The Naiades of Missouri

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The Naiades of Missouri

By

William |. Utterback, B.S., A.M.,
” (1914), and “‘Breeding

Author of ‘Mussel Resources of Missoun,

Record of Missouri Mussels,” (1916a).

Reprinted from The American Midland Naturalist, Vol. IV.,
Nos. I—10, with Plates LK—XXIX.
(1915-1916).

PRIVATE lLiprar Mi Gr

HARRY S. LAoR)y

University Press
Notre Dame,
Indiana
1916b

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THE NAIADES OF MISSOURI.

(Plates i—xxviit.) New Series.

Introduction.

After some years of intensive studies in the field, library and
laboratory an attempt is made to give a catalogued account of
the Nazadzs, or Fresh-water Mussels, of Missouri. Most of the
data for this descriptive and illustrated catalogue have been
collected through extensive, personal surveys of the most import-
tant streams and lakes of the State and now the typical anato-
mical and shell material from the different localities are pre-
served in the writer’s laboratory. No literature of any conse-
quence, dealing with the Nazades of Missouri, had been produced
until the author of this paper made a preliminary report on
“The Mussel Resources of Missouri.’’ This was, however, a
government report, published for economic purposes, the detailed
account of the scientific observations of which will not appear
until a later date.

The plan of classification, based on anatomical structures,
notably those of marsupial characters, has been carefully followed
in this work. The many changes in the nomenclature of this
catalogue from that of the Simpsonian system are due especially
to the recognition of Lindahl’s orthographic modification and of
the wise scheme of taxonomy for the Nazades begun by Sterki
(1906) and well consummated by Ortmann (1912); and also to the
acceptance of Rafinesque’s priority as recently revived by Mr.
Frierson and accepted by Dr. Ortmann. ‘The writer believes
that the ultimate taxonomic system will be based far more upon
the anatomical structure of juvenile and adult than upon their
shell characters from the fact that the soft parts are more constant

2 NAIADES OF MISSOURI

morphologically and less liable to parallelism and convergence
We should not, however, lose cognizance of the importance con-
cerning shell characters. External factors may so shape the
shell, as to individualize it, but, under normal conditions, do not
often destroy all traces of indentification with some group. Since
validity is so dependent upon the examination of both hard and
soft structures of large series of individuals, it is felt that the
species, as recorded for their extensive and intensive studies
herein, are fairly well settled within their genera. Fortunately
extensive field work has made this intensive study possible. On
one occasion the rare opportunity was given the author to make
a mussel survey of three hundred miles down the Osage River
in a row boat and ample time was given to the study of one of the
richest faunae of Missouri. Two papers, ‘‘ Mussel Studies Afield”’
for the years 1913 and 1914, are now in MS. recorded matter of
which is submitted herewith. The ecologic facts secured in these
field surveys are especially interesting. For example, in the long
trip down the Osage, the largest tributary of the Missouri in the
interior of this state, it was found that the flat or compressed
forms found at the headwaters, where the water is shallower
and swilter, become more swollen and heavier shells further down
stream where the water is deeper and more sluggish. The most
valuable data gathered from these field excursions are the ecologic
as illustrated in Plates x—xiv. Much physiologic and mor-
phologic information, however, has been obtained from these
immediate studies in nature that could not be secured otherwise,
since actual observation have been made of the animal carrying
on the nutritive and reproductive functions there as well as
observed through aquarium studies (See Plate ix). More accurate
idea of the morphology (especially of soft parts as to color, form,
etc.) is obtained while the specimens are fresh and uncontracted as
examined afield.

While this catalogued account is rather synoptical as to the
text of its animal and shell characters, yet it has been the effort
to be more complete than those literary works of somewhat
similar character that have devoted more space to the structures
of the shell; hence, much description will be found to be completely
given for the first time, notably those of M. heros (Say),
©, quadrula (Raf.), P. Utterbackii Frierson, R. tuberculata (Raf.),
U. tetralasma (Say), Las. suborbiculata (Say), Prop. capax (Green),

NAIADES OF MISSOURI a

Eur. (M.) brevicula (Call), T. Curtisi Frierson and Utterback,
and 7. Lefevret Utterback. Aside from the morphological synopsis
of the nutritive and reproductive parts and also of the external
and internal features of the shell the physiological and ecological
facts are especially dwelt upon in the miscellaneous remarks.
Because of the value of beak sculpture and glochidial characters
as bases for classification a special feature is respectively made
of the studies of juveniles and glochidia. I[ikewise, for classi-
ficatory reasons, a Breeding Record has been kept for the most
representative generic types, and, in many instances, more com-
plete records have been made than by other observers due to more
detailed observations during the winter season. ‘This Record
and also the Zodgeographic account of the Missouri Naiades
have been carefully kept in tabulated form, but, as these accounts
have been reserved thus for other special papers, they will only
appear here in extracts.

