(navigation image)
Home American Libraries | Canadian Libraries | Universal Library | Community Texts | Project Gutenberg | Children's Library | Biodiversity Heritage Library | Additional Collections
Search: Advanced Search
Anonymous User (login or join us)
Upload
See other formats

Full text of "Monography of the family Unionidæ : or, Naiades of Lamarck (fresh water bivalve shells) of North America ..."



fbrafjr 



7 



.Vo. 1. 



M N G R A P H Y 



FA3IILY UXIOXID.i! 



OR NAIADES OF LAMARCK. 



^FRESH WATER BIVALVE SHELLS.' 



OF 



NORTH AMERICA., 




ILLUSTRATED BV FIGURES DRAWN ON STONE FROM NATURE. 



BY T. A. CO.\ HAD. 



CURATOR OF THE ACADEMY OF NATURAL SCIENCES OF PHILADELPHIA. BOMBAST SIE1IBEK OF 
THE GEOLOGICAL SOCIETY OF PENNSYLVANIA. 



SMITHSONIAN INSTITUTION 

WASHINGTON 25, D.C# 

PHILADELPHIA: 

J. DOBSON, LOG CHESNUT STREET. 

E. G. DORSEY, PRINTER. 

/>• a ::'. ■ 1835. 



MONOGRAPHY 



OF THE 



FAMILY UNIONIDiE, 



OR NAIADES OF LAMARCK, 



(FRESH WATER BIVALVE SHELLS,) 



OF 



NORTH AMERICA, 



)H Of 

Sectional Library 



ILLUSTRATED BY FIGURES DRAWN ON STONE FROM NATURE. 



BY T. A. CONRAD, 



CURATOR OP THE ACADEMY OF NATURAL SCIENCES OF PHILADELPHIA, HONORARY MEMBER OF 
THE GEOLOGICAL SOCIETY OF PENNSYLVANIA. 



PHILADELPHIA: 

J DOBSON, 108 CIIESNUT STREET. 

1836. 




E. G. Dorsey, Printer, 
12 Library Street. 






TO 

CHARLES A. POULSON, Esa. 
Member of the Academy of Natural Sciences of Philadelphia, tf-c. 

THIS BOOK IS DEDICATED, 

AS A SLIGHT TRIBUTE OF ESTEEM, 

BY HIS OBLIGED FRIEND, 

THE A UTHOR. 



MONOGRAPH Y 



OF THE 



FAMILY UNIONIDil 



UNIO. 

GENERIC CHARACTER. 

Shell equivalved, inequilateral: cardinal teeth two 
in each valve, irregular, generally striated, simple or 
biparted; an elongated lamelliform tooth on the pos- 
terior hinge margin of the right valve, and two 
similar teeth on the corresponding margin of the left 
valve: muscular impressions two principal ones in 
each valve. 

OBSERVATIONS. 

Mr. Say justly remarks, that, "in North America, 
the shells of this genus excel those of any other 
country in magnitude, beauty, and diversity of spe- 
cies." The rivers of Tennessee have furnished the 
most beautiful specimens of many species common to 
the western waters. The Ohio or Mississippi has 



not hitherto furnished a single species existing in 
tide waters which flow into the Atlantic; and the 
only shell of this character is the Alasmodonta mar- 
gi?iata, Say. 

The shells of this genus may be divided into two 
groups, the "winged" and "not winged," as Mr. Sow- 
erby has proposed for the whole family of Unionid^e. 
The former are included in the genus SympJiynota, of 
Mr. Lea, which we cannot adopt, because, as Fe- 
russac justly remarks, "in the same family generic 
characters should be taken from the same parts;" 
thus the other genera are formed from the absence 
or arrangement of the hinge teeth, whilst SympJiynota, 
without any regard to the hinge, is constructed from 
a testaceous connexion of the valves, which Ferussac 
observes is "almost an organic character among the 
Acephala which have the mantle completely closed 
near the hinge margin, at least in young shells." 

Dr. Kirtland has made some interesting remarks 
on the sexes of this family, in which he has proved 
them to be distinct, in the opinion of many concho- 
logists; and the sex can be ascertained by the form 
of the shell. Almost every species has two promi- 
nent varieties of form, one of which is shorter and 
more ventricose than the other, which is happily ex- 
plained by the observations of the intelligent author 
of the essay referred to.* 

*Vide Silliman's Journ. vol. xxvi. p. 117. 










. 








Unto fascuttus.Raf. 



UNIO FASCIATUS. 

Plate I. 
DESCRIPTION. 

Shell elliptical, compressed, yellowish olive, with 
broad dark green rays, and a few intermediate nar- 
row rays; umbo slightly compressed, little promi- 
nent; anterior side short; ligament margin scarcely 
curved, slightly declining; posterior margin obliquely 
truncated; umbonial slope abruptly rounded; submar- 
gin slightly furrowed; basal margin protruding a 
little near and behind the middle; within white; 
cardinal teeth thick, direct; margin thin, showing the 
exterior rays. 

SYNONYMES. 

U. fasciatus, Raf. Ann. gen. des Sc. Phys. vol. v. p. 28. 

Poulson's translation, p. 20. Say, Amer. Conch. No. 6. 

FeriissaCy Mag. de Zool. 
U. carinatus, Barnes. Silliman's Journal, vol. vi. p. 126. 
Cab. A. N. S. No. 1020. 

OBSERVATIONS. 

This shell has been considered a variety of cario- 
sus by some conchologists, but it is invariably more 
ponderous and compressed, with very different mark- 
ings and cardinal teeth. It is most nearly related to 
the crassns, Say, but can be distinguished by its 
more elliptical outline, much broader and darker rays, 
and by the beaks being less nearly terminal. Fe- 
russac gives carinatus, Barnes, as a synonyme to 
crassus. Say. Common in the western waters. The 



figure is from a specimen from the Scioto, given me 
by my friend, Dr. William Blanding. 



UNIO OVATUS. 

Plate II. 
DESCRIPTION. 

Shell subtriangular, rather thin, compressed ante- 
riorly, inflated over the umbonial slope, which is pro- 
foundly angulated and subrectilinear; posterior slope 
flattened or slightly concave, much wrinkled; umbo 
inflated, prominent, sloping anteriorly, distant from 
the anterior margin; surface glabrous, olive-yellow; 
within bluish; cardinal teeth double in each valve, 
very oblique, compressed, elevated. 

SYNONYMES. 

U. ovatus, Say. Nicholson's Ency. (3d Amer. ed.) art. Conch. 

pi. ii. fig. 7. Lam. An. sans vert. vol. vi. p. 75. 
Cab. A. N. S. No. 1225. 

OBSERVATIONS. 

The great depression of the posterior slope distin- 
guishes this species from the cardium, Raf. Old 
shells are produced posteriorly. It varies consider- 
ably in form; some specimens are compressed, others 
very ventricose, with rather broad radii over the 
whole disk. This variety is so dissimilar to the 
specimen figured, that I propose to designate it by 
a distinct name, terming it variety ornatus; it is com- 
mon in the rivers of South Alabama. The species is 
common in the western waters. 



z 





Unto ovatus, Say. 




—, 






i unio clava. Lam. Z.Unio cfeeisus, Lea 



UNIO CLAVA. 

Plate III.— Fig. 1. 

DESCRIPTION. 

Shell cuneiform, very oblique; posterior side pro- 
duced, compressed, with an oblique furrow rapidly 
widening from the umbo; ligament margin arcuate, 
very oblique; umbo elevated, narrowed, inclining for- 
wards; beaks curved to a point, terminal; epidermis 
wrinkled, olive-yellow or brownish, with interrupted 
rays over the umbo, disappearing with age; within 
white, very iridescent posteriorly; cardinal tooth in 
the left valve nearly parallel with the ligament mar- 
gin. 

SYNONYMES. 

U. clava, Lam. An. sans vert. vol. vi. p. 74. 

U. scalenius, Raf. Ann. gen. des Sc. Phys. vol. v. p. 43. pi. 

lxxxi. fig. 24, 25. Poulson's trans, p. 47. 
U. modioliformis, Say. 
Cab. A. N. S. No. 1117. 

OBSERVATIONS. 

A beautiful species when perfect, and common in 
the western rivers. With age the posterior side be- 
comes greatly produced and compressed, and gene- 
rally furnished with irregular indentations. Allied to 
U. oviformis, nob. and decisus, Lea. 

B 



UNIO DECISUS. 

Plate III.— Fig. 2. 
DESCRIPTION. 

Shell cuneiform, oblique; anterior margin obtusely 
rounded; posterior side produced, somewhat com- 
pressed, with a very oblique indistinct furrow, and 
irregular indentations, frequently obsolete; extremity 
angular; beaks nearly terminal, eroded; umbonial 
slope rectilinear, subangulated; epidermis finely wrin- 
kled inferiorly, reddish-brown with obsolete brown 
narrow rays; within white. 

SYNONYMES. 

U. decisus, Lea. Trans. Amer. Philos. Soc. new series, vol. 

iv. p. 92, pi. xii. fig. 23. 
U. taitianus, ib. vol. v. p. 39, pi. iv. fig. 11. variety. 
Cab. A. N. S. No. 1733. 

OBSERVATIONS. 

This species much resembles the preceding, but 
can always be distinguished by its broader and less 
oblique umbo, uniform absence of green rays, and 
by its rectilinear umbonial slope, but more especially 
by the posterior extremity, which is never so nearly 
on a line with the base as in the former shell, which 
with age is greatly produced and compressed, whilst 
the present species, when old, never becomes so; 
the cardinal teeth, also, are very different. Com- 
mon in the Alabama river, and has hitherto been 
found only in the state of Alabama. 




/''' 



~"\ 






' 

























\ v 



w 



lUnio clava, Lam, £.Unio cteetsus, Lea. 




1 Wnifi reft* xm 



:. Ullifi /''"•■ ' ■■ ' ■ ' 



UNIO REFLEXUS. 

Plate IV.— Fig. 1. 
DESCRIPTION. 

Shell suboval, thick anteriorly; middle of the disks 
with a single row of distant elevated tubercles, about 
four in number; umbo not very prominent, subme- 
dial; umbonial slope subcarinated; posterior side 
slightly furrowed and emarginate at base; posterior 
slope flattened, with transverse undulations; poste- 
rior extremity truncated; within white; cardinal teeth 
large, direct, much sulcated. 

Var. A. disks covered with small tubercles. 

Var. B. epidermis blackish, nacre purple. 

SYNONYMES. 

U. reflexus, Raf. Ann. gen. des Sc. Phys. vol. v. p. 40. 

Poulson's trans, p. 40. Say, Amer. Conch. No. 6. Ferussac, 

Mag. de Zool. 
U. cornutus, Barnes. Silliman's Journ. vol. vi. p. 122. 
Cab. A. N. S. No. 1750. 

OBSERVATIONS. 

Allied to the U. flexaosas, but approaches nearest 
to U. gibbosus, Raf., yet may always be distinguish- 
ed from that species by its suboval outline, and the 
regularity and prominence of its tubercles. The 
two varieties I found in the Alabama river. The 
figure represents a tuberculated specimen. The 
species preserves its distinctive characters in very 



remote localities, specimens from south Alabama 
perfectly resembling others from the waters of Indi- 
ana. 



UNIO FLEXUOSUS. 

Plate IV. — Fig. 2. 
DESCRIPTION. 

Shell subtriangular, bifurcated, swelling and sub- 
nodulous in the middle; posterior side with a wide 
oblique furrow; umbonial slope obtusely carinated; 
umbo flattened, prominent; epidermis with numerous 
slender rays; within white, cardinal teeth direct, 
sulcated; lateral teeth short and thick. 

SYNONYMES. 

U. flexuosus, Raf. Ann. gen. des Sc. Phys. vol. v. p. 40. 
U. foliatus, Hildreth. Silliman's Journ. vol. xiv. p. 248, fig. 

16. 
Cab. A. N. S. No. 1050. 

OBSERVATIONS. 

A specimen of this shell in Mr. Poul son's cabinet 
was labelled by Rafinesque, whose description, un- 
der the name we have adopted, entirely accords with 
the species before it has attained its profound bifur- 
cation. 

This singular species, when young, is smooth, and 
simply emarginate behind the middle. It approaches 
nearest to U. gibbosas, Raf. Not uncommon in the 
western rivers. 




111.' ■.>•, Raj. 



o , ol.iatus, Hlldreth 



UNIO PHILLIPSII. 

Plate V.— Fig. 1. 
DESCRIPTION. 

Shell subovate, with concentric furrows; anterior 
side smooth; disk with a single row of irregular 
tubercles in the centre, some of which are elongated 
and grooved; posterior side narrowed, with a wide 
furrow and a few small tubercles; umbonial slope 
straight, carinated and tuberculated; posterior slope 
concave, indistinctly tuberculated; ligament slope 
rectilinear, oblique; extremity direct, emarginate; 
basal margin swelling centrally, emarginate behind; 
umbo prominent, rather broad, flattened at the sum- 
mit; beaks retuse; epidermis yellowish-brown, with 
indistinct filiform rays over the umbo; within white; 
cardinal teeth rather small, direct, double in each 
valve. 

OBSERVATIONS. 

This handsome species is allied to U. quadrulus, 
Raf., but is very distinct, the young shell having 
broad smooth and retuse beaks, whilst the young of 
the qaadrulus has the beaks narrowed, tuberculated, 
pointed and curved forwards. The specimen figured 
is from the Wabash, and is in the cabinet of Mr. 
John Phillips, who called my attention to it as a 
distinct species, and I have dedicated to him a small 
tribute of respect for his talents and scientific zeal. 



10 
UNIO METANEVRUS. 

Plate V.— Fig. 2. 
DESCRIPTION. 

Shell suboval, thick, ventricose; anterior side tu- 
berculated, except near the margin, which is smooth; 
disk with an oblique furrow; umbonial slope very 
prominent, broad and rounded, with numerous tu- 
bercles, some of which are very large; posterior slope 
wide, concave, or angular, with oblique slightly re- 
curved series of rib-like tubercles; umbo slightly 
prominent; beaks retuse; ligament margin oblique, 
rounded at the extremity; posterior margin emargi- 
nate; epidermis yellowish-brown, with interrupted 
green rays; within white, much thickened anteriorly. 

SYNONYMES. 

U. metanevra, Raf. Ann. gen. des Sc Phjs. vol. v. p. 39. 

Ferussac, Mag. de Zool. 
U. nodosus, Barnes. Silliman's Journal, vol. vi. p. 124, pi. vi. 

fig. 7. 
Cab. Jl. N. S. No. 1754. 

OBSERVATIONS. 

A common species in the western and southern 
rivers, easily recognised, when in perfection, by its 
swelling umbonial slope: very old specimens much 
resemble U. stapes, Lea, but are much larger. 









' 



.,#f 




LT.rnio PhUflfsiLj Con. &'. Unto M&tancurus> 

Dec. iSSS. 







/. ?/nu> Mprfpni-, C074.JE.ZWz/> frag psus ('oftraJ 

Der./SCJ. 



11 

UNIO MORTONI. 

Plate VI.— Fig. 1. 

DESCRIPTION. 

Shell suborbicular, not thick, ventricose; disk flat- 
tened, or slightly furrowed from beaks to base, co- 
vered with irregular tubercles; anterior margin sub- 
truncated; posterior margin straight, direct; ligament 
margin subarcuate, oblique, forming an angle with 
the posterior margin; umbo with an oblique furrow, 
prominent; beaks rather retuse, decorticated; umbo- 
nial slope angular, slightly arcuate; posterior slope 
flattened; epidermis yellowish brown, with fine crowd- 
ed wrinkles; within white; anterior margin not thick- 
ened; cardinal teeth compressed, very prominent, 
oblique. 

Cab. J. N. S. No. 1874. 

OBSERVATIONS. 

This pretty species is common in Bayou Teche, 
Louisiana; but I have seen it from no other locality; 
it approaches nearest to the (jiiadrulus, Raf., but dif- 
fers greatly in size, convexity, and want of a distinct 
furrow from beak to base. It is dedicated to my 
friend Dr. S. G. Morton, whose exertions have fur- 
nished a splendid collection of American and foreign 
fresh water shells to the Academy of Natural Sci- 
ences. 



12 
UNIO FRAGOSUS. 

Plate VI.— Fig. 2. 
DESCRIPTION. 

Shell suborbicular, ventricose, with an indistinct 
narrow furrow, and two approximate series of very 
prominent irregular tubercles, anterior ones largest; 
umbonial slope angular; posterior slope slightly con- 
cave, with a few narrow rib-like tubercles, more pro- 
minent near the margin; posterior margin direct, 
slightly emarginate; ligament slope straight, slightly 
oblique; umbo narrow, prominent; beaks much in- 
curved, pointed, tuberculated; epidermis brown, with 
two or three broad, widely interrupted green rays. 

OBSERVATIONS. 

This fine species approaches guadrulus, Raf., but 
is much more ventricose, has more prominent tuber- 
cles, and is very distinct. I am indebted to Dr. 
Blanding for the splendid specimen represented by 
the figure; it is from the Scioto river, Ohio. 











■ 






rt'oni,, 6 on. SL.Vnio fmqosus, Con.rad. 



CONTENTS 



Plate I. Unio ovatus. 
„ II. ,, fasciatus. 



III. 



S clava. 
( decisus. 



jy 5 reflexus. 

" \ flexuosus. 

Y ( phillipsii. 

" I nietaneovus. 



Note.— Several species were noticed in the prospectus, which we 
have omitted in this number, in order to figure others supposed to be 
new. 






JVo. 3. 



MONOGRAPHY 



FAMILY UNIONIDiE, 



OR NAIADES OF LAMARCK, 



(FRESH WATER BIVALVE SHELLS,) 



NORTH AMERICA, 



ILLUSTRATED BY FIGURES DRAWN ON STONE FROM NATURE. 



BY T. A. CONRAD, 



CURATOR OF THE ACADEMY OF NATURAL SCIENCES OF PHILADELPHIA, HONORARY' MEMBER OF 
THE GEOLOGICAL SOCIETY OF PENNSYLVANIA. 



PHILADELPHIA: 
J. DOBSON, 108 CHESNUT STREET. 

PARIS: 
ARTHUS BERTRAND, FILS, RUE HAUTEFEU1LLE No. 23 

HAMBURG : 
PERTHES & BESSER, No. 22, AM JUNGFERNSTIEG. 

E. G. DORSEY, PRINTER. 

January 1836. 








,.-' 









Unio co.ftatuA'y #o ,-. 



1? 

UNIO COSTATUS. 

Plate VII. 
DESCRIPTION. 

Shell suboval, slightly ventricose anteriorly; disk 
with profound oblique undulations, numerous and re- 
curved behind the umbonial slope; umbo narrow, 
slightly prominent, oblique, nearly terminal; ligament 
margin elevated, nearly straight; epidermis yellowish 
brown, sometimes blackish brown, much wrinkled 
posteriorly; within white, iridescent posteriorly, 
waved on the margin; cardinal teeth very thick. 

SYNONYMES. 

U. costatus, Raf. Ann. gen. des Sc. Phys. vol. v. p. 49. pi. 

lxxxii. fig. 13,14. Poulson's trans, p. 57. Say, Amer. Conch. 

No. 6. Ferus. Mag. de Zool. 
U. undulatus, Barnes. Silliman's Journ. vol. vi. p. 121, pi. 2. 

OBSERVATIONS. 

This shell very nearly approaches U. plicatus, Say, 
and some varieties can scarcely be distinguished 
from it. It has, in general, more undulations, a much 
less prominent umbo, is less ventricose, and has often 
a yellowish epidermis, which is not the case with the 
plicatus. Not uncommon in the western waters, and 
in the Alabama river; very large and fine in the 
rivers of Tennessee. 



18 

This species in some of its varieties so nearly re- 
sembles U. heros, of Say, when the latter is old and 
eroded on the umbones, that Mr. Say at one time 
considered them identical; the young shell of the he- 
ros, however, was found to be so entirely dissimilar 
to the young of the costatus, that the specific differ- 
ence was obvious to the most careless observer, and 
Mr. Say in his synonymy retains his species. This 
circumstance should induce those naturalists who 
live in favourable situations to study the young of 
every species, for as Mr. Lea has justly observed, 
they are the most certain guides to specific distinc- 
tions; when the umbones and beaks are perfect, most 
species will exhibit very nearly the prominent cha- 
racters of the very young shells, and hence the ne- 
cessity of procuring cabinet specimens of the most 
perfect description, if we would effectually trace the 
species and make ourselves acquainted with their 
affinities. 






Unto pffCusit^, Lam 



19 
UNIO RETUSUS. 

Plate VIII. 
DESCRIPTION. 

Shell transversely ovate, ventricose, with concen- 
tric furrows; umbo very prominent, curved forwards; 
beaks retuse, medial; ligament long and prominent; 
umbonial slope rounded, undefined; anterior and basal 
margins regularly rounded; posterior side with a 
slight furrow, and emarginate at the extremity; liga- 
ment slope arcuate, very oblique; within dark purple, 
margined with white. 

SYNONYMES. 

U. retusa, Lam. An. sans vert. vol. vi. p. 72. Ferus. Mag. 

de Zool. 
U. torsa, Raf. Ann. gen. ties Sc. Phys. vol. v. p. 45. pi. 

lxxxii. fig. 1, 2, 3. Poulson's trans, p. 40. 

OBSERVATIONS. 

This fine species is remarkable for the elegance of 
its form, and the prominent curved beaks which 
somewhat resemble those of an Isocardia. The colour 
of the nacre is remarkably constant. One variety is 
deeply sulcated and emarginate posteriorly; another 
is entire. Young shells much resemble U. subrotun- 
das, Raf. Common in the western waters. I did 
not observe it in Alabama. 



20 
UNIO PARVUS. 

Plate IX.— Fig. 1. 
DESCRIPTION. 

Shell oblong or elliptical, with prominent concen- 
tric lines, and slightly contracted from beak to base; 
inflated posteriorly and the basal margin dilated and 
rather abruptly ascending to the extremity, which is 
narrow, obtuse, and much above the line of the base; 
umbo when not decorticated, profoundly sulcated; 
umbonial slope undefined; posterior slope with a sub- 
marginal, slightly prominent line; ligament margin 
not oblique; posterior margin obliquely truncated 
above; within white; cardinal teeth very erect. 

SYNONYMES. 

U. parvus, Barnes. Silliman's Journal, vol. vi. p. 174. 
Cab. A. N. S. No. 1872. 

OBSERVATIONS. 

A small species, without any prominent character, 
yet very distinct. It approaches nearest to U. lieno- 
sus, nob. but that species is always more or less 
radiated and generally pink or purple in the interior; 
the parvus is white within and rarely rayed. Inhabits 
western rivers generally from Bayou Teche in Louisi- 
ana to Fox river in the North Western Territory. 

An elegant specimen from the Scioto river is dark 
olive-green and distinctly rayed; and the acutely an- 
gulated ridges on the beaks are very perfect. 





