetraplodon) Sow. ...... 1200
Oyatusy (Unio)! Kast aoe 40
Ovatusa (Unio) Says oe 48
Ovatus var. b CUnio) amanens se 44
Oviforme (Pleurobema) Con. .... 745
Oviformis (Margaron) Weal btaws 745
Oviformis (Pleurobema) Simp. ... 745
Oviformis (Unio) Con. .......... 745
Oncymatagh Hata stele tee sh srre ya. oes 999

Oxyrhyncha (Lanceolaria) Haas. . 958
Oxyrhyncha (Nodularia) Marts. .. 957
Oxyrhynchus (Nodularia) Simp... 958

Oxyrhynchus (Unio) Marts. ..... 958
Ozarkensis (Lampsilis) Call ..... 131
Ozarkensis (Unio) Call ......... 131
Pachostea (Obovaria) Raf. ....... 731
Pachynaras- GvQriRet e355: sce gor
Pachyodon (Pleiodon) Bieter 1377
Pachysoma (Margaron) Lea ..... 987
Pachysoma (Nodularia) Ben. .... 987
Pachysoma (Unio) Ben. ......... 987
Pachystoma (Unio) Pet. ........ 987
Pacifica (Anodon) Hde. ......... 403
Pahangensis (Rectidens) Smith 1161
Pahangensis (Unio) Smith ...... II61
Pahoembaensis (Unio) Haas ..... 1164
Paivanus (Unio) Morel. ......... 1013

Pajakomboense (Schizocleithrum)
Haas

Pajakomboensis @Unio)| Bull) 22 718

Palembangensis pahumbaénsis

GRectidens) Marts). = o2::....0.- 1164
Palembangensis pahumbaénsis
(UID IN rai oe ep eee 1164

T5175

Palembangensis( Rectidens) Strub. 11 63

Palembangensis (Unio) Strub. ye tLO3
Paliatus (Margarita) Lea ........ 676
Paliatus (Margaron) Lea ........ 676
Paltatus) (Unio)! Ravi-sece.. 2. 676
Pallegoixi (Anodon) Sow. ....... 1184
Pallegoixi (Anodonta) Cless. 1184
Pallegoixi (Trapezoideus) Sow. 1184
Eallens(Unio)e Kusts 0 eee 533
Ballens (Wino) Rates see 731
Rallenssi@Umio)! (Rass, soo.) ane 541
Pallescens (Margaron) Lea ...... 71
Pallescens 1@Umio)) eas sees eee 71
Palliatus (Unio) Rav. ........... 676
Pallida (Anodon) Anth. ......... 389

Pallida (Anodonta) B. H. Wr. ... 389
Pallidofulous (Margaron) Lea .... 761

Pallidofulvus (Unio) Wweaaer ae «iret 761
Perdix (Lampsilis) Learnt ee 88
Pallidus (Anodon) Sow. ......... 3890
Paludicola (Mutelina) Roch. 1361
Paludicolor (Unio) Con. ........ 713
Paludicolus (Margaron) Lea ..... 713
Paludicolus (Unio) Gld. ......... 713
Paludosa (Lampsilis) Morel. ..... 192
Paludosus (Anodon) urt. ....... 362
Paludosus (Iampsilis) Simp. .... 192
Paludosus (Unio) Morel. ........ 192
Pancos @Diplodon)) hye seeeen soe. 1309
Pangallicensis (Spatha) Roch. 1350
Pantoensis (Unio) Neum,. ....... 723
Panucoensis (Unio) Busch ....... 603
Paphos (Anodonta) Raf. ......... 1457
Papyracea (Anodonta) B. H. Wr. 350
Papyracea (I,ampsilis) Gld. ...... 146
Papyracea (Margaron) Tea -..... 350
Papyraceum (Alasmodon) Raf. .. ic
Papyraceus (Anodon) Anth. ..... 350
Papyraceus (lampsilis) Simp: 0. 147
Papyraceus (Margaron) Lea ..... 147
Papyraceus (Unio) Gld. .....24.. 147
Paradoxa (Cameronia) Bieter en ae 1379
Paraguayana (Margarita) Lea 1388
Paraguayana (Margaron) Weay nr 38s
Paraguayana (Monocondylza)

CEO cb teeter ee eee 1387
Paraguayana (Monocondylea)

SOUMTL ws ya A Mecca eee heed 1388
Paraguayana (Unio) Han. ....... 1388
Paraguayanus (Unio) C. & R. ...1388
Paraguayanus (Unio) Marts. 1312

Paraguayensis (Margaron) Lea... 1232
Paraguayensis (Unio) Lea ....... 1232
Parallelipipedon (Diplodon) Lea.. 1275
Parallelipipedon (Margarita) Lea. 1275
Parallelipipedon (Margaron) Lea.r275

1516 INDEX
Parallelipipedon (Unio) Lea aLe75 Patagonicus (Diplodon) d’Orb. 1275
Parallelus| (Wmio) li Conk See .c0s- 705 Patagonicus felix (Anodontites)
Paramattensis (Margaron) Lea ..1301 Pils Sea Ra ieee 1405
Paramattensis (Unio) Lea ....... 1301 Patagonicus felix (Glabaris) Simp. 1406
Paranensis (Diplodon) Lea ...... 1284 Patagonicus (Glabaris) Simp. 1404
Paranensis (Diplodon) Simp. .1285 Patagonicus (Margarita) Lea 1276
Paranensis (Margarita) Lea ..... 1285 Patagonicus (Margaron) Lea 1276
Paranensis (Margaron) Lea ..... 1285 Patagonicus (Unio) Han. ....... 1276
Paranensis (Unio) Bea tinecse. a 1285 Patelloides (Diplodon) Tea ...... 1279
Parcedentata (Nodularia) Haas .. 971 Patelloids (Margaron) Lea ...... 1279
Parcesculpta (Schepmania) Haas.1149 Patelloides (Unio) Lea .......... 1279
Parchappii (Margarita) Lea ..... 1387 Pattinoidess@Umio) Myean setae ieee 740
Parchappii (Margaron) Lea ..... 1387 Patsaligense (Pleurobema) Simp. 788
Parchappii(Monocondylea) d’Orb. 1386 Patsaligensis (Pleurobema) Simp. 788
Barchappin(@Unio)) silanseee eee 1387 PatularsaSiwsentantareemcietscvectcet 1403
Parcus @Diplodon)i Weayencss-- eee 1256 Patulus (Margarita) Lea ........ 737
Parcus) ((Miarearon)iibeal beni smite 1256 Patulus (Margaron) Lea ........ 737
Parceus) @Umio) Mlveawetse 1. sitet te 1256 Patulus) (Unio) Peay sence 737
Parishi ((Anodon)iMGray ea. - soe 1400 Pauciplicatus (Unio) Lea ....... 818
Parishii (Anodonta) Elan. ......: 1400 Paulas Ch unyriia) Ort eee eee 160
Parishii (Leila) H. & A. Ads. 1401 Paulas @vampsilis) mlyeas1-- hee 159
Parishit (Miancanitaleear cer.ia)cielerene 1400 Paulista @Diplodon)eidihweceaeee se 1229
Parishii (Margaron) Lea ........ 1400 Panlistas (@Unio) melhkes eee 1229
Parkeri (Quadrula) Geis. ........ 320 Paulus (Lampsilis) Simp. ....... 160
eeyaaoes (What) WwSet s5angaaouedoc IIIS Paulus (Margaron) Lea ......... 159
Panrey Silay Conten-mee cadence 1103 Patlus(Unio)iiwea see «2 eee 159
Parreysi schweinfurthi (Unio) Paupercula (Quadrula) Lea ..... 862
IMrairtS:? 858 can aie lesa eee cholo aus stevens 986 Pauperculus (Margaron) Lea .... 863
Parreyssi (Nodularia) Pall. ...... 1021 Pauperculus @Unio)eieas.sa.ece. 863
Parreyssi pruneri (Nodularia) Pall. ro2t Pavici (Chamberlainia) Roch...... 221
evades (Uhetio)) Ill, SooogcH6cc 1021 Paviei (Chamberlainia) Morl. .... 221
Parva’, GH unynia) Onto 152 EER KS e((USorie)) INoidl, Son ayauqoass 221
Parva (Glampsilis) Bam fac cor I5I Pavonia (Anodon) DeKay ...... 348
Patvay) (Mya)™ Baton ees. - > «errr 152 Pavonia (Anodonta) Lea ........ 348
Parvula (Anodonta) Drouet ..... 364 Pavonia (Margarita) Lea ........ 348
Parvula (Barbala) Beta en. «re 231 Pavonia (Margaron) Tea ........ 348
Parvula (CGristania) es Elides cere 231 Pavonina (Chamberlainia) Roch. . 220
Parvulus (Dipsas) Hde. ...'...231, 236 Pavonina (Dysnomia) Roch. ..... 1193
Paryulus ((Miarezaron)) Wea) cccieiere 248 Pavonius (Strophitus) Bak. ...... 348
Parvulus (Medionidus) Lea ...... 248 Pawensis (Margaron) Tea ....... 712
Parvulus) CUnto)iileal tc. see clr 248 Pawensis (Unio)! Gealeeee a: seeeee 712
Paryus lam psilis) i Bake wsteresreisters 152 Paxyodone Schtimeusess sie ereneee 1216
Parvus: (NManganita) leans aictere tiers 152 Bazi (Castalia) mblid) seee epee 1274
Parvus (\Manrgaron) i year nse sieictele 152 Pazim(Diplodom) attire ee eee 1273
Parvaism (Unio) bars cr.reielaleici sl ele 152 Raz (Anodonta) i Weauen eens 1409
Parvus Unio) Contes s .ctecs cicisiels 149 Pazii (Anodontites) Lea ........ 1408
Paschalis) @Unto)) eldes Sen eer ae 935 Paz“ (Glabaris)) Simp: i2ceeeer 1409
Pastasana (Anodonta) Cless. ..... 1449 Pazii (Margaron) Lea 997, 1387, 1400
Pastasanus (Anodontites) Cless. ..1449 Pazii (Monocondylea) Tea ...... 1387
Pastasanus (Glabaris) Simp. ..... 1449 Pazi (Nodtlaria)mWeare- asses «= 997
Patagonica (Anodon) C. & R. ...1404 Pazit \(Oxyrara)ewelads) eae asco oe 997
Patagonica (Anodonta) Lam. ....1404 Paziny (Wri 0) alge ames tiers Selene 212 0907
Patagonica (Margarita) Lea ..... 1404 Peale @Uiniopimiiyeas ein seen eee 300
Patagonica (Margaron) Lea ..... 1404 iPearlensis| @Umio)) Con. ...052200 817
Patagonica @Unio)) diOrby i. oe 1276 Pecten (Nodularia) Prest. ....... 1003
Patagonicus (Anodontites) Tam...1403 Pectitus (Unio): (Cons. ssn 15

INDEX

Pectinatum (Tetraplodon) Spix. ..

DT DOC ODON6 64 OOD OOD OUSOS I196, I197
Pectinatus (Tetraplodon) Spix...1197
Pectorosus (Margarita) Lea ..... 88
Rectorosusy @Uinio)y Cons... 4. 88
Peculiaris (Diplodon) Lea ....... 1232
Peculiaris (Maragron) Lea ...... 1232
eculiaris=@Winio)mibeaueaaacetern 1232
PEERS: Srreooe ccosgopuasonuaden 472

Peguensis (Margaron) Lea 1083, 1181
Peguensis (Monocondylea) Anth. 1083

Peguensis (Pseudodon) Anth. 1083
Peguensiss Unio) Amth: 2s. sc-clce 1181
Pellis-lacerti (Unio) Morel. ..... 993
Pellucida (Lampsilis) Lea ....... 144
Pellucidus (Lampsilis) Simp. 145
Pellucidus (Margaron) Lea ...... 145
Bellucidius s@Winto)) sljearves eee eee 145
Penchinatianus (Unio) Bet. ...... 568
Penicillata (Anodonta)H,& A. Ads. 1429
Penicillatus (Anodon) Gray ..... 1429
Penicillatus (Margaron) [ea 249
Penicillatus (Medionidus) Lea ... 248
Fenicillatus@Unio)) Wear secs ccroe 249
Peninsularis (Trapezoidus) Simp. 1186
Penisatus) (Unio) ReeG ©) 2e5sto: II55
Renitas@iruncilla)inConwes soe. soe 8
Peéenitus, (Margarita) ea -........ 9
iPenitus) @VMiargaroni)s Weal ‘jcas s <i 9
BRenitusmG@Unio)ie Coma were dele fe 9
Pennsylvanica (Anodonta) Lam. . 350
Pepiniana (Anodonta) Lea ...... 436
Pepiniana (Margarita) Lea ..... 436
Pepiniana (Margaron) Lea ...... 436
Pepinianus (Anodon) Sow. ...... 436
Pepinianus (Anodonta) Lea ..... 436
Pequottianus) (GUnio)siginss )..«e685 731
Pereformis (Diplodon) Lea ..... 1279
Pereformis (Margaron) Lea 1280
Bercetormuis, Unto) Sear aces oelele 1280
Perakensis (Rectidens) de M. ...1161
Werakensis) (Unio) de Min Se sa. II61
PRerakensis (Unio) Prest: jennie. 1159
Percoarctatus (Margaron) Lea ... 659
iRercoarctatus) (Unio) Wealacnse cic 659
Percompressa (Quadrula) Marts. . 912
Percompressus (Unio) Marts. . gI2

Perconvexa (Parreysia) Prest. ...1122

Berd @Gampsilis)i Tea ieetaas ¢ 88
Rerdixsa Margarita) ean sty or 88
Perdis @Miargaron)). Wea. asiy.nt on 88
Perdix (Nephronajas) Ort. ...... 88
Berdixs(Winto))elveal Rrcc «ssi 88
Perdix = CUin10)) meRvied 2icteiclo orsleuste vie 84
Perlatus (@Miargaron)) Wea ......0- 680
ietaclehnne. ((Uheivo)) IL Sop onodeosoc 680

Perlensis (Unio) Pet.
Perlucens (Margaron) Lea
Perlucens (Unio) Lea
Permiscens
Permiseens
Permiscens
Pernodosus
Pernodosus (Unio) Lea
Pernodulosa (Parreysia) Prest.
Perobliquus (Unio) Con.
Perovalis (Lampsilis) Con.
Perovalis (Margarita) Lea
(Margaron) Lea -
Perovalis (Unio) Con.
Perovalis (Unio) Sow.
Perovata (Pleurobema) Simp.
Perovatum (Pleurobema) Con.
Perovatus (Margarita) Lea
Perovatus (Margaron) Lea
Perovatus (Unio) Con.
Perpasta (Lampsilis) Lea
Perpastus (Lampsilis) Simp.
Perpastus (Margaron) Lea
Perpastus (Unio) Lea
Perpictus (Margaron) Lea
Perpictus (Unio) Lea
Perplexa cincinnatiensis (Trun-
cilla) Lea

(Unio) Lea

Perovalis

(Lampsilis) Lea ...
(Margaron) Lea ...

(Margaron) Lea ...

pete eee

Perplexa rangiana (Truncilla) Lea 25

Perplexa (Truncilla) Lea
Perplexus
Perplexus
Perplexus

(Margarita) Lea
(Margaron) Lea
Perplexus (Truncilla) Raf.
Perplexus (Unio) Lea
Perplicata (Crenodonta) Ort.

Perplicata (Quadrula) Con. ....
Perplicata quintardii (Quadrula)
Cra Sea Attain d hata eer ee

Perplicatus (Margaron) Lea ...

Perplicatus (Plectomerus) Con.
Perplicatus (Unio) Con.
Perpurpurea (Lampsilis) Lea

Perpurpureus (Lampsilis) Simp. .

Perpurpureus (Margaron) Lea
Perpurpureus (Unio) Lea
Perradiatus (Margaron) Lea
Perradiatus (Unio) Lea
Persculpta (Nodularia) Haas
Personata (Scalenaria) Ag.
Personata (Truncilla) Say

Personatus (Margarita) Lea
Personatus (Margaron) Lea
Personatus (Unio) Con. .......

Personatus (Unio) Say
Perstriatus

(Diplodon) Simp. ...

(Margaron) Tea ...

1518 - INDEX

Perstriatus, GUmio)ie Weed ise iene si 679
Persulcata (Nephronaias) Lea ... 277
Persulcatus (Margaron) Lea ..... 278
Persulcatus (Nephronaias) Simp. . 278
Persuleatus (Unio) Lea :.....4.. 278
Pertenuis (Margaron) Lea ...... 485
Rertenuis (Unio)) Leaye.. <.- 2. 485
Peruviana (Unio) Lam. ......... 815
Retersi (Miutela), Cless s-..100 x 1335
Petersi (Spatha) Marts. ........ 1335
Petersi . (Spathella) Bet. .:...... 1335
Petrina (Quadrula) Gld. ........ 860
Petrinus (Margaron) Lea........ 860
Petrinus. (Unio)! “Gla yi ai ers 860
Retroi «(Umio)e, cote r-telelstscvaiaisietens 547
Petrovichii (Unio) Kust. ........ 533
Petterianus (Margaron) Lea .... 572
Petterianus (Unio) Kust. ....... 572
Pfeiffer: (Spatha) (Ger, <7. ..- ..-si 1341
Aamiome(Usstko)) PO ogaaocuonc 1251

Pfeifferiana (Margaritana) Bern. .1341
Pfeifferiana (Margaron) Lea ....1341

Pfeifferiana (Spatha) Bern. ...... 1341
Pfisteri inspiratum (Ptychorhyn-

Gap) delle Eecachooooocooudcur 1145
Pfisteri inspiratus (Ptychorhyn-

Ghias)) Simipe, Gisracycveueretsisicterele <letele 1145

Pfisteri inspiratus (Unio) Hde. ...1145
Pfisteri mediastinum (Ptychorhyn-

is NMnlckay acautmoLanoocasodo7 1146
Pfisteri (Ptychorhynchus) Hde. ..1145
Phisteri: CUiniopy eden acre ustel wrens II45
Pharaania, pBiotiecstsetekeber-istaieleletetata 949
Pharaonum (Chambardia) ...... 1350
Phaselus (Margaron) Lea ....... 995
Phaselus (Nodularia) Lea ....... 995
Phaselus. (Unio) Tea -..........-- 995
Phaseolus camelus (Ptycho-

Jascehatolahity)) ILGA Se ooomooumooGaas 335
Phaseolus (Margarita) Lea ...... 334
Phaseoius (Margaron) Lea ...... 334
Phaseolus (Ptychobranchus) Hild. 333
Phaseolus) @Umio))eiilds 1. eri) - ie 334
Phayresi, (Unio), Dheobs 7 oi. n i 1107
Phenchooganjensis (Lamellidens) _

este, decker te steele cue tekers ekeere 1178
Philippi (CUmio)) Wie) leet oot eve 572

Philippianus (Anodontites) Simp. 1416
Philippianus (Glabaris) Simp. ....1416

Philippianus (Unio) Kust. ...... 1298
Philipsit \@Unto)) Ebamiyet-t-r ogee ait 331
Phillipsii (Margarita) Lea ...... 331
Phillipsii (Margaron) Lea ...... 331
Phillipsi. (CUmio) Conk s..ser ye 331
Bhillipsia, (CUinie) eR vier mare cucrouste tet 26
Pholadiformis (Anodon) Sow. :.... 390

Physunio

Simnipisad tees ove eecvaverte

Pranensis (@Uiari0))) Uildies iev-rancreterelorerete
Piceus (Diplodon) eaten fste Seorete
Piceus (Diplodon) Simp. ........
PRiceus, (Margaron) Wear the. fee
Prceus> CUmio)yelgeas “eeetereee-ctehovere
Rictay, Chunynia) i Ontienesnrtr eter
Picta. (lam psilis) Mea tits . cielo ei
Pictetiana (Anodonta) Brot .....