In this catalogue eighty species and twenty subspecies are
listed. Doubtless this list will be supplemented, although the
author has worked the State rather thoroughly in actual field
investigations—especially Central and Northwest Missouri—
and has examined all species catalogued except the following
which have been reported by Missouri collectors:—An. Bealii
(Lea). Cy. Aberti Lamarckiana (I.ea), Pleu. plenum (Lea), Lamp.
Reeviana (Lea) and Lamp. Powellii (Lea). According to a report
’ from the material sent away for identification, this State can claim
another species not yet on the list,—a new and undescribed
Lampsilis, near to Lamp. biangulata (Lea), and will soon appear
under the authorship of Mr. Frierson. ;

The author wishes to express his thanks to those who have
assisted him in this work. Especially is he thankful to Dr. George
Lefevre who assigned and directed this work and rendered it
possible through his numerous kindnesses and _ suggestions.
Much credit should also be given Dr. W.C. Curtis, the co-worker
with Dr. Lefevre, in the University of Missouri, Department of
Zodlogy, where the author gathered much of his data through
the facilities of the laboratory, library and museum. Besides
the invaluable instructions received. from these two gentlemen,
who have contributed so much to the Science of Fresh-water
Mussels, it was the author’s pleasure to receive many valuable
hints in person from Dr. R. EK. Scammon, author of ‘‘ Kansas

4 NAIADES OF MISSOURI

Unionidae.’”’ For other personal help while attending the Uni-
versity thankful acknowledgements are due to Dr. R. L.. Moodie,
Messers. G. T. Kline and F. A. Sampson. Under the illustra-
tions of the new species (Plates v and vi) credit is given Mr.
Kline, the University Artist-technician, for his excellent draw-
ings. Through the kindness of Mr. Sampson, author of the
“Mollusca of Missouri’ (Exclusive of the Unionidae), permis-
sion has been given to examine his collections of mussel shells
and make use of his list for same in determining geographic
distribution and in confirming the reports of other Missouri
collectors. Mr. B. F. Bush, a well-known scientist, and resident
of Courtney, Mo., has rendered invaluable aid in sending for
study immense collections taken mostly from the Ozark region
where the author has not been permitted to carry on such exhaus-
tive field studies as in the northern part of the State. Material
from Missouri, contributed to the author’s collection by Messrs.
C. C. Crouch of LaGrange, E. J. Palmer of Webb City and D. K.
Gregor of Fulton, has been thankfully acknowledged. The writer
is deeply indebted to old collectors and authors, who were former
residents of this State, viz:—Messrs. C. T. Simpson, W. A. Marsh,
Elwood Pleas and Dr. John H. Britts; also to those students of
Naiades for the nearest surrounding States viz:—Dr. F. C. Baker of
Illinois, Rev. W. E. Wheeler of Arkansas, Dr. D. H. Wolcott of
Nebraska, Dr. Junius Henderson of Colorado, Prof. F. B. Isely
of Oklahoma and Drs. R. E. Coker, Thaddeus Surber, A. D.
Howard, Prof. H. Walton Clark of Iowa. The last four named
students are of the personel of the U. S. Fisheries Biological Labora-
tory, located along the Mississippi at Fairport, Iowa, where the
author has done some study and has had pleasant personal contact
with these gentlemen who have contributed so much to the science
of Fresh-water Mussels. Besides being under obligations to the
above-named for their literary and conchological exchanges, as
well as for their valued correspondence and actual personal assist-
ance, special mention would also be made of Drs. A. E. Ortmann,
V. Sterki, C. B. Wilson, W. H. Dall, Harold Hannibal and Messrs.
B. H. Wright, Bryant Walker and IL. S. Frierson. The author is
most grateful to Dr. Ortmann as an authority concerning the soft
parts, to Mr. Walker for his treatment of the shell parts and to
Mr. Frierson for his general knowledge of Nazades as well as for his
special information concerning the Southwest forms. Through

NAIADES OF MISSOURI x5

very pleasant and extensive correspondence with these last -three
named gentlemen many problems have been solved and all novel-
ties and changes have passed through their censorship.

In order to elucidate the references in the text made to the
physiography and geography an excerpt of the geographic distri-
bution and also a tabulated Account of the Mussel Faunae of
Missouri are given here, although, when it is possible to secure
the desired data, it is the intention of the author to give a detailed
account of the zoogeography of the Naiades of Missouri and adjacent
territory in relation to the restoration of the ancient geographic condi-
tions of Central Mississippi Valley.