,<--- 



'V 



^ 




< nia parous, Bamas 'L.Un.io alan.1, I . •■ n 





"■Sa.i^ah.'.i.'i- 




i.U nio parous, Bam.es. %..Uniu iltanx, Lea. 



21 
UNIO GLANS. 

Plate IX. — Fig. 2. 
DESCRIPTION. 

Shell ovate-elliptical, thickened anteriorly; surface 
with numerous concentric lines; anterior side short; 
posterior side subcuneiform; umbo slightly prominent; 
beaks undulated; umbonial slope undefined; epidermis 
generally dark brown, sometimes rayed; within dark 
purple, except on the anterior margin; cardinal teeth 
prominent, direct. 

SYNONYMES. 

U. glans, Lea. Trans. Amer. Philos. Soc. new series, vol.iv. 

pi. viii. fig. 12. 
Cab. A. N. S. No. 1168. 

OBSERVATIONS. 

This does not appear to be an abundant species, 
yet it is occasionally found in the waters of Ohio, 
Tennessee and Alabama. In the latter state I met 
with it only in the tributaries of the Tennessee river. 
The purple nacre and white anterior margin will al- 
ways distinguish this species from any other, which 
resembles it in form. Another peculiarity is the 
posterior tooth of the left valve pointing to the pos- 
terior extremity, which causes the teeth to diverge 
greatly. It most resembles U. lienosus, nob. and U. 
parvus, Barnes. The figure represents the largest 
and best specimen I have seen, and the only one that 
is distinctly rayed; it is from the Harpeth river, 
Tennessee. 



22 
UNIO SILIQUOIDEUS. 

Plate X.— Fig. 1. 
DESCRIPTION. 

Shell ovate-oblong or elliptical, ventricose, mode- 
rately thick; surface glabrous, olive-yellow, with nu- 
merous green rays varying much in size; anterior 
side not very short, margin regularly rounded; liga- 
ment margin straight, not declining; posterior ex- 
tremity angulated; umbonial slope undefined; beaks 
with flexuous undulations; within bluish-white; cardi- 
nal teeth oblique, lateral teeth slightly decurved pos- 
teriorly. 

SYNONYMES. 

U. siLiquoiDEus, Barnes. Silliman's Journ. vol. vi. p. 269. 
U. inflatus, lb. p. 267. 
Cab. A. N. S. No. 1055. 

OBSERVATIONS. 

The species which most resembles this appears to 
be the radiatus, which for comparison we figure upon 
the same plate. Young specimens differ constantly 
from the radiatus in having a straw-coloured highly 
polished epidermis, and much undulated beaks; are 
more inflated, have the anterior side longer and the 
margin more regularly rounded. The sexual varie- 
ties are far more strongly marked, some specimens 
having almost the form of U. cariosus, whilst the ra- 
diatus offers comparatively slight differences of out- 
line. Old shells become thick and much inflated, and 



m 







■ 



23 

resemble in form the U. teres, Raf. common in the 
western rivers. I did not observe it in Alabama. 

Mr. Say, in his synonymy of the western species, 
has given the siliquoideus as a synonyme of U. cariosus, 
considering it a mere variety of that species, and 
more strangely merges the radiatus in the same. We 
have seen abundance of both the latter and cariosus, 
in the Schuylkill and Delaware, but never any varie- 
ties of either which could for one moment have led us 
to confound the two species. Mr. Lea informs us 
that a specimen of the siliqnoideus in the Garden of 
Plants at Paris, is labelled luteola of Lamarck; this 
name we should have adopted if Ferussac had not 
referred Lamarck's specimen of luteola to cariosus, of 
Say, which we presume to be correct, as that distin- 
guished naturalist is well acquainted with those 
species which are common in the United States. 

In Bayou Teche there occurs a beautiful species 
allied to this if it be not a variety; it is distinguished 
by a darker epidermis, with distant and dark green 
rays of nearly uniform size. We have not seen many 
specimens, but a figure of it will be given when its 
characters shall be determined and its affinity with 
the siliquoideus clearly ascertained. 



24 
UNIO RADIATUS. 

Plate X. — Fig. 2. 
DESCRIPTION. 

Shell oblong-ovate, thin, slightly compressed on 
the anterior side; surface with fine wrinkled lines 
and distinct furrows; olive, with numerous green rays, 
varying in size; anterior side short and narrowed; 
margin abruptly rounded; posterior side dilated; liga- 
ment margin elevated, slightly curved; anterior basal 
margin slightly contracted; umbonial slope undefined; 
posterior extremity subtruncated; within yellowish or 
salmon coloured, and thickened anteriorly; bluish and 
highly iridescent posteriorly. 

SYNONYMES. 

U. radiata, Lam. An. sans vert. vol. vi. p. 73. 

Barnes. Silliman's Journ. vol. vi. p. 265. 

Mya radiata, Spengl. Gmel. 

U. virginiana, Lam. An. sans. vert. vol. vi. p. 79. 

U. oblongata, Wood. Suppl. Index. Test. 

Cab. Ji. N. S.No. 1116. 

OBSERVATIONS. 

A common species in the tide waters of the middle 
states, and very abundant in those of Virginia, but it 
has not been found in any of the tributaries of the 
Mississippi, except the Ouisconsin river, where, 
according to Mr. Barnes, it was obtained by Mr. 
Schoolcraft. This naturalist remarks that it inhabits 
Saratoga lake. 



ro 




.-;'--' 



**<'" 







iquoideMS,Barne, ' • me rariitttus- , Lamarck. 



C ONTEN T S 



n , rT S Fig. I, Unio Mortoni. 

Plate VI. \ J 2 ; Unio fragosus , 

,, VII. Unio costatus. 
,, VIII. Unio retusus. 

ry S Fig. 1, Unio parvus. 

" t m 2, Unioglans. 

v J Fig. 1, Unio siliquoideus. 

" t )» 2, Unio radiatus. 



JVo. 3. 



MONOGRAPHY 



FAMILY UNION ID JE , 



OR NAIADES OF LAMARCK, 



(FRESH WATER BIVALVE SHELLS,) 



OF 



NORTH AMERICA, 



ILLUSTRATED BY FIGURES DRAWN ON STOJME FROM NATURE. 



BY T. A. CONRAD, 



CURATOR OF THE ACADEMY OF NATURAL SCIENCES OF PHILADELPHIA, HONORARY MEMBER OF 
THE GEOLOGICAL SOCIETY OF PENNSYLVANIA. 



PHILADELPHIA: 
J. DOBSON, 108 CHESNUT STREET. 

LONDON: 
O. RICH, No. 12, RED LION SQUARE. 

PARIS: 
ARTHUS BERTRAND, FILS, RUE HAUTEFEUILLE No. 23. 

HAMBURG : 
PERTHES & BESSER, No. 22, AM JUNGFERNSTIEG. 

E. G. DORSEY, PRINTER. 

February 1836. 



// 




Z- . . . 

). Vnio fiecterosux, C. «~ VMO fasctoliiS , fiaf- 



25 
UNIO PECTOROSUS. 

Plate XI.— Fig. 1. 
DESCRIPTION. 

Shell elliptical, inflated, moderately thick, yellow- 
ish or olive, with unequal green rays, the larger rays 
having distant dark spots; anterior side compressed, 
extremity acutely rounded; ligament margin parallel 
with the base; umbonial slope angular; umbo broad, 
prominent, summit obtusely rounded; beaks distant 
from the anterior extremity; within white, with a 
wide greenish margin; cardinal teeth thick, promi- 
nent, direct; cardinal plate dilated. 

SYNONYME. 

U. pectorosus, Nob. New fresh water shells, p. 37. pi. vi. fig. 1. 

May, 1834. 
U. perdix, Lea. Trans. Amer. Philos. Soc. new series, vol. v. 

p. 72. pi. xi. fig. 31. Sept. 1834. 
Cab. Jl. N. S. No. 2102. 

OBSERVATIONS. 

This shell has so nearly the outline of U.fasciolus, 
that I have figured both on the same plate for com- 
parison. It differs from that species in the rays, 
dilated cardinal plate, &c. It is allied to U. ovatus, 
Say, but is much more elongated. The specimen re- 
presented has double cardinal teeth in each valve, but 
the character is not permanent. It is in the splendid 
collection of Mr. Poulson, and was found in the Har- 
peth river, Tennessee. I obtained a few specimens 



26 

on the bank of Elk river, Alabama, in which the epi- 
dermis was dark and the rays obscure. Mr. Lea 
compares it with the crassus, Say, but we cannot 
find any point of resemblance. 



UNIO FASCIOLUS. 

Plate XI. — Fig. 2. 
DESCRIPTION. 

Male. Shell elliptical, inflated, yellowish, with nu- 
merous unequal flexuous green rays; anterior margin 
regularly, not obtusely rounded; posterior extremity 
angulated; ligament margin slightly declining; umbo 
wide, prominent; beaks retuse, distant from the an- 
terior extremity; umbonial slope obtusely rounded; 
within white; cardinal teeth prominent, diverging; 
margin horn-coloured, shewing the exterior rays. 

Female. Short ovate; posterior side dilated; umbo 
narrower and more oblique; ligament margin elevated. 

SYNONYMES. 

U. fasciolus. Raf. An. gen ties Phys. Sec. vol. 5. p. Poul- 
son's trans, p. 28. Say. Amer. Conch. No. 6. 

U. multiradiatus, Lea. Trans. Amer. Philos. Soc. new series, 
vol. 3. p. 48. pi. ix. fig. 15. 

Cab. Ji. N. S. No. 1429. 

OBSERVATIONS. 

Distinguished by its numerous unequal green 
undulated rays; without these the female might be 



// 




/. Unio bactt/TOgux, ti. 



x Unio ftr.sciaUis ■ Jiaf. 



) 4~ 






""'■ 






— - -"' 












V 




i.Unio Cortaaritus, Lett, I.Unio .Mafom t 



27 

mistaken for U. cariosus. Old shells are very thick 
and ponderous, and Mr. Poulson has a fine specimen 
of this description. Had the Baron de Ferussac seen 
this, we think he would not for a moment have deemed 
it a variety of U. subovatus. Mr. Phillips has two 
fine specimens, male and female; the former is repre- 
sented. 



UNIO CONGARiEUS. 

Plate XII.— Fig. 1. 

DESCRIPTION. 

Shell elliptico-rhomboidal, thin, somewhat flattened 
at the sides; epidermis olive or reddish-brown, with 
numerous green rays, sometimes obsolete; umbones 
flattened, broad; summits obtusely rounded, slightly 
prominent; umbonial slope profoundly angulated; 
ligament slope slightly oblique; posterior slope much 
depressed, with oblique, irregular, undulated lines; 
within white, highly iridescent; cardinal teeth oblique; 
lateral teeth elongated, slightly curved. 

SYNONYME. 

U. congarjEus, Lea. Trans. Amer. Philos. Soc. new series, vol. 

4. p. 72. pi. vi. fig. 4. 
Cab. A. N. S. No. 2101. 

OBSERVATIONS. 

Inhabits the eastern waters of South Carolina. I 
found it also at Augusta, Georgia, in great numbers. 



28 

It certainly approaches U. niger, Raf.; the young of 
the latter resembling it so much, as to lead to the 
inference that they may be varieties of one species, 
occasioned by difference of locality. Specimens from 
Augusta resemble the niger more than those from the 
Congaree river; and in Flint river, Georgia, is a va- 
riety of the latter, differing only from the congarceus 
in being rather larger and more ponderous. 



UNIO MASONI. 

Plate XII.— Fig. 2. 

DESCRIPTION. 

Shell suboval, thin; umbones broad, inflated, disks 
slightly flattened near the umbonial slope; beaks dis- 
tant from the anterior margin; ligament margin ele- 
vated; umbonial slope angulated; epidermis oliva- 
ceous, polished, wrinkled inferiorly; summits decor- 
ticated; within white, cardinal teeth oblique, rather 
thick. 

SYNONYME. 

U. masoni, Nob. New fresh water shells, p. 34. pi. 5. fig. 2. 
Cab. A. N. S. No. 2100. 

OBSERVATIONS. 

Inhabits Savannah river, at Augusta. When the 
description was originally published, I had seen only 



1% 





t.Unin Conqaraius, Lea. /L . V n 10 Mta.so iij, C 



/■ i 




//>„, a WMrtfb.A UctlOhu << 



29 

the young shell, but subsequently, in examining a 
number of specimens of U. congarceus from the same 
locality, an adult specimen was discovered, which has 
served for the figure and description. It is in Mr. 
Phillips's cabinet. The outline of the young shell is 
represented for comparison with that of IT. congarceus. 
Mr. Poulson's cabinet. 

It is dedicated to Mr. William Mason, whose dis- 
coveries have much advanced our knowledge of 
American conchology. 



UNIO COCCLNEUS. 

Plate XIII.— Fig. 1. 

DESCRIPTION. 

Shell oblique, subtriangular, compressed, slightly 
waved; epidermis blackish-brown, with crowded 
wrinkles; anterior side very short; posterior side sub- 
cuneiform, much compressed, extremity truncated; 
umbo slightly flattened; basal margin not much ar- 
cuated posteriorly; posterior margin slightly sinuous, 
oblique, rounded above; umbonial slope abruptly 
rounded; summits prominent, eroded; within salmon 
colour, rarely white; cardinal teeth double in each 
valve, direct. 



SYNONYME. 



U. coccineus, Hildrcth. 
Cab. A. N. S. No. 2104. 



30 

OBSERVATIONS. 

This shell, in having a slightly undulated disk, ap- 
proaches the mytiloides, Raf., but is very distinct. It 
is well known in the collections by the name we have 
adopted, but we are informed that Dr. Hildreth has 
not published his description of it. I have figured a 
fine specimen from Mr. Hyde's cabinet. This na- 
turalist observes that the species inhabits Mahoning 
river, near Pittsburg, and that of the very many 
specimens he has received, none has perfect beaks. 



UNIO CATILLUS. 

Plate XI II.— Fig. 2. 
DESCRIPTION. 

Shell oval orbicular, slightly oblique, moderately 
thick, convex, dark chestnut-brown, with crowded 
wrinkles; anterior margin obtusely rounded or sub- 
truncated; posterior margin rectilinear, nearly direct, 
extremity rounded; umbonial slope rounded; umbones 
inflated, narrow, prominent; ligament margin rectili- 
near, oblique, angular posteriorly; summits slightly 
flattened; beaks much incurved, pointed, slightly tu- 
berculated; lunule short ovate; within rosaceous; 
cardinal teeth thick, direct, profoundly sulcated; la- 
teral tooth of the left valve very thick, that of the 
right valve compressed, and rising from a very broad 
plate or base projecting on either side; cardinal plate 
profoundly dilated. 

Cab. A. N. S. No. 2103. 



n 




--:■-""■ ' 



„-■- 


—'•-"' " 





-.Ax. - - 



. 



T" —;■• 




Unio coco cne us, Mil dre tk. u ctitillus, C. 



// 












■'■ 



31 

OBSERVATIONS. 

This species has been sent from the west, under 
the name of coccineus, but is so very distinct that I 
should not otherwise have compared it with that 
species. It approaches nearest to the politus of Say, 
and obliquns. Lam., but the peculiarity of the teeth 
and greatly dilated cardinal plate, as well as many 
other characters, forbid a union with either. Mr. 
Hyde informs me that a great number of specimens 
in his possession, from the Scioto river, shew the in- 
terior to be generally of a rose colour or purple, oc- 
casionally nearly white, and rarely salmon. Of the 
latter Mr. Hyde possesses a specimen more beauti- 
fully coloured than any Unio I have seen — it will be 
figured in a future number. The figure is from a 
specimen in the cabinet of Mr. Phillips. 



UNIO PRODUCTUS. 

Plate XIV.— Fig. 1. 
DESCRIPTION. 

Shell narrow-elliptical, produced, moderately thick, 
slightly ventricose, somewhat contracted near the 
middle; anterior side short, dilated, margin obtusely 
rounded; basal margin sinuous; posterior side ros- 
trated; extremity rounded, much above the line of the 
base; ligament margin parallel with the line of the 
base; umbonial slope obtusely carinated; umbo decor- 
ticated, not elevated above the dorsal line; within 



32 

purplish; cardinal teeth thick, direct; lateral teeth 
thick. 

OBSERVATIONS. 

On a passing glance this shell would certainly be 
mistaken for U. nasutus, but the thickness of the shell, 
the dilated anterior side, and thick, direct, lateral 
teeth, will sufficiently distinguish it. The disk pos- 
teriorly has several small plicae or undulations simi- 
lar to those of U. gray anas, Lea, but as only one 
specimen can be examined this character may prove 
inconstant. 

In the cabinet of Mr. Phillips. I found it on the 
shore of Savannah river, at Augusta, and supposed 
it to be a variety of nasutus, but comparing it with 
that species from South Carolina and Florida, it was 
found to differ materially, and to form a link between 
it and the rectus. 



UNIO LANCEOLATUS. 

Plate XIV.— Fig. 2. 
DESCRIPTION. 

Shell narrow-elliptical, thin, ventricose, yellowish, 
smooth and polished; disks slightly flattened; ante- 
rior side somewhat compressed, not very short, mar- 
gin regularly rounded; umbonial slope regularly 
rounded, inflated; posterior side produced, extremity 







: 





I i n in /' rurliK-i'u.v ■■ ,%, . turn i al.alu-i , Ltd. Jan 



CONTENTS. 



Plate XI 5 Fi &- *> Unio pectorosus. 
I ,.2, Unio fasciolus. 

-v-tt 5 Fig. 1, Unio congarseus. 

" ^"" I „ 2, Unio Masoni. 

XIII $ ^ lff * 1 ' ^ n ^° c °ccineus. 

" c „ 2, Unio catilJus. 

^•jy S Fig. 1, Unio productus. 

" ___,' X r 3, 2, Unio lanceolatus. 
„ XV. Unio rectus. 



JVo. 4. 



MONOGRAPH Y 



OF THE 



FAMILY UNIONID^E, 



OR NAIADES OP LAMARCK, 



(FRESH WATER BIVALVE SHELLS,) 



NORTH AMERICA, 



ILLUSTRATED BY FIGURES DRAWN ON STONE FROM NATURE. 



BY T. A. CONRAD, 



CURATOR OF THE ACADEMY OP NATURAL SCIENCES OF PHILADELPHIA, HONORARY MEMBER OF 
THE GEOLOGICAL SOCIETY OF PENNSYLVANIA. 



PHILADELPHIA: 

J. DOBSON, 108 CHESNUT STREET. 

BOSTON: PERKINS & MARVIN.— PITT8B URGH: JOHN I. KAY & Co.- 

LONDON: O. RICH, No. 12, RED LION SQUARE.— PARIS: ARTHUS 

BERTRAND, FILS, RUE HAUTEFEUILLE No. 23- HAMBURGH: 

PERTHES & BESJER, No. 22, AM JUNGFERNSTIEG. 

E. G. DORSEY, PRINTER. 

March 1836. 



/s. 




l T nu r- -///"- .Law/trek 



33 

angulated; beaks not prominent; ligament margin 
short, elevated; within pale salmon colour; lateral 
teeth slightly recurved. 

SYNONYME. 

U. lanceolatus, Lea. Trans. Amer. Philos. Soc, new series, 

vol. iii. pi. 3. fig. 2. 
Cab. A. N. S. No. 1105. 

OBSERVATIONS. 

Inhabits Tar river, N. C, Mr. Lea. Mr. Hyde 
has received specimens from the Rappahannoc at 
Fredericksburg, Va. It approaches nearest in out- 
line to U. productus and nasutus, but cannot be easily 
confounded with either. 



UNIO RECTUS. 

Plate XV. 

DESCRIPTION. 

Shell profoundly elongated, thick; anterior side 
short; posterior side rostrated, cuneiform; extremity 
angular, compressed; umbo inflated, but not promi- 
nent, obtusely rounded; disks slightly contracted in 
the middle; ligament margin nearly rectilinear; epi- 
dermis dark green or olive-brown, smooth, frequently 
with broad green rays; within pink in the middle; 
cardinal teeth small, direct, double in each valve. 

SYNONYMES. 

U. rectus, Lam. An. sans vert. vol. vi. p. 74. 
E 



34 

U. latissima, Jiaf. An. gen. des Sc. Phys. vol. 5. p. 31. Poul- 

son's trans, p. 25. 
U. PRiELONGus, Barnes. Silliman's Jour. vol. vi. p. 261. 
Cab. A. N. S. No. 1112. 

OBSERVATIONS. 

This shell resembles in outline U. nasutus, Say, U. 
lanceolatits, Lea, and U. teres, Raf. With the latter 
it has most affinity. It is a common western species, 
found as far north as the Ouisconsin, and inhabits 
the Alabama river near Claiborne. The figure was 
taken from a fine male specimen in Mr. Poulson's 
cabinet. 



UNIO CRASSUS. 

Plate XVI. 

DESCRIPTION. 

Male. Shell ovate, thick, yellowish, with brown 
rays, obsolete inferiorly; umbo broad, flattened; beaks 
obtuse, nearly terminal; umbonial slope angulated; 
posterior side cuneiform; posterior dorsal margin 
arcuate; basal margin dilated behind the middle; pos- 
terior extremity angular; within salmon colour or 
white, with a horn-coloured margin; cardinal teeth 
direct, thick, very prominent, subtrifid. 

Female. Shell oval quadrate, ventricose, posterior 
side dilated; posterior margin widely truncated, di- 
rect; umbo oblique and terminal. 



16 






Unt i c rassus, Sat/. 



17 




"^■kt 





sjS: 




in in ■tiividiSjRjaf. Z.Unio oclivcLc&us, Say, 



35 

SYNONYMES. 

U. crassus, Say. Nich. Enc. (Amer. ed.) art. Conch, pi. i. fig. 

8. old male. 
IL crassidens, var. c. Lam. An. sans vert. vol. vi. p. 71. 
U. ligamentina, ib. p. 72. 

U. ellipticus, Barnes. Silliman's Jour. vol. vi. p. 259. male. 
U. suBORBicuLATUs, Hildreth. Silliman's Jour. vol. xiv. female. 
U. abruptus, Say. Amer. Conch, pi. 17, female, var. A. male. 
U. cyclops, Raf. Contin. of Monog. p. 2, female. 
Cab. A. N. S. No. 358. 

OBSERVATIONS. 

Closely related to U.fasciatus, Raf., but can be dis- 
tinguished from that species by fewer and narrower 
rays, generally distinct only over the umbones; by a 
lighter coloured more polished epidermis; more pro- 
minent teeth, and the prevalence of a salmon co- 
loured interior. Common in the rivers of Ohio, 
Indiana, and Illinois, but appears to be rare in the 
more southern states. I could not find it in the 
rivers of Alabama. The specimen figured was pre- 
sented by Dr. Blanding. 



UNIO VIRIDIS. 

Plate XVII.— Fig. 1. 

DESCRIPTION. 