Pictorum
Pictorum

Pictorum,

Pictorum
Pictorum
Pictorum
Pictorum
Pictorum
Pictorum
Pictorum
Pictorum
Pictorum
Pictorum
Pictorum
Pictorum
Pictorum
Pictorum

amurensis (Unio) Mouss.
(Baphiz) Meusch.

etc. (Unio) Chem.

longirostris(Unio) West.
longirostris (Unio) Ross.
(Lymnium) Oken .....
(@Miarsatcitan mean vere stae
(Margaron) Lea .......
CUMiya) aiGurel sina setae
(Miya) inns ence
(CMiysca)) lute yet. erect
GUnio) HBr eerste s
@Unio) mDrapiien eset.
@Uinio)y(Guers 6 fascia
@Uinio) Binnie. erento
Uno) VaRetziew eee
(Wn) Sim peels chelreintete

Pictus) GAnodon)moweeelcerts 437,
Pictus (Lampsilis)) Sintp. -..<.. .2:
Pactus (Margarita) Weav ieee...

Pictus (Margaron) [ea
Pictus (Unio) Lea

acts) CUnio) eS Ow, s.erciee clole ese

Pierrei (Pseudodon) Roch.

Piestius

(Pseudodontopsis) Kob. .

Bie trie (Unio) MISO b sertetelctetteriee
Pretriny@Un0) my ocsetceminesh ieee
Pigser, CDiplodon)myeal ea.. sessee

Bigers (Mar garoni)eeaunninie:ersierele ?

Piger: ((Unto)i Weak tite: teeterervorasrere
Pigerrimus (Unio) C. & F. ......
Pilanis) ((Miargaron)! Tear. . acier
Pillans. ((Ouadrula) ea, eye ...-teiere
Bilas (Unio) le cary rericre fo crcitele
Pilaris| (CUinio) * Riveleenisee eet
Pilatus i@Miarearon)) Ayea sac ate er
Pilatus; (CUmio) Maly eal terretera/otoreretonenele
Pilea Simipaliotnw sts ater ote eee
Paleus (Margarita) @ ease).
Pileus: “CWiargaron) ee Weamcnccleit-
Piles, 1 GUinio) mW ealremrcrerete tere r=6 re

Pilsbryi

GWiio) meester c's clei

Pilsbryoconchamoimpemes eeles cc =) <1
lexateh.< “AUborro)) Ion BAcagnoodccuds
Pinchoniana (Hyriopsis) Hde.

Pinchonianus (Hyriopsis) Simp. .
Pinchonianus (Unio) Hde........

85

INDEX

Rinem(@Uano) BEERS Wr <>. as<,2 65 647
Pinguis (Lampsilis) Simp. ....... 81
Pinguis (Margaron) Lea ...... Aeenen
Pinswms (Unie) hea: i4.<.5 ocences 81
Pinkstoni (Pleurobema) S. H. Wr. 785
Pinkstoni (Unio) S. H. Wr. ..... 785
Piscatorum (Anodon) Hde. ...... 403
Pisciculus (Cuneopsis) Hde. ..... 047
Pisciculus; (Unio)) Hide: ........5< 947
Piscinalis (Anodonta) Nils. ...... 368
Piscinalise/@Unio)) (Rosse =. o2e5- 571
Placidus) ((Unio)s Kust: =).sce0 a. 1469
Placitus (Margaron) Lea ........ 7
Placitius! @Umio)) Weal = 2-62 Aachen. 67
Rlagiodonmlyeay 9. eeer aceite sees 1392
Plagiola Raf. 63506 donut ceeauCooe 302
Plagiosoma (Unio) Ben. ........ IIII
Plana (Anodon) DeKay ......... 421
Plana (Anodonta)! Tjea, ¢).....:.. 421
Plana (Margarita) eleay «s..cecoe. 421
lana (Varcaron), Weasscss oss ace 421
manaa@Miya)) Baton cases. senses 182
Planca (QRampsilis) Lea. =.....-- 124
Plancus (Lampsilis) Simp. ....... 125
Plancus (Margaron) Lea ........ 125
Mancuss (Unio) meap «asses sce ois oe I25
Planicostata (Lampsilis) Lea 117
Planicostatus (I,ampsilis) Simp. . 118
Planicostatus (Margaron) Lea ... 118
Planicostatus (Unio) Lea ....... 118
Planior (Margaron) Lea ......... 803
Planior (Pleurobema) Simp. ..... 803
iPlanion @Wnio)iiveal 2 ccekiaeoccs 803
Planilaterus (Margaron) Lea 653
Planilaterus (Unio) Con. ....... 653
Planius (Pleurobema) Lea ...... 802
Planivalvis (Lampsilis) Morel. ... 193
Planivalvis (Unio) Morel. .....:. 193
Plantae larearon idee secs. 672
Plant (Unio) e weas sae ane eae oe 672
Planulata (Margaron) Lea ...... 1086
Planulata (Microcondylea) Pet. 1086
Planulata (Monocondylea) Tea ..1086
Planulata (Pseudodon) Con. ....1086
Planulata (Unio) Desh. ......... 334
Blanulatis: iGUnio)mel eas cases 334
IMGT (AVENE (Colne oo neneouscec 182
Iblatiolius (@Uinio)= Ration sas snaee 731
Platyrinchoideus (Unio) Dup. 535
Platyrhynchoideus (Unio) West. 536
Platyrhynchus (Margarita) Lea .. 535
Platyrhynchus (Margaron) Lea .. 535
Platyrhynchus (Unio) Ross. ..... 534
Platyrrhynchoideus (Unio) Sow. 536
Pleasii (ampsilis) Marsh ...... 129
Pleasii (Unio) Marsh .......... 129

I519
Plectophorus (Plectomerus) Con. . 605
Plectophorus (Unio) Con. ...... 605
Ederodan™ Cony ..25. a5 Accel. Oks 1375
Blenas (@Quadrulaimea!. 2.20... 2 886
Blenus) (Margaronm): Beaw o2..:... 887
Pirenusy (Unio) Beat vaa2se5 65... 887
Fiethohasuss Simps) seen ek. 805
iletholophus’ Simp. aseeeeen ens S 22
iPicucobemamRale -acoa eee ee 732
Plexus minor (Unio) F..& C. .... 590
lexis, /CUmio))e Cont aeieen ee 590
Plicata (Anodonta) Schr. ....... 22
Plicata (Barbala) H. & A. Ads. 22
Plicata clessini (Dipsas) Kob. .... 228
Plicata (Crenodonta) Ort. ....... 816
Plicata (Cristaria) Leach ...... 22
Plicata i(Cristaria)) Simp. ¢s:.2... 226
iBlicatas@Dipsas) iob= eee eeese 224
Plicata hippopea (Quadrula) Lea 816
Plicata japonica (Dipsas) Kob. .. 229
Plicata; ((Margaron) “Weal -...+...% 468
Pitcatra (Mutela) Cless. ........ 1470
Phicata’ @Miutela)' Sow: 25..255.-- 1363
Plicata (Mutelina) Ger. ........ 1363
Plicata” Cfya)l Baton! <.c905.... 815.
Plicata, ((Quadrula) “Say 22225... 814
Bhicatani@Unio)in Sayan ne oeee 815
Plicatula (Barbala) Pet. ...... 225
Plicatula (Nephronaias) Charp. 282
Plicatulus (Margaron) Lea ...... 1155
Plicatulus (Nephronaias) Simp. 282
Plicatulus (Unio) Charp. ...... 282
Piicatulus. (€Unio)r ‘eamenaneeee II55
Plicatus (Anodon) -Hald. ...... 468
Phcatus, (Appius), Gray) .J.5.e8- 22.
Plicatus. (Dipsas) Leach ........ 224
Plicatus (Margarita) Lea em eed mon
Plicatus (Margaron) Lea 224, 815
Plicatus (Mycetopus) Cless. LAST
Plicatus (Mycetopus) Sow. ..... 1363
Plicatus: @Viytilus)) Sols 222. 22 224
Plicatus. (Blatiris)) Wea +222. .... 1363
Plicatus (Plectomerus) Con. 815
Piicatus> (Unio)! Han: /..2....5. 815
Piicatus) @Unio) i Kust os os5). see 821
iPitcaruse”Uinio)), SowsN eno. sae 22
Pliciferus (Margarita) Lea ...... 590
Pliciferus (Margaron) Lea ...... 590
Pliciferus minor (Unio) F. & C. 590
Biciieruss (Wmio)) Wea osses. +e see 590
Pliculosa (Nodularia) Marts. 964
Pliculosus (Unio) Marts. ........ 964
Plombarius (Unio) Villa ........ 7311
Plumbea (Chama) Chem. ~...... 913
Plumbea (Quadrula) Chem. 913
Plumbeus (Unio) Kust. ........ 914

1520
Poeyanus (Margaron) Lea ...... 701
Poeyanush (Unio) Wear nn <. sletelcicte 701
Poirieri (Nodularia) Roch. 1045
Roirstert. CZairia) ea ROChs Hee eee 1045
Polita (Anodonta) Mouss. ...... 242
Politay \(Margaran) i eat clk wire 242
Politic 7 CAnodon)) i" Sow. wesc flit 2
Eolitus, (Unio) “Says cres.ceceme es 803
Polymorpha (Anodonta) Lea .... 437
Polymorphus (Unio) B. H. Wr. .. 608
Polysticta (Quadrula) Hde. .... 923
Polysticto-scriptus (Quadrula)

DIMIPs yc ciethnedeieus, seareverar oueve evel ote aos 924
Polysticto-scriptus (Unio) Hde. 924

Polystictus (Quadrula) Simp. .... 92

Polystictus (@Unto)m Hides i. 2 et 924
Ponderosa (Anodonta) C. Pfr. 369
Ponderosa) (Miya) mille. scr 942
Ponderosa (Pseudodon) Prest. 1103
Ponderosus (Bariosta) Raf. 731
Ponderosus (Margarita) Lea 043
Ponderosus (Margaron) Lea 2m O43
Ponderosus (Paxyodon) Schum. 1219
Ponderosus (Pseudodon) Prest. ..1102
Ponderosus (Unio) Han. ...... 943
Pope, CElliptio) Ort. cee ee ee 7OI
Ropew, GVampsilis) ss Pilssese eee 700
Popet (Unio) Sow. Gersierc-lec ctor 700
Popem (@Margaron) Jjea ........ 700
Popen COmio) Léa «cvi.csseaees 700
EFepenor (@Wxio) Call. .....0080. 329
‘Porcifer (Anodon) Gray ........ 1456
Porphyrea (Lampsilis) Lea ...... 2

Porphyreus (Lampsilis) Simp. .. 2
Porphyreus (Margaron) Lea .... 2

‘Porphyreus (Unio) Dea ........ 2
Porrestus (Unio) Con: «6.2.23. 706
Postellii (Margaron) Lea ....... 654
Bestellit ((Wmio)) Wea. eosnecsce sce 654
Postuma (Parreysia) Roch. ..... 1127
“Postumus (CUnio) Roch Ss. 1127
Poulsoni (Symphynota) Fer. 164
PoulsonwGWnio) Conta. scree 164
Poulsonw CUnto)) oowsaseieicie cer 167
Powellii (Lampsilis) Lea ........ 75
Powellii (Margaron) Lea ...... 76
Powellit> GUnito)" Wea see. etek 76
Preclara (Anodonta) Bet. ...... 439
Preclarum (Colletopterum) Bet. 439
Prelonga (Eurynea) Stimp. 96
Epeionsa (Miya) baton ames eeee 96
Prelongus \((Uni0) Bare “1s 96
Prasina (Mutelina) Roch. ...... 1360
Brasinatus) @Umio)n Conus ee oe cee 630
Brasinius) (Gini)? Conese eee 849
Pratt, ‘(yampsilis)i leas. ciccoiietere 108

. INDEX

Prattii (Margaron) Lea
Pratt GUnto)e bear pase eee
Pressa (Alasmodonta) Bak.
Pressidens™ ‘Haasy aac eee
Pressirostris (Rectidens) Marts.
Pressirostris (Unio) Marts.
Pressodonta soimp eres cee
Pressus’ (Margaron) Shea 27. 222.
Pressus (Unio) H. & A. Ads.
Prestoni (Rectidens) Simp.
Prevostianus (Margaron) Lea ...
Prevostianus (Unio) Lea
Prevostianus (Unio) Sow.
Prisodon™ Weavasn.ters sce eee
Prisodon Schum.
Proclinatus (Unio) Marts.
Productior (Unio) Lea
Products GE lliptio)= Orta
Productus (Margarita) Lea
Productus (Margaron) Lea
Productus, GUnio)ieConwieadonseose
Productus (Unio) Mouss.
Proechus (Unio) Bet.
Profugus (Diplodon) Gld.
Profugus (Margaron) Lea
Protugus —(Unio)). GldS %.o2nc.eee
Profunda (Quadrula) Simp.
Prolongatus (Rectidens) Drouet
Prolongatus (Unio) Drouet
Propinqua (Truncilla) Lea ......
Propinquus (Margaron) Lea
Propinquus (Unio) Lea
Propria (Lampsilis) Tea
Proprius (Lampsilis) Simp.
Proprius (Margaron) Lea
Proprius (Unio) Lea
Proptera state exy.tevertenine chore ore eee
IPAr OS KerneS (habs) Ilr Sh bocacsac
Rrotche1, ((Spatha)) Roches cee.
Protchei (Spathella) Roch.
Protensus (Margaron) Lea
Protensus (Unio) Lea
Protensus (Unio) T.-C.
?rotunio Haas
Provancheriana (Arconaia) Pils.
Proximus (Margaron) Lea
Proximus (Unio) Kust.
Proximus (Unio) Lea
Pruinosus (Unio) Schmidt
Prunoides (Diplodon) Tea
Prunoides (Margaron) Lea
Prunoides (Unio) Lea
Prusii (Unio) Bet.
Psammactinus (Unio) Phil.
Psammita (Anodonta) Bet.
Psammoica (Castalina) d’Orb.

see ee eee

see eee

1158

+ 907

1160

wt

INDEX 1521

PsammoicaCUnio)l Gd:Onrbe .- 16. 1207
Psammoicus (Margaron) Lea ....1207
Psammoicus (Unio) Sow. ...... 1207
ipPSeundanodontal sgt stentless > 358
Setidavarc mle Slip. weeileistelenseuelevere 1190
IPseudopaphiaseoimipsy yer elcieisielers\ ster 1138
Pseudodon: sGldts sitesi cress 1079
Pseudodontopsis (Anodonta) Cr. 440
Pseudodontopsis) 2Kobs “secs cise 444

Pseudodopsis (Anodonta) Loc. .. 440
Pseudodopsis (Gabillotia) Loc. .. 440
Pseudodus de M.
Pseudoleguminaia Ger. ......... 449
Pseudomutela Simp.
Pseudonymus (Unio) Simp. .... 560
Pseudo6n Simp.
Rseudospathay, (Olimlps) casei asic LOS
Pseudiunio) eelaaswre aere-eiete ice eisiele 520
Psoricus pigerrimus (Unio) Marts. 621
Psoricus (Unio) Morel.