In this connection the hydrography of the State may also be
given for the sake of clearness in the use of the text. The drainage
to the Mississippi is mostly through the Missouri River which
flows entirely across the State just above the central line, and.
because of the loess soil held in suspension, together with its
shifting sand bars and mud beds, it forms “a great faunal
barrier.’ Hence we may account for such a distinct mussel fauna
north of the Missouri (known as “Old Muddy’’) from that south
of it. The depauperization of mussel life is remarkable as noted
in this river, together with that of the Mississippi from the mouth
of the Missouri to a point below the southern boundary line of
the State. The chief river basins of North Missouri belonging
directly to this faunal barrier are the Chariton, the Grand, the
Platte, the Nodaway and other minor ones of the Northwest.
A chain of lakes, formed by the changing of the Missouri River
channel into ‘‘ox-bow cut-offs,’’ are found mostly in the north-
western part of the State along the Missouri in its eastern and
northern flood-plains. The largest river basins draining into the
Missouri River from the south are the Osage, Gasconade and
Black-water. The most important one which drains directly into
the Mississippi from this State is the Meramec. The chief basins
found on the south slope of the Ozarks are the White, Black and
St. Francis Rivers which are drained into the Mississippi through
Arkansas. South-west Missouri drains into the Mississippi River
partly and directly through the Neosho.

The following is a Classified Account, (although apparently
contrary to the geologic facts, yet self-explanatory), showing the
distinct mussel faunae of the State that coincide with the different

6 NAIADES OF MISSOURI

physiographic provinces because of their different ecologicai
conditions, namely, the muddy, sluggish streams of the north,
swift, clear-water streams in the south and the mediocre streams
of the Central. portion :—
a=Prairies; }=Mo. and Miss. R’s (Proper); c=Ozark Uplift.
I—NORTH MISSOURI= Primitive Mussel Fauna.
1.a—New Prairies, or Glacial Plains. (N. and N.W.Mo.)
1.b— Missouri-Mississippi Flood-plains—= Mo. Lakes and Miss R.
(Proper) to mouth of Mo. R. (N. E. Mo.).
Mo. R. (Proper)=Depauperated Mussel Fauna.
II—CENTRAL MISSOURI=Intergraded Mussel Fauna.
2.a—Old Prairies of W. Central Mo.
1.c—Ozark Border, or North Slope.
III—SOUTH MISSOURI= Modern Mussel Fauna.
2.c—Ozark Plateau.
3.c—Ozark Center, or South Slope.
2.b—Miss. R. (Proper) below mouth of Mo. R. and Miss.
Lowlands of S. E. Mo.=Depauperated Mussel Fauna.

The Species and Sub-Species, listed under the following
general Key to the Missouri Naiades, are assigned to the different
sub-physiographic provinces where they predominate by employ-
ing to the extreme right after their names the lettered numbers of the
above Classified Account: e. g., Amblema rariplicata (Deshayes)—
l.a..—thus indicating the New Prairies Fauna where mostly
found.

General Key for Identification of the Missouri Naiades.

This key is for very general use, being based upon the essential
reproductive and nutritive characters of the animal parts for
the Families, Sub-l’amilies and Generic Groups. These characters
are indicated under the lettering in the Scheme below and the
enumeration of all Nazades for Missouri is denoted both by the
Roman and Arabic numerals. The geographic distribution of the
Species and Sub-Species is indicated by the lettered numbers.
The following Scheme of progressive classification is employed :—

A.—FAMILY I.
(A).—SuB-FAmIty (I).
a.—GeENus I. °
(a..—GENERIC GROUP AND SuUB-GENUS (I).
I.— SPECIES.
(1).—SuB-SPECIES.

A.—Gills with no water-tubes, septa incomplete, obliquely arranged; gill-

NAIADES OF. MISSOURI f 7

diaphragm incompletely formed; supra-anal absent, branchial and anal
openings suppressed with no tendency to a siphonal form; all four gills
both respiratory and marsupial; post-ventral margin of mantle undiffer-
entiated; glochida semi-circular, ventral margin with irregular dentations;
tachytictic, or short period (‘‘Summer’’) breeders.

FAMILY I. MarGariITANIDAE Ortmann.

a.—Gill septa oblique from base of gills, more vertically arranged and
Shonen sveithaceu d 2 issn ce Genus I. CUMBERLANDIA, Ortmann
1.—C. monodonta (Say)—(l. c).

B.—Gills always with water-tubes, septa complete and_ parallel
with gill filaments; gill-diaphragm complete; branchial and
anal openings usually tend toward a siphonal form; all four
gills or only outer, or parts of outer, marsupial; glochida
generally suboval, spadiform, geltiform, spined or spine-
LESSEE inane ka eect: FAMILY II. Unronipag, Swainson

(A).—Connection between anal and supra-anal openings short
or absent; inner laminae of inner gills free from visceral
mass; post-ventral margin of mantle not specialized; mar-
supial undifferentiated, not distended when gravid; glochidia
suboval, spineless, tachytictic for the most part..........
Pra Ne inate cine t -Sub-Family (1), Unronrnar, Ortmann

a.—All four gills marsupial.