Shell elliptical or subovate, ventricose, thin; disks 
slightly flattened anteriorly, much inflated over the 
umbonial slope; lines of growth prominent; ligament 
margin elevated; posterior slope dilated; posterior 



36 

extremity truncated, direct; epidermis with green 
rays, obsolete anteriorly, distinct and very unequal 
posteriorly; umbo slightly prominent; beaks with an- 
gular furrows, pointed; within white, iridescent; car- 
dinal teeth compressed, oblique, that of the left valve 
double or trifid; lateral teeth of the left valve imper- 
fectly divided. 

SYNONYME. 

U. viridis, Raf. An. gen. des Sc. Phys. vol. v. p. 27. Poulson's 

trans, p. 19. 
Cab. A. N. S. No. 2105. 

OBSERVATIONS. 

The first specimen of this species which came 
under my observation, was found in the Schuylkill 
river, near Philadelphia, by Mr. Hyde, who kindly 
offered me the use of it, as I supposed it to be unde- 
scribed. Comparing it, however, with a single valve 
from the Kentucky river, in Mr. Poulson's cabinet, 
it proved to be of the same species with that speci- 
men which was labelled viridis by Rafinesque. Mr. 
Hyde has received specimens from a small stream 
near Lancaster, and from the Juniata river. One 
from the latter locality has been selected for the figure 
and description. It is allied to U. heterodon, but can- 
not be confounded with that species. 



■J: |- 



■ : ' 



- 




m 




, ; ■ nuU : />'!/ 'i i n 'ft ncJi '■■■■' 



37 
UNIO OCHRACEUS. 

Plate XVII.— Fig. 2. 

DESCRIPTION. 

Shell elliptical, inflated, thin; epidermis smooth 
and polished, rugose posteriorly, yellowish, with nar- 
row green unequal rays; anterior side narrowed, and 
the superior margin elevated and connate; ligament 
margin not oblique; umbo inflated; posterior extre- 
mity angular; umbonial slope angular; basal margin 
profoundly arcuate; within white, rarely pale rose or 
salmon; cardinal teeth very oblique, much compressed, 
bifid in the right valve; single or imperfectly divided 
in the left; lateral teeth arcuate. 

Var. A. Reddish brown; rays obsolete or want- 
ing; within rosaceous. 

SYNONYMES. 

U. ochraceus, Say. Nich. Enc. (Amer. ed.) art. Conch, pi. ii. 

fig. 8. 
Symphynota ochracea, Lea. Trans. Amer. Philos. Soc, new 

series, vol. iii. p. 69. 
Var. A. Mytilus fluviatilis, Gmel. Lister, tab. 157. fig 1<? 
Cab. A. N. S. No. 1063. 

OBSERVATIONS. 

Very common in the Schuylkill and Delaware 
rivers, and inhabits most tide waters north of Savan- 
nah river. Variety A. is very abundant in James 
river, Virginia, where I found vast numbers of shells 
brought ashore by seines used in the shad fishery in 



38 

the month of March. So accurately does the above 
mentioned variety agree with Lister's figure and de- 
scription, that I cannot doubt the identity. The 
species is, perhaps, most closely allied to U. cariosus, 
its common associate in the Delaware and Schuylkill. 
The specimen figured has a double cardinal tooth in 
each valve. 



UNIO xNASUTUS. 

Plate XVIII.— Fig. 1. 

DESCRIPTION. 

Shell elongated, compressed, thin; disks slightly 
flattened; anterior side short; posterior side rostrated, 
tapering, angular at the extremity; umbo not promi- 
nent; beaks small, eroded; umbonial slope profoundly 
oblique, angulated; ligament margin rectilinear, ele- 
vated; posterior superior margin profoundly oblique 
and slightly concave; within bluish, iridescent, rarely 
purple or salmon; cardinal teeth compressed and 
oblique, double in each valve. 

SYNONYMES. 

U. nasutus, Say. Nich. Enc. (Amer. ed.) art. Conch, pi. iv. 
fig.. I. 

U. ROSTRATA, ValetlC. 

Lister, tab. 151. fig. 6. 
Cab. A. N. S.No. 1123. 

OBSERVATIONS. 

A common species in the tide waters from Florida 






\.f 



>T" 






2, 



1. Vnia n (tstdas, S ay: Z. ' . icterin us, ami 



in 






vC -" 



nusutiis. 8 ay. &.T\ ic/er/.n us, ■■ > 



39 

to the eastern states. I found it in great abundance 
in the Potomac river, near Washington, where the 
specimens are exceedingly elongated. The smaller 
specimen figured is a female variety from James 
river, Virginia, where they are generally ornamented 
with rays; the other figure represents a rare purple 
variety from Chester river, Maryland: it is in the 
cabinet of Mr. Phillips. In old shells the teeth are 
often thick and direct. 



UNIO ICTERINUS. 

Plate XVIII.— Fig. 2. 
DESCRIPTION. 

Shell elliptical, moderately thick; anterior margin 
regularly rounded; posterior margin descending ob- 
liquely, and subtruncated at the extremity; umbo not 
prominent; summit decorticated; umbonial slope very 
oblique, angulated; epidermis smooth and polished, 
olive yellow; within salmon coloured; cardinal tooth 
in the left valve trifid, in the right, single. 

SYNONYME. 

U. icterinus, Nob. New fresh water shells, p. 41. pi. vi. fig. 5. 
Cab. Jl. N. S. No. 2106. 

OBSERVATIONS. 

I found the species in the Savannah river, at Au- 
gusta. It resembles U. lanceolatus in epidermis and 
colour. Its proper place, we think, is between nasu- 
tus and declivis, Say. 



40 
UNIO CARIOSUS. 

Plate XIX. 
DESCRIPTION. 

Shell subovate, ventricose, thick anteriorly; epider- 
mis yellowish or straw coloured, very smooth and 
polished, with a few narrow dark green rays poste- 
riorly, more numerous on the posterior slope; umbo 
prominent, decorticated; umbonial slope angulated; 
ligament margin elevated; ligament prominent; basal 
margin swelling posteriorly; within white; cardinal 
teeth double in each valve, prominent, oblique. 

SYNONYMES. 

U. cariosus, Say. Nich. Enc. (Amer. ed.) art. Conch, pi. iii. 

fig. 2. female. 
U. luteola, Lam. An. sans vert. vol. vi. p. 79. 
U. ovatus, Valenc. 
Cab. A. N. S. No. 1022. 

OBSERVATIONS. 

This is one of the most abundant species in the 
tide waters of the middle states, but I found it com- 
paratively rare in the Potomac and James rivers. In 
varieties of form it much resembles U. crassus, and 
both male and female are represented, in order to 
convey a clear idea of sexual differences, which are 
so striking in a large proportion of the species. It 
is very often destitute of rays, and I have seen only 
one specimen in which the rays extended over the 
disk to the anterior margin. 



0> 







/:!. 



| 




,■ ■■ r ' 



CONTENTS 



Plate XV. Unio rectus. 
,. XVI. Unio crassus. 



TVTT £ Fig. 1, Unio viridis. 
" -*-*"■$ „ 2, Unio ochraceus. 

"5TVTTT 5 Fig- 1> Unio nasutus. 
„ jl v in. ^ ^ ^ Unio j cter i nus# 



XIX. Unio cariosus. 



JYo. 5. 



MONOGRAPH Y 



OF THE 



FAMILY UNIONIDiE, 



OR NAIADES OF LAMARCK, 



(FRESH WATER BIVALVE SHELLS,) 



NORTH AMERICA, 



ILLUSTRATED BY FIGURES DRAWN ON STONE FROM NATURE. 



BY T. A. CONRAD, 



CURATOR OF THE ACADEMY OP NATURAL SCIENCES OF PHILADELPHIA, HONORARY MEMBER OF 
THE GEOLOGICAL SOCIETY OF PENNSYLVANIA. 



PHILADELPHIA: 

J. DOBSON, 108 CHESNUT STREET. 

BOSTON: PERKINS & MARVIN.— PITT SB VRGH: JOHN I. KAY & Co.- 

LONDON: O. RICH, No. 12, RED LION SQUARE.— PARIS: ARTIIUS 

BERTRAND, FILS, RUE HAUTEFEUILLE No. 23.— HAMBURGH: 

PERTHES & BESSER, No. 22, AM JUNGFERNSTIEG. 

E. G. DORSEY, PRINTER. 

June 1836. 



zo 




Unit) lift) aides, U.afin-es(fu.t>,. 



41 
UNIO MYTILOIDES. 

Plate XX. 
DESCRIPTION. 

Shell elevated, subtriangular; epidermis reddish- 
brown, with crowded wrinkles; posterior side with a 
broad furrow; anterior side gibbous; umbo tapering, 
curved, narrowed at the summit, which is much ele- 
vated; lunule obtusely cordate; within white, purple, 
and iridescent towards the posterior extremity; car- 
dinal teeth large, very thick, prominent, sulcated; 
posterior muscular impressions impressed, the smaller 
one profoundly. 

SYNONYMES. 

U. mytiloides, Raf. Ann. gen. des Sc. Phys. vol. v. p. 47. pi. 82. 

fig. 8. Poulson's trans, p. 53. 
U. rubra, Raf. 
U. pyramidatus, Lea. Trans. Amer. Philos. Soc, new series, 

vol. iv. p. 109, pi. xvi. fig. 39. 
U. caridiacea, Say of Guerin. 
Cab. A. N. S. No. 2017. 

OBSERVATIONS. 

This common species, since its first discovery in 
the western waters, has always been known by the 
name we have adopted. It is nearly allied to U. cor, 
Nob., and U. imdatus, Barnes, but is very distinct, 
although its varieties are intricate and perplexing. 
Young specimens are very short and greatly elevated, 
and frequently rayed; old shells are compressed, cu- 



42 

neiform, and produced posteriorly; the rays confined 
to the umbo and obsolete. Inhabits the Alabama 
and Black Warrior rivers. 



UNIO DILATATUS. 

Plate XXI. 
DESCRIPTION. 

Shell ovato-elliptical, thick and ponderous, slightly 
sinuous; posterior side produced, compressed, cunei- 
form; umbo broad, flattened, summit obtusely round- 
ed; anterior lunule large, elliptical; umbonial slope 
angulated, not very distant from the margin; basal 
margin slightly contracted near the middle; within 
obliquely sulcated from the umbo towards the poste- 
rior basal margin; colour purple, with a bluish mar- 
gin; cardinal teeth thick, direct; lateral teeth very 
thick, and terminating rather abruptly. 

SYNONYMES. 

U. dilatatus, Raf. Ann. gen. des Sc. Phys. vol. v. p. 31. Poul- 
scm's trans, p. 25. Say, Amer. Conch. No. 6. Ferr. Mag. de 
Zool. 

U. nasutus, Lam. An. sans vert. vol. vi. p. 75. 

IT. gibbosus, Barnes. Silliman's Journ. vol. vi. p. 262. 

Cab. A. N. S. No. 1072. 

OBSERVATIONS. 

In outline this species approaches U. fasciolaris, 
but "differs in the much less dilated cardinal plate, in 
having the anterior [posterior] smaller muscular im- 



%1 




Unto di/ulatu.y, Hafrne.fc/u.e. 



%% 




Unio tuberr.ulatiLSj & a f 



43 

pression situated immediately beneath the tip of the 
lamelliform teeth, in having the anterior [posterior] 
lunule much more depressed, with slightly elevated 
lines crossing the wrinkles."* It also differs in hav- 
ing a purple interior, varying from an intense shade 
of that colour, approaching an indigo blue, to a pale 
reddish-purple. The great thickness of the superior 
portion of the shell causes the cavity of the umbo to 
be very shallow. 

Common in the tributaries of the Ohio, Upper 
Mississippi, and Missouri. In Alabama, I found it 
only in the Tennessee and its tributaries. It is a 
common species in the mountainous region of North 
Carolina and Virginia, where, from a poverty of cal- 
careous matter, it is always comparatively small. 
U. cuprea and U. atroviolacea, Raf., appear from the 
descriptions to be mere varieties of U. dilatatus. 



UNIO TUBERCULATUS. 

Plate XXII. 
DESCRIPTION. 

Shell subquadrangular, convex, thick; disk covered 
with irregular tubercles, except towards the anterior 
margin; tubercles largest near the centre of the disk; 
anterior margin obtusely rounded; posterior margin 
direct, emarginate; anterior lunule elliptical, profound; 
umbo narrow, very prominent; beaks pointed, ap- 
proximate, but generally eroded or worn in maturity; 

* Say. Amer. Conch, pi. 22. 



44 

umbonial slope angulated; basal margin arcuate; epi- 
dermis green olive, with green capillary rays over 
the umbo; within chocolate colour; cardinal teeth 
very large, direct, prominent, trifid in the right valve; 
cavity of the beak very profound. 

SYNONYMES. 

U. tuberculatus, Rcif. Ann. gen. des Sc. Phys. vol. v. p. 42. 

Say. Amer. Conch. No. 6. Ferr. Mag. tie Zool. 
U. verrucosus, Barnes. Silliman's Journ. vol. vi. p. 125, pi. 5, 

fig. 6. 

U. TUBERCULOSA, VuhnC. 

Cab. Ji. N. S. No. 1430. 

OBSERVATIONS. 

Some varieties of this species closely resemble U. 
bullatus exteriorly, but independent of other charac- 
ters, the chocolate coloured interior, which, though 
sometimes pale, never wholly disappears, will at once 
distinguish the present species from all its congeners. 
It is a very variable shell; some specimens from the 
Harpeth river, Tennessee, being much dilated and 
compressed, and the ligament margin so much ele- 
vated as to give the posterior side an alated appear- 
ance. Other specimens are far more elevated in 
proportion to their length, and the posterior sulcus 
and emargination profound. These great differences 
may be sexual characters, but require an anatomical 
investigation of the animal to settle that point. 

Common in the western rivers, and inhabits Lake 
Erie and the Ouisconsin, according to Mr. Barnes. 
It is not found in Alabama south of the Tennessee 
river and its tributaries. 



zs 





UTyiio decllvU, Say.A-.USlandin^ittntts, Lea 



45 



UNIO DECLIVIS. 

Plate XXIII.— Fig. 1. 

DESCRIPTION. 

Shell trapezoidal, moderately thick; anterior mar- 
gin obtusely rounded; beaks slightly elevated, with 
oblique undulations; hinge margin rather elevated 
and compressed, angulated at tip; posterior margin 
rectilinear, descending obliquely to a prominent ros- 
trum of the posterior basal margin at the extremity of 
the umbonial slope; umbonial slope abruptly rounded, 
and bounded on its posterior side by two slightly im- 
pressed lines; basal margin arcuate; surface deeply 
wrinkled; within tinged with purplish; cardinal teeth 
oblique; lateral teeth distant from the cardinal teeth. 

SYNONYMES. 

U. declivis, Say. Trans. Journ. vol. iv. p. 527, Amer. Conch. 

pi. 55. 
U. geometricus, Lea. Trans. Amer. Philos. Soc. new series, 

vol. v. p. 38, pi. 4, fig. 10. 
Cab. A. N. S. No. 1875. 

OBSERVATIONS. 

This species resembles a variety of the complanatus 
in its general form, and its teeth and posterior angle 
are somewhat similar to those of nasutus. It is very 
distinct from either. The figure is from a fine speci- 
men which I found in a small creek in Greene county, 
Alabama, where the species is abundant, but usually 
more compressed than the one I have selected for 
representation. I was unable to find a specimen in 



46 

any of the large rivers. It is common in Bayou 
Teche, Louisiana, and has been found in the Ohio 
canal near Louisville, whence Mr. Hyde has received 
it. 



UNIO BLANDINGIANUS. 

Plate XXIII.— Fig. 2. 

DESCRIPTION. 

Shell subtrapezoidal, rather thin, ventricose; ante- 
rior margin very obtusely rounded; ligament margin 
much elevated, slightly arcuate, angulated at tip, pos- 
terior margin long, oblique and rectilinear; extremity 
subtruncated or obtusely rounded; beaks slightly ele- 
vated, eroded; umbonial slope rounded, very distant 
from the margin; epidermis finely wrinkled; within 
purplish, with green stains; cardinal teeth small, single 
in the right valve and compressed; widely bifid, and 
rather obtuse in the left; lateral teeth distant from 
the cardinal teeth, and arcuate; anterior muscular 
impressions marginal. 

SYNONYME. 

U. blandingianus, Lea. Trans. Amer. Philos. Soc. new series, 

vol. v. p. 101, pi. xv. fig. 44. 
Cab. A. N. S. No. 1859. 

OBSERVATIONS. 

A species allied to complanatus and declivis, but 
differing from both in the elevated ligament margin 
and inflated disks. The anterior lunule resembles 



'U 






l£§^ 




declivls, Say. *,.U£la.ndinaian,u& l lea 



%1 






I n; o TieT.vrmotu.i' s>"i. 



47 

that of the preceding species. It was obtained in 
East Florida, from an Indian, by Dr. Blanding, and 
to this worthy naturalist the species has been pro- 
perly dedicated. 



UNIO PERSONATUS. 

Plate XXIV. 

DESCRIPTION. 

Shell sublenticular; length rather more than the 
height; anterior margin forming with the basal mar- 
gin a regular curve to the termination of the umbo- 
nial slope; posterior side narrowed; posterior margin 
subtruncated; umbo rounded, very prominent, subme- 
dial; umbonial slope swelling near the base, gaping 
and denticulate on the margin; epidermis with nu- 
merous capillary rays, profound and undulated on 
the posterior side; within pink; cardinal teeth direct, 
thick, prominent; lateral teeth slightly recurved; cavity 
of the beak not profound. 

SYNONYMES. 

U. personatus, Say. New Harmon y Disseminator, p. 509, 1829. 
U. capillaris, Lea. Trans. Amer. Philos. Soc. new series, vol. 

v. p. 29, pi. 2, fig. 2, 1832. 
Cab. A. N. S. No. 1382. 

OBSERVATIONS. 

It would seem from the observations of Dr. Kirt- 
land, that all those Uniones which have the peculiar 
denticulated and dilated base, are female shells; and 



48 

if so, we are unacquainted with the male personatas. 
The exterior somewhat resembles V. Icevigatus, and 
the cardinal teeth are very like those of U. nexus; 
Say's description applies only to the immature shell. 
For the use of the splendid specimen here represented 
and described, we are indebted to G. W. Feather- 
stonhaugh, Esq., who procured it from Cumberland 
river, Tennessee. Mr. Say's specimens were from 
the Wabash. 



UNIO CORDATUS. 

Plate XXV. 
DESCRIPTION. 

Shell subtriangular, not oblique, length and height 
nearly equal; beaks distant from the anterior margin, 
prominent, incurved and pointed; anterior lunule very 
broad and obtusely obovate, beneath which is a flat- 
tened cordate space with the opposite margin recti- 
linear; inferior portion of the anterior margin regu- 
larly rounded to the middle of the basal margin, 
which is emarginate and ascending posteriorly; sinus 
of the posterior side not oblique, slightly arcuate; 
posterior margin rounded above, angulated at its 
junction with the basal margin; epidermis fuscous, 
with green interrupted rays over the umbo; within 
white. 

SYNONYME. 

U. cordatus, Raf. Ann. gen. des Sc. Phys. vol. v. p. 46. Poul- 

son's trans, p. 52. 
Cab. A. N. S. No. 2018. 



Hi 




l/i/o covdal a x , Rnf'iiirx-ifur. 



• hi , //, 1 jlii :' ,'■■ ' 



DESCRIPTION OP A NEW ANODONTA. 



ANODONTA VIRGATA. 

Description. 

Shell subovate, thin and fragile, inflated; umbo prominent, distant 
from the anterior extremity; beaks pointed, incurved, undulated; um- 
bonial slope angulated; posterior margin arcuate, extremity angulat- 
ed; basal margin dilated posteriorly; within bluish and iridescent; 
cavity very capacious. 

Observations. 

This pretty Anodonta is related to A. undulata, Say, but can be 
known by the posterior dilatation of the basal margin, which inclines 
the outline to an ovate form, and by the rays, which are very numerous 
and unequal, of a beautiful dark green, or the epidermis is green with 
narrow pale rays, and much resembles Anodonta radiata, nob.; it is 
comparatively shorter than that species. 

This species was afforded me for description by Dr. Jacob Green, 
Professor of Chemistry in Jefferson College. Mr. William Mason has 
specimens from Buck Creek, Clarke county, Ohio. 



CONTENTS 



Plate XXI. Unio dilatatus. 
,, XXII. Unio tuberculatus. 

Yyjit $ Fig. 1, Unio declivis. 
„ ^^111.^ ^ 2, Unio Blandingianus. 

,, XXIV. Unio personatus. 
,, XXV. Unio cordatus. 



.TVtf. 6. 



MONOGRAPH Y 



FAMILY UNION ID JE , 



OR NAIADES OF LAMARCK, 



(FRESH WATER BIVALVE SHELLS,) 



NORTH AMERICA, 



ILLUSTRATED BY FIGURES DRAWN ON STONE FROM NATURE. 



BY T. A. CONRAD, 



CURATOR OP THE ACADEMY OF NATURAL SCIENCES OF PHILADELPHIA, HONOUAUV MEMBER OF 
THE GEOLOGICAL SOCIETY OF PENNSYLVANIA. 



PHILADELPHIA: 

J. DOBSON, 108 CHESNUT STREET. 

BOSTON: PERKINS & MARVIN.— PITTSBURGH: JOHN I. KAY & Co. 

LONDON: O. RICH, No. 12, RED LION SQUARE.— PARIS: ARTIIUS 

BERTRAND, FILS, RUE IIAUTEFEUILLE No. 23.- HAMBURGH: 

PERTHES & BESSER, No. 22, AM JUNGFERNSTIEG. 

E. G. DORSEY, PRINTER. 

July 1836. 



Z6 




Tntn nititr. Raj. 



49 

OBSERVATIONS. 

I formerly supposed this shell a variety of myti- 
loides, but the differences are so constant in a great 
number of specimens, that it may be useful to intro- 
duce it to conchologists by the name which Rafinesque 
has bestowed upon it. It differs from mytiloides in 
not being oblique, in being about as long as it is high, 
in having the beaks distant from the anterior margin, 
and never in any stage of growth having the poste- 
rior side prolonged obliquely downwards. 

Inhabits the Ohio and its tributaries. The speci- 
men figured belongs to the cabinet of Mr. Feather- 
stonhaugh, and is from Cumberland river, Tennessee. 
It connects U. mytiloides with U. undatus. 



UNIO NIGER. 

Plate XXVI. 
DESCRIPTION. 

Shell elliptical; with age, subovate, or subtriangu- 
lar; thick and ponderous; disks somewhat flattened; 
posterior lunule with short, oblique, vermicular raised 
lines; posterior side compressed, cuneiform; umbo 
broad, flattened, summit obtusely rounded; umbonial 
slope angulated; epidermis reddish-brown, frequently 
rayed; within purple or salmon colour; cardinal teeth 
direct, prominent; lateral teeth thick, distant from 
the cardinal teeth; posterior muscular impression 
slightly impressed; cavity of the beak shallow. 

G 



50 

SYNONYMES. 