Saeve dea lerets 595
Bteranodons Busch, israceieieistsers ¢ 358
IAroGheaiel IREVE” GhoscuonougbadoG 490
Pty chobranchus) (\Simpa ates a. ece 332
Btychorhynchus) Simp: decee ss 1144
iRtychodermaim Simps meee cee: 311
leiwolaleyenn eke) 5 Greoctolg Coco cil Oreos 332
Puberula. (Anodonta) Gld. ...... 1415
Pudica (Pleurobema) Simp. ..... 755
Pudicum (Pleurobema) Tea ..... 755
Budicus i@Vargaron)) Wears. snieess 755
edicts) «(Unto rlyeam ey. ci cess oes) < 755
Puelchana (Anodonta) d’Orb. ...1420
Puelchana (Margaron) Lea ..... 1421
Puelchanus (Anodontites) Pils. ..1421
Puelchanus (Glabaris) Simp. ....1421
Puerorum (Anodon) Hde. ....... 404
Puerorum (Andonta) Pet. ..... 404
Pugio (Nodularia) Ben. ........ 990
Bugion(@xynata) ebliaaS as seca 990
1eeeestoy ((UpaKo)) 1S, geocgapeccuc 990
Pulchella (Anodon) Hde. ........ 412
Pulchella (Anodonta) Pzt. ...... 412
Pulchella (Cameronia) Bet. ....1384

Pulcher (Iamellidens) Simp. ....1170

Pulcher W(Margarita)) Wea 22... 84
Pulcher (@Wiasgeron)) Weal 75.4026: 84
ulcher (Unio) Weal eases scr cee 84
Bulcher! (Unto) si=-C) sees or 1170
iPullas@vampsilts)imCont .)serccee ete 160
Rullatisss@Unio)) Wea oc. s ters cele 661
Pullatus (Margaron) Léa ...... 661
Pallatusmee CUNO) wa Wea ace eerie 661
Pulluss|@lampsilis)) Simp: <<... 160
Rialliusm@Mlarearom)) Gea) cs. ccs -. «ies 160
IM nh (AUK) (Core sas oqomdo pO 160

Pulvinata (Columba) Cless. ....14o01

Rulvinata (leila) Eupé 5:2... 5.- 1401
Pulvinatus (Anodon) Sow. ...... I401
Pulvinulus (Margaron) Lea ..... 777
Bulvaniwlus! (Uniolm Weal jes «oss 777
Pramilas | CArrodon)) mi Eldes rca cleje scl 412
Pumila CAnodonta)) Pte vase: 412
Pamilay (@vadrula) jee eaeerr. cl -t- 868
Birmilton (Unio) NouStemse vere ees 1002
Pumilus (Margarita) Lea ........ 869
Pumilus (Margaron) Lea ...... 869
Pumulauss. (Unio) im dsea saeco. 868
PRumilus: (Unio)! Ziess eerie 1021
Runctata: G@eampsilis)) Wealnurenc 87
Punctata (Mycetopoda) Prest. ..1464
Punctatus (Lampsilis) Simp. .... 87
Punctatus (Margaron) Lea :..... 87
Punctatus (Mycetopus) Prest. ..1465
Punctatus s@Uinio) eal scree oes 87
Punicea (Lampsilis) Hald. ..... 104
Puniceus (Lampsilis) Simp. .... 104
Puniceus (Margaron) Tea ...... 104
Ramiceuss a Wii) elaldaaaacseiserre 104
Purpurascens (Anodon) Sw. .... 189
Purpurascens (Unio) Lam. ..... 652
Purpurata (Lampsilis) Lam. .... 166
Purpurata (Proptera) Ort: .....- 167
Purpucata, Unio), dam. sense 167
Purpuratus (Lampsilis) Simp. ... 167
Purpuratus (Margarita) Lea .... 167
Purpuratus (Margaron) Lea ..... 167
Purpuratus @Unio)! Wears s-nec. cae 167

Purpurea (Anodon) C, & R. ....1071

Purpurea (Anodonta) Val. «...-107%
Purpurea: (Dalliella) “Simps sessee IO7I
Purpurea (Margarita) Wea ...:.. 1071
Purpurea (Margaron) Lea ...... 1071
Putpurea (Miya); Baton” 3.5... 652
Purpurea (Simpsonella) Val. ....1070
Rurpureay (Unio, Deshs aa. rere 652
Purpurellus (Margaron) Lea .... 646
Rurpurellise (Unio) pers. crmentatcincs 646
Purpureus, (Unio) Say .2c.0.-.- 652
Purpuriatus (Unio) Say ...... 255, 728
Pocus @Miargaron))h Weay..1 slelelesopels 673
1eAcrRO, (CUE) IUGEY GanocccoGuce 673
BPusillan¢@ bitquanta)iy Rates ce eli 731
Pusillus; (Margcaron)) Weal vice. 1. 612
leeches: ((Ufarte)) ALCEY Saogodoudas 611
Bustulata, GOuadrula) Bea... 856
Bastitlatas (WidO})s en owietlecrelelere.«ieseie'> 319
Pustulatus (Margarita) Lea ...... 856
Pustulatus (Margaron) Lea ...... 856
Bustulatius, GWmio)) Weal canis. ce 856

Pustulosa keineriana (Quadrula)
Sinks) | GOO UEC OOS Doo aEser 852

1522 INDEX
Pustulosa kieneriana (Quadrula) Radiata (Alasmodonta) Con. .... 356

Te Gal ci ttale Valerervccheter nersthrcatracchussverse eee 851 Radiata (Anodontites) Val. ..... 438
Pustulosa pernodosa (Quadrula) Radiata conspicua (lampsils)

WEA anes eyete ra tisneel er taste ecm vues Liens tare e 851 WC arm aici ststeycns Chtveue busts ciavehats erate 66
Pustulosa (Quadrula) Tea ...... 848 Radiata (Cristaria) Simp. ........ 236
Pustulosa schooleraftensis (Quad- Radiata (Glabaris) alba eee 1432

MTU) EA | ace « siereveepaevs eves ates colors 850 Radiata (Lampsilis) Gmel. ..... 64
Pustulosus (Margarita) Lea ..... 849 Radiata (Margarita) Lea ..356, 1432
Pustulosus (Margaron) Lea .... 840 Radiata (Margaron) Lea ....«.... 356
Rustulosus’ (Unio) Gall. eee eel 855 Radvata "@viva)suGmel was oo eee 64
Pastulosus CUnto)) “Wea Sans. 849 Radiata (@datelia)) Rat. scececee 454
Pybasi, (Margaron)) Weals-...- 106 Radiata GOmro), danas soeicesele - 64
Pybasi “WU nio)miseasemnciccs. sre ts 106 Radiatas GUmniapsis)) se Oweue-niemee 495
Pygmza (Mycetopoda) Spix 1462 IReVabey aie Stren) Sedocomeceaeaar 1016
Pygmzus (Margaron) [Lea ...... 649 Radiatulus (Unio) Marts. ...... 261
Pygmeus (Mycetopus) Hupé ....1463 Radiatus! -CAnodom)s Spiscu siete eae 1432
Pygmzus (Mycetopus) Sow. ....1462 Radiatus (Anodonta) Mill. .... 361
Pygmzus .(Platinis) Dea .....0- 1462 Radiatus (Anodontites) Spix 1432
Pyonreuse (Winiio) sp Wyeame. steleciere + te 649 Radiatus conspicuus (lampsilis)
Pyramidata (Quadrula) Lea ..... 888 SUMP,” achedats arbors boiersisachers whete aiazee 66
Pyramidatum (Pleurobema) Ort. 889 Radiatus. (Glabaris) Simp. ...... 1432
Pyramidatus (Margarita) Tea .. 889 Radiatus (Lampsilis) Simp. ..... 65
Pyramidatus (Margaron) Lea ... 889 Radiatus (Margarita) Dea ...... 65
Pyramidatus (Unio) Lea ........ 889 Radiatus (Margaron) Lea ..65, 1432
Pyriforme (Pleurobema) Lea .... 793 Radiatus (Strophitus) Con. ...... 356
Pyriformis (Margaron) Lea .... 794 Radiatus (Unio) De Way senecee 116
Pyriformis (Pleurobema) Simp. .. 704 Radiatus ((Unio)) Spengy oi... enc 65
Pyriformis, GUmio) Wear cis -crtaiciaie 794 Radiolus 1 GUinio) ye calmer teenies 640
Quadrangulosus (Unio) Hde. .... 934 Riadrasis (Unio) e Cammeereciciercyeiele 751
Quadrans (Diplodon) Lea ...... 1277 Radiota (Nodularia) Simp. ...... 1044
Quadrans (Margaron) Lea ...... 1278 Radula (Dysnomia) Roch. ...... ro18
Ouadrans sGUinio) year pe aes 1278 Radula Unitas Ben accor 6 srcire 1018
@Quadratay (Castalia) Sows) ts 1201 Radulay o@Wnio)s Savant clerics 731
Quadrata (Margaritana) Lea .... 488 Radulosa (Discomya) Haas ...... 938
Quadrata (Margaron) Tea ...... 488 Radulosa (Quadrula) D. & C. .. 937
Quadrata (Quadrula) Simp. .... 911 Radulosa rhomboidea (Quadrula)
Quadrata (Symphynota) Lea .... 487 Gimps etna ees cence eee sees 938
Quadratus (Margaron) [Lea ...... 655 Radulosus (Unio) D. & C. ..... 938
Quadratus (Tetraplodon) Sow. 1201 Raeensis (Margaron) Lea ..... 655
Quadratus (Unio) Lea .......... 655 Raeensis (Unio) Tea .......... 655
Quadratus (Umia)! Ryver 2.2. 842 Rajahensis (Margaron) Lea 1118
Quadrilatera (Castalia) d’Orb. ..1199 Rajahensis (Parreysia) Lea 1117
Quadrilaterum (Tetraplodon) Simp. Rajahensis: (Unio) Wea —..--.c-- II17

S Asx chalie vous veushgne: shetpatetehe ketene hes saenetarets 1199 Raleighensis (Margaron) Lea .... 655
Quadrilaterus (Margaron) Lea .. 660 Raleighensis (Unio) Lea ........ 655
Quadrilaterus (Tetraplodon) d’Orb. Ranarum (Anodonta) Morel. .... 363

PRR Mn ee cm Groaccne Ne nec OS Randabeli (Brazzea Bet. .......-.1374
Quadrilaterus (Unio) Lea ...... 660 Randabeli (Cameronia) Bet. 1384
Quadriplicatus (Anodon) Sow. .. 350 Randabeli (Nodularia) Bet. 1024
QOuadrula (Obliquaria) Raf. ..... 731 Randabeli (Unio) Bet. ........ 1025
OuadrulapeRate ire eit tre 811 Randalli (Anodonta) Trask .... 464
Quadrulius) CUn10 Say, cette elites 842 Rangiana (Jruncilla) Ort. ...... 26
Ouinqueannulatus (Unio) Kust. 533 Rangianus (Margarita) Lea .... 26
Quintardy (Unio) "Crags 04-1 818 Rangianus (Margaron) Lea ...... 26
Radians (Margaron) Lea ........ 120 RangianiseGUn10)) Wear caer 26
Radians) (GUinto)) sea: cormcieraccre ase 120 Rariplicata (Unio) Desh. ........ 815

INDEX

Rarisuleatas Guni1o)) Teams cle. 652
Rasuse @viarearon)) Weal... ace. 543
ars uss G@Witaromlyear macrs.evs%s 6s eles ete 543
Ratidota (Nodularia) Char. ...... 1044
Ratidotus, “@Wnio) (Char. 2.2.4.2. 1044
RatiSeamia))s Ayeak es clei sais e orereners 65
Ravenel. @Wn1o)) (Cont ceases. cr 653

Raveneliana (Alasmidonta) Lea .. 507
Raveneliana (Alasmodonta) Fer. 507
Raveneliana (Baphia) H..& A. Ads.

Raveneliana (Margaritana) Chenu 517
Raveneliana (Margarita) Lea .... 507
Raveneliana (Margarittana) Lea .. 507
Raveneliana (Margaron) Lea .... 507
Raveneliana (Pleurobema) Simp. .797
Ravenelianum (Pleurobema) Tea 796
Ravenelianus (Margarita) Lea .. 797
Ravenelianus (Margaron) Lea .. 797
Ravenelianus (Strophitus) Con. .. 508
Ravenelianus (Unio) Lea
Ravenelianus (Unio) Rve.
Ravistella majuscula (Nephronaias)

Marts.
Ravistella (Nephronaias) Morel. 283

Ravistellus majusculus (Unio)

WicintSen sepeatets owvateisicteee ein aveletmotete 284
Ravistellus (Margaron) Lea ..... 283
Ravistellus (Nephronaias) Simp. 283
Ravistellus (Unio) Morel. ...... 283
Ravistellus (Unio) Marts ...... 285°
Ravistellus verepacis (Unio)

UNAS SiGe arcs OS mora cece 701
Ravoisieri issericus (Unio) Kob. 541
Ravoisieri (Margaron) Lea ...... 541
Rayoisiert, (€Wnio) Desh: 23.3... 541
Ravoisieri (Unio) Simp. ........ 542
Rayi (Anodonta) Drouet ........ 364
Raymond Unio) Wocs |. ...-..- 732
Raymondopsis (Unio) Kob. ...... 732

Reclusa (Pluerobema) Simp. .... 784
Reclusum (Pleurobema) B. H. Wr. 783
Reclusus (Unio) B. -H. Wr. .... 783
Recognitus (Mycetopus) Hde. .. 460

Recta GE unymnia)) Ort. vpereci serie 95
eeeiey (sheer) Seis cobocedoo0dc 1222
Recta GWampsilis)) Tams sje 95
Recta sageri (Lampsilis) Con. .. 96
Rectams@Wmio)) Warns vere svoccinepeisvete 95
PNECEIGCE MSM OITMD As tel <\-1ciels cp clele oie! sisters 1157
Rectilinearis (Unio) Sow. ...... 576
Rectus (Lampsilis) Smith ...... 96
Rectus (MWarearita)) Wea .......- 96
Rectus (Margaron) Lea ........ 96
Rectus (Prisodon) Sow. ........ 1222

1523
RVEGHIS MIO) MuCOTer sa therchers,c)ersicie 95
Recupvatus, (Unio) Wea .:....2. 753
Recurvirostra (Anodonta) Lea .. 438
Reeviana (Lampsilis) Lea ...... 74
Reevianus (Lampsilis) Simp. .... 75
Reevianus (Margaron) Lea ...... 75
Reevianus (Unio) Lea .......... 75
Reflexa (Obliquaria) Raf ...... 330
Reflexa phillipsi (Obliquaria) Con. 331
Reflexuss((Wnio))) Sayalccn saciieste 331
Refulgens (Margaron) Lea ...... 855
Refulgens (Quadrula) Tea ...... 855
Retulgens’ (@Unio)e Wea oases 855
Regularis (Anodonta) Morel. .... 363

Regularis (Margaron) Lea ...... 12
Recularis (Um10)) Weal) ay. ons sretioe 123
Regulartse (Unio)! Sows se oc <csyeres 51
Reiniana (Anodonta) Ih. ....... 232
ReinianayCBarbata)l yet. exci 232
Reiniana, (Cristaria) Martsy sscces 232
Reiniana, (@Dipsas)) Kops asc-eere 232
Reiniana (Nodularia) Kob. ..... 974
Reiniana (Pletholophus) Prest .. 232
Reinianus (Unio) Kob. .......... 975
Renea (Nodularia) Jouss. ...... 1027
ReneteCSnatia)) Jousss: asic ccoeiee 1317
RVEMEUs) -VOUSS:0) ras wis colevenciei ere ats ois 949
Reneus (Reneus) Jouss. ........ 1027
Reniformis (Unio) Ross. ........ 571
Requieni) @Unio)» ROSS: .stacie oi\-ece 573
Requienit, @Unio)y Michh ~o-necer 540
Resupinatus (Pseudodon) Marts. 1090
Retiaria (Acuticosta) Haas ...... 114i
Retiaria (Parreysia) Hde. ....... II4I
Retianirs | CUmio)s eidess ae .serceeer II4I
Reticulata (Anodonta) Pet. ....1415

Reticulata (Margaritana) Pet. 1389
Reticulata (Margaron) Lea 1389, 1415
Reticulata (Monocondylea) Moric.

Sho GOED DODeG Cane DOO oO Bb ob 1389
Reticulata (Nephronaias) Simp. .. 268
Reticulatus (Anodon) Sow. ...... 1415
Reticulatus (Aplodon) Ih. ...... 1389
Reticulatus (Nephronaias) Simp. 269
Reticulatus (Unio) Sow. ........ 1389
Retortus) (@Unzo)) Hides sree. = a=: 917
Retortius, (Unio), Marts.) Ace... 947
Retteri (Anodonta) Drouet ...... 370
Retusa (Anodonta) Hde. ........ 405
Retusa, (Castalia) lupe! f. 3-5 1201
Retusa (Obliquaria) Raf. ........ 302
Retusa (Obovaria) Lam. ........ 290
RefuSae (Unio) sWyamis “Sertertaereyeroiore 291
Retusus (Margarita) Lea ....... 291
Retusus (Margaron) Lea ....... 291

1524

Retusus (Tetraplodon) Hupé

Retusis nto) COM: seyarstetetsielers -
REHISHS MCUIMIO) MEDAN: Telecie cic sie ree
Revoiliana (Cameronia) Bgt. ....
Rhombeus (Diplodon) Wag.

Rhombeus (Margarita) Lea ...
Rhombeus (Margaron) Lea ....
Rhombeus (Unio) Wag. ........
Rhombica (Alasmodon) Anth.

Rhombica (Margaritana) Pet.

Rhomboidea (Leguminaia) Kob.

Rhomboidea (Margaron) Lea ....

Rhomboidea (Microcondylea) Pet. 443

Rhomboidea
Kust.

(Monocondylza)

Rhomboidea (Monocondylea) Lea 443

Rhomboideus (Pseudodon) West.
Rhomboideus (Unio) M.-T.
Rhomboideus (Unio) Sow.
Rhomboidopsis (Unio) Loe.
Rhomboidopsis (Unio) Kob.
Rhombula (Unio) Lam.
Rhombunio_ Ger.
Rhuacoica (Unio) d’Orb.
Rhuacoicus (Diplodon) d‘Orb.
Rhuacoicus (Margaron) Lea
Rhuaconicus (Diplodon) Kust.
(User) NES agoac
Rhyacceca (Monocondylea) Pet.
Rhyacoicus (Unio) Marts.
Rhynchoidea (Chambardia)
Rhynchonella (Chambardia)
Rhynchonella (Grandidieria) Bet.
Richardsoni (Anodonta) Marts.
Richthofeni (Anodonta) Neum.

Rhuaconicus

Richthofeni (Unio) Marts. ......
Riddellit (CMiargaron) Wea .:...
Riddellii (Pleurobema) Ort.

Riddellii (Quadrula) Lea ......
Ravataiben (Okrioy) ILE S5aso0u0dc
Ridibundus Unio) Say seis
Ruieiday “(Miya = SWioods Wremrerelsrejers
idehaoverbe; (CGhar@y)) Ikebin- sooooooon
Rioplatensis (Anodon) Sow.

Rioplatensis (Anodonta) Cless.
Riparia (Unio) C. Pfr.
Riparius (Unio) Scholz
(Unio) Con.

(Anodon) Hde.
(Anodonta) Hde.
(Mycetopus) Hde.
(Solenaia) Hde.

(Unio) Con.
(Unio) Raf.

Rivicolus
Rivularis
Rivularis
Rivularis
Rivularis
Rivularis
Rivularis

Roanokensis (Margarita) Lea ....

Roanokensis (Margaron) Lea

INDEX
1200 Roanokensis northamptonenesis
291 (Unio) “Weaw£ . teeter orien 668
830 Roanokensis (Unio) Lea ........ 666
1384 Rochebruneana (Moncetia) Begt. 1346
1228 Rochebrunei (Spatha) Jouss. ....1322
122 Rochechouarti (Quadrula) Hde. 926
1229 Rochechouarti (Unio) Hde. a3. 1920
1229 Roissyi (Margaritana) West. 516
348 Rossyie GUmio) Witchs -\ ene ie 516
248 Rolleiy (Unio) sophie am cercreee 558
444 Rosaveus (Unio) eon eee eee 50
443 Rosaceus (Unio) De Kay ...... 62
RosanoZhamphiuse mcm siecle cece 949
Rosea (Amodon): Hde <..2-.%... 405
1086 Rosea (Anodonta) Pt. ........ 405
Rossmassleriana (Anodonta) Dup. 364
444 RostelliumeGUnio) Weds eee eee 608
555 Rostreformis (Unio) Lea ...... 695
444 Rostralisy (Unto) eviantss eerste ete 1056
558 Rostrata (Anodonta) Held. ..... 369
559 Rostrata (Anodonta) Ross. ..... 369
652 Rostrata (Grandidieria) Bet. 1056
550 Rostratas Ciniding)) sivarcee stereos 1359
1242 Rostrata (Mutela) Rang ...:.-.. 1359
1242 Rostrata (Mutelina) Bgt. ........ 1360
1242 Rostrata ((Spatha)) Martsy "eee: 1359
1263 Rostratass|GUn10) meme arias sarees 532
1263 ostrata, (Unto) is salen reste 98
1242 Rostratus (Anodon) Sow. ....369, 380
1242 Rostratus (Unio) Chenu ........ 532
1350 Rostriformis (Margaron) Lea 606
1350 Rostriformis (Unio) Lea ...... 606
1058 Rostrum (Margaron) Tea ...... 660
382 Rostrum CWn10) © years tre talerere 660
406 Roswellensis (Margaron) Lea 654
930 Roswellensis (Unio) Mea \i-cc o 654
879 Roth CUnito)! Bet, wcee-icrciniee 555
879 Rothschildi (Grandidieria) N. & A. ..
Cv! seosnaanosooucodooopUDoceeouubo.’ 1057
870 Rotulata (Obovaria) B. H. Wr. 2097
15 Rotulatus (Unio) B. H. Wr. 298
653 Rotunda (Anodon) Kust. ...... 1410
731 Rotunda (Glabanis)— Uhs oon een 1410
1431 Rotunda (Margaron) [Lea ...... 1410
1431 Rotunda’ (CMiya)) Wiood? oe.) ees 292
570 Rvottimd ania eon mienacvereccyaterererereneneters 811
570 Rotunidantay (Rateemeurtete tec cietstateete 903
713 Rotundata (Glebula) Tam. ...... 287
41I Rotundata (Grandidieria) Bet. 1061
4II Rotundata (Thringella) Mouss. 1395
461 Rotundata (Spatha) Marts. ...... 1316
461 Rotundatay (GUnio)) Wam. 2.225. 288
711 Rotundata (Unio) Mand. 571
731 Rotundatus (Anodon) Sw. ....--. 402
667 Rotundatus (Margarita) Lea 288
. 667 Rotundatus (Margaron) Lea 288

- Rubellianus (Unio) Sow.
Rubellinus (Margaron) Lea ......