(a)—Conglutinates club-shaped, pinkish, solid; beak sculpture:
concentric and slightly nodulated at base of post-umbonal
ridge; disk unsculptured....Genus II. Fusconata Simpson

2. F. undata (Barnes)—(1. b)
(1). F. undata trigona (Lea)—(t1. c)
‘(2). F. undata trigonoides Frierson—(1. a)
3. F. flava (Raf.)—(3.c)
4. F. hebetata (Conrad)—(t. c)
5. F. ebena (Lea)—(t. b)

(b)—Conglutinates leaf-like, compressed, subsolid white; beak
sculpture concentric, extending zigzag out on disk which is greatly
SCul pueda amet s) ade is Oa Se Genus III AmBLEMaA (Raf.)

6. A. peruviana (Lamarck)—(t1. c)
7. A. rariplicata (Deshayes)—(r. a)
8. A. perplicata (Conrad)—(3. c)
-(3).. A. perplicata Quintardi (Cragin)—(1. c)
9. A. (plicata) costata (Raf.)—(1. a)
Genus IV. MacGnonaras Utterback.
10. WM. heros (Say)—(t1. a)
Genus V. QUADRULA (Raf.)
11. Q. pustulosa (Lea)—(t. b)
(4). Q. pustulosa Schoolcraftensis (Lea)—(t1. a)
(5). Q. pustulosa asperata (ea)—(t. c)
12. Q. quadrula (Raf.)—(1. b)
(6). Q. quadrula contraryensis Utterback—(1. a)

NAIADES OF MISSOURI

13. Q. nodulata (Raf.)—(1. b)
14. Q. fragosa (Contrad)—(1. b)
15. QO. aspera (Lea)—(1. c)

16. Q. nobilis (Conrad)—(2. a)
17. Q. verrucosa (Raf.)—(1. ¢)
18. Q. metanevra (Raf.)—(1. c)

(7). Q. metanevra Wardii (1ea)—(1. b)
19. (Q. cylindrica (Say )—(3. c)
b.—Only outer gills marsupial.
(a)—Supra-anal opening absent; beak sculpture zigzag; disk greatly
Ye BUG ONSET r(eXs IR aeroin CGT ket cee ney coe Genus VI. RoTuNDARIA (Raf.)
20. RR. tuberculata (Raf.)—(1. c)
21. R. grantfera(Lea)—(1. b)
(b)—Supra-anal present but short; beak sculpture concentric but
disappearing toward disk which is mostly unsculptured.
Genus VII. PLETHOBASUS (Simpson;
22. P. Cooperianus (Lea)—(2. c)
23. P. aesopus (Green)—(t1. b)
Genus VIII. PLeEUROBEMA (Raf.)
24. FP. obliquum (Lamarck)—(t1. b)
(8). P. obliquum plenum (1ea)—(3. ¢)
(9). P. ebliquum pyramidatum (1ea)—(1. c)
(10). P. obliquum catillus (Conrad)—(1. c)
(11). P. obliquum coccineum (Conrad)—(1. c)
25. FP. catillus (Conrad)—(3. c)
26. P. coccineum (Conrad)—(3. c)
27. P. mitssourense (Marsh)—(3. c)
28. P. Utterbackit Frierson—(3. c)
Genus IX. Ev..iprio (Raf.)
29. E. nigra (Raf.)—(2. c)
30. E. dilatata (Raf.)—(2. a)
(12). E. dilatata subgibbosa (Lea)—(3.c)
(13). £. dilatata delicata (Simpson)—(3. c)
Genus X. UNromMERUS (Conrad)
31. U. tetralasma (Say)—(t1. a)
(14). U. tetralasma comptodon (Say)—(1. a)

(B).—Mantle connection between anal and supra-anal openings always
present, very long and moderate; inner laminae of inner gills usually
free from the visceral mass; marsupia occupying entire outer gills
only, distended ventrad and with lateral water-tubes when gravid;
post ventral margin of mantle not differentiated; glochidia subtrian-
gular, or spadiform, spined; bradytictic or long period (‘‘ Winter’’)
breeder Wrsin sinenaneerueese rele Sub-Family II. ANODONTINAE Ortmann
a.—Inner laminae of inner gills free from visceral mass; beak sculpture

coarse, double-looped.

(a)—Mantle connection between anal and supra-anal openings
moderately long; hinge rather complete, shell sculptured and
somewhat) thick: «:n. ..eee ae Genus XI. Sympuynota (Lea)

NAIADES OF MISSOURI 79

32. S.complanata (Barnes)—(1.a)

33. S. costata (Raf.)—(3. c)
Genus XII. ARrcIDENS Simpson)

34. A. confragosus (Say)—(2. c)

(b)—Mantle connection between anal and supra-anal openings very

long; hinge completely absent; disk smooth; shell thin. |
Genus XII. LASTENA (Raf.)
35. L. suborbiculata (Say)—(1. b)
36. L. ohiensis (Raf.)—(1. b)
Genus XIV. ANnoponra (Lamarck)
37. A grandis (Say)—(1. b)
38. A. dakotana Frierson —(1. b)
39. A. corpulenta Cooper—(t. b)
40. A. Daniels Lea—(1. a)
41. A. Bealit Lea—(1. 2c)

(c)—Mantle connection between anal and supra-anal openings
moderately long; hinge almost absent; shell rather thin, disk
tnsciuplttrediiiy 6.5 44. Genus XV. ANODONTOIDES (Simpson)

42. A. Ferussacianus (Lea)—(1. b—)
b.—Inner laminae of inner gills with tendency to connect with vis-
ceral mass; mantle connection between anal and supra-anal openings
moderate; beak sculpture, heavy, concentric.