U. niger, Raf. Ann. gen. des Sc. Phys. vol. v. p. 25. Poul- 
son's trans, p. 15. Say. Amer. Conch. No. 6. Ferr. Mag. de 
Zool. 

U. crassidens, var. b. Lam. 

U. cuneatus, Barnes. Silliman's Journ. vol. vi. p. 263. 

Cab. A. N. S. No. 2400, 2401, 2402. 

OBSERVATIONS. 

In the observations on U. congarceus, I compared 
that species with the niger, but however the young 
of both may resemble each other exteriorly, the car- 
dinal teeth of the latter are always more robust and 
less oblique, and the interior very often dark purple, 
which is never the case with the congarceas. It dif- 
fers most obviously from U. dilatatus, in being com- 
paratively much shorter, and in the raised lines on 
the posterior lunule. 

Common in the western streams, and very abun- 
dant in the Black Warrior and Alabama rivers. In 
Detroit river, Michigan, it has been obtained by Dr. 
Sager. 



UNIO GIBBOSUS. 

Plate XXVII.— Fig. 1. 

DESCRIPTION. 



Shell subovate, oblique, with a submedial nodulous 
ridge projecting at base; concentric sulci very dis- 
tinct; posterior side with a wide furrow; umbonial 
slope angulated; umbo prominent; posterior end and 



%1 





Unio tjihbosu.3, Hat. Z.partety. 



■11 





j. UniO qihboSU «? . Ji li r. Z.l'GCT 



51 

posterior basal margin emarginate; epidermis smooth, 
shining, yellowish with numerous green rays; within 
white, rarely rose coloured. 

SYNONYMES. 

U. gibbosus, Raf. Ann. gen. des Sc. Phys. vol. v. p. 49. Poul- 

son's trans, p. 56. 
U. torulosus, Raf. lb. p. 48. Poulson's trans, p. 56. 
U. perplexus, Lea. Trans. Amer. Philos. Soc. new series, vol. 

iv. p. 122, pi. 17, fig. 42. 
Cab. A. N. S. No. 1051. 

OBSERVATIONS. 

Besides its affinity with the preceding species, this 
shell has a general resemblance to three others, with 
none of which, however, can it be confounded by 
those who are familiar with the subject; these are 
U.flexuosiis, U. Phillipsii, and U. rejiexus. 

Common in the Wabash and Scioto, and I have 
found it in the Tennessee river, at Florence, Alabama, 
but not farther south. The female may be readily 
distinguished by the dilated margin, which is more 
profound in this species than in any other. 



UNIO GIBBOSUS. 

VARIETY PEROBLiaUUS. 
Plate XXVII.— Fig. 2. 

OBSERVATIONS. 

This is perhaps a mere variety of U. gibbosus, Raf., 
but it is much more oblique, the beaks nearer the 



anterior extremity, the posterior basal emargination 
much less profound, and the central tubercles are 
obsolete: in outline it closely resembles U. obliqiiatus, 
but that species is always of a purple colour within, 
though the tint is sometimes pale. 

Inhabits the "Wabash river, Indiana, and Detroit 
river, Michigan. 



UXIO TERES. 

Plate XXVIII. 
DESCRIPTION. 

Shell narrow — elliptical, subcylindrical. moderately 
thick; umbo slightly prominent; summit obtusely 
rounded; umbonial slope abruptly rounded, submar- 
ginal; posterior side produced, cuneiform: epidermis 
yellowish and polished, rarely rayed; within white or 
pale salmon colour; cardinal teeth double in each 
valve, subcompressed. vers* erect; lateral teeth distant 
from the cardinal teeth. 

SYNONYMES. 

U. teres, Raf. Ann. gen. des Sc. Phys. vol. v. p. 55. Poulson's 

trans, p. 68. 
U. anodoxtct.des, Lea. Trans. Amer. Philos. Soc, new series, 

vol. iv. p. 91, pi. viii. fig. 11. 
Cab. A. V. S. No. 1385. 

OBSERVATIONS. 

A well characterized species, approaching the rec- 
tus in outline, but is comparatively shorter and emi- 



2,8 




Unto t&reSj R af. 



2,9 








fte ' 



5L 




I | wo Snyri, C. &. U. Iajn.ll ti.s: Say. 



53 

nently distinguished by the peculiarity of its pale 
epidermis. The sexes are well marked by difference 
of outline. 

Not uncommon in the Western rivers, and in Bayou 
Teche, Louisiana, where it is ornamented with pale 
green rays. In the Alabama river it is partial to a 
muddy bed, and rare on the bars. 

I have figured a specimen in Mr. Poulson's cabinet, 
brought from the west and labelled by Rafinesque. 



UNIO SAGERI. 

Plate XXIX.— Fig. 1. 

DESCRIPTION. 

Shell narrow — elliptical, moderately thick on the 
anterior and thin on the posterior side; disks slightly 
contracted from beak to base, causing the basal mar- 
gin to be slightly sinuous; anterior side short, margin 
regularly rounded; posterior side produced, somewhat 
pointed, extremely obtuse; ligament margin elevated; 
umbo not prominent, flattened; umbonial slope round- 
ed; within bluish-white and iridescent; cardinal tooth 
in the right valve thick, direct, divided at the summit 
by a deep groove; in the left valve widely bifid, with 
a submedial lamelliform elevation; lateral teeth com- 
pressed. 

OBSERVATIONS. 

This interesting species was found in Detroit river, 
Michigan, by Dr. Abraham Sager, of Detroit, to whom 



54 

I have a pleasure in dedicating it. The outline of 
a young specimen is very similar to a variety of I). 
dilatatus, but the thinness of the shell, colour of in- 
terior, and particularly the form of the teeth, will 
readily distinguish it. The old shell might perhaps 
be mistaken for a variety of the U. rectus, but the 
young has very little resemblance to that of the latter. 
U. dilatatus is fomid in company with this species, 
retaining all the peculiarity of habit which it pos- 
sesses in the Ohio and other tributaries of the Missis- 
sippi, which confirms our opinion that the shell we 
described above is new and distinct. 



UNIO LAPILLUS. 

Plate XXIX.— Fig. 2. 

DESCRIPTION. 

Shell suboval, thick, yellowish, with very numerous 
dark green undulated rays; anterior margin not very 
short, rounded; beaks but little elevated, simple; liga- 
ment margin declining gradually in an arcuate line; 
posterior extremity rounded; umbonial slope unde- 
fined; basal margin straight or slightly contracted in 
the middle; within pearly white; cardinal teeth direct, 
thick; lateral teeth thick, oblique; cicatrices very deep 
and rounded; cavity of the beaks almost obliterated. 

SYNONYMES. 

U. lapillus, Say. Trans. Journ. of Med. vol. iv. p. 528, Amer. 
Conch, pi. 41. 



9J) 




y 




I Lino Saqrri, C . &. U. /(tm.ll u.s; $aif. 



30 





Uv-io -frac/ilis, ltd 



j -frag 



55 

U. fabalis, Lea. Trans. Amer. Philos. Soc. vol. iv. p. 96, pi. x. 

fig. 16. 
Cab. A. N. S. No. 2404. 

OBSERVATIONS. 

Mr. Say observes that "the robust teeth and the 
thickness of the whole shell have induced many, and 
myself amongst the number, to consider this shell as 
the young of gibbosus, Barnes, [dilatatus, Raf.] but a 
very slight examination serves to show that it is very 
distinct. The young of that species is always much 
more elongated transversely, not so thick, with the 
beaks much undulated," &c. 

It is usually smaller than the specimen represented, 
and, except the acidissimus, is the least of North 
American Uniones yet described. Dr. Sager found 
it in Detroit river, Michigan, and it is not uncommon 
in the Ohio and its tributaries. The figure repre- 
sents a fine specimen, of more than ordinary size, 
which we owe to the politeness of Professor J. Green. 



UxNIO FRAGILIS. 

Plate XXX. 

DESCRIPTION. 

Shell ovate, thin, fragile, somewhat inflated over 
the umbonial slope; disks flattened towards the base; 
hinge margin elevated into a large wing, connate; 
within bluish and highly iridescent; cardinal teeth 
very oblique, compressed, disposed to be single in 
each valve; lateral teeth arcuate. 



56 

SYNONYMES. 

U. fragilis, Raf. Ann. gen. des Sc. Phys. vol. v. p. 29. Poul- 
son's trans, p. 22. Say, Amer. Conch. No. 6. 

U. gracilis, Barnes. Silliman's Journ. vol. vi. p. 174. 

U. fragilis, Stvains. 

Symphynota gracilis, Lea. Trans. Amer. Philos. Soc. new se- 
ries, vol. iii. p. 66. 

Cab. Ji. N. S. No. 1657. 

OBSERVATIONS. 

Allied to U. alatus, but is longer in proportion, 
thinner, and lighter coloured in the interior and epi- 
dermis. In some localities the wing is small, but in 
others generally elevated. 

Found by Mr. Schoolcraft in Fox river; it inhabits 
the Detroit river, Michigan, lakes, and the western 
rivers generally, and I found it common in the Ala- 
bama at Claiborne. 



UNIO ALATUS. 

Plate XXXI. 

DESCRIPTION. 

Shell triangular, ovate, moderately thick; disks 
flattened anteriorly, and inflated over the umbonial 
slope; anterior side narrow, margin obliquely recti- 
linear above; posterior side profoundly dilated, and 
rising into an elevated connate wing; umbo oblique, 
inclined, not prominent; posterior lunule with two 
subangulated lines; umbonial slope regularly rounded; 
wing emarginate inferiorly; posterior end biangulated; 



3) 




:ni it al at H.s, i Sin 



CONTENTS 



Plate XXVI. Unio niger. 
,, XXVII. Unio gibbosus. 
„ XXVIII. Unio teres. 

yyiy 5 Fig. 1, Unio Sageri. 
" AA1A ) „ 2, Unio lapillus. 
,, XXX. Unio fragilis. 



Erratum. — Page 53, tenth line from bottom, for "extremely obtuse," 
read extremity obtuse. 



NEW FRESH WATER SHELLS OF THE UNITED 

STATES, &c. 

For sale by J. Dobson, a few copies of this work, which contains 
coloured illustrations of bivalve and univalve shells, and embraces a 
monography of the genus Anculotus. Most of the species described 
in this book were obtained by the author in Alabama. 



JVo. 7. 

MONOGRAPHY 

OF THE 



FAMILY UNIONID^, 

OR NAIADES OF LAMARCK, 
(FRESH WATER BIVALVE SHELLS,) 



OF 



NORTH AMERICA, 



ILLUSTRATED BY FIGURES DRAWN ON STONE FROM NATURE. 



BY T. A. CONRAD, 



CURATOR OF THE ACADEMY OP NATURAL SCIENCES OF PHILADELPHIA, HONORARY MEMBER OF 
THE GEOLOGICAL SOCIETY OF PENNSYLVANIA. 



PHILADELPHIA: 

J. DOBSON, 108 CHESNUT STREET. 

BOSTON: PERKINS & MARVIN.— PITTSB URGH: JOHN I. KAY & Co.- 

NEW YORK: HALL & VOORHIES, 118 NASSAU STREET.-ZOA^OA 

O. RICH, No. 12, RED LION SQUARE.— PARIS: ARTHUS 

BERTRAND, FILS, RUE HAUTEFEUILLE No. 23 — 

HAMBURGH: PERTHES & BESSER, 

No. 22, AM JUNGFERNSTIEG. 

E. G. DORSEY, PRINTER. 

December 1836. 



3X 




I aid in ft a I a a 



57 

epidermis dark green-olive, wrinkled; wrinkles lamel- 
liform posteriorly; within reddish-purple, iridescent; 
cardinal teeth direct, double in each valve; lateral 
teeth arcuate. 

SYNONYMES. 

U. alatus, Say. Nich. Enc. , Am. ed., art. Conch. 

U. (metaptera) megaptera, Raf. Ann. gen. des Sc.Phys., vol. 

v. p. 299. 
Symphynota alata, Lea. Trans. Amer. Phil. Soc, (new series,) 

vol. iii. p. 448. 
Cab. A. N. S. No. 20409. 

OBSERVATIONS. 

This well known species approaches a variety of 
U. purpiiratus, Lam., but is less inflated and has a 
more elevated wing. From the fragilis it can be 
distinguished by its larger size, dark epidermis, purple 
nacre, thicker cardinal teeth, &c. 

Inhabits Fox and Ouisconsin rivers, North- West 
Territory, Mr. Barnes; Detroit river, Michigan, Dr. 
Sager; western streams generally, and the great lakes. 
It is extremely rare in South Alabama. 



UNIO INFLATUS. 

Plate XXXII. 

DESCRIPTION. 

Shell triangular, ovate, thin; contracted obliquely 
from beak to base; inflated over the umbonial slope; 
valves elevated into a small wing anteriorly and into 

H 



58 

a broad high wing posteriorly, and connate in both; 
posterior margin of the wing arcuate, and slightly 
emarginate or angulated at base; beaks slightly pro- 
minent; cardinal teeth single in both valves, and 
lamelliform; lateral teeth arcuate, prominent towards 
the extremity; nacre purple. 

SYNONYMES. 

Symphynota inflata, Lea. Trans. Amer. Phil. Soc, new series, 

vol. iv. p. 99, pi. xiv. fig. 28. 
U. Alabamensis, Nob. New Fresh Water Shells, p. 67". 
Cab. A. N. S. No. 20405. 

OBSERVATIONS. 

Differs from U. (Symphynota) Icevissimus in the 
inflated umbonial slope and more elevated wing. It 
was discovered near Claiborne, Alabama, by Judge 
Tait, and sent to Mr. Lea. I have since found it 
very abundantly a few miles south of Claiborne, but 
it is rare in the upper part of the Alabama and in the 
Black Warrior rivers, and has not hitherto been found 
elsewhere. 



UNIO LEPTODON. 

Plate XXXIII. 

DESCRIPTION. 



Shell narrow-elliptical, very thin and fragile, com- 
pressed anteriorly, and slightly inflated over the um- 
bonial slope; beaks very small, approximate; posterior 




Tltio I ehtodrjTh: faaf. 



59 

side produced, pointed; hinge margin elevated; pos- 
terior margin very oblique, extremity acutely angular, 
and much above the line of the base; basal margin 
regularly arcuate; epidermis olive-yellow, with very 
oblique narrow rays; within bluish, tinged with violet 
above, highly iridescent; cardinal teeth obtuse, smooth, 
nearly obsolete; lateral teeth single in each valve. 

SYNONYMES. 

U. leptodon, Raf. Ann. gen. des Sc. Phys., vol. v. p. 295. 

Poulson's trans., p. 21. Say, Amer. Conch. No. 6. Ferr. 

Mag. de Zool. 
U. planus, Barnes. Silliman's Journal, vol. vi. p. 272. 
Anodonta purpurascens, Swainson. 
Symphynota tenuissima, Lea. Trans. Amer. Philos. Soc, (new 

series,) vol. iii. p. 453, pi. xi. fig. 21. 
Cab. A. N. S. No. 20406. 

OBSERVATIONS. 

This shell has an exterior much resembling that of 
an Anodonta, but the teeth are generally sufficiently 
developed to constitute it a true Unio. It is allied 
to U.fragilis, but differs widely in the teeth, in being 
pointed posteriorly, and in not being alated. It is 
connate when perfect. 

Inhabits the Ouisconsin, Mr. Barnes. I found a 
single specimen in Alabama. The specimen figured 
is from the Scioto river, and was presented by Dr. 
William Blanding. 



60 
UNIO ELLIPSIFORMIS. 

Plate XXXIV.— Fig. 1. 

DESCRIPTION. 

Shell elliptical, slightly ventricose, produced pos- 
teriorly, moderately thick; disks slightly contracted 
anteriorly; umbonial slope rounded; beaks slightly 
prominent, approximate, simple; basal margin dilated 
posteriorly to the middle; within bluish; cardinal teeth 
thick, direct. 

OBSERVATIONS. 

This species I have seen only in the cabinet of Mr. 
John Phillips, who received it from Michigan. It is 
very similar in outline to U. Henosus, but the short, 
thick, direct teeth, simple beaks, and bluish nacre, 
form a very distinctive character. 



UNIO LIENOSUS. 

Plate XXXIV.— Fig. 2. 

DESCRIPTION. 

Shell elliptical, inflated, slightly furrowed or con- 
tracted from beak to base; substance of the shell 
thickened towards the base; posterior dorsal and 
posterior basal margin rounded, extremity subangu- 
lated; beaks pointed, approximate, slightly prominent, 



34 



■ ■■ 






■ 



t^— ~7> 





1. Unto e.'l/pJ-iforrni.r,C Z. IJ.licnoxiui,C 



61 

with interrupted undulations; concentric lines promi- 
nent; epidermis dark olive, obscurely rayed, wrinkled 
on the margins; cardinal teeth double in both valves, 
slightly compressed, oblique, striated; nacre varying 
from bluish white to deep salmon or purple; cavity 
most capacious under the umbonial slope. 

SYNONYMES. 

U. lienosus, Nob. Silliman's Journal, vol. xxv. p. 339, pi. 1, 

fig. 4. 
U. Nashvillianus, Lea. Trans. Amer. Phil. Soc, (new series,) 

vol. v. p. 100, pi. xiv. fig. 43. 
Cub. Ji. N. S. No. 20407. 

OBSERVATIONS. 

This shell is remarkable for inhabiting exclusively 
the small streams, and is common in Greene county, 
Alabama. It is a variable species, sometimes not 
easily recognised, and the sexual distinctions are as 
obvious as in U. siliquoideus. The colour of the in- 
terior is remarkably inconstant, but a purple ap- 
proaching to salmon is the most prevailing tint, and 
the margin is bluish-white. The affinities are U. 
parvus, Barnes, and V. glans, Lea, but it is much 
larger than either, has very different beaks, and does 
not inhabit the same waters with those species. 



62 
UNIO STAPES. 

Plate XXXV.— Fig. 1. 

DESCRIPTION. 

Shell subtriangular, compressed, thick; anterior side 
with numerous approximate, angulated, slightly ele- 
vated tubercles; disks with a distinct furrow from 
beaks to base; umbonial slope swelling; posterior 
slope greatly contracted, tuberculated, angulated sub- 
medially, and forming a right angle with the umbonial 
slope; posterior margin direct, forming a regular curve 
with the ligament margin; emarginate inferiorly; base 
slightly emarginate; within white; cardinal teeth thick, 
direct; lateral teeth short, very oblique. 

SYNONYME. 

U. stapes, Lea. Trans. Amer. Phil. Soc, (new series,) vol. iv. 

p. 77, pi. vii. fig. 8. 
Cab. A. N. S. No. 20408. 

OBSERVATIONS. 

A rare species, remarkable for the small area be- 
hind the umbonial slope, which gives it somewhat the 
form of U. truncahis, Raf. It approaches nearest to 
the metanevra, but is very distinct. The shell is not 
in the least oblique, and the beaks are central, flat- 
tened and prominent. I found it only in the Alabama 
river, near Claiborne, where it was first obtained by 
Judge Tait and forwarded to Mr. Lea. 



3d 





l Unto stapes, tea £ tj: inter w,et£iu.A; 



36 




I. Unto stop 



es Leu Z. i.ailei-wediui: Conrad. 



63 



UNIO INTERMEDIUS. 

Plate XXXV.— Fig. 2. 

DESCRIPTION. 

Shell suboval, compressed; disks flattened or slight- 
ly furrowed from beaks to base, covered, except on 
the posterior side, with small slightly elevated tuber- 
cles, which are rib-shaped on the posterior slope; 
umbonial slope not prominent, and rounded or sub- 
angulated; posterior slope obtusely angulated; beaks 
oblique, not prominent; ligament margin long, arcu- 
ate; posterior margin direct, emarginate; within white; 
cardinal teeth direct. 

OBSERVATIONS. 

Three specimens of this species were obtained by 
Dr. S. Blanding, of Columbia, S. C, from Nolachucky 
river, Tennessee, and were kindly submitted to my 
inspection. They differ from the preceding in being 
somewhat oblique, in having less prominent beaks, a 
wider posterior slope, but particularly in being desti- 
tute of tubercles anteriorly. From the metanevra it 
is easily distinguished by the want of a swelled um- 
bonial slope. It is so evident a link between these 
two species, that I have given it the name of inter- 
medins, suggested by my friend Mr. John Phillips. 
In a young specimen which I have figured, the epi- 
dermis is covered with small crowded angular green 
spots, but in the old shell they disappear. The latter 
becomes distinctly angulated or furrowed on the pos- 



64 



terior slope, and profoundly emarginate posteriorly, 
as represented in the outline, fig. 3. 



UNIO OCCIDENTALS. 

Plate XXXVI.— Fig. 1. 

DESCRIPTION. 

Shell elliptical, convex, anterior margin very regu- 
larly rounded; anterior dorsal margin elevated; basal 
margin straight and parallel with the ligament mar- 
gin; posterior margin oblique, extremity rounded; 
umbonial slope undefined; beaks slightly prominent, 
with undulated grooves; summit rounded; epidermis 
yellowish, with narrow green rays, which are obso- 
lete or wanting on the anterior side; within bluish; 
cardinal teeth direct, prominent, acute; lateral teeth 
lamelliform. 

OBSERVATIONS. 

This shell has an outline similar to that of U. com- 
planatus. It differs from that species in its yellow 
epidermis, the peculiarity of its rays, more elevated 
anterior margin, lamelliform lateral teeth, &c. 

Inhabits Currant river, Arkansas, whence it was 
brought by Mr. Featherstonhaugh, to whose kindness 
I owe the use of this and several rare and beautiful 
species. 



36 






: i 






^*- 



___ i l i^. 







; ' o OcnidentalU, a. Z.jj.coiUnu 



CONTENTS. 



Plate XXXII. Unio inflatus. 

„ XXXIII. Unio leptodon. 

„ XXXIV. Fig. 1, Unio ellipsiformis. 

,, „ Fig. 2, Unio lienosus. 

,, XXXV. Fig. 1, Unio stapes. 

,, ,, Fig. 2, Unio intermedius. 

,. XXXVI. Fig. 1, Unio occidentals, 

No. VIII. will be published in January. 



NEW FRESH WATER SHELLS OF THE UNITED 
STATES, &c. 

For sale by J. Dobson, a few copies of this work, which contains 
coloured illustrations of bivalve and univalve shells, and embraces a 
monography of the genus Anculotus. Most of the species described 
in this book were obtained by the author in Alabama. 



NORTH AMERICAN HERPETOLOGY. 



Just Published, and for sale by J. Dobson, 108 Chesnut Street, 
NORTH AMERICAN HERPETOLOGY; 

OR A DESCRIPTION OP THE 

REPTILES INHABITING THE UNITED STATES. 

BY JOHN EDWARDS HOLBROOK, M. D. 

Professor of Anatomy in the Medical College of the State of South Carolina, Member 
of the Royal Medicai Society of Edinburgh, Corresponding Member of the 
Academy of Natural Sciences of Philadelphia, and of the New- 
York and Baltimore Lyceums of Natural History. 