Rotundatus (Plagiodon) Mouss.
otundatus (Unio) Han.
Rotundus (Anodon) Spix
Rotundus (Anodontites) Spix
Rotundus (Diplodon) Wag.
Rotundus (Glabaris) Simp.
Rotundus (Margaron) Lea
Rotundus (Unio) Wag.

Rotundovata (Anodonta) Trask ..

Roubaudi (Unio) Ger.
Roubaudi (Chelidonopsis) Ger.
Rousii (Unio) Dup.
Rovirosai (Lampsilis) Pils.

Rovinosat GUnio)yebilss <2). cles oe
Rowellit (Margaron) Lea ......
Rowellii (Nephronaias) Lea

Rowelliuo’ CUnto)i) Weal Yecer see

Rubella (Andon) Hde.
Rubella (Anodonta) Pet.
Rubella (Pleurobema) Simp.

Rubellinus (Unio) Lea
Rubellum (Pleurobema) Con.
Rubellus (Margarita) Lea
Rubellus (Margaron) Lea
Rubellus (Unio) Con.
Rubens (Anodon) Sow.

Rubens (Anodonta) Aud.
Rubens (Anodonta) Tam.

Rubens cailliaudi (Spatha) Marts.
cailliaudi (Spatha) Simp.

Rubens
Rubens chudeaui (Spatha) Ger.
Rubens lepsii (Spatha) Ger.

Rubens (Iridina) Rang
Rubens (Platiris) Lea

Rubens rotundata (Spatha) Ger.

Rubens (Spatha) Lam.
Rubens (Unio) Mke.
Rubens wismanni (Spatha) Ger.
Ruber (Unio) Con.
Rubicunda (Anodonta) Lea
Rubicunda (Margaron) Lea
Rubicundus
Rubicundus (Anodontites) Lea
Rubicundus (Glabaris) Simp.

Rubicundus (Unio) Marts.
Rubida (Quadrula) Lea
Rubidula (Quadrula) Fr.
Rubidus (Margaron) Lea
Rubidus (Unio) Tea
Rubiginosa (Fusconaja) Ort.
Rubiginosa (Quadrula) Lea
Rubiginosa (Unio) Desh.
Rubiginosus (Margarita) Lea
Rubiginosus (Margaron) J,ea

ee ea

see ew eens

(nodon)itSowm ase

xX 1525
Rubiginosus (Unio) Tea .+.....% 872
Rubra GAmblema)) Raf i)... <5. 731
Rudis (Quadrula) Simp. ........ 910
RuadiseidUinio)) (Cong teen cleyierelaet. 777
Ieee (ClO fkertop ee Wh ot once eoaad 1235
Radus= GDiplodon)iy Igealy mci 1235
Rudus) @Margaron)) Weaseesc. «+ 1235
RudusyCWinio)) yea, wyeveretoyerevetelaversisr= 1235
Ruellani bayoni (Parreysia)

(ES ae CONROE IGIOEE con corona 1128)
Ruellani bayoni (Unio) Ger. 1129
Ruellani (Parreysia) Bet. ....... 1128
Ruellani @Unio)) “Bgt, ‘Seeoeccciete 1128
Rutfescens (Cuneopsis) Hde. 948
Rufescens (Unio) Hde. ........ 948
Rufofuscus (Diplodon) Lea ...... 1254
Rufofuscus (Margaron) Lea 1254
Bufofuscus (Unio) Wea ..:..... 1254
Rutuses @Wargaromn)elleai)\ shslcias eels 5900
RittiskMGUinione aveaw init. ciscelete 599
Rufusculus (Margaron) Lea 653
Ratkusculuss (@Unio)) Weal cin seere 653.
Rugata “(Solenaia)> Jidex acy.-1--. 462
Rugatus (Mycetopus) Hde. ...... 462
Ricatuse i@blatiris)melbeas annie 462
Rusatuss \@Unio) i Elutt. <.cpetercctor 1291
Rugatus ¥@Unito)= Mikes) 222s 570
[Rib kesh ere (Oforto)) Wee Gogdooouone 1021
Rugifera (Anodonta) Dunk. 438, 1348
IRGrenh ert ASOD (SGoebo One AOOO OO OC 504
Rugosa (Alasmodon) De Kay .... 489
Rugosa (Alasmodonta) Bar. 489
Rugosa (Baphia) H. & A. Ads. 480
Rugosa (Complanaria) Stimp. 4890
Rugosa (ayria)) Desh. %..0.20.o6 1213
Rugosa (Margarita) Tea ........ 489
Rugosa (Margaritana) Calk. 490
Rugosa (Margaron) Tea ........ 489
RusosaeuCMy.a) ens atonmesteres arletere 489
Rucosay 1@Miya)e Gmelis series 1118
Rugosa (Parreysia) Gmel. ...... 1118
Rucosa@Winio) i Elan ee sshiee cecee 480
Rucosaes GWinionm me Oleic errr 518
Rugosissima (Hyria) Sow. ...... 1214
Rugososuleata (Quadrula) Lea .. 902
Rugososulcatus (Margaron) Lea 902
Rugososuleatus (Unio) Lea - 902
Rugosum (Lasmigona) Raf. ..... 490
Rugosum (Triplodon) Spix ...... #213
Rugosus (Anodon) Sw. ......... 346
Rugosus (Anodonta) Han. ...... 346
Rugosus (Strophitus) Dall. ...... 346
Rugosus) CWUnio)) Chenw <. .2.. - 834
Rasosuse Unto) ee @& Aes ee. cre 985
Rugosus (Unio) Kust. ...... 490, 1118

Rugulosa (Mya) Wood 507

1526

Rugulosus -(Nephronaias) Charp. 277
Rugulosus (Nephronaias) Simp. .. 277

Rugulosus (Unio) Charp. ........ aT,
Rumphiana (Quadrula) Lea ...... 847
Rumphianus (Margaron) Lea .... 848
Rumphianus (Unio) Lea ........ 848
Rustica (Nodularia) Wea -n eee ae 1013
Rusticus (Contradens) Haas 1013
Rusticus (Margaron) Tea ...... 1013
Rusticus @Unio)) “Wea ...s.ceee 1013

Rutersvillensis (Margaron) Lea .. 100
Rutersvillensis (Unio) Lea ...... 100

Rutilans (Margaron) Lea ...... 137
Rutilans; (CUnio)) Wea --2eeeeeee 137,
Saccatuss (Unio)! Kust; =e 31
Sacculus’ CUnio): IRve) eeeo see 31
Sacellus (Nodularia) D. & C. ....1011
Sacellius, “CUnio)! Dike Cae IOIL
Sager’ (Unio) “Contineeeeeee eee 96
Sagittaria (Nodularia) Lea ...... 977
Sagittaria (Oxynata) Elaas) eee 977
Sagittarius (Margaron) Tea .... 977
Sagittarius «(Unto) miyeameneetine ee 977
Sagittiformis (Margaron) Lea .... 677
Savittizonmis: (Winio)piveamenneceee 676
Sagrinatus (Unio) Sow. ........ 313
Saladeensis (Lampsilis) Lea ...... 169
Saladceensis (Margaron) Lea ...... 170
Saladcensis' Unio) weal se soeee 170
Salaputium (Quadrula) Marts. .. 919
Salebrosus (Margaron) Lea .... 662
Salebrosus, (Unio) deea aes cee 662

Salinasensis (Lampsilis) Simp. .. 178
Sallei grossa (Plagiola) Marts. ... 315
Sallei grossus (Unio) Marts. .... 315

Salle: (Blagiola)iiC,Ge1Bs sense cee 315
walleneGUnio) iC. agen nes eee 315
Salmonea (Anodonta) Cless. .... 348
Salmonia (Anodon) Sow. ........ 420
Salmonia (Anodonta) Lea ...... 420
Salmonia (Margarita) Lea ..... 419
Salmonia (Margaron) Lea ...... 420
Salweniana (Anodon) Gld. ..... 1093
Salweniana (Anodonta) Gld. 1093
Salweniana (Margaron) Lea 1093
Salweniana (Moncondylea) Pet. 1093
Salweniana (Pseudodon) Con. ...1093

Salwenianum (Pseudodon) H. & T.

PEROT O-CIe EL CIE NOInIC oe OEIC onnle 1094
Salwenianus (Pseudodon) Gld. ..1093
Salwenianus (Unio) Sow. ........ 1093
Sampsonii (Margaron) Lea ...... 27
Sampsonii (Truncilla) Lea ...... 27
Sampsonit “CUnio)Mijea “ssc. .cce. 27
Sancta-paulie (Unio) Th. ........ 1312
sandr (CWmio)) YRosss\ceece cs see 572

INDEX

Santa-marie (Diplodon) Simp.
Santeensis @Wn1o)! bea, ss. see cee 642
Sapotalensis (Margaron) Lea ... 257

Sapotalensis (Nephronaias) Lea 237
Sapotalensis (Nephronajas) Ort. 257
Sapotalensis (Unio) Lea ........ 257
Sapper! “(i ampsilis)) ih. Sse eemeee 176
Satillensis (Margaron) Teo ...... 686
Satillzensisy (Unio)! Weal nance eee 686
Satur CMarearom)) Wea ss eeeeeeee 41
Satur’ (Umi) Wea see eeecceeere 41
Saulcyi (Leguminaia) Bet. ...... 448
Sauleyi (Margaron) Lea ........ 448
Sauleyi (Microcondylea) Cless. .- 448
Saulcyi (Pseudodon) Con. ...... 448
Sauleyi (Unio) Bet uesne ce smeeee 448
Savannahensis (Margaron) Lea .. 654
Savannahensis (Unio) Tea ...... 654
Savoyensis ((Wiio)) Bat: Jos. .ss. IIIs
Saxeus “(Miargaron))= Ivea. ss. see IOI
Saxeus 3@Unio) Cons eee eee IOL
Sayanus. CWnro)! wBs7 be Winn eee 709
Sayles CUnio) se VWiands sacs 709
Scabies =Haas ateee seen ee 993)
Scaldiana (Anodonta) Dup. ...... 364
Sealeniania’ Ratt. . cents vestctecsisee 14
Sealeniits CUini0) = Sayauee csi cee cee 759
Scamnata (Nephronaias) Morel. .. 272
Scamnatus (Margaron) Lea ...... 272
Scamnatus (Nephronaias) Simp. .. 272
Scamnatus ((Unio)" Marts’. ee... 275
Scamnatus (Unio) Morel. ........ 272
Scaphidium (Anodonta) Pet. .... 404
Scaphydium (Anodon) Hde. ..... 404
Schefferiana (Strophitus) Con. .. 348
Schistodesmius Simp: occ ce + ome 939
Schizocleithrum Haas’ \ ac. eeoe 718
CHEM MaMiay wELAAS irate teleleteveriatete 1149
Schlaflii (Anodonta) Simp. ...... 373
Schleflii (Anodonta) Mouss. .... 373
Schlegeli (Barbala) Pet. ........ 217
Schlegeli (Hyriopsis) Marts. .... 217
Schlegeli (Unio) Marts. =). .:.<.. 217
Scheefferianus (Anodon) Sow. .... 348
Schombergiana (Castalia) Sow. 1202
Schombergianus (Tetraplodon)

SOMA MOO Or ome cs cotcobcdanioc 1202

Schomburgianum (Ptychorhynchus)

Hde.
Schomburgianus (Anodon) Sow. .1418
Schomburgianus (Glabaris) Simp. 1418

Schomburgianus (Ptychorhynchus)
Simpan). c -bee e ee eeeet 1148
Schomburgianus (Unio) Hde. 1148

Schomburgki (Anodonta) Marts. 245

INDEX

Schomburgki (Pilsbryoconcha)
I ATESS BAG se ele cite a cima hastelereieye 244
Schomburgkiana (Anodonta) Cless.

Schoolcraftensis (Margarita) Lea 850
Schoolcraftensis (Margaron) Lea 850
Schooleraftensis (Unio) Lea .... 850
Schoolcraftii (Margaron) Lea .. 851
Schoolcraftii (Unio) B. H. Wr. .. 851
Schrencki (Unio) West. ........ 961
Schroteriana (Anodon) Sow. ....1452
Schrdteriana (Anodonta) Lea ....1452
Schréterianus (Anodontites) Lea 1452
Schroteriana (Margaritana) Pet. 1452
Schroteriana (Margaron) Lea ....1452
Schroterianus (Glabaris) Simp. ..1452
Schweinfurthi (Unio) Marts. ....1193
Schwerzenbachi (Unio) Bet. .... 563

Scigiias “NMarearon)) lea... 0.-- 120
SCieus MCInIO)) WEAN... cc. 6c ice's's 120
Scobina (Nodularia) Han. ...... 996
Scobina» CUnio)> Han. <i. < sie. 996
Scobinata (Nodularia) Lea ...... 992
Scobinatus (Margaron) Lea .... 993
Scobinatus GUnio)| Tea si5..6.0.% 993
Scripta. (Ouadrula)) Hide. =... .... 936

‘Scripto-polystictus (Unio) Hde. .. 924
Scripto-polystrictus (Unio) Pet. 924

Scriptum (Alasmodon) Raf. ...... 510
Scriptus (Anodon) Sow. ........ 1431
Seriptus, (@nio) Hide “ja... eee 936

Sculptilis (Alasmodonta) Say .... 495
Sculptilis (Strophitus) Stimp. .... 495
Sculptus' (Unio) Desh. .......... 960
Scutulata (Lampsilis) Morel. .... ror
Scutulatus (Lampsilis) Simp. .... 192

Scutulatus (Unio) Morel. ....... 192
Scutum humilior (Lamellidens)
MV aac Gs wo Fateushec a atahstie elo Acailsis:s ai alee 1174

Scutum humilior (Unio) Marts ..1174
Scutum (Lamellidens) Sow. ....1173

Scutum (Unio) Sow: <2. ssc. 0 1174
Scy phir wm1o)) Must. o.. cscs 807
Sepastane Clinio) Th. s..scs foe < 1312
Secundus (Pseudodon) Hde. ....1100
Secundus: (Unio): (Pet. 2.05. ieee II00
Securiformis (Anodon) Hde. .... 403
Securiformis (Anodonta) Pet. .... 403
Securiformis (Unio) Con. ...... 864
Secuiris (Margarita) Tea ........ 305
Securis (Margaron) Lea ........ 305
Securis) Gelasiola) Tea 2........- 304
Siem (Uh fis) VE eae omio 305
Sedakowi (Anodonta) Siec. ..... 438

Semialatus (Physunio) D. & J. ..1066
‘Semialatus (Unio) D. & J. ....1066

Semicorrugata (Spatha) Prest.
Semidecorata (Nodularia) Morl. ..
Semidecoratus (Unio) Morl.
Semigranosa (Quadrula) Pils.
Semigranosus (Diplodon) Simp.
Semigranosus distinctus (Unio)
Marts.

595

Semigranosus (Margaron) Lea 176 593

Semigranosus testudineus (Unio)
Marts.

Harel aie haters COI recy CT 595
Semigranosus (Unio) Rve. ...... 595
Semigranosus (Unio) Busch - 592
Semiplicatus (Unio) Kust.- ...... 252
Semiplicatus (Unio) Trosch. 7 252
Semiquadrata (Unio) Sow. ...... 1068
Semiquadratus (Unio) Pet. 1068
Semirasa (Lampsilis) Pils. ...... 199
Semirugatus (Unio) Chenu ...... 1107
Semirugatus (Unio) Lam. ...... 557
Semisulcata (Iheringella) H. Ads. 1394
Semisulecata (Monocondylea) H.
AS Rae yates tk tte Wa eee 1394
Semmelinki (Contradens) Haas 1007
Semmelinki laticeps (Contradens)
Eads. certence iweb ee atures 1008
Semmelinki (Nodularia) Marts. 1006
Semmelinki (Unio) Marts. ...... 1007
Sempervivens (Anodonta) Desh. 242
Senegalensis (Anodon) Sow. 1342
Senegalensis (Anodonta) Lea ....1342
Senegalensis (Margaron) Lea ....1342
Senegalensis (Spatha) Ger. ...... 1342
Senegalica (Mutelina) Jouss. 1342
Sennaariensis (Unio) Kust. ...... 1021
Sennariensis (Unio) Marts. ..... 986
Serpentina (Anodonta) Cless. 1405
Serradelli (Dalliella) Simp. ...... 1076
Serradelli (Simpsonella) Drouet 1075
Serradelli (Unio) Drouet ........ 1076
Servainiana (Grandidieria) Bgt. 1053
Shefferiana (Anodonta) Lea . 348
Sheefferiana (Margaron) Lea . 348
Shafferiana (Anodonta) B. H. Wr. 348
Shanghaiensis (Unio) Lea ...... 961
Shefferiana (Anodonta) Cless. .. 348
Shepardianus (Margarita) Lea .. 699
Shepardianus (Margaron) Lea ... 699
Shepardianus (Unio) Lea ...... 698
Sheppardianus (Unio) C. & R. 609
Shireensis (Unio) Prest. ........ 727
ShistodesSmus Simp: ..6002 0cccc 939
Sheefferianus (Anodon) Sow. 348
Showalterii (Anodon) Sow. ...... 472
Showalterii (Anodonta) Lea 472
Showalterii (Margaron) Lea ..472, 774
Showalterii (Pleurobema) Lea 774

1528

Showalterii (Unio) Lea ......... 774
Shurtlefiana (Nodularia) Lea .... 983

Shurtleffianus (Margaron) Lea ... 984
Shurtlefhanus (Unio) Lea ....... 984
Shuttleworthi (Unio) Kust. ...... 1298
Shuttleworthii (Diplodon) Lea 1306
Shuttleworthii (Margaron) Lea 1306
Shuttleworthii (Unio) Lea ...... 1306
Siamensis (Margaron) Lea 1183
Siamensis = (W110) ely eae ane eheelepsl elale 1183
Siamensis (Unio) Morl. ......... 1015
Siculi @Potamrda) iow.) eee seeds oi 533
Sieuluss=@Umio) i blianensse sie eieteion 533
Siculus @Uinio) aS owspereiel-leire tert 541
Signata Geyamipsilis)) Pils secrete 198
Sikkimensis (Margaron) Lea 1121
Sikkimensis (Parreysia) Lea ..... 1120
Sikkimensis (Unio) Lea .2..2ss.- I121
Siliguriensis (Unio) Prest. ...... 1018
Siliqua (Anodonta) Kust. ....... 242
Siliquoidea (Lampsilis) Stimp. .. 61
Siliquoidea (Mya) Eaton ........ 61
Siliquoides (Unio) Kust. ......... 61
Siliquoideus (Unio) Bar. ........ 61
Siliquosa (Anodonta) Kust. 1459
Siliquosa (Mycetopoda) Simp. 1461
Siliquosa (Mycetopda) Spix ..... 1458
Siliquosa (CPlatinis)— Weal io .rre4 clr 1459
Siliquosa staudingeri (Myceto-

pesY) Ul oooghosgnsuqnboDoA0eaG 1460
Siliquosus (Anodon) Spix ....... 1459
Siliquosus (Mycetopoda) d’Orb. 1461
Siliquosus (Mycetopus) H. & A.