(a)—Marsupium with simple ovisacs; hinge teeth rather well de-
veloped with cardinals sharp and prominent.

_ Genus XVI. ALASMIDONTA (Say)
43. A. calceolus (Lea)—(3. c)
44. A. marginata Say—(2. c)

(b)—Marsupium with transverse ovisacs; hinge rudimentary with

cardinals rounded and suppressed. .Genus VXII. Stropuitus (Raf)
45. SS. edentulus (Say)—(2. a)

(C)—Mantle connection between branchial and anal openings present,
never very long; inner laminae of inner gills rarely ever entirely free
from visceral mass; post-ventral margin of mantle usually highly
differentiated with papillae, flaps, etc.; part of outer gills in most
genera specialized as marsupia, which, when gravid, bulging beyond
original edge of gills, ruptured at ventral edge of ovisacs for escape of
larvae; glochidia semi-circular, (LAMPSILIS type), or axe-head shape
(PROPTERA type), ventral margin rounded, rarely spined; bradytictic.

Sub-Family III. LampstLinaAge Ortmann.

a.—Marsupium with subcylindrical ovisacs; post ventral margin of

mantle smooth; shell sometimes with disk sculptured, sex dimor-
phism of shell not distinct.

(a)—Marsupium occupying almost entire outer gill, edges folded,
ovisacs several, small, short....Genus XVIII. E.Liipsaria (Raf.)

46. E. clintonensis (Simpson)—(3. c)
(b)—Marsupium occupying outer gill in a few, large, long ovisacs.
Genus XIX, OBLIQUARIA (Raf.)
47. O. reflexa (Raf.)—(1. c)

1O. NAIADES OF MISSOURI

Genus XX. CyYprROGENIA (Agassiz)
48. C. Aberti (Conrad)—(3. c) F
(15). C. Aberti Lamarckiana (Lea)—(3. c)
b.—Marsupium with compressed and dilated ovisacs; post ventral
margin of mantle smooth to papillose; shell generally without disk
sculpture, sex dimorphism usually very distinct.

(a)—Inner post-ventral edge of mantles without flap or papillae,
but slightly lamellate and crenulated; glochidia elliptic and celti-
form, when normal in shape either extremely large or small.

Genus XXI. OBOVARIA (Raf.)
Sub-Genus (I)—PsEupDooN (Simpson)
49. O. (Pseudoon) ellipsis (lLea)—(1. b)
Genus XXII. NEPHRONAIAS (Cross and Fisher)
50. N. ligamentina (Lamarck)—(t1. b)
(16). N. ligamentina gibba (Simpson)—(t. c)
51. WN. ellipsiformis (Conrad)—(1. c)
(17). JN. ellipsiformtis vennsta (Lea)—(1. c)
52. N. Pleasit (Marsh)—(3. c)
53. WN. ozarkensis (Call)—(3. c)
Genus XXIII. AmMyGpALonatAs (Cross and Fisher)
54. A. donaciformis (Lea)—(1. a)
55. A. truncata (Raf.)—(t. c)
Genus XXIV. PLAGIOLA (Raf.)
56. P. securis (Lea)—(1. b)
Genus XXV. Lasmonos (Raf.)
57. L. fragilis (Raf.)—(1. a)
58. L. Simpsoni (Ferriss)—(3. c)
59. L. leptodon (Raf.)
Genus XXVI. PrRoOprTERA (Raf.)
60. P. alata (Say)—(1. a)
61. P. purpurata (Lamarack)—(3. c)
62. P. laevissima (1ea)—(1. a)
63. P.capax (Green)—(1. b)

(b)—Inner post-ventral edge of mantle differentiated with papillae

and flaps; glochidia normal in shape, medium in size.
Genus XXVII. CaARUNCULINA (Simpson)

64. C. parva (Barnes)—(1.b)

65. C. texensis (Lea)—(t. a)

66. C. glans (Lea)—(1. a)
Genus XXVIII. Euryntia (Raf.)

Sub-Genus (II). Micromya (Agassiz)

67. E. (Micromya) lienosa (Conrad)—(3. c)

68. E. (Micromya) iris (Lea)—(3. c)

69. E. (Micromya) brevicula (Call)—(3. c)

(18). E. (Micromya) brevicula Brittsi (Simpson)—(t. c)

Sub-Genus (III).) Eurynta (sens. strict.)