Vol. I. royal 4to. with splendid Coloured Plates. 
This beautiful work will consist of four volumes, royal quarto, illus- 
trated by numerous finely coloured plates— price $10 per volume. 



JVo. 8. 



MONOGRAPHY 



OF THE 



FAMILY UNIONIDiE, 



OR NAIADES OP LAMARCK, 



(FRESH WATER BIVALVE SHELLS,) 



OF 



NORTH AMERICA, 



ILLUSTRATED BY FIGURES DRAWN ON STONE FROM NATURE. 



BY T. A. CONRAD, 



CURATOR OF THE ACADEMY OP NATURAL SCIENCES OF PHILADELPHIA, HONORARY MEMBER OF 
THE GEOLOGICAL SOCIETY OF PENNSYLVANIA. 



PHILADELPHIA: 

J. DOBSON, 108 CHESNUT STREET. 

BOSTON: PERKINS & MARVIN.— PITT SB URGH: JOHN I. KAY & Co.- 

NEW YORK: HALL & VOORHIES, 118 NASSAU STREET.— LONDON: 

O. RICH, No. 12, RED LION SQUARE.— PARIS: ARTHUS 

BERTRAND, FILS, RUE HAUTEFEUILLE No. 23.— 

HAMBURGH: PERTHES & BESSER, 

No. 22, AM JUNGFERNSTIEG. 

E. G. DORSEY, PRINTER. 

February 1837. 







-■'" _—««•-•!-" •rr-n-rii-nnrr-rr; 



.X 




,: 



">: 



N -4 S ,- ( ^'" ..- 




1.T/7LL0 OccidentalU, c Z.V.colUnuA 



65 
UNIO COLLINUS. 

Plate XXXVI. —Fig. 2. 

DESCRIPTION. 

Shell elliptical, rather thin, with coarse concentric 
lines; umbonial slope rounded; posterior side slightly- 
produced, and rapidly narrowed to the extremity, 
which is rounded; basal margin straight near the 
middle; beaks small, slightly prominent, approximate, 
undulated; umbones with two or three small tubercles 
posterior to the middle; epidermis yellowish-brown, 
obscurely rayed; within white or pale rose colour; 
cardinal teeth oblique, robust. 

Cab. A. N. S. No. 20408. 

OBSERVATIONS. 

This species may readily be known by the small 
tubercles on the umbones. The female, when young, 
closely resembles U. heterodon in outline, but the usual 
formation of the lateral teeth and the tubercles emi- 
nently distinguish it. Inhabits North river, a branch 
of James river, Virginia, where it was found by Mr. 
Constant Newkirk, of Washington College, from 
whom I received three specimens. 



66 
UNIO SOWERBIANUS. 

Plate XXXVII. — Fig. 1. 
DESCRIPTION. 

Shell ovate, convex, with concentric furrows; disks 
slightly gibbose in the middle; posterior side with a 
furrow from beak to base; a slight groove on the pos- 
terior submargin; raised radiating lines extend from 
the angle of the larger furrow to the posterior extre- 
mity, which is direct and slightly retuse; basal margin 
retuse posteriorly; epidermis glabrous, with faint fili- 
form brown rays; within purple or rose colour; car- 
dinal teeth very large and prominent, double in each 
valve. 

SYNONYME. 

U. sowerbianus, Lea. Trans. Amer. Phil. Soc., new series, vol. 
v. p. 68, pi. x. fig. 28. 

OBSERVATIONS. 

The fine specimen of this beautiful and very distinct 
species which I have figured, was kindly loaned for 
the purpose by Mr. Featherstonhaugh, who procured 
it from Cumberland river, Tennessee. I found one 
in the summer of 1833 on the bank of Elk river, 
Alabama, and judging from Mr. Lea's figure of the 
pilcus, I supposed it to be that species.* The speci- 
men is in the cabinet of Mr. Poulson. 

The Sowerbianus is remarkable for its highly po- 
lished epidermis and raised lines on the posterior side. 

* New Fresh Water Shells, p. 69, note. 










■% 



v^ 



/ 




Og@*\. 



( U( 




67 
UNIO POLITUS. 

Plate XXXVII.— Fig. 2. 

DESCRIPTION. 

Shell suborbicular, convex, with slight concentric 
furrows; anterior margin obtusely rounded; posterior 
margin nearly direct; ligament margin rectilinear, 
slightly declining; umbonial slope rounded; disks flat- 
tened or very indistinctly furrowed posteriorly; basal 
margin rounded, or slightly gibbous in the middle; 
epidermis glossy, with fine concentric wrinkles; umbo 
prominent, smooth and polished, with dark green 
interrupted rays; within white; cardinal teeth thick, 
very direct. 

SYNONYMES. 

U. politus, Say. Araer. Conch., No. 6. 

U. subrotundus, Lea. Trans. Amer. Phil. Soc, new series, vol. 

iv. p. 117, pi. xviii. fig. 45. 
Cab. A. N. S. No. 20409. 

OBSERVATIONS. 

Related to U. Kirtlandicus, Lea, from which it dif- 
fers in being proportionally more elevated and much 
less compressed. It is also a smaller species. The 
name of subrotundus has necessarily been abandoned, 
as it is preoccupied for a different species. 



68 
UNIO NEXUS. 

Plate XXXVIIL— Fig. 1. 

DESCRIPTION. 

Shell triangular, sub-rhomboidal, much inflated, 
thick; umbo prominent; posterior slope much de- 
pressed, with a broad, shallow groove, which extends 
from the beak to the posterior margin; posterior 
margin forming nearly a right angle with the base, 
obtusely emarginate in the middle by the termination 
of the groove; umbonial slope carinated, in conse- 
quence of the depression of the posterior side; lunule 
very short; epidermis yellowish-brown, obsoletely ra- 
diated; within white; cardinal teeth direct; lateral 
teeth short, with but little obliquity. 

SYNONYMES. 

U. nexus, Say. Trans. Journ., vol. iv. p. 527, 1831. Amer. 

Conch., pi. li. 
U. arcteformis, Lea. Trans. Amer. Phil. Soc, new series, vol. 

iv. p. 116, pi. xvii. fig. 44. 
Cab. A.N. S.No. 20410. 

OBSERVATIONS. 

Mr. Say remarks that this species is "related to 
tric/ueter, Raf., but differs in the greater prominence 
of the superior portion of the anterior [posterior] 
margin." There is also a great difference in the 
teeth and in the markings of the epidermis, which in 
the nexus are filiform rays, but in the triqueter gene- 
rally sagittate spots. Not uncommon in the Cumber- 



38 




1. Vnio Jiexw.r, Jay. «.. U. Greenii. Gotirdd 



; --v 




• V*- 



---^^3^1111 



■; 



'■■,-.'-/■?!■' '*"• - 



^mjw 



< ^ 




■v.;: 



69 

land river, and it seems chiefly confined to the waters 
of Tennessee — I saw none in Alabama. The figure 
is from a specimen in the cabinet of Mr. Feather- 
stonhaugh. 



UNIO GREENIL 

Plate XXXVIII. —Fig. 2. 
DESCRIPTION. 

Shell sub-triangular; disks slightly flattened; ante- 
rior side not very short, margin rounded, not very 
obtuse; umbo flattened, not elevated; beaks eroded; 
umbonial slope straight, subangulated; ligament short, 
ligament margin forming with the posterior margin a 
nearly regular arcuate line; extremity obtusely round- 
ed or subtruncated; basal margin slightly arcuate; 
epidermis wrinkled on the margins, with narrow 
green rays on the posterior slope and interrupted 
rays on the umbo; within white; cardinal teeth slightly 
oblique; lateral teeth oblique and very slightly curved. 

SYNONYME. 

IT. greenii, Nob. New Fresh Water Shells, p. 32, pi. iv. fig. 1. 
Cub. A. N. S. No. 20413. 

OBSERVATIONS. 

Dedicated to my friend Jacob Green, M. D., Pro- 
fessor of Chemistry in Jefferson College, a gentleman 
well known as a contributor to Conchology. Inhabits 
the head waters of Black Warrior river, Alabama; 
not uncommon. 



70 
UNIO SHEPARDIANUS. 

Plate XXXIX. 
DESCRIPTION. 

Shell profoundly elongated, sinuous, compressed, 
tapering to the posterior extremity, which is trun- 
cated; valves rather thin, with concentric lines, pro- 
found over the umbonial slope, which is slightly ele- 
vated; a carinated line passes between the umbonial 
slope and posterior dorsal margin; beaks very small, 
hardly raised above the dorsal line; within purple; 
lateral teeth long and rectilinear, somewhat dilated 
or thickened near the anterior termination. 

SYNONYME. 

U. shepardianus, Lea. Trans. Amer. Phil. Soc, new series, vol. 

v. p. 95, pi. xiii. fig. 38. 
Cab. A.N. S.No. 20411. 

OBSERVATIONS. 

This is perhaps the most elongated, proportionally, 
of any known Unio, except the Grayanus, and differs 
chiefly in this respect from U. angustatus, which is 
the species most nearly related to it. 

Inhabits Alatamaha river, near Hopeton and Da- 
rien, Georgia. 



39 




l nio jShetiardianu^fLecf:. 



40 





. / nio compress iif. &. V.C(Lh^cejormls,hett. 3.Umale. 



71 
UNIO COMPRESSUS. 

Plate XL. — Fig. 1. 
DESCRIPTION. 

Shell oblong or elliptical; disks flattened; anterior 
margin regularly rounded; umbonial slope slightly 
elevated, rounded; beaks undulated, not prominent, 
distant from the anterior extremity; ligament margin 
elevated, connate; posterior margin oblique, recti- 
linear, extremity truncated and slightly projecting 
beyond the line of the base; epidermis ochraceous, 
with numerous unequal green rays, some of which 
are very broad; within white, tinged with pale salmon 
under the beaks; cardinal tooth scarcely double in 
the right valve, very oblique, elongated, rather thick; 
in the left valve widely trifid, compressed, posterior 
lobe rather behind the apex. 

SYNONYMES. 

U. compressus, Deshayes. 

Symphynota compressa, Lea. Trans. Amer. Phil. Soc, (new 

series,) vol. iii. p. 450, pi. xii. fig. 22. 
Cab. A. N. S. No. 1098. 

OBSERVATIONS. 

This species can at once be distinguished from all 
others by the peculiarity of its hinge. It inhabits 
the Ohio, Scioto, and Wabash rivers; also Oak Orch- 
ard creek, in the State of New York, and Norman's 
Kill, near Albany. The figure is from a specimen 
which I found in a mill pond at the village of Adams, 



72 



Jefferson county, New York, where the species is 
extremely abundant. 



UNIO CAPSJEFORMIS. 

Plate XL. — Fig. 2. 
DESCRIPTION. 

Shell sub-oval, slightly ventricose, moderately 
thick; posterior side flattened or very slightly grooved; 
umbonial slope obtusely angulated; basal margin 
rounded medially, straight or slightly emarginate 
posteriorly; posterior extremity direct, truncated, 
narrowed, slightly produced; summits obtusely round- 
ed, not prominent; epidermis yellowish, with nume- 
rous narrow unequal green rays; within white; cardi- 
nal teeth very erect and prominent. 

SYNONYME. 

U. capsvEformis, Lea. Trans. Amer. Philos. Soc, new series, 

vol. iv. p. 145, pi. ii. fig. 4. 
Cab. A. N. S. No. 20414. 

OBSERVATIONS. 

Inhabits Cumberland river near Nashville, Tennes- 
see. I have found it in the Tennessee river at Flo- 
rence, Alabama. It bears a slight resemblance to 
the young of U.JIexuosus, and is a very distinct spe- 
cies. The female is represented in figure 3. Be- 
tween the sexes the difference in outline is greater 
than in any species with which we are acquainted, 
except U. gibbosus, Raf. 



40 



' 





'fff. 



X 




3ft 

M 






■rnn.yre-f.ru.r. 2, V.r.ajt#tefvcmis,Lrtt. ■'..;,,:,.,'■ 



CONTENTS. 



Plate XXXVI. Fig. 2, Unio eollinus. 

,, XXXVII. Fig. 1, Unio sowerbianus. 

,, ,, Fig. 2, Unio politus. 

„ XXXVIII. Fig. 1, Unio nexus. 

,, ,, Fig. 2, Unio greenii. 

,, XXXIX. Unio shepardianus. 

., XL. Fig. 1, Unio compressus. 

,, XL. Fig. 2, Unio capssformis. 

DESCRIPTION OF A NEW ANADONTA. 

ANADONTA CARINIFERA. 

Shell narrow, elliptical, compressed, thin and fragile; anterior side 
narrow, rounded at the extremity; posterior side produced, subcunei- 
form, truncated at the extremity; hinge margin long, straight, elevated 
or slightly ascending, from anterior to the posterior extremity; beaks 
not elevated above the dorsal line; basal margin straight in the middle; 
colour of epidermis olive-green inferiorly, darker above; hinge margin 
Avithout a callous. Length, 21 inches; height, 11 inch. Inhabits rivers 
in Kentucky. 

This species is in the fine collection of my friend Mr. John Phillips, 
who informs me that it is from the Ohio or one of its tributaries below 
Louisville. It has much the outline of Unio carinifera of Lam. (the 
common variety of U. complanatus ,) but is proportionally more elon- 
gated, and the posterior extremity resembles that of Unio declivis, 
except that it is truncated at the tip. 



Unio gibbosus, var. perobliquus, pi. xxvii. fig. 2, 1 have ascertained 
to be a species; it will therefore take the name of Unio per obli quits. 



NEW FRESH WATER SHELLS OF THE UNITED 
STATES, &c. 

For sale by J. Dobson, a few copies of this work, which contains 
coloured illustrations of bivalve and univalve shells, and embraces a 
monography of the genus Anculotus. Most of the species described 
in this book were obtained by the author in Alabama. 



NORTH AMERICAN HERPETOLOGY. 



Just Published, and for sale by J. Dobson, 108 Chesnut Street, 
NORTH AMERICAN HERPETOLOGY; 

OR A DESCRIPTION OF THE 

REPTILES INHABITING THE UNITED STATES. 

BY JOHN EDWARDS HOLBROOK, M. D. 

Professor of Anatomy in the Medical College of the State of South Carolina, Member 

of the Royal Medicai Society of Edinburgh, Corresponding Member of the 

Academy of Natural Sciences of Philadelphia, and of the New 

York and Baltimore Lyceums of Natural History. 

Vol. I. royal 4to, with splendid Coloured Plates. 
This beautiful work will consist of four volumes, royal quarto, illus- 
trated by numerous finely coloured plates — price $10 per volume. 



JWo. 9. 



™ 



F/5 



MONOGR APHY 



OF THE 



FAMILY UNIONID^, 



OR NAIADES OF LAMARCK, 



(FRESH WATER BIVALVE SHELLS,) 



OF 



NORTH AMERICA, 



ILLUSTRATED BY FIGURES DRAWN ON STONE FROM NATURE. 



BY T. A. CONRAD, 



CURATOR OF THE ACADEMY OP NATURAL SCIENCES OP PHILADELPHIA, HONORARY MEMBER OF 
THE GEOLOGICAL SOCIETY OF PENNSYLVANIA. 



PHILADELPHIA: 

J. DOBSON, 108 CHESNUT STREET. 

BOSTON: PERKINS & MARVIN.— PITTSBURGH: JOHN I. KAY & Co.- 

NEW YORK: HALL & VOORHIES, 118 NASSAU STREET. -LONDON: 

O. RICH, No. 12, RED LION SQ.VKS.E.— PARIS: ARTHUS 

BERTRAND, FILS, RUE HAUTEFEUILLE No. 23.— 

HAMBURGH: PERTHES & BESSER, 

No. 22, AM JUNGFERNSTIEG. 

E. G. DORSEY, PRINTER. 

March 1837. 



» 



& 



41 




. 



Uruo v tdliianu.it, C. ? . U-flavus, n.uf 



73 

The two fine specimens figured belong to the 
splendid collection of Mr. Poulson. They were sent 
from Nashville, Tennessee. 



UNIO SUBPLANUS. 

Plate XLL— Fig. 1. 
DESCRIPTION. 

Shell sub-oval; disks flattened; anterior margin 
regularly rounded, obliquely descending; umbonial 
slope rounded; posterior slope dilated; beaks not pro- 
minent, distant from the anterior extremity; ligament 
margin elevated, slightly oblique; posterior extremity 
truncated; epidermis yellowish-brown, with numerous 
fine concentric wrinkled lines; within pale rose colour; 
cardinal teeth oblique; lateral teeth rectilinear. 

Cab. A. N. S. No. 20412. 

OBSERVATIONS. 

I have recently received several specimens of this 
shell from Lexington, Rockbridge county, Virginia, 
where they were found by Mr. Newkirk in a branch 
of the James river. Approaches U. Masoni, but is 
more compressed and elongated, and cannot be con- 
founded with it. 



71 
UNIO FLAVUS. 

Plate XLI.— Fig. 2. 

DESCRIPTION. 

Shell sub-triangular, moderately thick; disks flat- 
tened on the posterior side; anterior margin obtusely 
rounded; ligament margin oblique, rectilinear; poste- 
rior margin wide, straight, nearly direct; extremity 
obtuse; basal margin straight from the posterior ex- 
tremity to beyond the middle; umbonial slope cari- 
nated; umbo rather prominent; beaks flattened, with 
a few obtuse oblique undulations; within salmon 
colour; cardinal and lateral teeth large and very pro- 
minent. 

3YN0NYMES'. 

U. flava, Ff. Ann. gen. des Sc, vol. v. p. 39. Foulson's 

trans., p. 38. 
U. rubiginosus, Lea. Trans. Amer. Phil. Soc, new series, vol. 

iii. p. 41, pi. viii. fig. 10. 
Cab. M.N. S.No. 1126. 

OBSERVATIONS. 

This shell is so distinctly described and even figured 
by Rafinesque, that no honest inquirer can refuse 
him credit for the species. He remarks that he found 
"it only in the small rivers falling into the Kentucky, 
Salt or Green rivers." This peculiarity of habitat 
is remarkable, and I was unable to find a specimen 
in either the Alabama, Tombeckbe, or Black Warrior 
rivers, although several were found in a small mill 
stream in Greene county, Alabama. Rafinesque re- 



41 




- JC eas^g*s 






c^f^V 



\ 













/ Vnio xu.lt>Lttnu.t,C. £,. U-fldvas, Kef. 



\% 




I 






/ 



..,.,-"« UigJS-^-- 



Unto cap ax, &rct 



75 

marks that the "young shells arc almost yellow, and 
the animal of a deep or orange-yellow colour," which 
accords with my own observation. I do not, how- 
ever, consider the colour of the animal any safe guide 
in specific distinction, as I have found the same spe- 
cies, particularly V. decisus, to contain in some spe- 
cimens an orange coloured, and in others a perfectly 
white animal. 



UNIO CAPAX. 

Plate XLII. 
DESCRIPTION. 

Shell very globose; valves rather thin, translucent, 
connate; umbones tumid, summit obtusely rounded, 
prominent, distant from the anterior margin; epider- 
mis straw colour, polished, with two faint green rays 
on the posterior slope; within white and iridescent; 
cardinal teeth lamellar, prominent, double in the right 
valve, crenate and single in the left; lateral teeth 
arcuate. 

SYNONYMES. 

U. capax, Green. Cab. of Nat Hist., vol. ii. p. 290. 1832. 
Symphvnota globosa, Lea. Trans. Amer. Phil. Soc, new series, 

vol. iv. p. 153, pi. iv. fig. 12. 1834. 
Cab. A. N. S. No. 1227. 

OBSERVATIONS. 

The most ventricose of all the Unios known, and, 
when young, one of the most delieate and beautiful. 



76 

It most nearly resembles U. cardium, Raf., but the 
tumid umbones will always prove a destructive cha- 
racter. Dr. Green was the first to recognise this as 
an undescribed species, and his name, having priority, 
must necessarily be adopted. He observes, "I now 
describe a fine large shell, which seems to have 
escaped the notice of our conchologists. The first 
specimens of this shell which I observed were from 
the Falls of St. Anthony. I afterwards received it 
from the Bayou Teche, but I never discovered or 
ascertained that it exists in the Ohio." Mr. Lea, on 
the authority of Col. Long, informs us that it inhabits 
the Ohio, 150 miles below Louisville, Ky. 



UNIO RUDIS. 

Plate XLIIL— Fig. 1. 
DESCRIPTION. 

Shell ovate-acute, thick anteriorly; diameter great- 
est at the umbones; beaks eroded; posterior side 
cuneiform; ligament and posterior margins arcuate, 
extremity subangulated; epidermis brown, wrinkled 
inferiorly; within white; cardinal teeth small, direct; 
lateral teeth slightly arcuate. 

SYNONYME. 

U. uavenelianus, Lea. Trans. Amer. Phil. Soc, new series, vol. 

iv. p. 144, pi. iii. fig. 5. 
Cab. A. N. S. No. 20415. 

OBSERVATIONS. 

Inhabits French Broad river, North Carolina, Dr. 







i 



■ 




1.1 ' mo rudi.s, Qnn. ■?,. U. nhliaua-^Ln:-ti'a.roIc. 




- 






■-=~=^_^7F^^~ r'T-;-;:.- ■ 



z~~~ 



1. 1 uio rudis, Cn/i. '-L. if. ooli&uu-t, Lccni.&rck 



77 

Ravcnel. I found it in the upper part of the Black 
Warrior river, Alabama, where it is rare. 

Resembles U. perovatus in outline, but the shell is 
far greater in diameter through the umbones, and the 
beaks nearer the anterior extremity. The most 
striking character, perhaps, is the accurate wedge- 
shaped form of the posterior side. Mr. Lea first 
published this species under the name of Ravcnclicmiis, 
but as I had previously published a different species 
with the same name, I am compelled to substitute 
another. 



UNIO OBLIQUUS. 

Plate XLIIL— Fig. 2. 
DESCRIPTION. 

Shell ovate-rotundate, oblique; disks with a slight 
narrow furrow on the posterior side; umbonial slope 
carinated; posterior slope with an obtuse carinated 
line; ligament and posterior margins arcuate; posterior 
extremity obliquely truncated; beaks very prominent, 
curving forward; lunule sagittate; within white; car- 
dinal teeth directed obliquely backwards; lateral teeth 
arcuate; cardinal plate much thickened under the 
cardinal teeth, contracting the cavity of the umbo. 

SYNONYMES. 

U. OBLiquA, Lam. An. sans Vert, vol. vi. p. 72. Ferus. Mag. 

de Zool. 
U. ebenus, Lea. Trans. Amer. Phil. Soc, new series, vol. iii. 

p. 94, pi. ix. fig. 14. 
Cab. A. N. S. No. 1259. 



78 

OBSERVATIONS. 

Inhabits the Black Warrior and Alabama rivers, 
where I found it in abundance; also the Ohio and its 
tributaries. 

The ovate form of this species and its obliquity 
will distinguish it at a glance from undatus, Barnes. 
The young is remarkable for being of yellow colour 
behind the umbonial slope, which soon disappears in 
general as the shell increases in size. 