TN GK ES G0 0.8 CRE o OOO. O0 DDD OO 1459
Siliquosus (Mycetopus) d’Orb. ...1461
Siliquosus (Platiris) Tea ......... 1459
Siliquosus var. b. pygmenum (Ano-

Glo) ASHP HoogooadacdocumcRoCG 1462
Silongweensis (Unio) Prest. ..... 726
Sima @Wampsilis) ile caareyl-: crteteteret- 123
Simplex (Margaron) Lea ........ 339
Simplex (Unio) meas aarejeve areketeretave 339
Similaris (Quadrula) Simp. ...... 924
Similis @(Miargaron)) Wea <i... <1 640
Similis (Mycetopus) Hde. ....... 461
Sicapihis) (dOfavo)) IER Sooscuchonodc 640
Sihankonbicy (lUhgitop) AMain Koromaoo bon 558
Simplicidus (Anodon) Sow. ...... 365
Simpsonelliay Cock gs -terectenstacraneray= 1069
“Simpsonia IRochy /ie.ictete ons) se orotic 221
Simpsonianus (Medionidus) Walk. 249
Simpsoni (Lampsilis) Ferr. ...... 187
Simpsoni (Mutela) Anc. ......... 1357
Simpsoni Unio) BY wei Wiser or 630
Simpsoniana (Anodonta) Lea .... 435

Simpsoniana (Margaron) Lea .... 435

INDEX

Simpsonianus (Anodon) Sow. .... 435
Simpsonianus (Anodontites) Pils. 1432

Simpsonianus (Glabaris) Pils. ~....1433
Sinipularis (Parreysia) Simp. ....1123
Simpularis (Unio) (oid enema 1123
Simulans (Pleurobema) Lea ..... 786
Simulans: (Unio) Weawer ema 786
Simus, @Yampsilis)) (Simp: sir mraeren 124
Simus (@Viarearita)) Weay eyecaeecuenten 124
Simus, (Miargaron)) Wea “2.2... 124
Shrechbey (Uhr) IW So oonaccest soo 124
Sinensis levis (Unio) Hde. ..... I14I

Sinensis squammosus (Unio) Hde. 1140
Singleyana (Iampsilis) Marsh.... 147
Singlevanus (Lampsilis) Simp. ... 147

Singleyanus (Unio) Marsh ...... 147
Singularis (Grandidieria) Bgt. ....1058
Singularis (Unio) B. H. Wr. .... 683
Sintoxia (Obliquaria) Raf. ...... 731
Sinuata (Margaritana) Ort. ...... 519
Sinuata (Obliquaria) Raf. ....... 731
Sintiatas(spatha)) sVlartsie int step 1333
Sinuata. (Unio)! (Csi Bins se. - see 516:
Simuata, Umi) is Wari were ayenetetaterat-te 518
Simuatiuse (Wmi0) se ROSSe mateo ieteneie le 519:
Sinuosa. (Anodon)) Gs & Re fase 1433
Sinuosa (Anodonta) Cless. ....... 1405
Sinuosa. (Anodonta) Lam. ....... 1433
Sinuosa (Margarita) Lea ....:...1433
Sinuosa’ @Marcaron) i Weauiae.'- tele 1433
Sinuosis (Anodon) Sow. ......... 1434
Sinuosus (Anodon) Sow. ........ 1433
Sinuosus (Glabaris) Simp. ....... 1434
Sirionis (Anodon) C. & R. ...... 1408
Sirionis (Anodonta) d’Orb. ...... 1407
Sirionis (Anodontites) d’Orb. 1407
Sirionis (Glabaris) Simp. ....-.... 1408
Sirionis iheringi (Anodontites)

GleSss 25 Ses Mea ne 1408
Sirtonis (Margarita): Beaten... 1407
Sirionis (Margaron) Wea <<... 2... 1408
Sitifensis (Unio) Morel. ....563, 1193
Sloatianus (Margaron) Lea ...... 605
Sloatianus (Plectomerus) Con. ... 605
Sloatianis (Unio) elyeGa ieee errata 604

Smaragdina (Craspedodonta) Ant. 228

Smaragdites (Parreysia) Prest. ...1110
Smaragdites (Unic) Ben. ........ I110
Smithi (Grandidieria) Bgt. ...... 1055
Smithi (Margarita), Wea> s...~.-: 1257
Smithii (Margaron) Lea ......... 1257
Skeabidannt (Usa) (Ga uke TEES aooaoo 1257
Soboles (Nodularia) Fisch. ...... 10I5
Sol Hvis (GUkavio)) Jes Beoeacoon oc Tots
Sobolus (Contradens) Haas ..... 1015
Sobolus (Nodularia) Simp. ...... 1015

INDEX

Soledadensis (Nephronaias) C. &

TB in pene hetein ce eherete ote nclere a ola ana anenels 271
Soledadensis (Unio) C. & F. .... 271
Sole letn G@Un70)) Pee tae se kersietereeret aie 1193
SolenatamConweeeaseiinte sede ae ore 455
Solenidea (Anodon) Sow. ........ 1450
Solenidea (Margaron) Lea ...... 1450

Soleniformis (Anodonta) Ben. ... 459
Soleniformis (Anodonta) d’Orb.
Soleniformis (Anodontites) d’Orb. 1450
Soleniformis (Glabaris) Ih.
Soleniformis (Margarita) Lea ....
Soleniformis (Margaritana) Pet... 522
Soleniformis (Margaron) [ea ....
Soleniformis (Mutela) Bet.
Soleniformis (Mycetopoda) d’Orb. 1467

Soleniformis (Mycetopus) Fisch. .459
Soleniformis (Mycetopus) Rve. ...1467
Soleniformis (Platiris) Lea ...... 1467
Soleniformis (Solenaia) Ben. .... 459

Soleniformis (Spatha) H. & T. .. 459
Soleniformis (Unio) Lea ......... 522
Solenoides cylindrica (Unio) Raf. 834

Solenoides (Loncosilla) Raf. ..... 1193
Solenoides (Myctopus) Sow. ..... 1467
SolidacAnodonta)” Kust) <i «ree 1315
Solida (Iridina) Anton ......... 1315
Salida: OMiy.sca)r “besten vars eretayelotel siete 539
Solida’ (Quadrula) Wea ssi-1. 1 - <r 885
Solidula (Anodon) Sow. ......... 1444
Solidula (Anodonta) D. & H. ....1444
Solidula (Margaron) Lea ........ 1444
Solidulus (Diplodon) Phil. ...... 1258
Solkhsiltc (Usa) Tle connooacuss 1258
Solidus’ (Margarita) ea <2... 2. 886
Solidus (Margaron) Lea ........ 886
Solidus (Pseudodon) Haas ...... IIO1
Syolivahiey (Upeivo)) Ibe (Aan cacida diogore 885
Solisianay @Wmio) vd2@xrbe cic clos 1287
Solisianus (Diplodon) d’Orb. ..... 1287

Somboriensis (Harmandia) Roch. 1049

Somersi (Anodonta) Call ........ 438
Sondermannii (Anodonta) Kust. . 365
Sordida (Nodularia) Roch. ...... 1045
Sordiday (Zaria) me Roch omeicts sie crete == 1045
Sordidus (Margaron) Lea ....... 681
Sordidss, GUnio)m@ bear wanestenssrcte 680
Sorint, CAnodon)) “Hides os «sms osm e 405
Sorini (Anodonta) Pet. ......... 405

Sowerbyanus (Margarita) Lea ... 17
Sowerbyanus (Margaron) Lea.... 17

Sowerbyanus (Unio) Lea ....... 17
Spadiceus (Margaron) Lea ...... 68\2
Spadiceus, (Wmio)) Wea os... ....n 681
Sparsa (Quadrula) Simp. ........ 837
Sparsus (Margaron) Lea ........ 837

1529
Sparsus’ (Unio) eikKtust. 0. 4s fel daee 865
Sass (Uma )e eases). ones 837
Sparus) (Miargaron) Wea ..a.ces- 120
Sparus: «(Unio))* leat. ssc gen. eels 120
SDaAtha WVeamea sy tae eee, eee 1313
Spatha sorithy soe eaten oe co eee 20s
Spathella abet eee ee eee oe 1313
Spathopsis Simpe eee ereee eee oe: 1179
Spathuliformis (Leptospatha) R. &

Crea RR OCI CORR Te i IR ae s 1328
Spathuliformis (Spatha) Ger. ....1328
Spathuliformis (Spathella) Bgt. ..1328
Spatiosa (Anodonta) Cless. ...... 229
Spatiosa (Barbala) Pet. ......... 229
Spatiosa (Cristaria) Cless. ....... 228
Spatulatus (Lampsilis) Bak. ..... 128
Spatulatus (Margaron) Lea ...... 128
Spatulatus! G@Unio))- Weare. 4... cee 128
Spatulatus-(Unio) Sow. .......... 124
Specialis, (Unio)/Kobs. 5 scene. «nie 732
Speciosa (Quadrula) Lea ........ 845
Speciosus (Margaron) Lea ....... 846
Speciosus: (Unio)s ean erie cease: 846
Speker Geliodon)) Gers 2. ..-. 25 eee 1379
Spekii (Cameronia) Bet. ........ 1378
Spel (inidinadim Wood.. ave doce 1378
Spekii (Mutela) Marts. .......... 1379
Spekity @blatiris)) [jeaviiyastsac ae 1378
Spekii (Pleiodon) Wood. ........ 1378
Spherica (Quadrula) Lea ....... 854
Sphericus (Margaron) Lea ...... 854
Sphericus) CUnio))-Leal -Js-s cine 854
Spheniopsis (Quadrula) Morel. ... 9o1
Spheniopsis (Unio) Morel. ...... oI
Sphenorhynchus (Unio) F. & C. 623

Spillmanii (Margaritana) Lea .... 353

Spillmanii (Margaron) Lea ...54, 353
Spillmanii (Strophitus) Lea ...... 352
Spillmanii GUnio)! Lea ..5.......- 54
Spillmanir (@Winio)) Sow. sae ee 353
Spinellimn@Unio)= Wallai ee cee ie eters 572
Spinosa (Canthyria) Sw. .....:... 703
Spinosa . (Unio)» Good. ...23s.0he. 703
Spinosus (Elliptio) (Oxtes. scam. 703
Spinosus (Margarita) Lea ....... 703
Spinosus (Margaron) Lea ....... 703

Spinosus (Schistodesmus) Simp. .. 941

Spinosus (Shistodesmus) Simp. .. 941
Spinosus? CWnio) Weaken dete 702
Spissus (Magaron) Lea ..:...:... 688
Spissuse (Unio) |e dyeawrsts staeitece aera 687
Spixii (Anodontites) d’Orb. ..... I4II
Spixie(Columba) Thyra socos series 1402
SpiKdteMGlaparts)! sOlMps Aeje/aeteletelen: I4II
Sjopeit (LE GIED IU, con oGsacousonoc 1402
Sprxiie Wmro) © d2Orbie oe os cts sercles< I41t

1530
Spixoconchayebalssemereyesiersiete eters eliels 1384
Splendens (Anodonta) de C. ..... 1315
Splendens (Pleiodon) Con. ...... 1377
Splendida (Iridina) Chenu ...... 1377
- Splendida (Lampsilis) Wea <2 .7.5: 50
Splendidus (Lampsilis Simp. ..... 51
Splendidus (Margarita) Lea ..... 51
Splendidus (Margaron) Lea ...... 51
Splendidus: (Unio) Wea 2.2.5.0... 51
Spuria (Miya) (Gimeleysen cls cise = 1106
Spuria (Miya)= Woods -m- = =o 1109
Sourius’ (Unio) Elidenwerr wie tole 919
Squalidus (Margaron) Lea ...659, 711
Squalidus (Unio) Lea ....... 659, 7II
Squameus (Margaron) Léa ...... 655
Squameus (Unto) eieea ws a... usncteee . 655
Stabile (Pleurobema) Lea ....... 769
Stabilis @Margaron) Wea s. 252 769
Stabilis (Pleurobema) Simp. ..... 769
Stabilis (CWinio) Weaorina ste seca 769
Stagnalis (Anodonta) Bose ...... 362
Stagnalis (Margaron) Lea ....... 137
Stagnalis (Mytilus) Turt. ........ 362
Stagnalis (Unio) Cons) 32.222... 137
Stagnorum (Diplodon) Dautz. 1309
Stagnorum (Unio) Dautz. .-...:. 1309
Stapes) (Margarita) Weal... ae 839
Stapes’ (Margaron) Tea) 22sec «cr 839
Stapes: (Ouadrula) Wea. i. ts oie &38
Stapes) CWini10) plea tarirereisietereleusierors 838
Staudingeri e«quatorialis (Myceto-

HOda)|, has memeptrhore we errors 1460

Staudingeri (Mycetopoda) Simp. .1460

Staudingeri (Mycetopus) Ih. ....1460
Stearnsii (Unio) B. H. Wr. ...... 146
Stegaria (Obovaria) Raf. ........ 302
Stegarius irroratus (Unio) Pet. .. 328
Stegarius (CUnio)) Kast -e.-.2 ea. - 830
Stegarius (Unio) Say, 22... eee 328
Stevenianus (Unio) Drouet ..... 1469
Stevensi (Hiyria) deal ssa. ccc 1216
Stevens (CUinto)miyear criiemiee setae 1216
Stewardsoni (Margaron) Lea .... 22
Stewardsoni (Truncilla) Lea ..... 21
Stewardsoni (Unio) Lea ......... 22
Stewartiana (Anodon) C. & R. .. 430
Stewartiana (Anodonta) Lea ..... 429

Stewartiana (Margarita) Lea .... 429
Stewartiana (Margaron) Lea .... 430

Stewartianus (Anodon) Sow. .... 430
Stolatus Unio)» Marts. “22.55... 720
Stolli (Quadrula) Marts. ........: 828
Stolli, CUnio)i Marts eo. cscs elo 829
Stonensis (Margaron) Lea ....... 601
Stonensis) (Unio) wea eens). se 600
Straminea (Lampsilis) Con. ..... 72

INDEX

Stramineus (Lampsilis) Simp. .... 73
Stramineus (Margarita) Lea ..... 73
Stramineus Margaron) Lea ...... 73
Stramineus| CWUnio) ‘Cons s.cs....er A}
Strebeli’ Clampsilis)i (Pils. > c2 256
Strebeli (Margaron) Lea ....256, 1419
Strebelin (Unio) ea" seisee a = seri 256
Strebelii (Anodonta) Lea .:...... 1419
Strebelii (Anodontites) Tea ..... 1418
Strebelii (Glabaris) Simp. ....... 1419
Striata (Anodon) Hde. .......... 403
Striata (Anodonta) Pet! ..2.-: «- 403
Striata (@iridina) s@ken! 22... 1352
Striata=(@Obovanta) eiRiai sees eke 302
Striata (Pleurobema) Simp. ...... 7:96
Striatissimus (Unio) Anth. ...... 804
Striatulum (Pleurobema) Lea .... 788
Striatulus (Margaron) Lea ....... 789
Striatulus: (¢Unio)) siyeay aaees cece 789
Striatum (Pleurobema) Lea ..... 795
Stratus: (Margaron)) Wear =. cases 796
Stratusy (Unio) telyeal eee cm seen 795
Striatas; | GUN) ORWes sc eres oreereirare 853
Stratus (Unro) a Sows sicse ore 104, 503
Strigosus (Margaron) Lea ....... 682
Stmigosus Unio) Weapeeemeetoeee 682
Strodeana (Pleurobema) Simp. ... 788
Strodeanum (Pleurobema) B. H.