70. E. (Eurynia) subrostrata (Say)—(1. a)

71. £. (Eurynia) recta (Lamarck)—(1, c)

NAIADES OF MISSOURI Sai

Genus XXIX. Lampsi cis (Raf.)
72. L. anodontoides (1ea)—(1.-a)
73. L. fallaciosa (Smith)—(t. a)
74. L. Higginsi (Lea)—(1. b)
75. L. Powellat (Lea)—(3. c)
76. L. luteola (Lamarck)—(3. c)
(19). JL. luteola rosacea (DeKay)—(3. c)
77. L. Reeviana (Lea)—(3. c)
78. L. ventricosa (Barnes)—(3. c) y]
(20). L. ventricosa satura (Lea)—(3. c)
Genus XXX. TRUNCILLA (Raf.)
79. T. Curtisi Frierson and Utterback—(3. c)
80. T. Lefevret Utterback—(3. c)

ENUMERATION OF MISSOURI NAIADES.

TE ANEMIA OSS PS Sy rs ee ene ley AC ae Bee es PS 2
SES VAINEET: TESS eM ate tiel Ls ico orl Heme utr MANTA Sa PRP ot egal alate N aucne wa tahlan afi 5 3
(GRIN Ae es OE ee. Urea (Ue any tate Ie] Gi dey oN ie oe ee Re 30

SO GOMER IN or ees teva ee Va i NAMA Ne ec in (A Seta fatale 3

SES UES Slee a ee ea Bs or SEAM Cave be aretcomeUt eter el entnetas aye 80
Slip - SPE CEES ire, Sees cereale SR Merge ne ad satiate ete ares ye 20

MOVArMOK: SPRCINS: AND OUB= SPE CIS is cis) oiddos ce tareials suaisy siete sycue at esl sis She 100

EXPLANATION OF FIGURES.—For the purpose of illustrating the
characteristic structures of the animal a few text-figures have
been inserted immediately under the different Sub-Families.
All figures illustrating these characters are about life-size and,
while they are drawn from actual specimens in gravid
condition, yet the sketches are more or less diagrammatic in or“er
to emphasize the essential features. The sketches of the glochidia
(most of them figured here for the first time) are actual camera-
lucida drawings by using lenses to magnify 87 diameters. In
both sets of these inserted figures, as well as in some of the plates
at the close of the text, the following meanings are given to the
letters for the labels :—

A=anal opening; I=inner gill;

AN =anterior end; M = marsupium;

AV =antero-ventral margin; P=palp;

B=branchial opening; PO=posterior end;
D=dorsal, or hinge line; S=supra-anal opening;
F=foot; V=ventral margin.

EXPLANATION OF TERMS, ABBREVIATIONS, ETC., USED IN THE
TEXT, BIBLIGGRAPHY AND CHECK LIST.—A few technical terms intro-

[2 NAIADES OF MISSOURI

duced here are suggested for general use. Reference to the four sec-
tions of the shell or mantle edges, limited by the anterior, posterior,
dorsal and ventral extremities, can be expressed adjectively and
adverbially by the respective terms, ‘‘antero-ventral,’’ “‘antero-
ventrad,”’ ‘‘ post-dorsad,” etc. (See Plates I—III). ‘‘Spadiform”’
(shape of a spade head) and ‘“‘celtiform’’ (shape of a celt, or axe-
head) are used as adjectives in describing glochidia. In a few shell
measurements adoption has been made of Scammon’s term,
‘““umboidal ratio,” (um ra.) which is secured by dropping a line
perpendicularly from the tips of the beaks to the longitudinal
axis and expressing the distance from the intersection of the two
lines to the anterior margin of the shell as a decimal fraction
of the entire length of the longitudinal axis. The term, ‘‘inter-
dentum,”’ is used here for the bridge between the lateral and cardi-
nal teeth. The terms, “bradytictic”’ and “‘tachytictic,” as suggested
by Ortmann, are adopted as meaning respectively, ‘‘long period”’
and ‘‘short period’’ breeders. ‘The term ‘‘diaphragm,’’ is also
used here for the partition between the branchial and anal open-
ings formed by the gills.

All shell measurements are reckoned in terms of millimeters
(mm.) and length, height and diameter are considered consecutively.
‘““Diameter’’ is the distance between the greatest convexities of
closed valves. All other usages employed in this work have been
in such common adoption as to need no explanation.

To make plain those parts of this catalogue,—-especially
the Synonomy and Bibliography,—the equalities for the abbrevia-
tions are given as follows :—

Am. J. Conch.—American Journal of Conchology.

Am. Jl. Sci. and Arts——American Journal of Science and Arts.

Am. Nat.—American Naturalist.

An. Car. Mus.—Annals of the Carnegie Museum.

Biol. Bull.—Biological Bulletin.

Bull. Wash. Coll.—Bulletin of Washburn College.

Bull. U. S. Mus.—Bulletin of the United States Museum.

Bull. U. S. B. F.—Bulletin of the Unites Stated Bureau of Fisheries.