Mr. Lea appears to be ignorant of the true distinc- 
tive character of this species, since he affirms that I 
have published it under the name of mytiloides; the 
latter is destitute of the callosity of the cardinal plate 
which characterizes the oblujuus, has a very different 
lunule, and is dissimilar in outline to that species. 
Those who are conversant with the two shells will 
not confound them. 

Mr. Lea considers the obliqaa of Lamarck to be 
identical with undatus of Barnes, but Lamarck's de- 
scription is wholly inapplicable to the latter, whilst 
it agrees with the ebcnus of Lea, with which it is 
identical, according to Ferussac. 



UNIO APICULATUS. 

Plate XLIV.— Fig. 1. 

DESCRIPTION. 



Shell subquadrate, compressed; summits not very 
prominent; hinge margin declining; disks with a dilat- 
ed not deeply impressed furrow; umbonial slope 



ii 



£ W> 



\k ■ 






' \ 



-~"\ 



\ 









f r . ■) 

i 1 •■'' ' 

MP 






■y 



,.-- 



-^ 






\ 

/'■' AS 



V-_,_^" : 



l ^°^«^*«y^.c:f, a < t/ll/J . c ^ 



li 







. s v' 





, ,. . ... ../' bra sinus, Cmi. 



79 

arcuate, carinated; posterior margin dilated, direct, 
produced, and rounded or subtruncated at base; disks 
covered with small subequal tubercles, arranged more 
or less in symmetrical lines; within white. 

SYNONYMES. 

V. apiculatus, Say. Disseminator, 1829. American Conch. 

pi. 52. 
U. asper, Lea. Trans. Amer. Phil. Soc, new series, vol. iii. p. 

95, pi. ix. fig. 15, 1832. 
Cab. A. N. S. No. 1877. 

OBSERVATIONS. 

Inhabits the Alabama river, near Claiborne, where 
I found specimens, but they were not numerous nor 
comparable in beauty to those which inhabit Bayou 
Teche in Louisiana. 

Mr. Say thinks this may prove to be a variety of 
U. quadrulus, but although it is nearly related to that 
species we believe it to be very distinct. Old shells 
become proportionally more elongated and produced 
at the posterior extremity of the basal margin, and 
the tubercles nearly disappear on the inferior half of 
the disks. The figure is from a specimen from Bayou 
Teche. 



UNIO PRASINUS. 

Plate XLIV.— Fig. 2. 

DESCRIPTION. 



Shell suborbicular, compressed, with distant con- 
centric impressed lines; anterior margin obtusely 



, 80 

rounded; posterior margin wide, direct; basal margin 
straight, parallel with the ligament margin; summits 
rather prominent; disks smooth, with a few very 
small tubercles on the posterior side; epidermis olive- 
yellow, very broadly rayed with green; within white. 

SYNONYMES. 

U. prasinus, Nob. New Fresh Water Shells, p. 44. May, 1834. 
U. schoolcraftensis, Lea. Trans. Amer. Phil. Soc., new series, 

vol. iv. p. 149, pi. iii. fig. 9. Sept. 1834. 
Cab. A.N. S.No. 1128. 

OBSERVATIONS. 

Inhabits the Scioto river, Indiana. 

The specimen of this shell in the cabinet of the 
Academy of Natural Sciences was brought by Mr. 
Schoolcraft from Fox river, of Green Bay — others 
are in the collection of Mr. Hyde. The species differs 
from U. bullatus, Raf., in being of a suborbicular out- 
line, more compressed, with much less prominent 
beaks and fewer tubercles. Some specimens have a 
few rather large tubercles near the base. 



UNIO NODULATUS. 

Plate XLV.— Fig. 1. 
DESCRIPTION. 

Shell suborbicular, slightly ventricose, moderately 
thick; posterior margin direct, retuse in the middle; 
ligament margin straight, elevated, scarcely declining; 
disks with two series of distant prominent tubercles; 



i6 




f-Vn.io-noduUtuSjAaf. Z. V. bullatu.3, ftaf 



CONTENTS 



Plate XLI. Fig. 1, Unio subplanus. 

,, ,, Fig. 2, Unio flavus. 

,, XLII. Unio capax. 

„ XLIII. Fig-. 1, Unio rudis. 

,, ,, Fig. 2, Unio obliquus. 

,, XLIV. Fig. 1, Unio apiculatus. 

,, ,, Fig. 2, Unio prasinus. 

,, XLV. Fig. 1, Unio nodulatus. 

DESCRIPTION OF A NEW ANADONTA. 

ANADONTA CARINIFERA. 

Shell narrow, elliptical, compressed, thin and fragile; anterior side 
narrow, rounded at the extremity; posterior side produced, subcunei- 
forrn, truncated at the extremity; hinge margin long, straight, elevated 
or slightly ascending, from anterior to the posterior extremity; beaks 
not elevated above the dorsal line; basal margin straight in the middle; 
colour of epidermis olive-green inferiorly, darker above; hinge margin 
without a callous. Length, 2J inches; height, 11 inch. Inhabits rivers 
in Kentucky. 

This species is in the fine collection of my friend Mr. John Phillips, 
"who informs me that it is from the Ohio or one of its tributaries below 
Louisville. It has much the outline of Unio carinifera of Lam. (the 
common variety of U. complanatus,) but is proportionally more elon- 
gated, and the posterior extremity resembles that of Unio declivis, 
except that it is truncated at the tip. 



Unio gibbosus, var. perobliquus, pi. xxvii. fig. 2, 1 have ascertained 
to be a species; it-will therefore take the name of Unio perobliquus. 



NEW FRESH WATER SHELLS OF THE UNITED 

STATES, &c. 

For sale by J. Dobson, a few copies of this work, which contains 
coloured illustrations of bivalve and univalve shells, and embraces a 
monography of the genus Anculotus. Most of the species described 
in this book were obtained by the author in Alabama. 



NORTH AMERICAN HERPETOLOGY. 



Just Published, and for sale by J. Dobson, 108 Chesnut Street, 
NORTH AMERICAN HERPETOLOGY; 

OR A DESCRIPTION OF.THE 

REPTILES INHABITING THE UNITED STATES. 

BY JOHN EDWARDS HOLBROOK, M. D. 

Professor of Anatomy in the Medical College of the State of South Carolina, Member 

of the Royal Medicai Society of Edinburgh, Corresponding Member of the 

Academy of Natural Sciences of Philadelphia, and of the New 

York and Baltimore Lyceums of Natural History. 

Vol. I. royal 4to. with splendid Coloured Plates. 
This beautiful work will consist of four volumes, royal quarto, illus- 
trated by numerous finely coloured plates— price $10 per volume. 



JTo. 10. 



M0N0GRAPHY 



OF THE 



FAMILY UNIONIDH, 



OR NAIADES OF LAMARCK, 



(FRESH WATER BIVALVE SHELLS,) 



NORTH AMERICA 



ILLUSTRATED BY FIGURES DRAWN ON STONE FROM NATURE. 



BY T. A. CONRAD, 



CURATOR OF THE ACADEMY OF NATURAL SCIENCES OP PHILADELPHIA, HONORARY MEMBER OF 
THE GEOLOGICAL SOCIETY OF PENNSYLVANIA. 



PHILADELPHIA: 

J. DOBSON, 108 CHESNUT STREET. 

BOSTON: PERKINS & MARVIN.— PITTSB URGH: JOHN I. KAY & Co.- 

NEW YORK: HALL & VOORHIES, 118 NASSAU STREET.— L ONDON. 

O. RICH, No. 12, RED LION SQUARE.— PARIS: ARTHUS 

BERTRAND, FILS, RUE HAUTEFEUILLE No. 23.— 

HAMBURGH: PERTHES & BESSER, 

No. 22, AM JUNGFERNSTIEG. 

E. G. DORSEY, PRINTER. 

May 1838. 



81 

posterior slope dilated, with nodules towards the 
margin; beaks slightly elevated, granulate at tip; 
epidermis olive-brown and rather smooth; within 
white; cardinal teeth large and prominent; lateral 
teeth subrectilinear. 

SYNONYMES. 

U. nodulata, Raf. Ann. gen. des Sc. Phys., vol. v. p. 41, pi. 

lxxxi. figs. 17, 18. Poulson's translation, p. 42. Say. Amer. 

Conch., No. 6. Ferrns. Mag. de Zool. 
U. pustulatus, Lea. Trans. Amer. Phil. Soc, new series, vol. 

iv. p. 79, pi. vii. fig. 9. 
Cab. d. N. S., No. 1755. 

OBSERVATIONS. 

Inhabits the Ohio river and its tributaries. It is 
related to U. bullatus and U. Mortoni. From the for- 
mer it differs in the regularity of its tubercles, in the 
dilatation of the posterior slope, and in the absence 
of the broad green ray on the umbo. From the latter 
it may be distinguished by the same characters, and, 
in addition, by the want of a broad depression or 
furrow, which characterizes U. Mortoni. Rafinesque's 
outlines of this shell, though rude, are characteristic 
enough; and his description, though short, perfectly 
clear and applicable to this species only. 



82 
UNIO BULLATUS. 

Plate XLV.— Fig. 2. 

DESCRIPTION. 

Shell elevated, equilateral, inflated, irregularly tu- 
berculated on the middle and posterior slope; medial 
tubercles generally large; substance of the shell thick; 
beaks elevated and granulated at tip; ligament slope 
descending, short; posterior margin direct, nearly 
straight; epidermis bright brown, a single broad in- 
terrupted green ray passes from the apex to the middle 
of the disk; within white; lateral teeth very short, 
straight, thick and oblique. 

SYNONYMES. 

U. bullata, Raf. Ann. gen. des Sc. Phys., vol. v. p. 41. Poul- 

son's trans., p. 43. 
U. verrucosus albus, Hild. Silliman's Journ., vol. xiv. p. 289. 
U. pustulosus, Lea. Trans. Amer. Phil. Soc, new series, vol. 

iv. p. 76, pi. vii. fig. 7. 
Cab. A. N. S.,No. 1175. 

OBSERVATIONS. 

Inhabits the Ohio and its tributaries, Alabama and 
Black Warrior rivers. This common species is 
easily recognised, and will be found to differ con- 
stantly from U. prasinus by its more elevated and 
ventricose form and more numerous tubercles. It 
wants the furrow of the Mortoni, and is besides dis- 
tinguished by its green ray and larger tubercles. 
The white colour of the nacre is remarkably constant, 



i$ 

















t.unLo-noduLatus haj z r bul.La.Ca 8i ■ tf. 



46 















<(-,,., st fccri,j A :7f.«f Z.mx-io dramas, t,ta. 



83 

as I have never found it to vary in a great number 
of specimens, which is seldom the case in most other 
species. A variety is remarkably abundant in the 
Black Warrior river, at Erie, Alabama. 

Mr. Say has referred this species to V. nodidosus, 
Wood, but the figure of that shell in Wood's Con- 
chology appears to me to represent a very different 
species. 



UNIO STEGARIUS. 

Plate XL VI. —Fig. 1. 

DESCRIPTION. 

Shell elevated, ovate; valves thick, with concentric 
furrows and ridges; disk with a narrow, not deeply 
impressed furrow from beak to base; umbo and beaks 
inclining forward; lunule large, ovate-acute, very dis- 
tinct; beaks pointed and incurved; umbonial slope 
carinated over the umbo; epidermis yellowish-brown, 
with crowded, fine, green dotted rays, and broad 
rays, composed of large dots; posterior margin direct; 
within white; cardinal plate greatly dilated; cardinal 
teeth direct, deeply sulcated; muscular impressions 
small. 

SYNONYMES. 

U. stegaria, Raf. Ann. gen. des Sc. Phys., vol. v. p. 46. 

Poulson's translation, p. 51, Say, Amer. Conch., No. 6. 

Ferr., Mag. de Zool. 
U. irroratus, Lea. Trans. Amer. Phil. Soc, new series, vol. 

iii. p. 269, pi. v. fig. 5. 
Cab.A.N. S.,No. 1122. 



84 

OBSERVATIONS. 

Inhabits the Ohio, Scioto, Wabash, and more 
rarely the rivers of Tennessee. I have not observed 
it so far south as the Tennessee river, in Alabama. 
It is a very beautiful species, remarkable for its very 
numerous dotted rays and its regular and graceful 
outline, which approaches that of U. retusus. 



UNIO DROMAS. 

Plate XLVI.— Fig. 2. 

DESCRIPTION. 

Shell obliquely ovate; disks flattened above, and 
with a very prominent concentric angular ridge in 
the middle; a slight furrow from beak to base on the 
posterior side; beaks prominent, summit rather wide, 
flattened; lunule angular; epidermis yellowish-brown, 
with very numerous green interrupted capillary rays, 
and a few broad rays; within white; cavity shallow. 

SYNONYME. 

U. dromas, Lea. Trans. Amer. Phil. Soc, new series, vol. v. 

p. 182, pi. x. fig. 29. 
Cab. A.N. S., No. 20416. 

OBSERVATIONS. 

Inhabits Harpeth and Cumberland rivers, Tennes- 
see; Elk river, near the muscle shoals, Alabama. I 
have not found it further south. 

My father, many years since, received this elegant 



46 




ll/nin sCecrariui-, 



Z. Wilo dramas, Lee 



4/ 







' 




- ■ — -_ r*"^ — ■' ■■' l sj.— 




,->-"' 




K>«, subten-tus, Saif.2 I a .ci>U*s> n.u*,Mea :y A r „„ radi,,*. U 



85 

species from Harpeth river, Tennessee. It cannot 
be confounded with U. stegarius, in consequence of 
its remarkable gibbose disk. The rays are more 
strongly marked than those of the latter species; the 
disk is never tuberculated, whilst the stegarius is 
sometimes covered with tubercles, as Mr. Lea has 
stated in his remarks upon the dromas. A single 
valve in my cabinet measures about four inches from 
beak to base. 



UNIO SUBTENTUS. 

Plate XL VII. —Fig. 1. 

DESCRIPTION. 

Shell oblong-suboval, very widely and slightly con- 
tracted at base; summits hardly elevated, decorti- 
cated, obtusely rounded; posterior basal angle a little 
prominent, rounded; posterior dorsal slope with nu- 
merous subramose, slightly arcuate, oblique, parallel 
costse; epidermis with broad interrupted green rays, 
sometimes obsolete; within reddish-fulvous; cavity of 
the umbo not deep; cardinal teeth somewhat direct, 
not transverse; lateral teeth slightly arcuate. 

SYNONYME. 

U. subtentus, Say. Jour. Acad. Nat. Sc, vol. v. p. 130. 

Amer. Conch., pi. xv. 
Cab. Ji. N. S„ JVo. 20417. 

OBSERVATIONS. 

Mr. Say observes, " in general outline, this shell 



86 

has some resemblance to U. purpureus, JNbb.; but it 
is distinguished by many characters, and more ob- 
viously by the character of the anterior costated 
margin. It is a native of South Carolina,* and was 
sent to me by Professor Vanuxem, who obtained it 
from the North Fork of the Holston river." 

Dr. William Blanding presented me with specimens 
from Nollichucky river, Tennessee, the largest of 
which is nearly destitute of the posterior ribs. I 
found a few dead shells on the bank of Elk river, 
near the muscle shoals, Alabama. 



UNIO ACUTISSIMUS. 

Plate XLVIL— Fig. 2. 

DESCRIPTION. 

Shell narrow-elliptical; posterior side produced, 
gradually narrowed to a point; valves thin; posterior 
side with parallel furrows extending from the umbo- 
nial slope to base; posterior slope with slightly arcuate 
ribs and furrows; umbonial slope carinated; beaks 
not elevated above the dorsal line; epidermis yellow- 
ish, with green dotted rays; within yellowish, highly 
polished, exhibiting the ribs of the exterior. 

SYNONYME. 

U. AcuTissiMirs, Lea. Trans. Amer. Phil. Soc, new series, vol. 

iv. p. 89, pi. x. fig. 18. 
Cab. A.N. S.,No. 20418. 

*Mr. Vanuxem informs me that he found it in Virginia. 



AT 




• 











tVnio eu,liertlu.s J*ay. 2, Uncut i.\.^iyanis.J,ta ?,.U.conradiu,s i,t 



.-v. 







87 

OBSERVATIONS. 

Inhabits the Alabama and Black Warrior rivers: 
rare. 

This is one of the smallest species of Unio, and 
resembles the young of the conradius, but is much 
more elongated. Mr. Lea observes that the lateral 
teeth are single in each valve; but the specimens be- 
fore me have the usual form of a divided tooth in the 
left valve. The epidermis is marked with pale green 
zig-zag lines, and the furrows on the disk are some- 
times obsolete or wanting. I found two fine indi- 
viduals at the village of Erie, Greene county, Ala- 
bama, on a bar in the Black Warrior river. 



UNIO CONRADIUS. 

Plate XLVIL— Fig. 3. 
DESCRIPTION. 

Shell elliptical, basal margin straight or slightly 
emarginate; ligament margin slightly declining; valves 
rather thin, with undulations on the posterior side, 
sometimes obsolete; posterior slope with arcuate 
ribs; beaks very slightly prominent and undulated, 
decorticated; epidermis finely wrinkled, yellowish- 
brown, with numerous green rays; within inclining 
to salmon colour; very iridescent and furrowed pos- 
teriorly. 

SYNONYME. 

U. conradius, Lea. Trans. Amer. Phil. Soc, new series, vol. v. 

p. 63, pi. ix. fig. 23. 
Cab. A. N. 8., No. 20419. 



88 

OBSERVATIONS. 

Inhabits Flint river, Alabama, near its junction 
with the Tennessee river, and is common in the 
vicinity of Nashville, Tennessee. This small species 
is related to U. subtentus, but is very obviously dis- 
tinct. It is proportionally shorter than the acutissimus, 
and has more obvious beaks, but young individuals 
much resemble the latter species, as may be observed 
in fig. 4. In some specimens the posterior undula- 
tions are large and profound, in others more nume- 
rous and not so distinct. 



UNIO INTERRUPTUS. 

Plate XLVIII. 
DESCRIPTION. 

Shell subtriangular, disks flattened; umbones broad, 
flattened, summits obtusely rounded; posterior slope 
much depressed; umbonial slope abruptly rounded, 
nearly terminal; epidermis brownish-yellow, wrinkled, 
except on the umbo; rays numerous, narrow, inter- 
rupted, of a dark olive colour; on the umbonial and 
posterior slopes consisting of series of small quad- 
rangular spots; within white; cardinal and lateral 
teeth very robust; anterior and posterior muscular 
impressions deeply impressed. 

SYNONYMES. 

U. interrupta, Ruf. Ann. gen. des Sc. Phys., vol. v. p. 36. 

Say. Amer. Conch., No. 6. Ferr. Mag. de Zool. 
U. brevidens, Lea. Trans. Amer. Phil. Soc, new series, vol. 

iv. p. 75, pi. vi. fig. 6. 
Cab. J. N. S., No. 1114. 



48 










V. cn.ttrru.btu a, Kafint-S'f'ue . 



49 




1.[f.blcx&s,C. %,. U.heteroeCon £.&&. 3.V. aanstrictus } Conrttd. 



89 

OBSERVATIONS. 

Inhabits Cumberland river near Nashville, Ten- 
nessee, and Elk river, near the muscle shoals, Ala- 
bama. 

In outline it somewhat resembles Unio lineolatus, 
but more nearly approaches the penitus. The rays, 
very wide umbo, and the proportionally shorter out- 
line distinguish it from the latter species. The lower 
figure represents the female. 



UNIO PLEXUS. 

Plate XLIX.— Figs. 1 , 2. 

DESCRIPTION. 

Shell suboval, ventricose; posterior margin trun- 
cated or obtusely rounded; posterior slope with nar- 
row ribs; umbo flattened, with longitudinal undula- 
tions; umbonial slope subangulated; beaks eroded, 
not prominent; epidermis nearly black, wrinkled; 
within purple; cardinal teeth direct; anterior muscular 
impression very rough. 

Cab. A. N. S., No. 20421. 

OBSERVATIONS. 

This species was sent from Vera Cruz by the 
American consul, Dr. Marmaduke Burrough. I am 
unacquainted with its habitat. The larger speci- 
men, of which an outline is given on the plate, much 
resembles U, niger, but the undulations on the um- 
bones, the proportional length in the smaller speci- 
al 



90 



men, and other characters, render it sufficiently 
distinct. It has, perhaps, more general resemblance 
to Unio trapezoides than to any other species. 



UNIO HETERODON. 

Plate XLIX.— Fig. 3. 

DESCRIPTION. 

Shell rhomboidal-ovate, ventricose, valves thin; 
ligament margin short, elevated, parallel with the 
basal margin; umbonial slope rounded; beaks decor- 
ticated; basal margin straight in the middle; posterior 
extremity rounded or very obtusely angulated, a little 
above the line of the base; within bluish; cardinal 
tooth in the left valve trilobed; in the right valve, 
single, elongated, oblique, compressed; lateral teeth 
slightly curved, double in the right valve. 

SYNONYME. 

U. heterodon, Lea. Trans. Amer. Phil. Soc, new series, vol. 

iii. p. 428, pi. viii. fig. 11. 
Cab. A. N. S., No. 20425. 

OBSERVATIONS. 

Inhabits the Schuylkill and other rivers in Penn- 
sylvania. This interesting little species was first 
found by Messrs. Mason and Hyde, and my father 
suggested the name of heterodon, which Mr. Lea has 
adopted. It is related to V. viridis and compressus, 
but the double cardinal teeth being in the right valve 
will distinguish it from every other species. 



49 





.U.t>lcxMs,C. X. V 'hrtf.ro don j^&a ; . 3. V. eon-stri.otus } Conrad. 



49 




/ 






1 l\ ' 



\ 




'-. / hrterodon L-:<> 3 1 constrictus, Conr/fd 



91 
UNIO LIENOSUS. 

VARIETY CONSTRICTUS. 
Plate XLIX.— Fig. 4. 

DESCRIPTION. 

Shell elliptical, ventricose; beaks rather prominent, 
undulated, distant from the anterior margin; posterior 
side furrowed, contracted at base; posterior angle 
much above the line of the base; epidermis obscurely 
rayed; within white; cardinal teeth robust. 

Cab. A. N. S., No. 20423. 

OBSERVATIONS. 

Inhabits North river, Rockbridge county, Virginia. 
Several specimens of this variety exhibit the peculiar 
groove on the posterior side, which has suggested the 
name. In other respects it agrees with U. lineosus 
of the south-western streams, except that the cardi- 
nal teeth are more robust. 



UNIO STRAMINEUS. 

Plate L. — Fig. 1. 
DESCRIPTION. 



Shell ovate, ventricose; disk with coarse prominent 
lines of growth; umbo with numerous undulated plicae; 
umbonial slope undefined; ligament margin elevated; 



92 

anterior side slightly contracted or furrowed from 
beak to base; basal margin slightly emarginate; epi- 
dermis straw-coloured, polished; within white; car- 
dinal teeth double in each valve; lateral teeth slightly 
arcuate. 