Withe cod citer SeeetG eietna Pesos 787
Strodeanus (Unio) B. H. Wr...... 788
Strophitus) Rak: scissile le .clttersicns sors 344
Strumosuse GUmto)nmyeay cc. 672
Stuarti (Anodon) Sows .. 0665-00 1303
Stuart (Anodonta)! Reet... rier 1303
Stuart) (Miarearitana) seat. sates 1303
Stuart? @Margaron): Weae..eascees 1303
Stuarti (@Un10) CSOws ase iainra sete oe 1303
Stuhlmanni comoeensis (Spatha)

Ger weihias « ahiehtes aeeeoreneee 1338
Stuhlmanni (Parreysia) Marts. 1126
StuhImanni (Spatha) Marts. ..... 1338
Stuhlmanni (Wnio) Marts. 2.22)... 1126
Styganodonm Marts: 5. c.0s0 +6000 1448
Suavidicus (Diplodon) Lea ...... 1240
Suavidicus (Margaron) Lea ..... 1240
Sitavidicus (Unto) plveal nace ese 1240

Subequilatera (Spatha) Marts. ...1333
Subamygdalinus (Unio) Drouet ..1193
Subangulata (Anodon) Anth. .... 422
Subangulata (Anodonta) B. H. Wr. 422
Subangulata (ampsilis) Tea ..... 125
Subangulatus (Lampsilis) Simp. .. 126
Subangulatus (Margaron) Tea ... 126
Subangulatus (Unio) Lea ....... 126
Subangulatus (Unio) Sow. ....... 138
Subcarinata (Anodonta) Curr. ... 389

TNDEX

Subcircularis (Anodonta) Cless. .. 372
Subclathratus (‘Trapezoideus)

Elia a Sh vee o ievencrevere stele or araxete ley are cele 1184
Subcrassa (Anodon) Sow. ....... 1074
Subcrassa (Anodonta) Lea ....... 1074
Subcrassa (Dalliella) Simp. ...... 1074
Subcrassa (Margaron) Lea ...... 1074
Subcrassa (Simpsonella) Lea ....1074
Subcroceus (Unio) Con: ..-......6 706
Subcylindracea (Anodon) DeKay. 469

Subcylindracea (Anodon) Sow 390, 468
Subcylindricaa (Anodonta) Cless. 469
Subcylindracea (Anodonta) Lea .. 469
Subcylindracea (Margarita) Lea .. 469
Subcylindracea (Margaron) Lea .. 469
Subcylindraceus (Anodontoides)

124) as Reto inca cere che Dec prove. lo CLA 470
Subcylindraceus (Unio) Lea ..... 679
Subdiaphana (Mutela) Bet. ...... 1360
Subellipsis (Margaron) Lea ...... 137
Subellipsis (Unio) Lea .......... 137
Subflavus (Margaron) Lea ....... 654
Subflayus @Unio) Wea’ ..2..2:.2.. 654
Subgibbosa (Anodon) Anth. ..... 425
Subgibbosa (Anodonta) Anth. .... 425
Subgibbosus (Anodon) Sow. ..... 425
Subgibbosus (Margaron) Lea .... 590
Subgibbosus (Unio) Tea ........ 599
Subglobata (Pleurobema) Simp. .. 753
Subglobatus (Unio) Lea ........ 753
Subglobosa (Margaron) Lea ..... 425
Subglobosus (Unio) Lea ......... 288
Subinfiata (Anodon) Anth. ...... 423

Subinflata (Anodonta) B. H. Wr. 423

Subinflatus (Margaron) Lea ..... 694
Subinflatus: @Unio) “Con: ......... 693
Sublatus (Margaron) Lea ...,.... 662
Sublatus; GUnio)® ea aaecises sen ere 662
Subluridus (Unio) Simp. ........ 630
Subluxata (Anodonta) Kust. ..... 365
Subnigra (Nodularia) Prest. .....1042
Subnisray(@Winio)) Prest: ... cee sis. 1043
Subniger (Margaron) Lea ....... 674
Subniger (Unto) sljeay he... cece 673
Subolivaceus (Unio) Lea ........ 657
Suborbiculata (Anodon) C. & R. 400

Suborbiculata (Anodonta) Say ... 400
Suborbiculata (Margarita) Lea .. 400
Suborbiculata (Margaron) Lea ... 400

Suborbiculata (Unio) Lam. ...... 288
Suborbiculatus (Anodon) Sow. ... 400
Suborbicuatus (Unio) Fer. ....... 288
Siilyonorcmils Skah) qoageeerogoooc 1081
Subovatus (Margarita) Lea ...... 40
Subovatus (Margaron) Lea ...... 40

Subowatus @Wmio)ie weal ce isc 10 40

DAs
Subparallelus) (Unio) Lea ....-..<. 656
Subplanum (Pleurobema) Con. ... 804
Subplanum (Unio) Sow. ......... 805
Subplanus (Margaron) Lea ...... 804
Subplanus <(Uinio)i Gorm sees «clecies 804
Subponderosa (Anodonta) Dup. .. 364
Subreniformis (Anodon) Sow. ....1340
Subreniforims (Anodonta) Pet. ..1340
Subreniformis (Spatha) Sow. 1340
Subreniformis (Unio) Bgt. ....... 555
Subrostrata (Anodonta) Phil. ....1441
Subrostrata (Eurynia) Ort. ...... 99
Subrostrata furva (Lampsilis)

SSIRILD caste eiehe a choeivetcaine oasis Seeiere 100
Subrostrata (Lampsilis) Say ...... 990
Subrostratus (Lampsilis) Simp. .. 90
Subrostratus (Unio) Kust. ....116, 120
subrostratus @Unio) Say) 5-.....- 99
Subrotunda (Fusconaja) Ort. .... 893
Subrotunda (Obliquaria) Raf. .... 731
Subrotunda (Quadrula) Lea ...... 8g2

Subrotundus circulus (Unio) Pet. 292
Subrotundus (Margarita) Lea ... 893
Subrotundus (Margaron) Lea .... 893

Subrotundus (Unio) Fer. ........ 292
Subrotundus (Unio) Lea......... 893
Subrotundus (Unio) Sow. ....... 755
Subsinuata (Anodonta) Phil. 1416
Subsinuata (Mycetopoda) Sow. 1461
Subsinuatus (Anodon) Sow. ..... 1431
Subsinuatus (Anodon) Sow. ..... 1431
Subsinuatus (Mycetopus) Sow. ...1461
Subsquamosus (Unio) Lea ....... 665
Substriata (Nodularia) Tea ...... 980
Substriatus (Margaron) Lea ..... 980
Substratus~ @Unio)- Weary. sede 980
Subtenta GUnio)y Deshy es. \).saees 340
Subtentum (Ptychobranchus) Say. 330
Subtentus (Margarita) Lea ...... 340
Subtentus (Margaron) Lea ...... 340

Subtentus (Medionidus) Simp. ... 340

Subtentus (Ptychobranchus) Ort. 340
Subtentus: (GWUnio)i (Say, is. 0. de 340
Subtetragona (Anodon) Hde. .... 403
Subtetragona (Unio) Mich, ...... 554
Subtetragonus (Unio) Dup. ...... 555
Subtignidis. CWn1o)) Woes eiiemsiclce 548
Subtrapezius (Unio) Phil. ..:.... 1412
Subtrianguaris (Burtonia) Bet. ... 206
Subtriangularis (Pseudospatha)

EGG Pte avias) cle sala oveievs’ a) ate ayetoeserere eae 206
Subtortus (Unio) B. & Ads. ..... 916
Sibtriatus CUmio)il,ea, .cieasclercles 980
Subtrigonus (Margaron) Lea ..... 215
Subtrigonus (Unio) Sow. ........ 215
Subvexa (Anodon) C. & R. ...... 356

1532

Subvexa (Anodonta) Con. ...... 356
Subvexa (Lampsilis) Simp. ...... 356
Subvexa (Margarita) Lea ....... 356
Subvexa (Margaron) Lea ........ 356
Subvexus (Strophitus) Con. ...... 355
Subviridis (Margaron) Lea ...... 1218
Subviridis (Triquetra) Klein ..... 1218
Succinea (Anodon) Hde. ........ 404
Succinea (Anodonta) Pet. ....... 404
Succineus (Mycetopus) Hde. .... 460
Succissa (Quadrula) Lea ........ 867
Succissus (Margaron) Lea........ 867
Succissus (CUmrol Weal mica - ctor else 867
Sudam @lampstlis)) melo e cer renel-yrtenee ioe 141
Sudus Cvampsilis)) Simp: 2.20... 14!
Suduss @Miar carom) mya alee eleielelele 141
Syrahee, (QUiario)) IUGR scoosdqpovogss 141
Suilla (Anodonta) Marts. ....... 241
Suilla (Pilsbryoconcha) Marts. ... 240
Srellay (Ukr) MaeOo), aac oas doo.coc 521
Sulcata (Anodonta) Kust......... 423
Sulcata (Anodonta) Ijam. ....... 362
Sulcatas (Castalia) Kirssaerr <tr ielle- 1209
Sulcata (Castaliella) Krss. ....... 1209
Suleata delicata (Truncilla) Simp. 16
Suicata Clruncillay Wea sae ee ects 14
Sulcatay (Unio) Desh ease seer 15
Sulcatantamatemenne ital icreletts 511
Suleatum (Pseudodon) Roch. 1103
Sulcatus (Margarita) Lea ....... 15
Sulcatus (Margaron) Lea ........ 15
Sulcatus: (Unto) Weare leteltele 15
Silene (Ui) Ilan, sogoéooddc 653
Sulcosa (Anodonta) H. & A. Ads. 438
Sumatrensis (Unio) Tea -....-.-. 1009
Sumatrensis (Rectidens) Dun. 1158
Sumatrensis (Unio) Dun. ........ 1158
Sumatrensis (Unio) Sow. ........ 1186
Superbus (Margaron) Lea ....... 1064
Superbus (Physunio) Lea ....... 1064
Superbus (CUinio)) sSowe secrete. 1063
Superbus) (Unio) heater pee ceieirere 1064

Superiorensis (Lampsilis) Marsh.. 62

Superiorensis (Unio) Marsh ..... 63
Superstes (Unio) Neum. ........ 722
Suppositus (Diplodon) Simp. 1245
Susanne (Anodon) Gray ........ 1429
Susanne (Anodonta) Pet. ....... 142
Sutrangensis (Hyriopsis) Morl. ... 213
Sutrangensis (Unio) Morl. ....... 213
Syrirnerast (Uhabnoy) 135 lel Whites So acaco 648
Swainsoni (Margaron) Lea ...... 495
Swaimsondis (GWmio0)) PSOWs) eistlcteleles 405
Swananoensis (Unio) Han. ...... 508
“Swinhoei (Anodon) Sow. ........ 234

Swinhoei (Anodonta) H, Ads. .... 234

INDEX

Swinhoei (Cristaria) H. Ads. .... 233

Swinhoei (Cristaria) Simp. ...... 728
Swinhoei (Margaron) Lea ....... 728
Swinhoei (Pletholophus) Prest. .. 234
Swinhoei (Umno)! EE Adsia s/c. 728
Swinhoei (Unio)! Sows ci. acct slertets 728

Swordiana (Pleurobema) Simp. .. 757
Swordianum (Pleurobema) S. H.

Wirt! - hanasaraiavace: chanted o¥ar tetas, ore eke orotate 757
Swordianus (Unio) S. H. Wr. ... 757
Symmetricus (Margaron) Lea .... 706

Symmetricus (Unio) Lea ........ 705
Symphymota sljeaieerciel sei clene 223, 480
Syriacus (Margaron) Lea .....:. 565
Swankveey (Ua) Wes) 65 docacdgosen 565
Syrmatophora (Hyria) Sow. 1218, 1219
Syrmatophora (Mya) Meusch. 1218
Syrmatophora (Unio) Desh. ..... 1219
Syrmatophorus (Margarita) Lea ..1219

Syrmatophorus(Prisodon) Meusch. 1218
Szechenyii (Unio) Neum. ........ Wait
Tabascensis (Anodonta) Morel. .. 433
Tabascoensis (Anodonta) Simp. .. 433
Tabascoensis (Margaron) Lea .... 282
Tabascoensis (Nephronaias) Charp. 281

Tabascoensis (Unio) Charp. ..... 282
‘TabulasiCAnodon)) owe ecmecrciecr 1327
Tabula, (Anodonta) Bzetameieciec ee 13:27
Teniata ideampsilas)) Cone erreeacte 83
Tzeniatus (Lampsilis) Simp. ..... 83
‘Tzaeniatus. (Wargarita)) Wea 5.%....- 83
digeabenaecy ((Ukate)) (Cori “somacoetcce 83
‘Tahetianus (Unio)! (G2 8&2 Ro). 731

Taitiana (Pleurobema) Simp. .... 764
Taitianum (Pleurobema) Lea .... 764

Naitianus, (Marcanita) Wear fee). 764
Taitianus (Margaron) Tea ....... 764
Maitlantsa CW none lean erudelelercteteiete 764
Aeieenaty (UUiaris)) Sone, coscoacoes 300

Tampecoensis (Lampsilis) Simp. .. 173
Tampicoensis (I,ampsilis) Lea ... 172
Tampicoensis (Margarita) Lea ... 173
Tampicoensis (Margaron) Tea ... 173

Tampicoensis umbrosus (Unio)

INES rhshal nig che ora-op oroad.o.¢ 3 Olena acd 171
Tampicoensis' (Unio) Lea ....... 73
Tamsana (Monocondylea) Dun. 1392
Tanganikana (Grandidieria) Bgt. .1054

Tanganicensis (Burtonia) Pet. .. 203
Tanganyicensis (Grandidieria) Sm. 1054

Tanganyicensis (Pseudospatha)

Si.) cs dase etietereieistireos sia sie oilers 203
Tanganyicensis (Spatha) Sm. 203, 205
Tanganicensis (Unio) Sm. ....... 1054
Taniatuse @umio)) (sty csi tele 83
Tanousi (Anodonta) Bet. .......- 439

INDEX 1533
Tanousi (Colletopterum) Bgt. .... 439 Tenwis»(Anodon)) Sow. 22... 5.2. 1073
Tappanianus (Margarita) Lea .... 485 Tenuis (Anodonta)! Gea 2ac..055 1073
Tappanianus (Margaron) Tea .... 485 hens CDalliella) Simips. 3224. < =. 1073
Tappantanus @Unio)) Wea 2--..... 485 Genus. (Margaron) Lea 2s. 22... 1073
tap pianis | (Uinto)) (Gs Sa IRI... s: 485 Tenuis (Simpsonella) Lea ....... 1073
Taumilapanus (Unio) Con. ....... 718 Absyayoket Ups) (Enehy Goooecssopede 230
Taumilapasensis (Unio) F. & C. .. 718 Renuisculus, (@Uinio)y Eirsaevscrtel 633

Tauriformis (Cuneopsis) Prest. ...949

Tavoyensis (Margaron) Lea ..... III5
Tavoyensis (Parreysia) Gld. ....1114
Tavoyensis triembolus (Parreysia)

Bey | Gauddd1.0-bin OC OOOO OeD OO Cc IIIS
Mavoyensis (Unio) Gld. ......... III5
"Tawai (Anodonta) Rang ........ 1320
Mawata(opatha), Rang-s2. 1 cis. eclce 1320
hawim@Anodonta)! Simps ~ -.. scree 1320
Tchadiensis (Pleiodon) Ger. ..... 1382
Tchadiensis (Pliodon) Ger. ...... 1382

Tecomatensis (Iampsilis) Lea ... 173
Tecomatensis (Margaron) Lea ... 173
‘Tecomatensis (Unio) Lea ........ 173
Tehuantepecensis (Anodonta) F.

Sees as cderee Re sierdacloeyeste wis teeee 1426
Tehuantepecensis (Anodontites)
(CAP ise sab, Kay eG Hun eaniceNtes GIO DTS 1426

Tehuantepecensis copanensis (Unio)
MATES Ror. cree Psrayevsrapete ts) steel ersten eratere 268
Tehuantepecensis (Glabaris) Simp. 1426

Tehuantepecensis (Nephronaias)

(CR Se, PAST oes Seedy eta sieveie rere 267
Tehuantepecensis (Unio) C. & F. 267
‘Tellicoensis (Unio) Lea ......... 754
‘Tenebricosa (Anodon) Sow. ...... 1449
Tenebricosa (Anodonta) Lea ..... 1449
Tenebricosa (Glabaris) Ih. ...... 1449
Tenebricosa (Margarita) Lea 1449
Tenebricosa (Margaron) Lea 1449
Tenebricosus (Anodon) Sow. 1449

‘Yenebricosus (Anodontites) Tea..1448

Tenebricosus (Glabaris) Simp. 1449
Tenebricus (Margaron) Lea ..... 106
Tenebricus: (Winio)) Weaw a. nace once 106
Tenebrosus (Unio) Con. ......... 65
Tenella (Anodonta) Kust. ....... 364
emeltuse. (Wnt) wRataw saerelersiersicrers 731
denera CWampsilis)) Wear sia. ele 122
Tener (lampsilis) Simps J..0s5 +. 123
Mener i@Miangaron)- Tea... vss: 123
fhener s(Wmio))) Woeat clccievensromtstetersye 123
Tenerus (Margarita) Lea......... 135
Tenerus (Margaron) Tea ........ 135
Menertiss@Wnto)) Ravi so ccreciewevere 135
Tenerus (Unio) Simp. ........... IIo
Tennent CUmio)) He & I 3s. soos 1107

Tennesseensis (Margaron Lea .... 84
Tennesseensis (Unio) Lea ....... 84

Tenuissima (Symphynota) Lea ... 189
Tenuissimus (Margarita) Lea .... 189
Tenuissimus (Margaron) Lea .... 189

Renuitssimus @Unito)) “hiany sane. 189
Meress (Anodonta)! (Cony ” sseeensere 390
eres (Wntal) say: sake clo ete te gi
Teretiuscula lithophaga (Nodu-

laiia) haeallee et aeke ears ae ee 98r
Teretiuscula (Nodularia) Phil. ... 981
Teretixsculus lithophaga (Nodul-

Aris) ball eaeyey-ahs co color tee 982
Teretiuscula (Nodularia) Simp. .. 982
‘heretiusculus’ (Unio) ick, 22... -- 579
Teretiusculus (Unio) Phil. ....... 981
Terminalis (Margaron) Lea ...... 550
Merminalis «CUnio)) (Betas... .-sce 549
Tesserule (Margaron) Tea ...... 750
Tesserule (Pleurobema) Lea .... 749
shesserule, (Unto) Wear <2 cnc 750
Testacrassa (Miya) Schrot: <.55. 518
Testudinarius (Unio) Speng. ..... 1167
Testudineus (Unio) Morel. ...... 595
Testudineus (Unio) Rve. ........ 175
Metnagenezer writen dee ee eters 810
Tetragona (Anodonta) Lea ...... 347
Tetragona (Margaron) Lea ...... 347
Tetragona (Strophitus) Con. .... 347

Tetralasmus camptodon (Unio) Say 706
Tetralasmus declivis (Unio) Say.. 708
Tetralasmus manubius (Unio) Gld. 707
Tetralasmus (Margarita) Lea .... 705
Tetralasmus (Margaron) Lea .... 705

‘etralasmus sayi (Unio) Ward .. 709
Tetralasmus (Unio) Say ...*...... 705
Tetralasmus (Uniomerus) Ort. ... 705
Metraplodons Spi, -.1ermereeietencie lereke II1Q4
ihetricus: -(Margaron)) Wear jo... 646
hetricusyGUnio)alyeay nieces. aie 646
Texasensis (Anodon) Sow. ...... 427
Texasensis (Anodonta) Lea ..... 427
Texasensis compressa (lampsilis)
SLTp Se toner hehe ctie ecole 150
Texasensis compressus (lLampsilis)
SSIMIUP 3) easel se jaeuslnve farsiatis aise ok cvccertar ate 150
Mexasensis) @Bunynia) Ort: 2.4. o- 149
‘Texasensis (Lampsilis) Lea ...... 148
Texasensis (Margaron) Lea -:149, 427
Aaya. (MUinio))) Leh San deosoo 149
Mexasianus s@Wni0)) SOW. 2s... .0.0s 149