Jl. (or Jour.) Ac .N. Sci. Phila.—Journal of the Academy of Natural
Science of Philadelphia.

J. Cinn. N. Hist. Soc.—Journal of the Cincinnati Historical Society.

ji. Phila. A. Sci.—Journal of the Philosophical Academy of Science.

Mal. Soc. Lon.—Malacological Society of London.

Moll. Chicago, Pt. I.—Mollusks of Chicago, Part I.

Monog. Biv, Ohio.— Monograph of the Bivalves of Ohio,

NAIADES OF MISSOURI 13

Naut.—Nautilus.

N. Harm. Diss—New Harmony Disseminator.

Pr. (or Proc.) Ac. N. Sci. Phil.—Proceedings of the Academy of Natural
Science, Philadelphia.

Pr. Am. Phil. Soc.—Proceedings of the American: Philosophical Society.

Pr. Mich. Ac. Sci.—Proceedings of the Michigan Academy of Science.

Pr. Ohio Ac. Sci.—Proceedings of the Ohio Academy of Science.

Pr. U. S. Nat. Mus.—Proceedings of the United States National Museum.

Tr. (or Trans.) Ac. Sci. St. Louis—Transactions of the Academy of Science
of St. Louis.

Tr. Am. Fish. Soc.—Transactions of the American Fish Society.

Tr. Am. Phil. Soc.—Transactions of the American Philosophical Society.

U.S. B. F. Ec. Cir —United States Bureau of Fisheries,. Economic
Circular.

U.S. B. F. Doe.—United States Bureau of Fisheries Document.

CATALOGUE OF THE NAIADES OF MISSOURI.

Famity I. Margaritanidae Ortmann.

1911— Margaritantdae Ortmann., Nautilus, Feb.

“Diaphragm incomplete, formed only by the outer gills;
outer laminae of outer gills only in part connected with the mantle,
posteriorly free for considerable distance. Anterior end of inner
gills separated from the palpi by a wide gap. The margins of the
mantle do not unite or approach each other anywhere and there
is no tendency to form branchial and anal siphons and no supra-
' anal opening is present. Gills without water-tubes, inter-lamellar
connections forming oblique rows. Marsupium formed by all
four gills. Glochidia small, semicircular and globular, without
hooks, but with irregular, small teeth at the ventral margin.’’—
Ortmann (1912 b, p. 223).

This Family presents the most primitive characters of the
Naiades and is represented in Missouri by only one species, Cum-
berlandia monodonta (Say), for which -it was necessary to create
a special genus because of its peculiar gill structure as determined
by histological studies. Even in this Family, shell characters
are not constant enough to be considered in the diagnosis. Like
the sub-families, Unioninae and Anodontinae of Unionidae, the
glochidal discharge is effected through the anal opening.

Genus Cumberlandia Ortmann.
18912a—Cumberlandia Ortmann, Nautilus, XXVI pp 13 and 14.

(Type, Unio monodonta Say.)

ANIMAL CHARACTERS:—Diaphragm and supra-anal opening
absent; gills long and narrow, inner broader anteriorily than

16 NAIADES OF MISSOURI

outer, inter-laminar connections not irregularly distributed but
arranged obliquely parallel to each other, outer lamina of outer
gill free from mantle posteriorly, inner lamina of inner gill almost
entirely free from visceral mass; all four gills marsupial; anterior
adductors reinforced posteriorly.

SHELL CHARACTERS:—Shell narrowly elliptical, no sculpture
on disk, low beaks scuptured with ridges parallel with growth
lines; epidermis black; anterior cardinals lacking, posterior
ones conical; anterior adductor muscle scar deeply impressed
post-dorsad; nacre pearl blue to white.

Cumberlandia monodonta (Say).

(‘‘Spectacle Case.’’)
Pl. XV. Figs. 28A and B.

1829— Unio monodonta Say, N. Harm. Diss., IIp. 293; 1830, Am.
Conechplr selves

1853— Margaritana monodonta Conrad, Pr. Ac. N. Sci., Phila. VI, p 262.

1912a—Cumberlandia monodonta Ortmann, Nautilus XXVI, pp 13
and 14.

Fic. 1.—Cumberlandia monodonta (Say). 9 Diagram of sterile indi-
vidual from the Osage River, Sagrada, Mo., showing animal
characters in left valve. (Nat. size.)

ANIMAL, CHARACTERS.

NUTRITIVE STRUCTURES:—Branchial opening with papillae
reduced to mere crenulations; no gill partition (diaphragm)
between branchial and anal openings; no true supra-anal opening;
gills very long and narrow with interlaminar connections regularly
arranged as. ‘‘continuous septa which run obliquely forwards;”’
inner lamina of inner gill free from visceral mass except at its

NAIADES OF MISSOURI 17

anterior end; outer lamina of outer gill slightly free posteriorly
from mantle, all four gills marsupial; palpi, large, comparatively
broad, hangs low, united two-thirds of way toward base; color
of soft parts soiled white, mantle edge blackish chiefly at the
branchial openings.