SYNONYME. 

U. stramineus, Nob. New Fresh Water Shells, pi. vii. fig. 3. 
Cab. A. N. S., No. 20420. 

OBSERVATIONS. 

Inhabits brooks or mill streams in Greene county, 
Alabama. 

This species may be compared to some varieties 
of siliguoideus, but is sufficiently distinct, being desti- 
tute of rays on the disk, and having remarkably 
prominent lines of growth. The siliquoideus has not 
been found in Alabama. 



UNIO PATULUS. 

Plate L. — Fig. 2. 
DESCRIPTION. 

Shell ovate; convex anteriorly, and compressed 
and cuneiform posteriorly; substance of the shell thick 
on the anterior and thin on the posterior side; beaks 
not terminal, prominent, undulated, almost contigu- 
ous; umbonial slope undefined or obtusely rounded; 
epidermis brownish-yellow, with broad interrupted 
green rays composed of fasciculi of hair like lines; 
within white; cardinal teeth, in the left valve pro- 



M 










/ U. strccailn en s, 6, I VJtatu lu$, Lea. 



,57 








' -" ft'? f ( d 





C/)m'« Ifenubeli, GonraxC. 



93 

foundly diverging; in the right valve single, robust, 
sulcated; lateral teeth rectilinear. 

SYNONYME. 

U. patulus, Lea. Trans. Amer. Phil. Soc, new series, vol.iii. 

p. 441, pi. xii. fig. 20. 
Cab. A. N. S., No. 20424. 

OBSERVATIONS. 

Inhabits the rivers of Tennessee and Kentucky, 
and appears to be comparatively rare. It may be 
distinguished from U. clava by its less oblique and 
more compressed form; and the beaks are less pro- 
minent and not terminal. The beaks are acutely 
pointed at the apex, and nearly touch each other; 
and they are somewhat flattened on the summit and 
have tubercular undulations. It is probable that U. 
oviformis is but a variety of this species. 



UNIO HEMBELI. 

Plate LI.— Fig. 1. 
DESCRIPTION. 

Shell elliptical, convex, posterior extremity angular, 
much above the line of the base; posterior slope with 
obtuse undulations; beaks eroded, scarcely elevated 
above the dorsal line; umbonial slope undefined; epi- 
dermis dark brown, becoming black with age, much 
wrinkled; within white; cardinal teeth robust, double 
in each valve, direct, profoundly striated. 

Cab. Ji. N. S. , No. 20422. 



94 

OBSERVATIONS. 

Many specimens of this shell was sent from New 
Orleans in company with the declivis, Mortoni, pur- 
puratus, &c, but the locality was not given. It has 
some affinity with the subtentus, but is thinner in sub- 
stance, and differs widely in the posterior angle. 
It is never rayed, whilst that species has well marked 
interrupted rays. Some specimens which are desti- 
tute of the undulations on the posterior slope might 
be confounded with U. complanatus. 

It is named in compliment to my friend William 
Hembel, Esq., Vice-President of the Academy of 
Natural Sciences of Philadelphia. 



END OF VOL. I. 



INDEX 



page. pl. fig. 
Unio fasciatus, - - - - -311 

OVATUS, ----- 4 2 



CLAVA, 
DECISUS, 



5 3 1 

6 3 2 



REFLEXUS, - - - - -741 

8 4 2 

9 5 1 

10 5 2 
11 6 1 

12 6 2 

COSTATUS, - - - - -17 7 



FLEXUOSUS, 

PHILLIPSII, 

METANEVRUS, 

MORTONI, 

FRAGOSUS, 



RETUSUS, 

PARVUS, - 

GLANS, 

SILIQUOIDEUS, 

RADIATUS, 

PECTOROSUS, 



19 8 

-20 9 1 

21 9 2 

-22 10 1 

24 10 2 

-25 11 1 



FASCIOLUS, - - - - -26 112 

CONGARjEUS, - - - - -27 121 

masoni, 28 12 2 

coccineus, - - - - -29 131 

catillus, - - - - -30 132 

productus, - - - - - 31 14 1 

lanceolatus, - - - - 32 14 2 

RECTUS, - - - - - - 33 15 

crassus, - - - - - 34 16 

viridis, - - - - - -35 17 1 

ochraceus, - - - - - 37 17 2 

NASUTUS, - - - - - 38 18 1 

39 18 2 
40 19 



icterinus, - 

cariosus, - 

mytiloides, - - - - - 41 20 

dilatatus, - - - - -42 21 

tuberculatus, - - - - 43 22 

declivis, - - - - - 45 23 1 

blandingianus, - - - - 46 23 3 

personatus, - - - - - 47 24 

cordatus, - - - - - 48 25 



IV 

PAGE. PL. FIG. 

Unio NIGER, - - - - . - 49 26 

GIBBOSUS, - - - - 50 27 1 

PEROBLIQUUS, - - - - - 51 27 2 

TERES, - - - - - 52 28 

SAGERI, - - - - - - 53 29 1 

LAPILLUS, - - - - 54 29 2 

FRAGILIS, - - - - - 55 30 

ALATUS, - - - - - 56 31 

INFLATUS, - - - - - 57 32 

LEPTODON, - - - - 58 33 

ellipsiformis, - - - - - 60 34 1 

lienosus, - - - - 60 34 2 

stapes, - - - - - - 62 35 1 

intermedius, - - - - 63 35 1 

occidentals, - - - - - 64 36 1 

collinus, - - - - 65 36 2 

sowerbyanus, - - - - - 66 37 1 

politus, - - - - - 67 37 2 

nexus, - - - - - -68 38 1 

greenii, - - - - - 69 38 2 

shepardianus, - - - - - 70 39 

compressus, - - - - - 71 40 1 

caps.3sformis, - - - - - 72 40 2 

subplanxjs, - - - - -73 411 

flavus, - - - - - - 74 41 2 

capax, - - - - 75 42 

RUDis, - - - - - - 76 43 1 

obliquus, - - - - - 77 43 2 

apiculatus, - - - - - 78 44 1 

prasinus, - - - - - 79 44 2 

nodclatus, - - - - - 80 45 1 

BULLATUS, - - - - - 82 45 2 

STEGARIUS, - - - - - 83 46 1 

DROMAS, - - - - - 84 46 2 

subtentus, - - - - - 85 47 1 

acutissimus, - - - - 86 47 2 

conradius, - - - - - 87 47 3 

interruptus, - - - - 88 48 

plexus, - - - - - - 89 49 1 

heterodon, - - - - - 90 49 3 

lienosus, - - - - - 91 49 4 

stramineus, - - - - - 91 50 1 

patulus, - - - - - 92 50 2 

HEMBELI, - - - - " - 93 51 1 



U.VIO CERINUS, 

LATIKADIATUS, 
SUBINFLATUS, 

ANGUSTATUS, 
EXCULTUS, 
PULLUS, 
MEL1NUS, 

Sayanus, - 



PAOt. 


PL. 


FI( 


95 


52 




9o 


53 




97 


54 


1 


98 


54 


2 


99 


55 


1 


100 


55 


2 


101 


56 




102 







ERR^T' 
Page 2, tenth line from the 
towards the ca 
" 35, ninth line 1 

• ' 
9! :■■■ - , for "LFV 

illui •.. v ." } 

ader U. meliims, - , i., for "LV." 

■ .cad pi. LVI.. for "LV." 



' ~ 



CONTENTS. 



Plate 



XLV. 
XLVI. 

XLVII. 



XLVIII, 
XLIX. 



LI. 



Fig. 2, Unio bullatus. 
Fig. 1, Unio stegarius. 
Fig. 2, Unio dromas. 
Fig. 1, Unio subtentus. 
Fig. 2, Unio acutissimus. 
Fig. 3, Unio conradius. 
Unio interruptus. 
Figs. 1, 2. Unio plexus. 
Fig. 3, Unio heterodon. 
Fig. 4, Unio lienosus. 
Fig. 1, Unio stramineus. 
Fig. 2, Unio patulus. 
Fig. 1, Unio hembeli. 



NEW FRESH WATER SHELLS OF THE UNITED 
STATES, &c. 

For sale by J. Dobson, a few copies of this work, which contains 
coloured illustrations of bivalve and univalve shells, and embraces a 
monography of the genus Anculotus. Most of the species described 
in this book were obtained by the author in Alabama. 



NORTH AMERICAN HERPETOLOGY. 



Just Published, and for sale by J. Dobson, 108 Chesnut Street, 

NORTH AMERICAN HERPETOLOGY; +^' 

OR A DESCRIPTION OF THE 

REPTILES INHABITING THE UNITED STATES. 

BY JOHN EDWARDS HOLBROOK, M. D. 

Professor of Anatomy in the Medical College of the State of South Carolina, Member 

of the Royal Medical Society of Edinburgh, Corresponding Member of the 

Academy of Natural Sciences of Philadelphia, and of the New 

York and Baltimore Lyceums of Natural History. 

Vol. I. royal 4to, with splendid Coloured Plates. 
This beautiful work will consist of four volumes, royal quarto, illus- 
trated by numerous finely coloured plates— price $10 per volume. 



JYo. 11. 


MONOGRAPHY 


* OF THE 


FAMILY UNIOIVIDtE, 


OR NAIADES OF LAMARCK, 


(FRESH WATER BIVALVE SHELLS,) 



NORTH AMERICA. 



ILLUSTRATED BY FIGURES DRAWN ON STONE FROM NATURE 



BY T. A. CONRAD : 

MEMBER OF THE ACADEMY OF NATURAL SCIENCES OF PHILADELPHIA; 
PALAEONTOLOGIST OF THE STATE OF NEW YORK, ETC. 



PHILADELPHIA: 

J. DOBSON, 108 CHESNUT STREET 

BOSTON: PERKINS & MARVm.— PITTSBURGH: JOHN I. KAY & Co, 

LONDON: O RICH, No. 12, RED LION SQUARE. -PARIS: ARTHUS 

BEliTRAiSO, FILS, RUE HAUTEFEUILLE No. 23.— HAMBURGH: 

PEItTHF.S & BESSER, No. 22, AM JUNGFERNST IEG. 

E. G. DORSEY, PRINTER. 

November, 1838. 



Je 



6% 




Unlo c&rLftA/sS-, Conrad. 



95 

UNIO CERINUS. 

Plate LIL 
DESCRIPTION. 

Shell triangular, subrhomboidal, compressed; disks 
flattened, slightly undulate; ligament margin slightly 
declining; posterior margin obliquely truncated, ex- 
tremity obtusely angulated; umbonial slope angulated; 
beaks decorticated, not prominent; anterior margin 
truncated above; basal margin widely and slightly 
emarginate; epidermis brownish-yellow; within white 
with wax-yellow stains; cardinal teeth direct, robust, 
single in one valve and double in the other; lateral 
teeth rectilinear. 

OBSERVATIONS. 

A few specimens of this species were sent me from 
New Orleans by Mr. Josiah Hale. It probably in- 
habits the waters of Louisiana, not far from New 
Orleans. The two most characteristic species of 
Louisiana were contained in the box of specimens, U. 
Mortoni and U. Hydia?ius, Lea, and also U. Hembeli. 

It has a general resemblance to U.fiavus and sub- 
planus; from the former of which it may be distin- 
guished by its much less prominent beaks, more 
compressed disks and proportionally longer outline: 
it differs from the latter in having a broader umbo, 
emarginate base, longer ligament margin, less oblique 
posterior margin, truncated anterior margin, and 
more robust cardinal teeth . Old shells have some- 



96 



what the outline of U. niger, as represented in the 



lower figure. 



UNIO LATIRADIATUS. 

Plate LIII. 
DESCRIPTION 

Shell elliptical, rather thin; posterior side produced, 
extremity obtuse, and subangulated; umbonial slope 
rounded, undefined; beaks slightly prominent, with 
rather coarse angulated plicae; basal margin arcuate; 
posterior margin rectilinear and very oblique; epider- 
mis yellow, polished, with very broad and intermediate 
slender green interrupted rays; within white, highly 
iridescent; cardinal teeth direct, pyramidal; posterior 
side shewing the exterior rays through the substance 
of the shell. 

SYNONYME. 

U. ixterruptus. Lea. Trans. Amer. Philos. Soc, new series, 
vol. vi., pi. vL, p. 15, fig. 15. 

OBSERVATIONS. 

Inhabits streams in the vicinity of Nashville, Ten- 
nessee. I have received a fine series through the 
kindness of Richard O. Currey and Samuel M. Edgar 
of Nashville. The species is remarkable for the 
broad interrupted rays, and resembles in this charac- 
ter and in general aspect U. tcenkdus; it is, however, 
a thinner and less ventneose, as well as more elon- 



6 



) 












Unio Udiradiatus , (tan. 



m. 





f. Unto $ub i aflat ua ) C & W. an m d crtu .y, X £ a. 



97 

gated shell, and will hardly be confounded with it. 
The name Interruptus cannot be retained for this 
shell, since, if Rafinesque's species be rejected, it 
must be applied to the trapezoides of Lea, in right of 
priority, as the latter was described by Say under 
the name of interruptus. The largest specimen 
measures 3| inches in length. 



UNIO SUBINFLATUS. 

Plate LIV.— Fig. 1. 

DESCRIPTION. 

Shell ovate-oblong, posterior side slightly ventri- 
cose; ligament margin elevated, slightly ascending; 
umbones very wide; beaks distant from the anterior 
margin, not in the least prominent, decorticated; 
anterior margin rounded, not very obtuse; umbonial 
slope scarcely angulated; posterior extremity obtuse, 
direct; epidermis reddish-brown and olivaceous, 
smooth, with unequal green rays; within pale purple; 
cardinal teeth robust, not very prominent, sulcated; 
lateral teeth arcuate, rather thick. 

SYNONYME. 

U. complanatus, variety subinplatus, Nob. New Fresh 

Water Shells, Appendix, p. 5, pi. ix., fig. 2. 
Cab. Ji. N. S., No. 20426. 

OBSERVATIONS. 

I found this species several years since in the 
Savannah river, at Augusta, Georgia, and considered 



98 

it a variety of U. complanatus, but a re-examination 
of the specimens has led me to regard it as a distinct 
species. It is proportionally longer, and may always 
be recognised by its elevated ligament margin, and 
the remarkable inflation of the upper part of the 
umbonial slope. The sinus of the cartilage is much 
shorter than in the variety of the allied species which 
it most nearly resembles, (U. cariniferns, Lam.) the 
posterior margin more oblique, and the umbo is much 
wider; it has also more robust and much less promi- 
nent cardinal teeth; a much smoother and less 
wrinkled epidermis, and the interior is never dark 
purple. 



UNIO ANGUSTATUS. 

Plate LIV.— Fig. 2. 
DESCRIPTION. 

Shell elliptical, elongated, ventricose; disks slightly 
contracted obliquely from beak to base; ligament and 
basal margins parallel; anterior dorsal margin ele- 
vated, obtusely rounded at tip; posterior margin 
rectilinear, profoundly oblique; extremity obliquely 
truncated, the inferior angle or tip acute; considera- 
bly above the line of the base; umbonial slope angu- 
lated, rectilinear; beaks decorticated, slightly promi- 
nent, acute, approximate; basal margin slightly 
contracted in the middle, epidermis brown olivaceous, 
obscurely rayed; within pale chocolate colour and 








f, Uruo #ub mftrrt us ; 0. 1i (I an crust <ztu #, Ltd. 



66 







' 



















I 



Wruo &xoultm,c!.on. &.U. pullus, ' o 



99 



highly polished; cardinal teeth very prominent, ob- 
lique; lateral teeth long and rectilinear. 



SYNONYME. 

U. angustatus, Lea. Trans. Amer. Phil. Soc, new series, 
vol. iv. p. 114, pi. xvii. fig. 43. 

OBSERVATIONS. 

Inhabits the tide waters of South Carolina. It has, 
perhaps, more general resemblance to U. nasutus and 
Fisherianus than to any other species, but is too ob- 
viously distinct to need a careful comparison with 
either. I doubt whether it occurs in any stream 
north of the Carolinas. 



UNIO EXCULTUS. 

Plate LI V.— Fig. 1. 

DESCRIPTION. 

Shell subrhomboidal, thin, ventricose; ligament 
margin straight, rounded at tip, scarcely oblique; 
beaks rather distant, slightly prominent, decorticated, 
with traces of oblique plicae, and distant from the 
anterior extremity; anterior margin regularly rounded; 
posterior margin rectilinear, very oblique; extremity 
truncated or obtusely rounded, scarcely angulated; 
epidermis olive-brown, with dark concentric bands, 
polished; within bluish, with wax-yellow stains, and 
highly iridescent; cardinal teeth compressed, elon- 



100 

gated, very oblique; the posterior lobe of the tooth in 
the left valve rudimentary and remote; muscular im- 
pressions large, the anterior ones slightly impressed; 
accessory cacatrix remarkably large. 

Cab. Jl. N S., No. 20427. 

OBSERVATIONS. 

The exterior aspect of this shell is remarkably like 
that of an Anodonta, and the resemblance is main- 
tained in the highly polished and iridescent interior; 
but the teeth are remarkably well defined for so thin 
a shell; middle aged shells have very nearly the out- 
line of U. Sayanus, but cannot be confounded with 
that species, on account of their large size, polished 
and iridescent interior and very different cardinal 
teeth. It differs from U. tetralasmus, Say, in being 
portionally shorter and wanting the important cha- 
racter of a double lateral tooth in each valve. Like 
that species, the sayanus and camptodon, it has very 
oblique plicae on the beaks. 

Several specimens of different ages were sent me 
from New Orleans by Mr. Josiah Hale. 



UNIO PULLUS. 

Plate LIV.— Fig. 2. 

DESCRIPTION. 



Shell elliptical, inflated, particularly about the 
umbo and umbonial slope; disks slightly contracted 
towards the middle; ligament margin elevated, not in 



,) ■') 




■ 




'^kv 



lijltin d'SCC'id tllS, (yon. Z..U. puU-UX, Conrad. 



$6 








fj/fico m.eliruus, Can,. L. U. Sawanafi, Wa.rd. 



101 

the least declining; posterior margin very oblique, 
rectilinear; extremity obtusely rounded, considerably 
above the line of the base; beaks decorticated, 
slightly prominent; umbonial slope rounded; epider- 
mis very dark olivaceous, wrinkled; within chocolate 
purple; cardinal teeth oblique, single in one valve and 
double in the other; cavity of the umbo and posterior 
side very capacious. 

OBSERVATIONS. 

A small species found by Dr. William Blanding in 
the Wateree river, South Carolina. It resembles the 
U. parvus, but differs in having a much less wrinkled 
epidermis, and inflated umbonial slope, more obtuse 
posterior extremity, but more obviously in the dark 
purple colour of the interior. Since the figure was 
drawn, I have seen a larger specimen in the cabinet 
of Mr. Vanuxem, from the Warm Springs of North 
Carolina. It is less inflated and more regularly 
elliptical than the Wateree shell. 



UNIO MELINUS. 

Plate LV.— Fig. 1. 
DESCRIPTION. 

Shell oval, slightly ventricose, moderately thick, 
slightly contracted from beak to base; beaks promi- 
nent, with fine crowded undulations; ligament margin 
elevated, not oblique; posterior margin oblique, ex- 
tremity obtusely rounded; umbonial slope rounded; 



102 

epidermis yellow, polished, with numerous obsolete 
rays; within white; cardinal teeth double in each 
valve, oblique, prominent; lateral teeth lamellar, very 
prominent. 

OBSERVATIONS. 

I found a few specimens of this species about two 
years since in Salina lake, New York, and delayed 
the publication of it in the expectation of obtaining 
other specimens. The young and adult shells, how- 
ever, are before me, and present a marked difference 
to either cariosus or siliquoideus, the two kindred 
species which abound in the neighbouring waters. 
It is proportionally shorter and less inflated than the 
latter, and differs more obviously in being destitute 
of distinct rays. It is proportionally longer, less 
inflated, and has a longer ligament margin than the 
cariosus; the cardinal teeth are very different. 



UNIO SAY ANUS. 

Plate LV.— Fig. 2. 
DESCRIPTION. 

Shell subrhomboidal, rather thin, slightly ventri- 
cose; beaks prominent, obliquely plicated; anterior 
margin obtusely rounded; ligament margin scarcely 
declining, straight, angulated at tip; umbonial slope 
rounded; posterior margin subrectilinear, oblique, ex- 
tremity rather acutely angulated, the angle being 
considerably above the line of the base; basal margin 



.j o 



- 












ilfiiLo m< Lulus, Con,, 'I. U. SfCi/rmus; l\ (trd 



The 12th No. is in press and will contain the following new species:— 
Unio cuneus. 

Shell obliquely cuneiform, very thick; diameter through the umbones 
remarkably large; within pink. Resembles U. obliquus. Inhabits 
Little Red river, Arkansas. 

Unio metastriatus. 
A small species resembling U. interruptus, Raf., from the Black 
Warrior river, Alabama; it has slightly raised radiating lines on the 
posterior slope; whence its name. 

Unio lenis. 
Obovate, regularly convex; epidermis brown olive, rayed. Inhabits 
rivers in North Illinois. Distinguished from cariosus by its-dark epi- 
dermis, rays over the whole disk, &c. 

Unio planilateris. 
Oblong subovate, disks flattened; posterior slope with raised lines; 
Inhabits Black Water, Yadkin and Neuse rivers. Allied to U. con- 
garcBus. 

Unio iridescent. 
Elliptical, compressed, thin; epidermis yellow, with rays on the 
posterior side. Inhabits rivers in North Illinois. Resembles U.fascio- 
laris in outline. 

Unio Scuveus. 
Obovate, ventricose, thin, epidermis dark, yellowish-brown, rather 
obscurely rayed. Inhabits Alabama river at Claiborne. Length 2 
inches. 

Correginda. 
Page 94, first fine from top, for "'was sent" read were sent. 
" 91, for U. lienostts var. constrictu's, read U. constrictus. 
38, pi. 18, fig. 1, is U.jisherianus, Lea. 
45, for U. declivis, read U. sayanus, Ward. 

Note. — In the Trans. Philos. Soc, Pleiodon macmurtrii, nob. is 
referred by Mr Lea to the Iridina ovata, Swain, because Mr. Gray 
thinks them identical. This must be a wilful error on the part of Mr. 
Lea. 



Wo. 19. 



MONOGRAPH Y 



FAMILY UNIONIDil, 

OR NAIADES OF LAMARCK, 
(FRESH WATER BIVALVE SHELLS,) 



NORTH AMERICA 



ILLUSTRATED BY FIGURES DRAWN ON STONE FROM NATURE. 



BY T. A. CONRAD, 

MEMBER OF THE ACADEMY OF NATURAL SCIENCES OF PHILADELPHIA; 
PALAEONTOLOGIST OF THE STATE OF NEW YORK, ETC. 