1534

Thexasiensis (@Wnio))Wweas a. s.e:setere 149
Theca (Trapezoideus) Ben. ...... 1185
‘Theeay CWinio)? Bent facwiasicelonie ioe 1185
‘Bhelidermiay tS we. -ceissisitooisle stevevsiaie 8390
Theobaldi (Nodularia) Prest. 1002
Thomsoni (Grandidieria) Sm. 1057
Thomsoni (Margaritana) Pet. 1092
Thomsoni (Pseudodon) Morl. ...1092
Thomsoni (Unio), Smithy ae cssielener 1058
Thorntonii (Margaron) Lea ...... 752
horntonit) (Unio) tlyearee otra 752
Tholloni (Mutelina) Roch. ....... 1360
Thottoni (Mutelina) Simp. ....... 1360
Thwaitsii (amellidens) Lea ..... 1170
Thwaitesii (Margaron) Lea ...... 1171
Thwaitesii (Unio) Lea ........:. 1171
Thwaitesi (@Unio)! (Ho ’ “E. k eek 1175
Tiberiadensis (Unio) Loc. ....... 548

Tientsinensis (Margaron) Lea .... 917
Tientsinensis (Quadrula) C. & D. 917
Tientsinensis (Unio) C. & D. ... 917

Tientsinensis (Unio) Hde. ....... 918
igridiss (Unto) eBietameyeiecet eer 545
Tieris ((Margaron)) Weaeece-. aces: 646
Minas! @Uni0))) Mocks wares seer 558
Tinker, (Obovaria)y Simp! >... 205
Pinker: (Unio)) Bs dee Was sa oeoee 205
Tombecbeensis (Margaritina) Lea 354

Tombigbeanum (Pleurobema) Fr. . 764

Tombigbeensis (Margaritana) Tea 354
Tombigbeensis (Margaron) Lea ... 354
Tombigbeensis (Strophitus) Lea.. 353
Topekpensis (Margaron) Lea .... 100
Topekensis (Unio) Lea ......... 100
Torrentis (Anodon) Hde. ........ 414
Norsa M@bovaria)h Rath weyers 302
orsus: (Unio) =P. Sap Ms ee tenes 291
Hortilis (CAnodon)) Sowsec- +46 1417
Hortiliss Anodonta) leales.as- ose 1417
Tortilis (Anodontites) Lea ...... 1417
Tortilis, (Glaharis))Simps sne.celee 1417
Lortilis: (@Miagcaroni)i leas snj0ei 1417
Tortivus (Margaron) Lea ....... 646
Tortivis, (Unio) Weannecee ce eee 646
Tortuosa (Quadrula) Tea ........ 916
Tortuosus (Margaron) Lea ...... 916
oxtuosus: (Unio) leanne ie oe 916
‘Dortuosus, @Wnio)) «Sows 4) cee cee 656
Torulosa (Amblema) Raf. ....... 731
‘Toriwlosism @Unio) pe Consaerie sistas 25
Terulosus) (CUnio)), Bera... eee 598
Toxztlosus (Unio) Sa caebe see 331
rabalis (CH any iia) sa nts e-ie tania 132
Trabalis (Lampsilis) Con. ....... 132
Trabalis' (Unio) ig Contac ceehic.s oe 132
Trachez) “(Wni0) se Roby sec «ae « axes 558

INDEX

‘Trazosuss GWarlo)mmliameaneeine-: Seraetete 844
Transversa (Hyria) Hupeé ....... 1215
Trapesialis (Anodonta) Iam. 1428
Trapesialis (Anodontites) Lam. ..1428
Trapesialis anserinus (Anodontites)

SPL Se cater Oa a Toes 1430:
Trapesialis anserinus (Glabaris)

Simip:, esses ase eee ORL eee 1430"
Trapesialis cygnzeformis (Anodon-

tItES) PI Sar ert ohace eee eee 1432
Trapesialis cygneformis (Glabaris)

121 CoE Gr oro ae ate ere ty rere 1432
Trapesialis exoticus (Anodontites)

IL Atria, %s Sage soneus roreie teleue okw iehoiet si eioeee 1430
Trapesialis exoticus (Glabaris)

Simp: \2::,. eee ae eee 1430
Trapesialis scriptus (Anodontites)

SOWe hasssiae coaebe eee eres ome 1430
‘Trapesialis scriptus (Glabaris)

SUMP. coool vate Nee 1430
Trapesialis (Glabaris) Pils. ...... 1429
Trapesialis (Iridina) d’Orb. ..... 1428
Trapesialis moretonianus (Anodon-

ites) Sows pneccluae ema ae 1431
Trapesialis moretonianus (Glabaris)

SUP, 3 ccs tetera Rei 1431
Trapesialis rioplatensis (Anodon-

tites) MSow. esmcchiotee ee cae 1431
Trapesialis rioplatensis (Glabaris)

SUMP, devastate tuition emurretees 1431
Trapezea (Anodonta) Kust. ...... 1404
Trapezea’ ((Glabanis)- [hs os. ~saai0 oe 1404
Trapezeum (Anodonta) d’Orb. 1404
Trapezeus (Anodon) Spix ....... 1404
Trapezia senilis (Spatha) Marts...1322
Trapezia (Spatha) Marts. .....<.. 1322
Drapezialisy (Anodon)) (Gry a-eee 1429
‘Trapezialis (Anodonta) Blain. 1429
Trapezialis (Columba) Pet. ..... 1429
Trapezialis (Margarita) Lea ..... 1429
Trapezialis (Margaron) Lea ..... 1429
Trapezoides (Crenodonta) Ort. .. 831

Trapezoides (Margarita) Lea .... 831

Trapezoides (Margaron) Lea .... 831
Trapezoides pentagonoides (Quad-
riila)) a Eile 2 Apecciavceee ree ee 831
Trapezoides (Quadrula) Lea ..... 830
Trapezoides (Unio) Tea .:....... 831
Grapezcideus’ Simp yseeeetee eee 1180
Trautwiniana (Anodonta) Lea ...1427
Trautwiniana (Margaron) Lea .1427
Trautwinianus (Anodon) Sow. ...1427

Trautwinianus (Anodontites) Lea 1426
Trautwinianus (Glabaris) Simp.

.1427
Traversii (Nodularia) Simp. ..... 578
TrayersuieG@unio)) Polly sachsen oe 577

INDEX

Triangularis (Anodon) Sow. ..378, 438
Triangularis (Anodonta) Trask .. 378
Triangularis (Margarita) Lea .... 6
Triangularis (Margaron) Tea .... 6

Triangularis (Mya) Eaton ....... 6

Triangularis (Mycetopus) Hde. .. 462
Triangularis (Obliquaria) Raf. ... 731
Triangularis (Solenaia) Hde. .... 462

Triangularis (Unio) Bar. ........ 6
Triangularis (Unio) Kust. ....... 881
Triangularis (Unio) Say ......... 300

Triangulata (Alasmidonta) Lea .. 500
Triangulata (Margaritana) Lea .. 510

Triangulata (Margaron) Lea ..... 510
Triangulata (Unio) Sow. ..:..... 510
Triclava (Quadrula) Simp. ...... 927
Triclavus (Quadrula) Hde. ...... 927
Triclavus (Unio) Hde. .......... 927
Rricoloc. @Wmio)eKousts sect ecee 1168
Tricostatus (Anodon) Sow. ...... 403
Uziembolus. (Umio), Bens osc .c.ek 1116
Duafidus, (Diplodon)- Teal ¢.:...-5 1272
Trifidus (Margaron) Lea ........ 1272
Aeirdiss (Unio) ljeausaeniceeeere oe 1272
Triformis (Ianceolaria) Haas ... 956
Triformis (Nodularia) Hde. ..... 956
WriformisiGUmio)) vElides ae ile\ioeior 956
Trigona (Anodon) C. & R. ...... 1441
Trigona (Anodonta) Held ....... 438
Trigona (Anodonta) Han......... 1441
Trigona (Margarita) Lea ........ 1441
Trigona (Margaron) Lea ........ 1441
Trigona (Quadrula) Bak. ....... 881
UrreonodomuCons 5. sacs 1079, 1081
Trigonus (Anodon) Spix ........ 1441
Trigonus (Anodontites) Spix ..... 1441
Trigonus (Glabaris) Simp. ....... 1441
Trigonus (Margarita) Lea ....... 881
Trigonus (Margaron) Lea ....... 881
‘Trigonus pallescens (Anodontites)
SUNAD Physi shes isi SIGS ae te 1442
iuiconuse (Unio) bea tsniteceencee 881
rigonusa@Unio)) Sawap scies. eee ce 873
Trinacrium (Ptychobranchus) Lea 337
Trinacrus (Margaron) Lea ....... 338
Trinacrus (Ptychobranchus) Simp. 338
irimacrus «@Unio)| sea s.ee sane 338
‘Tripartitus (Margaron) Lea ..... IIIO
dicipartitusaG@WUinio): Wea. sscecaaee IIIO
BETA LOC OMM SPER s «5 «5b :s)e.cieters aloes I2I1
Tripolitana (Leguminaia) Bet. ... 447
Tripolitanus (Margaritana) Cless. 447
Tripolitanus (Pseudodon) Con. .. 447
Usipolitanuss@Unio)) Bet. ......-- 447
Triqueter (Truncilla) Raf. ....... 6
M@riqueter, (Unio) Sa 6 GE. . oc... 6

L330)
damrgtetraciKleimy iysiets cvcrlisse oie elke ore 1216
Griquetra Ciruncilla))) Rafe. ....... iS
Wiginuetranas Simp, /asie)s5).vet cies ee 1215
Trirostris (Unio) Mus. .......~.. 1110
Mrirostris= (Unto)! Sows tec <ce 9790
Txistis) (Spatha)yJiouss- eis -ceccie ce 1321
Unistis, CUnio))) Morel: =eesce acc 516
itistram: @Unio) Wocs eeesesde. 548
Trisulcata (Acuticosta) Haas 1124
Trisulcata (Parreysia) Hde. ...... 1123
Trisulcatus (Unio) Hde. ......... 1123
nigOgontawACs meee eye a ee ee 317
Tritogonia (Quadrula) Ort. ...... 320

Triumphans (Quadrula) B. H. Wr. 823
Triumphans (Unio) B. H. Wr. .. 823

Trivialis (Diplodon) Simp. ....... 1250
Trompi (Elongaria) Haas ....... 1001
Trompi (Nodularia) D. & C. 1000
Lhempi (Unio) iD. 18 iCa ee ee 1001
Troostensis (Margarita) Lea .... 133.
Troostensis (Margaron) Lea ..... 133
Eroostensis™@Unio)) slseal pee 132
Troostensis (Unio) Sow. ...... 50s 134
Troostii (Margaron) Lea ........ 133
Troostii (Unio) B. H. Wr. .:.... 133
Troscheliana (Pleurobema) Simp. 770

Troschelianum (Pleurobema) Lea. 770
Troschelianus (Margaron) Lea ... 770

Troschelianus (Unio) Lea ....... 770
Trossulus (Lampsilis) Lea ....... 143
Trossulus (Margaron) Lea ...... 144
inassulus: .(Uinio)m bea sae aeee 144
Troutwiniana (Anodonta) Cless. al gez
Troutwiniana (Margaron) Lea 2 k427
Truncata (Alasmidonta) Simp. ... 505
Truncata (Alasmodonta) Con. 497, 505
Truncata (Anodonta) Kust. ..... 438
Truncatus elegans (Unio) Pet. .. 308
Truncatus (Margarita) Lea ...... 546
Truncatus (Margaron) Lea ...... 546
Truncatus (Prisodon) Schm. ..... 1196
iruncatusi(Unio)\ «Say, oceans 308
Truncatus (Unio) Speng. ..1167, 1193
Touncatus; (Unio)! Swe .- 4s. e: 546
SGUTCUl aasRatiew. cist sic ee teens 2
PrvonieG@Wnio) iB. is Wits oaseses 630
Tryonii (Anodon) H. & M. ...... 387
Tryonii (Anodonta) Lea.......... 387
Tryonii (Margaron) Lea ........ 387
Tsadianus (Grandidieria Marts. 1060
Tuberculata (Cristaria) Schm. ... 225
Tuberculata (Mya) Eaton ....... 319
Tuberculata obesa (Tritogonia)

SIMU tove cat eparata oa eee Rice es 320
Tuberculata (Obliquaria) Raf. .... 0904

Tuberculata (Quadrula) Ort. ..... 319

1536

Tuberculata (Quadrula) Raf. .... 903
Tuberculata (Rotundaria) Ag. .... 904
Tuberculata (Tritogonia) Bar. ... 318
Tuberculatus (Margarita) Lea ... 319
Tuberculatus (Margaron) Lea ... 319

Duberculatus @Unio) Bar. ....... 319
Tuberculatus (Unio) Con. .a....- 904
Tuberculosa (CUnio) Vale 2.2 2-10 904
Tuberosa (@Quadrula) Dea ....... 836
Tuberosa sparsa (Quadrula) Lea.. 837
Tuberosus (Margaron Lea ....... 836
Tuberosis) GUmi10) els earie sete ceteris 836
Tumescens (Margaron) [Tea ..... 751
Tumescens (Pleurobema) Lea .... 751
ihumrescens™ GUinio) Me Ca Ne.ty-eloler rele 751
Tumescens ‘@Wnio)) Weal ia. cae cee PET
Tiamida (Anodon)) Eide? 2 sa. c 403
Pumiday(Anodonta)eMI<usts Sei. aiele 365
Maumida (GAnodonta)! Bet. soccer 403
Tumida (Monocondylea) D. & J. 1094
Atinaprakey (Uke) (Cy Its “Gaooncaoos 538
Tumidula (Nodularia) Lea ...... IOT4
Tumidula (Oxynaia) Haas... IOI4
Tumidulus (Margaron) Tea ..... 1014
Pamidulusi@Unio)) MWeal wae. actor 104
Tumidus (Margaron) Lea ....... 538
Tumidus (Monocondylus) Morel. 1tog2
Tumidus (Pseudodon) Morel. ....1o9r
Mumidiuss | (Wnio) Retzaerteciets serene 537
Tunizana (Anodonta) Morel. ..... 438
Tuomeyi (Margaron) Lea ....... 661
ittomey. (Wind) may eae eerie 661
Turcicus CWnio)Kasta saiesie cele 573
hureiday (Castalia) Elup eee 1196
Turgidulus (Margaron) Lea ..... 31
Abtrrearakoilocy (Ufarte)) IbEe aaboaands 31
Tucgidus (Margarita)! Weal \. 5 o.0c 854
Turgidus (Margaron) Tea ....... 854
duinreidus (Unto) Wealeswiecles acter 854
Ubipereacahelsy (Clete) ROWS Sonenaboscc 841
Turtoni moreleti (Unio) Desh. ... 542
Adiirimoyerl (Winey) IEE GonosonnooG 539
Tuscumbiense (Pleurobema) Lea.. 748
Tuscumbiensis (Unio) Tea ...... 749
Wiber 1dUinio) Con eee cetciets lore 850
Ucayalensis (Anodonta) Phil. ....1441
Uhareensis (Margaron) Lea ..... 565
Whareensis' Unio) Wea a. os eecee 656
Ujijiensis (Grandidieria) Bgt. ....1134
Ujijiensis (Parreysia) Bet. ..... 1133
Umbonatus (Anodontites) Simp. .1436
Umbonatus (Glabaris) Simp. ..... 1436
Wanbonatus GUnto) me Biets eitecsrcrene 555
Umbrans (Margaron) Lea ...... - 106
Wanbrans |@Wn1o)) ean cvcteles cies «ere 106
Umbrosa (Lampsilis) Lea ....... 171

INDEX

Umbrosus (lampsilis) Simp. ..... 171
Umbrosus (Margaron) Lea ...... 171
Umbrosus (Unio)- Vea 22.522. 106, I71
Unadilla (Anodon) De Kay ...... 347
Unadilla (Strophitus) Con. ...... 347
Undata (Eusconaja) Ones eee 880
Undata (Miya) baton mcpeletetelercronets 880
Undata-(Quadrula) Bara o-eicltele 880
Wadatusi GW o) mae atemererictels eee 880
Undivaga (Lampsilis) Pils. ...... 197
Undosa (Castalia) Marts: 22.1. 1207
Undosa (Castalina)) Marts. .2...% 1207
Undulata (Alasmidonta) Say .... 404
Undulata (Alasmodon) Sw. ...... 494

Undulata (Alasmodonta) C. B.

Ads.
Undulata (Alasmodonta) Say .... 404
Undulata (Anodon) C. & R. .... 350.