PHILADELPHIA: 

J. DOBSON, 108 CHESNUT STREET. 

BOSTON: PERKINS & NARVIK— PITTSBURGH: JOHN I. KAY & Co.- 

LONDON: O. RICH, No 12, RED LION SQUARE.— PARIS: ARTHUS 

BERTRAND, FILS, RUE HAUTEFEU1LLE No. VS.— HAMBURGH: 

PERTHES & BESSER, No. 22, AM JUNGFERNSTIEG. 

E. G. DORSEV, PRINTER. 

June, 1840. 



67 







5 





On, i.ij ploilfiUris. 2,.U.mctccsl rltttus, CWratf. 



4 



103 

very slightly contracted anterior to the middle; car- 
dinal teeth compressed and oblique; within bluish- 
white. 

SYNONYMES. 

U. sayi, Ward, Silliman's Journal, vol. xxxv., pi. 3. fig. 1. 
U. declivis, nob., p. 45, pi. xxiii. fig. 1 of this work. 

OBSERVATIONS. 

This shell I found several years since in a small 
stream in Greene county, Alabama, and supposed it 
to be a perfect specimen of the declivis of Say, but 
it differs from that species in having a narrower 
umbo, plicated obliquely on the summit, a lighter 
coloured and smoother epidermis, and especially in 
wanting the "rostrum or prominent angle" of Say's 
description of U. declivis. It inhabits the canal near 
Savannah, where it was found by Mrs. Say; also the 
canal at Louisville, Kentucky. The name was in- 
advertently given as Saya?ius instead of Sayi. 



UNIO PLANILATERIS. 

Plate L VII.— Fig. 1. 

DESCRIPTION. 

Shell oblong-subovate, rather thin; disks flattened, 
compressed anteriorly; ligament margin elevated, 
parallel with the base, rounded at tip; umbonial slope 
inflated and angulated; posterior slope flattened, and 
having on its upper part short, slightly prominent 
o 



104 

oblique lines; beaks not prominent, eroded; basal 
margin nearly straight; posterior extremity truncat- 
ed, direct; epidermis olivaceous, with crowded pro- 
minent wrinkles, and with rather indistinct green 
rays; within bluish or purplish; cardinal teeth com- 
pressed, oblique. 

OBSERVATIONS. 

Some specimens of this shell might be readily mis- 
taken, without close examination, for U. complanatus, 
but the species is more nearly allied to U. congarceus. 
It differs in having a more elevated ligament margin, 
an inflated umbonial slope, and is proportionably 
longer. It is a very abundant species in the Black 
Water river, Virginia, and occurs also in the Neuse 
river, North Carolina, where it always has a very 
rough wrinkled epidermis, of a dark colour. The 
figure is from a specimen found by Dr. Blanding in 
the Yadkin river, North Carolina, where it is more 
narrowed posteriorly, smoother, thicker, and has a 
lighter coloured epidermis than those from the Black 
Water and Neuse rivers. One specimen is quite 
thick and salmon coloured within. 



UNIO METASTRIATUS. 

Plate LVIL— Fig. 2. 

DESCRIPTION. 

Shell subtriangular, moderately thick; umbo and 
disk flattened, but forming a strongly arcuate line 



67 



a 



' 



^§i 



.,?v 










tin i.u plo i il i t< ■ i I U, rrifitasl rltxtus, i ^mrf 



S>8 










■ 



%. 












Dniu '! np.u n. '' . U. ICTli S, Hon. 



105 

from beak to base; beaks rather distant from the 
anterior extremity, eroded; umbo very broad; umbo- 
nial slope abruptly rounded, nearly terminal; posterior 
slope with slightly prominent radiating lines; poste- 
rior margin nearly direct; margin of the tip obtuse; 
epidermis wrinkled, yellowish brown, with capillary 
rays over the umbo; within white; cardinal teeth 
direct, robust; lateral teeth short, rather thick, very 
distant from the cardinal teeth. 

OBSERVATIONS. 

This small species has considerable resemblance 
to U. interruptus, but the disks are less flattened, the 
posterior slope much less depressed and wider, the 
base more arcuated, and it is destitute of distinct 
dotted rays. I found a few specimens in the Black 
Warrior river, near Blount's Springs, Alabama. 



UNIO CUNEUS. 

Plate LVIIL— Fig. 1. 

DESCRIPTION. 

Shell obliquely cuneiform, very thick; diameter 
through the umbones profound; disks flattened be- 
hind the middle, and descending wedge-shaped to 
the posterior extremity, which is obtuse; beaks much 
eroded, terminal; umbo broad and very prominent; 
umbonial slope rounded; epidermis dark reddish- 
brown, rough and much wrinkled; within pink; car- 



106 

dinal and lateral teeth very thick; posterior cicatrix 
impressed. 

OBSERVATIONS. 

I have seen but one specimen of this Unio, which 
was found by Mr. Featherstonhaugh in Little Red 
river, Arkansas, during his investigations of the 
geology of that region. It has something of the 
interior colour and general outline of U. catillus, but 
the diameter through the umbones is far greater. 
The beaks, if they ever occur perfect, must be ex- 
ceedingly prominent. 



UNIO LENIS. 

Plate LVIII.— Fig. 2. 

DESCRIPTION. 

Shell obovate, rather thin, regularly convex; an- 
terior side narrowed; extremity obtusely rounded; 
posterior side dilated; ligament margin elevated, 
forming with the posterior margin an arcuate line; 
extremity obtusely rounded; base arcuate, profoundly 
so towards the posterior extremity; umbonial slope 
rounded; beaks slightly prominent, with rather small 
plicse, not interrupted by well defined angles; epider- 
mis brown-olive, wrinkled, with rather distant slender 
green rays; within white; cardinal teeth crested, 
oblique, single in one valve, and double in the other; 
lateral teeth distant from the cardinal teeth. 



Ha 










I e ti i s 



59 








S0^ 



, .- ..' ' 



M" Sax Del. 



CTiehovU S, 



107 



OBSERVATIONS. 



This shell may readily be distinguished from U. 
cariosus by its darker, less polished, more wrinkled 
epidermis, more regular convexity of the disks, and 
by the rays extending over the whole surface, which 
is very rarely the case with the former; the plicated 
beaks constitute another point of difference. Two 
specimens were sent me from Illinois by Dr. Fussel, 
who found them in the upper part of White river. 



UNIO HEROS. 

Plate LIX. 
DESCRIPTION. 

Shell oval, somewhat oblong, with large distinct 
undulations, three or four in number, directed to- 
wards the posterior margin, and not proceeding di- 
rectly from the umbo; surface with a few abbreviated 
transverse lines, placed without any regularity; umbo 
placed far forward, not prominent, hardly elevated 
above the general curvature, more or less literate 
with short irregular lines or slight elevations; hinge 
margin compressed, nearly rectilinear, prominently 
angulated or subalated at tip; in the more perfect 
specimens with numerous connected regular lines, 
curved to the edge and undulating it; posterior mar- 
gin rectilinear from the extremity of the hinge margin 
to the rounded inferior half, and undulated by the tip 
of the grooves of the disk; anterior margin very 
short, regularly rounded; base very obtusely rounded, 



108 

in many specimens a little contracted near the pos- 
terior termination; within bluish-white, pelaceous. 

SYNONYMES. 

U. heros, Say, Disseminator of Useful Knowledge, vol. ii., p. 

291, Sept. 1829. American Conch, No. vii. pi. xvi. 
U. undttlatus, Say, (not Barnes,) American Conch, pi. 16. 
U. multiplicatus, Lea, Trans. Amer. Philos. Soc, (new series) 

vol. iv. p. 70, pi. iv., 1831. 
Cab. A. N. S., No. 

OBSERVATIONS. 

Say remarks of this species, that "it resembles the 
p/icatus, nob., but on comparison it will be observed 
to differ essentially from that common species." It 
is, however, more nearly related to the costatus of 
Rafinesque, with which Say at one time confounded 
it, although he had previously published it under the 
name of heros. In his synonomy of the western 
species of Unio and Alasmodonta, he very properly 
reclaims the species. It may readily be distinguished 
from the costatus by the small letter-shaped undula- 
tions on the umbo, darker epidermis, and by other 
less obvious characters. Say informs us that it in- 
habits the Wabash river and tributaries. I am in- 
debted to Mrs. Say for the use of the beautiful and 
very accurate plate, originally published in the 
American Conchology. 

Deshayes considers this species identical with the 
undulatus of Barnes, and refers it to U. peruviana, 
Lam.* 

* Anim. sans Vert., vol. vi. p. 533. 



60 






/ £ saxf-us. Con. ?-. C trabwL.r, (lonrad. 

3. L r . CO I.I IYlV.S-. (I. 



109 
UNIO SAXEUS, 

Plate LX. — Fig. 1. 
DESCRIPTION. 

Shell obovate, ventricose, rather thin; beaks de- 
corticated, slightly prominent, summits obtuse; urn- 
bonial slope subangulated or obtusely rounded; 
ligament margin elevated, not oblique; posterior 
margin obliquely rectilinear or slightly concave; 
extremity truncated, direct; basal margin regularly 
arcuated; epidermis yellowish-brown, rather ob- 
scurely rayed; within bluish; cardinal teeth direct, 
compressed; lateral teeth straight. 

OBSERVATIONS. 

I found a few individuals of this species in the 
summer of 1833 on the shore of the Alabama river 
at Claiborne, where there is an indurated calcareous 
platform. They were all dead shells; and like its 
associate, U. arctatus, this species I never saw on the 
muddy shores or gravelly bars. 



UNIO COLLINUS. 

Plate LX.— Fig. 3. 

OBSERVATIONS. 



Since the publication of this species in a former 
number of this work, I have received a few specimens 



110 

from the same locality with the first described, which 
present the very remarkable character of spines, one 
on each valve, proceeding in an erect position from 
near the middle of the disk. In one old specimen 
there is no trace of these spines, but in the only two 
middle aged specimens I received the spines are as 
well developed as represented in the figure. A spi- 
nous Unio, no doubt the same species, is said to 
occur abundantly near Columbia in South Carolina. 
This is a smaller species, less pointed posteriorly, 
and otherwise distinct from the U. spinosus of Lea. 



UNIO TRABALIS. 

Plate LX.— Fig. 2. 

DESCRIPTION. 

Shell oblong-ovate, ventricose, thick anteriorly; 
anterior side short, margin obtusely rounded; poste- 
rior side cuneiform, produced, obtusely rounded at 
the extremity, which is narrow; hinge margin decli- 
ning; posterior margin slightly contracted just above 
the extremity of the valve; umbonial slope rounded; 
posterior slope flattened or concave, in old shells 
furrowed; beaks eroded and rather prominent; basal 
margin arched; epidermis smooth and polished, dark 
olive-brown tinted with green, and with dark green 
unequal rays, not very distinct; within dull white or 
slightly salmon-coloured anteriorly; bluish and very 
iridescent posteriorly; cardinal tooth in the right 
valve very thick and direct, in the left valve the car- 



60 






1.0- .s-axf.us, (.hi ?_. t frifliu/i.y, c i. n i-ikI 

3. U. c ■nil i n u .y, c . 



FOSSILS OF THE MEDIAL TERTIARY of the UNITED 
STATES, by T. A. Conrad. No. 2. containing 12 Plates, recently 
published and for sale by J. DOBSON, No. 106 Chestnut street. 



A MONOGRAPH of the FLUV1ATILE BIVALVE SHELLS 
of the RIVER OHIO, containing Sixty-eight Species. Translated 
from the French of C. S. Rafinesque, by C. A. Poulson. For sale 
by J: DOBSON, No. 106 Chestnut street. 



Generic Labels for Cabinets of Shells. 

The subscriber respectfully informs Conchologists and Curators ol 
the different Lyceums of Natural History, that he has published, in 
sheets, complete sets of the names of all the genera of Shells, in such 
a way that they can be easily cut up into neat labels, of uniform length 
and breadth. To facilitate the finding of any desired genus, the genera, 
about 305 in number, have been printed alphabetically. Each set of 
genera is accompanied by a set of labels of the six classes of the Mol- 
lusca, printed on a different coloured paper, and in a larger type. — 
Price One Dollar per set. 

E. G. DORSEY, 12 Library street 






Ill 



I MO TETRALASMUS. 

Plati LXI. 
DESCRIPTION. 

Shell oblong, elliptic, rather thin, moderately con- 
vex; beaks but little elevated, decorticated; hinge 
margin parallel to the basal margin, subrectilinear; 
anterior margin regular]) rounded; posterior >\'<\*' 
with t\*<» compressed lines; posterior margin declin- 
ing in an oblique rectilinear hue from the extremity 
ol the hinge margin to the subrostrated tip; basal 
iiwiri.Mii subrectilinear; umbonial slope n<>t prominent; 
within white, iridescent posteriorly and on the mar- 
pin; numerous minute slightly impressed radiating 
lines; cardinal teeth transverse!) l<»n<:. slender, very 
oblique; lateral teeth distant from the cardinal teeth, 
two in each valve, equally prominent in the two 
valves. 

SYNOXYME 
I . jiir u A-m «, Say. Amer. Conch., pi. xxiii. 

DESCRIPTION 

I have not seen this species, and have, therefore, 
copied Say's description in |>art, and am indebted 
to the great liberalit) of Mr>. Say for the use of the 

plate originally published in the American Con- 

v 






hfT Sm /W 



I I 



112 



chology. "For an opportunity to examine this spe- 
cies, I sun indebted to Mr. Lesueur, who obtained it 
in Bayou St. John, Dear New Orleans. It is readily 
distinguishable from any other species." Say. 



UNIO QUADRULUS. 

l'LATK LXII. 

DESCRIPTK N 

Shell narrowed, compressed, and thin behind; short, 
obtuse 1 , rounded, and wider before; beaks slightly 
elevated; ligament more elevated than the beaks; 
binge margin compressed, carinate; basal margin 
falcate, emarginate and compressed; posterior mar- 
gin subangulate; posterior dorsal margin subtrun- 
cate, nearly straight; posterior basal inarL r in project- 
ing; epidermis dark brown in obi specimens, ol an 
olive-colour in others; surface with distinct irregular 
transversely compressed tubercles; a broad, nodulous, 
elevated, somewhat double ridge extending from the 
beaks to the [>osfenor basal edge, and a furrow be- 
hind, separating the posterior hinge and [losterior 
dorsal margin: (animal teeth sukatcd; lateral teeth 
striated, rough, and in th» righl valve somewhat 
double; anterior muscular impression deep and partly 
rough; eavit\ of the beaks angular, compressed, and 
directed forwards under the cardinal tooth; nacre 
pearly white, and on the posterior side iridescent. 





\r 5-v m 



I lllii rfllili/ni/n 



II .< 



BYTfONYMM 



1 T . ur »nti 1 1 «, Paf. Knn. jj^n. o'o* Sc. Ph\s.. vol. v. p. 41. 
Poaboa'i tnin«ila'ion. p. 42. *«y- Amer. Coach., pi. 53. 

I . »i i.im «, liarntt. Sil'iman's Journ., vol. vi. p. 136. //»/- 

dreth. Silliman's J<>urn., vol. xiv. p. J-'J. 
( . Lacbtmmvs, Jsa. Trans. Anier. IMnlo>. Soc., vol. in. p. 14. 

pi. M. 

I larnsunrt, I.ta. lb. vol. iv. p. M, pi. v. 

ORSERVATlUNS. 

The description, uitli a few alteration?, is copied 
fr«>rii thai of Barnes. Tin* species, Mr. Say remarks, 
"approximates bj its \arieties, some <»1 the varieties 
of l\ buUatus, Raf." It hai likewise affinity with V, 
prisinus, I . Morloni, and I . apiculatus. Barnes com- 
pares it with U. verrucosus, Raf., to which, Mr. Say 
observes, it has but a remote affinity. 

Inhabits the Ohio and its tributaries, and some of 
the rivers of Louisiana. 

I am indebted to the hl>crahty of the Academy of 
Natural Sciences for the use of the plate which was 
engraved for Say's American Concbology. 



INK) CYPHIUS. 

Platr LXIII. 

DESCRIPTION 

Shell ovate, ventricose anteriorly; substance of the 
shell very thick anteriorly; valves with a wide do- 





! pkiu.i 



114 

pression on the posterior side; middle of the valves 
with an oblique slightly elevated tuberrulated ridge, 
the tubercles becoming more numerous and promi- 
nent with age; dorsal margin very oblique, straight; 
posterior side somewhat produced, the end margin 
obliquely truncated, extremity truncated obliquely 
inwards; l>eaks prominent; epidermis brownish-yel- 
low, polished, not rayed; surface with remarkably 
deep distant lines of growth <>r furrows; basal mar- 
gin projecting in the middle and emarginate poste- 
riorly; within white; cardinal teeth double in one 
valve, single in the opposite valve, deeply striated 
and rough; lateral teeth rectilinear and very oblique; 
anterior muscular impression profound; posterior 
very slightly impressed. 

BTNONTMGfl 

I*. cvfhia, Raj. Ann jrcn. des Sc. Phya., roi. * |>- 39. Poul- 

son's trans., p. •'(;». 
V. F.soM s, dretn. Contribution* of tba Maclurian Lyceum, vol. 

i. p. 4fl, pi. %. 

OMEftVATK !ffi 

This specie* is nearly allied to U. ricatricomu, Say, 
but is very easily distinguished in young and middle 
aged specimen! 1»\ the lighter coloured and more 
polished epidermis. The specimen figured belongs to 
the cabinet of C. V. Poulson, Esq., in which is also 
the original specimen described by Rafinesque. 

Inhabits the Ohio and its tributaries. Dr. Green 
observes that he obtained eight or ten of these shells 
from the rivers in the neighbourhood of Pittsburgh. 



115 



INK) CICATRICOSLS. 

Plati LX1V. 
DESCRIPTION 

Shell Mibovate; anterior margin very short, hardly 
extending beyond the beaks regularly rounded; pos- 
tehor margin rounded, or very obtusely angulated; 
umbo t levated; Cosset behind the beaks moderate, 
wider than long, not angulated before; disk deeply 
wrinkled or undulated, with a series of transverse 
elevations, sometimes separated by small longitudinal 
lines, so as to resemble, as it were, drops of a liquid, 
extending from the umbo to the base; within white; 
cardinal teeth direct. 

BYNONYMES. 

IT. < n vTBirosis, Say. New Harmony Disseminator, 1*29. 
17. vAHicosrs, Lea. Trans. Amer. Philos. Hoc., new series, vol. 
u. p. 100, p|. 11, fig. xx. 

OBSERVATIONS. 

" \ common species, distinguishable by the single 
■eriea of transverse elevations on the middle. The 
allied species are U. cardisce and U. incurvus* nob. 
Amongst the numerous species sent to me by Mr. 
Barnes, previously to the publication of his paper, 

* I think these two species have long since been published 
under the names -of cordata and iniorta, I therefore suppress the 
descriptions." Say 



116 

was a small valve of this species, but it was then 
referred as a variety to the convenient but obsolete 
receptacle of this genus, U. crassus." Say. 

It most nearly resembles the preceding, (\ rgpAsW, 
but may be distinguished by its more triangular ele- 
vated outline, and more elevated umltn and ligament 
margin. The posterior furrow is much narrower 
the tuberculated ridge is nearest the j>osterior ex- 
tremity, which is the reverse in U. cyphiu*. and the 
epidermis is darker and less polished. 

Inhabits the Ohio and its tributaries. The figure 
is from a fine specimen in Mr. PoulsonV cabinet. 



UNIO PLICATl S. 

Plate LXV. 
DESCRIPTION. 

Shell subrhomUudal, very vcntncose; j>ostcrior 
side x*ith large oblique irregular folds, profound about 
the umbonial slope, and but slightly impressed on the 
posterior slope; ligament margin parallel with the 
base; posterior margin long, slightly oblique, rounded 
above, and slightly emarginate towards the extremity, 
which is obliquely truncated inwards; umlx) very 
prominent, tumid, plicated, nearly terminal; epider- 
mis blackish or brownish, coarsely striated; within 
white; cardinal teeth deeply sulcated. 




IT. IMicatus ■<•" 



II 



SYNONYM ES 



U. nn atis, Say. Nicaotaon'a Km yclopedim, third American 
edition, articW- Conchology. 

I . r iKiPi.u ATI ■-. Aam. \n. sans. Vert., vol. ii. p. 71. 

OBSERVATIONS 

This shell is most neari) related to V. hcros. Say, 
and /'. costatus, Rat. It differs from l>oth in baying 
fewer folds and a much more prominent umbo. 
There is no trace of the fine plica? on the uml>o, 
which so distinctly characterize ( . hems. 

Inhabits the Ohio and its tributaries. I have a 
remarkably large and perfect specimen, presented by 
Richard C. Taylor, Esq., who found it with many 
others in St. Peter's n\» r. Wisconsin. 



I MO CARDIIM. 
Plati LXVI. 

DESCRIPTION. 

Shell with the posterior side very broad, subtrun- 
cate; anterior side rapidly narrowed, subangulated; 
disks very convex; umbones large, rounded, elevated; 
beaks recurved over the ligament; ligament large and 
prominent, passing under the beaks; posterior lunule 
depr e ss ed at tin- margin, fuscous, broad-lieart-sha[)ed, 
longitudinally waved; lunge margin depressed between 
the beaks; epidermis yellow ish-ohve, becoming chest- 



118 



nut-brown on the umbones, rayed with green, more 
conspicuous iu young specimens; in old ones the 
dark chestnut-brown covers the whole and conceals 
the rays; surface smooth and shining; within white, 
iridescent; cardinal troth broad, prominent, and ob- 
liquely flattened; lateral teeth broad, elevated, and 
terminating abruptly posteriorly; muscular impres- 
sions large; cavity of the' beaks unusually lame. 

SYN0N1 Ml>. 

I". (ARiiliM, liaf. Ann. gen. des Sc. Phys., vol. v. p. 32, |>l 

Ixxx. tigs. 16, IT, 1~. 19. 
U. vkntkicosi *, Jiamcu. Silliman's Journal, vol. vi. p. J<>7, pi. 

13, fig. 1 I, a. h, c. 
U. ovatub, Var. 6. I.nm. Vn. aans Vert., vol. v. p. 7f». 
I. mi [dens, Lea. Trans. Amer. Philos. So< ., ii< w series, vol. 

in. p. 4W, pi. v. 

< IBSERVATH >NS 

I have in part copied Barnes' description. This 
naturalist, Mr. Say observe-, "tirst distinguished the 
species from U. ovatus, nob., to which it is v rv 
closely allied, and appears to be absolute!) connect- 
ed by a gradual transition of intermediate varieties. 
The most striking difference appears to b< the more 
depressed anterior [posterior] slope ol the ovatus. 
Some old specimens and varieties an transversely 
more elongated, as i- repr< scnted in Barm s 1 figure r. 
The colour also is more <t less yellow, radiated with 
green, or tinged with reddish-brown, parti< ularly on 
the umbo, and sometimes extending over the whole 
surface, almost obliterating the rays. On the inner 
anterior [posterior] side, some Bpe< miens are beauti- 




V . TudefculuSus. /£<*/'. 
76 



SMITHSONIAN INSTITUTION LIBRARIES 



3 9088 00048 7298