Undulata «(Anodon)) (Glde ey 1e 1 347
Undulata (Anodonta) Hild. ..... 346
Undulata (Anodonta) Say ..:... 349
Undulata (Baphia) H. & A. Ads. 495
Undulata (Crenodonta) Ort. ..... 820
Undulata latecostata (Quadrula)

IESE Dn cints dio Gomi omOo O00 O00 0 821
Undulata (Margarita) Lea ...349, 494
Undulata (Margaritana) Kust. .. 404
Undulata (Margaron) Lea ....350, 495
Undulata (Monodonta) Say .... 494
Wndulatas CMiyay) wEyatonmncrs serterere 820
Undulata (Nodularia) Haas ...... 975
Undulata pilsbryi (Quadrula)

IMA STIS IE Eee Perle ne vores eotenoioconetele 821
Undulatay(@nuadnula)y Ban <1. 819
Undulata, (Unio) yDeshy “iicaece 347
Windiulataws @Winto) mectarree verse velsicnee 494
Undulata WCUmioye Wales tercisteieiete 820
Undulatus (Anodon) Sow. ...... 347
Undulatus (Margarita) Lea ...... 820
Undulatus (Margaron) Tea ...... 820

Undulatus quadriplicatus (Strophi-

£US) PSOW.Y hence citron oes onto olor 350
Undulatus (Strophitus) Say ..... 349
Undulatus (Strophitus) Stimp. .. 495
WUndulatus i@Unito)i Bats seers. 820
Unditlatiusi Wino) Car cceheareererter 495
Undulatus (Unio) Says wae see ele 826
Undulifera (Anodonta) Cless. ... 415
Unicolor (Margaron) Lea ...... 205
Unicolor (Obovaria) Lea ........ 295
Wharteoylors (GUS) ILE Sobannodose 205
Unicostatus (Unio) B. H. Wr. .. 102
Wire Olen pioosoococcenncoucdt 511
Winey INGA, oodosoopooDoadods 511, 529
UiiomnascS (Com Sooocosoaods 527, 704
Wnitonellambliaas! se ci. = etencreter sie ace big

INDEX

Wintonid zest ae nse ole eh tek I
Winioninc peel nner ee eee ht I
Winiop sist Arey apie d eves ee 344
Uniopsis (Anodon) Sow. ........ 451
Uniopsis (Anodonta) Lam. ...... 451
Uniopsis (Ieguminaia) Iam. 450
Uniopsis (Margarita) Lea ...... 451
Uniopsis (Margaron) Lea ....... 451
WNlOpsiss Swart ycsh eect 492
Upsoni (Unio) Marsh .......... 81
Uruguayensis (Anodonta) Lea 1405
Uruguayensis (Columba) Pet. 1405
Uruguayensis (Diplodon) Lea 1234
Uruguayensis (Margaron) Lea

AS OC Eee HORA ATOM Ce oe 1234, 1405
Uruguayensis (Unio) Lea ...... 1234
Usumasinte (Quadrula) C. & F. 908
Usumasinte (Unio) C. & F. 909
Utriculum (Pleurobema) Tea 787
Utriculus (Margaron) Lea ...... 787
Utriculus (Quadrula) Simp. ..... 787
Witticulus) (Unio) hearse... te 787
Vaalensis (Unio) (Chap) eee seee 576
Vagula (Hyriopsis) Fisch. ...... 215
Vagulus (Hyriopsis) Simp. ...... 215
Vagulus (Unio) Fisch. ......... 215
Valdivanus (Unio) Phil. ........ 1261
Valentinus (Margaron) Lea ...... 541
Valentinus (Unio) Ross. ........ 541
Valentinus (Unio) Sow. ........ 555
Waleuss Giidiia) payee eee eee 1377
Valeus (Mutela) H. & A. Ads. 1377
Valida (Pleurobema) Simp. ..... 751
Validum (Pleurobema) Lea ..... 750
Validusm (Unio) wlyeae a. ss. 751
Vallata (Quadrula) Lea ........ 858
Vallatus (Margaron) Lea ........ 859
Mallatusmi@WUnto)malveal eri. Smee 8590
Vanuxemensis (Eurynia) Ort. .... 105
Vanuxemensis (Lampsilis) Tea 105
Vanuxemensis (Margarita) Tea 105
Vanuxemensis (Margaron) Lea 105
Vanuxemensis (Unio) Lea ...... 105
Vanuxemensis (Unio) Sow. ...... 133
Vanuxemii (Margaron) Lea 105
Vanuxemii (Unio) B. H. Wr. .... 10s
Variabilis (Anodonta) Drap. 362
Variabilis (Diplodon) Mat. ...... 1287
Variabilis (Margarita) Lea ..... 1288
Variabilis (Margaron) Lea ..... 1288
Variabilis (Mya) Mat. .......... 1288
Variabilis (Unio) d’Orb. ........ 1288
Varicosa (Alasmidonta) Lam. 506
Viantcosas @Unio)) Tam, «.. 2.56. 506
Varicosus (Margarita) Lea ...... 808
Varicosus (Margaron) Lea ...... 808

LS OH
Maxicosns \(Winio)s eau s....20eee 808
Matishe (Unio) eBata terres ccm eee 665
Vaughaniana (Lampsilis) Lea 109
Vaughanianus (Lampsilis) Simp. 109
Vaughanianus (Margarita) Lea 109
Vaughanianus (Margaron) Lea 109
Vaughanianus (Unio) Lea ...... 109
Vaughanianus (Unio) Sow. ...... 98
Velaris (Physunio) Simp. ...... 1069
Velazis. (Unio): Hans.) yee e ee 1064
Melanisy GUmnio) Sows sane enone 1069
Melatusn (Unio)mCon. esc 337
Vellicata (Nephronaias) Rve. 284
Vellicatus (Nephronaias) Simp. 285
Wellicatus™ (Unio) Rive, 9.2. sone 285
Velthuizeni (Hyriopsis) Roch. 216
Velthuizeni (Unio) SCheps eae 216
Velthuzeni (Hyriopsis) Simp. 216
Melumm@GUnio)mSay. “eee ae 189
Ventricosa (Anodonta) C. Pfr. 362
Ventricosa (Iampsilis) Bar. 38
Ventricosa lurida (Lampsilis)

SIMD clays. 0 sy eer. Ae 41
Ventricosa (Mycetopoda) d’Orb. 1466
Ventricosa satura (Lampsilis) Lea 41
Ventricosus (Lampsilis) Simp. 39
Ventricosus (Margarita) Lea 39
Ventricosus (Margaron) Lea 39
Ventricosus (Mya) Eaton ...... 39
Ventricosus (Platiris) Lea ...... 1466
Ventricosus satur (I,ampsilis) Simp. 41
Wentricosus) Unio)! Bares ene ee 39
Ventrosa (Brazzea) Bet. ........ 1374
Menus @Unio) i Rat. 4 eee eee 731
Venusta (Lampsilis) Lea ........ 89
Venustus (Lampsilis) Simp. 89
Venustus (Margarita) Lea ...... 89
Venustus (Margaron) Lea ...... 89
Venustusm (Unio)! Hea, @enn. see 89
Venustus (Unio) Morel. ........ 993
WMenustus) @Umio)! Sow. sso one 8r
Vera (Pleurobema) Simp. ...... 775
Veracruzensis (Margaron) Lea 171
Veracruzensis (Unio) Lea ...... 171
Merze-pacis (@Wmio)) -Drist. | seen. 701
Verbecki (Contradens) Haas 1016
Verbecki (Nodularia) Béttger 1016
Merbeckis (Unio)! Botts) eee. eeee a. 1016
Merecunduss (Unio)! Clas)... oe. IO7I
Verrauianus (Unio) Sow. ...... 575
Verreauianus (Unio) Lea ....... 575
Merreauxig i@Umio)) “Pat. -secaecs 575
Verreauxianus (Margaron) Lea 575
Verrucifer (Unio) Marts. ........ 965
Verrucifera (Nodularia) Marts. 964
Verrucosa (Mya) Eaton ........ 904

1538 INDEX
Verrucosa (Obliquaria) Raf. ..... 320 + Virens (Margaron) ea ..... 430, 654.
Verrucosa (Nodularia) Haas 1043 Wirens, 9 CWnito) ale camer y-vrncie cheters 654
Verrucosa (Quadrula) Bak. 904 Virescens (Lampsilis) Lea ...... 93
Verrucosa (Tritigonia) Sm. ..... 320 Virescens (Margaron) Lea ...... 04
Verrucosa (Tritogonia) Ag. 320 Virescens s@Winio)) seal eras. eet 94
Werniucosa: ((Unioiavialeues cic eeiesieie 840 Virgata (Anodonta) Con. ........ 347
Verrucosus albus (Unio) Hild. 327 Virgatus (Strophitus) Con. 347
Verrucosus (Margarita) Lea 904 Virginiana ((Unio)s Bam: eva... 65, 653
Verrucosus (Margaron) Tea 904 Virgulata (Anodonta) Lea ;...... 387
Verrucosus purpureus (Unio) Hild. 904 Virgulata (Margaron) Lea ...... 387
Verrucosus, (Unio) Bars. seme 904 Vireula, SSimipson eames sclera 1454
Verrucosus (Unio) Say ........ 319 Vines! Simp sompieraccreiieisic <necetee 1150:
Verruculosus (Unio) Hde. ...... 935 Viridana (Anodonta) Cless. 1424
Versus (Margaron) [Lea ........ 989 Viridans (Margaron) Lea ...... 662
Verum»(Bleurohema)) Wear. cctceie 9775 Viridans iGUnio) eau a .1. eee 662
Verus (Margaron) Tea .......... 775 Viridicatus (Margaron) Lea 642
Verus) (CUinio)imiyeamec macieniiee 775 Winidicatus, @Umio) eae. ses eects 642
Verutus (Margaron) Weav... <.. 5 662 Viridiflavus (Unio) Kust. ....... 533
Vierutuss (Unio) elseameerione scence 662 Viridiradiatus (Margaron) Lea 662
Wescow (Marearon)i Wea n-ccieene 563 Viridiradiatus (Unio) Tea ...... 662
Viescots (Unio)? Bitar aivteneicitetes 563 Viridis:' (Alasmodon) Raf. .......: 510.
Vescoiana (Anodonta) Bet. ..... 373 Viridis (Anodonta) H. & A. Ads. 438
Vescoiana (Margaron) Lea ...... 373 Viridis (Mycetopus) Hde. ...... 460
Vescoiana mesopotamica (Anodonta) Viridis (Symphynota) Con. ...... 484
IMIGUSS.0 p caraeeecrsiooe eters eaters 373 Waridis) @Uinio)) i Conwmeeianenae 485
Vesicularis (Lampsilis) Tea ...... 142 Vinidiss (Unio) makers spree ae 44
Vesicularis (Unio) Wea 2.22.0... << 142 Viridiss ((Uinio)) (Rati ssc sas aaeeer 731
Vestitus (Margaron) Lea ...... 610 Viridulus (Margaron) Lea ...... 690
Mestitus, (Unio) vl) cara detersisiscieitehs 610 Wiridulus® (@Umt0))) Seance ses srehe 6890
Vestitus var. a (Unio) Hde. 9034 Wasser (Miutela)y (Bigitaisecnrotsie stele 1355
Vestitus var. b (Unio) Hde. 941 WVissert (Unio) (Bets aaasaciae cle T1193)
Vibex (Ch unynia)imOnts sa. ooeere 137 NMittatise @Bariosta) somata yenrlecrets 731
Wabex, (vamp silisiin Gon emcees 136 Vittatus (Diplodon) Lea ........ 1296
Waibex: (Margarita) eleeanencieieriie 137 Vattatus) GMliarcanom))jE/ea) i siete 1296:
Wabex) ((Marcaroni mils camer genera) seteisie 137 Wekritabin (Uber) IG Sas eaaqogaca« 1296
Vibex nigrina (Lampsilis) Lea ... 138 Vion. buschea, (Unto) Sow: 24. oc 1086.
Vibex nigrinus (Lampsilis) Simp. 138 Vondembuschiana (Margaritana)
Vabex; | (Uintoi) Conscience cle 137, 640 Wea) Wake shake certian ler 1086
Vicinus (Margaron) Lea ........ 676 Vondembuschiana (Margaron)
Wiaemtus (CUni0) peak emcee cet 676 lyr eR PERE nS tie on clos 1086
Viteiitisi @Wii10) lees temas semreratare 726 Vondembuschiana (Monocondylea)
Vignonana (Anodonta) Mus. 1348 FETs (SEPANG SS oy rth tr eatoencaey sree eiewoe 1086
Vignoni! ((Spatha)ai Gere ciclem ener 1348 Vondembuschiana (Pseudodon)
Vignoniana (Margaritana) Bern. 1347 (Caverns obra Hume UbaS mao 1086
Vignoniana (Margaron) Lea 1348 Vondembuschianus (Pseudodon)
Vignoniana (Spatha) Bern. ...... 1347 TOR ajiesisaveentcvcudee,egepegarevegabowtons temas 1085
WVienonianay Unio) ives since 1347 Vondembuschii (Unio) Sow. 1082
Vignonianus (Anodon) Rve. ..... 1348 Vulcana (Parreysia) Simp. ...... 1116
Vignouana (Margaron) Lea 1348 Vulcanus (Parreysia) Han. 1116
Villosa (Lampsilis) B. H. Wr. 143 WVaulcanus! (C(Uinio) blame e.c =r scietate 1116
Villosus (Lampsilis) Simp. ...... 143 Vynckei (Cameronia) Bet. ...... 1381
Vallosus) (@Uni0)) Be Els \Warse sire 143 Vynckei (Pleiodon) Bet. .......- 1381
Wancke (Unio) ub ets 0. cence 1193 Vyncke1 \@bliodom)eGery .).).. stem 1382
Violaceus (Unio) Speng. ........ 652 Vynckii (Cameronia) Simp. 1381
Visens (GAnodon)ieSow. fic sae 430 Vysseri (Mutela) Bet. .......... 1355
Virens, CAnodonta)) Wea ........ 430 Waccamawensis (Margaron) Lea 620

INDEX

Waccamawensis (Unio) Tea .... 620
Wiarneriga@Umto) > ikobs teehee 558
Wagnerianum (Diplodon) Simp. . -1246
Wagnerianus (Diplodon) Simp. ..1246
Wagnerianus santanus (Diplodon)

NaS ROIS OMAP IOAN OG meaci to cee 1246
Wahlametensis (Anodon) C. & R. 380
Wahlametensis (Anodonta) lea 379
Wahlametensis (Margarita) Lea 380
Wahlametensis (Margaron) Lea 380
Wahlbergi bourguignati (Spatha)

BS ite Nyt ane Use enencrares or cbetecratenceeees 1327

spre folionsValisvafelicy oVenevaneler's: cies) ee -ciaroleeate forme 1328
Wahlbergi hartmanni (Spatha)

Ia its se steko Srey. deen Selon RE 1327
Wahlbergi (lridina) Krss. ...... 1326
Wahlbergi (Mutela) Smith ...... 1326
Wahlbergi (Platiris) Wealsccs soir 1326
Wahlbergi (Spatha) Krss, ...... 1326
Wahlbergi (Spatha) Simp. ...... 0327
Wahlbergi spathuliformis (Spatha)

Mia mtsh aicreieacictoecsis:ae tas ee ee 1328
Waikarensis (Diplodon) Col. 1294
Waikarensis (Unio) Col. ........ 1294
Walkeri (Medionidus) B. H. Wr. 252
Wialkert (Unio) Bi HL Wa .:-. 253
Wallisi (Anodonta) Mouss. ...... 1457
Walpolei (Monocondylea) Han. . . 1096
Walpolei (Pseudodon) Han. 1096
Walteni (Unio) B. H. Wr. .... 695
Wardiana (Anodon) Sow. ...... 347
Wardiana (Anodonta) Lea ...... 347
Wardiana (Margarita) Lea ...... 347
Wardiana (Margaron) Lea .... 347
Wardii (Margaron) Lea ........ 835
Wrardi® (@Umio)eiyea .--.0.2n 0. s.. 835
Watereensis (Margarita) Lea .... 653

Watereensis (Margaron) Lea .... 653
Watereensis (Unio) H. & A: Ads. 653

‘Websteri (Diplodon) Simp. ...... 1307
Websteri (Unio) B. H. Wr. .... 619
Weddellii (Anodon) Sow. ...... 1443
Weddellii (Anodonta) Hupé 1443
Weddellii (Anodontites) Hupé ..1442
Weddellii (Glabaris) Simp. ...... 1443
Weddellii (Margaron) Tea ...... 1443
Weddellii (Mycetopoda) Ih. 1463
Weddellii (Mycetopus) Hupé 1462

Weldonensis (Margaron) Lea .... 655

Weldonensis (Unio) Lea ........ 655
Welwitschii (Iridina) Morel. 1367
Wheatleyanus (Diplodon) Lea 1228
Wheatleyanus (Margaron) Tea 1228
Wheatleyanus (Unio) Lea ...... 1228
Wheatleyi ,Anodonta) Tea ...... 1444

1539

Wheatleyi euphratica (Leguminaia)

Kob.
Wheatleyi (Leguminaia) Lea .... 447
Wheatleyi (Margaron) Tea --448, 1444
Wheatleyi (Microcondylea) Cless. 448

Wheatleyi (Monocondylza) Tea 448
Wheatleyi (Pseudodon) Con. .... 448
Wheatleyi (Unio) Lea........... 660
Wheeleri (Arkansia) O. & W. .... 478
Whiteianus (Margaron) Lea .... 640
Whiteianus (Unio) Dea ..)..... 640
Williamsii (Anodonta) Lea ...... 387
Williamsii (Margaron) Lea ...... 387
Wilsonii (Diplodon) Lea ........ 1302
Wilsonii (Margaron) Lea ...... 1302
Walsonmis (Wino) veal 2s. s 5 eee 1302
Wissmani (Spatha) Marts. ...... 1315
Wolwichii (Unio) Morel. ........ 572
Woodiana (Anodon) Sow. ...... 402
Woodiana (Anodonta) Kob. .... 409
Woodiana (Anodonta) Lea ...... 401
Woodiana (Margarita) Lea ...... 402
Woodiana (Margaron) Lea ...... 402

Woodiana (Symphynota) Lea .. 402
Woodwardianus (Margaron) Lea 337
Woodwardianus (Unio) Lea ..... 337
Woodwardius (Unio) Lea ........ 337
Wrighti (Quadrula) Simp. ...... 868
Wirighti (GWargaron) Wea ‘.......- 960
Winichtis (GUinio)y Leal -sseceae cn: 960
Wrightianus (Strophitus) Walk. .. 357
Wymani:(Anodon) Sow. ........ 1407
Wymanii (Anodonta) Lea ...... 1407
Wymanii (Anodontites) Lea 1407
Wymanii (Diplodon) Lea ...... 1230
Wymanii (Glabaris) Simp. ...... 1407
Wymanii (Margaron) Lea ..1231, 1407
Winans (Unig): weal wae sseeee 123!
Wynegungeensis (Margaron) Tea 1109
Wynegungensis (Parreysia) Lea 1ro8
Wynegungensis (Unio) H. & T. 1107
Wynegungensis (Unio) Lea II09
Yadkinensis (Unio) Lea ........ 656
Youcanensis (Anodonta) Pet. .. 374
Youconensis (Anodonta) Lea .... 374
Youkanensis (Anodonta) Lea .... 374
Youkanensis (Margaron) Lea .... 374
Yubaensis (Alasmodon) Trask ... 517
Yzabalensis (Nephronaias) C. &

1 es Eee rs ST ORG ae OEE ean 276
Yzabalensis (Unio) C. & F. .... 276
Zabulonicus (Unio) Kob. ...... 551
Zabulonicus (Unio) Toc. ........ 548
ANTI AMINOC DU ee a ec he gee 949
Zambesiensis (Unio) Prest. .... 724
Zealandicus (Unio) Pet. ....... 1312

1540 INDEX

Zeiglerianus (Margarita) Lea .... 107
Zeiglerianus (Margaron) Lea .... 107
Zeiglerianus, (Unio) Lea ......+.. 107
Zelebori (Diplodon) Dun. ...... 1204
Zelebor (Maresaron) Tea ......- 1295
Zelebori (Unio) Dun. 22. ......-. 1295
Zellensis (Anodonta) Waard. .... 361
Zellensis (Mytilus) Gmel. ....... 361
Zeynern (Unio) Mikes Ses).6.61oe 575
Zieglerianus (Margaron) Lea .... 107
Zigzag (Margarita) Tea ........ 309

Aigzas (Marcaron)) ueamanaeeeee
Ziszage a (Unio) Mie eae eee

Zollingeri (Alasmodonta) Mouss.
Zollingeri (Margaritana) Kust.
Zollingeri (Monocondylea) Pet.
Zollinger} (Pseudodon) Mouss.

Zonata (Quadrula) Hde. ........
Lonatas (Unio) menace see
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