REPRODUCTIVE STRUCTURES:—No gravid females found so
far.t The gills of several specimens from the Mississippi River
presented no variations of structure; hence this peculiar oblique
arrangement of septa may not be a sex distinction.

SHELL CHARACTERS.

EXTERNAL STRUCTURES :—Elongate-elliptical, arcuate in old
specimens, not sexually dimorphic; rounded before, usually more
pointed behind; beaks small, low, sculptured by a few coarse
concentric bars; lines of growth rough, coarse; epidermis black,
shell moderately thick anteriorly, but very thin posteriorly,
being disposed to crack easily upon exposure to air.

INTERNAL STRUCTURES:—Cardinals conical, single in both
valves, rudimentary to lacking in left; laterals low, single in right,
inclined to double posteriorly in left; scars well impressed anteri-
orly—especially the one taking the position of anterior cardinals
in most other Nazad shells; beak cavities shallow; nacre bluish
with a slight tint of salmon in umbonal cavity; no vein marking
as in most Unzoninae.

ST SX A Asie Xa) 62)5 tai (Osage R., Bagnell, Mo.)

Cie he 7A Xe VAS X27. 5 tad Ga ” Sagrada, Mo.)
ORI T22 | x4 A7 x 26mm (Miss. R., Louisiana, Mo.)
ro 96 x 40 xX 20.5mm (Miss. R., Jouisiana, Mo.)

MISCELLANEOUS REMARKS:—C. monodonta is most typical in
the Mississippi above the mouth of the Missouri. Bryant Walker
records it from Tennessee to Ohio, thence Northwestward to
Nebraska. From the fact that the author found this primitive
species at several points in the Osage and Gasconade Rivers, its
known distribution 1s now carried farther south and west of the Miss-
isstppi River, than recorded before. ‘The existence of this, as well as
other primitive forms of the Naiades, also in the Cumberland-

’ Dr. A. D. Howard, (Scientific Assistant, U. S. Biological Station,
Fairport, Iowa), has however recently discovered that this species bears
unusually small glochidia and has the peculiar habit of bearing two broods
in aseason (Nautilus, XXIX, p. 6, May, 1915.),

18 NAIADES OF MISSOURI

Tennessee basin may furnish some interesting data for the recon-
struction of ancient geographical features for the central Missis-
sippi Valley.

FamiLy II. Unionidae Swainson (restricted).

“Diaphragm complete, formed only by the gills; the outer
lamina of the outer gills connected with the mantle at its posterior
end. Anterior end of inner gills separated from palpi by a more
or less wide gap. Margins of the mantle held together by the gill-
diaphragm, but not united, thus separating the anal from the
branchial opening, and the anal is generally closed above by the
union of the margins of the mantle, (it rarely remains open),
and when closed, it always leaves a supra-anal opening (which
is very rarely obliterated). Gills always with water tubes formed
by interlamellar connections developed as continuous septa,
running parallel to the gill-filaments. Marsupium formed by all
four gills, or by the outer gills alone, or by parts of the outer gills.
Glochidia of various shapes, suboval, or subtriangular, or celt-

shaped, with or without hooks on the ventral margin.’’—(Ortmann
1912b.)
Simpson’s terse diagnosis of this family is:—‘‘ Hinge with schizo-

dont teeth; embryo a glochidium.”’

The family, Unionidae, naturally falls, into three divisions
on the basis of physiological and morphological characters; how-
ever, this family may fall into two sub-divisions on the sole basis
of reproductive functions. The Unioninae and Anodontinae
would form the first and the Lampsilinae the second group from
the fact that the discharge of the glochidia takes place in the
former through the primitive and natural way of passage from the
ovisacs through natural openings into the suprabranchial canals
and then on out through the anal opening and in the latter the dis-
charge is effected in a more direct and seemingly unnatural manner;
that is, in the passage from openings forced through the ventral
edges of the ovisacs, and thence out through the branchial open-
ing. Yet the two sub-families, Unioninae and Anadontinae, have
morphological differences in marsupial characters and in struct-
ures of the glochidial masses that are correlated with physiological
differentiation in breeding habits. On the same grounds, Lamp-
silinae is set aside as well a defined group; however the latter,
although the modern group, is related to the primitive one Unioni-

NAIADES OF MISSOURI 19

nae, in that the morphology of the Lampsiline glochidium would
indicate a reversion to the primitive type as is the natural course
in the cycle of evolution. Thus on the basis of glochidial characters,
the Family Unionidae may be grouped as:

t ANODONTA, bearing non-conglutinated glochidia, spadi-

form, spined.
PROPTERA, bearing conglutinated glochidia, celtiform.
spined or spineless.

3. Unito-LAmpsILis, bearing conglutinated glochidia, apron-

form, spineless.

The key to the whole situation governing the approach to
the modern arrangement is in the differentiation of structures for
the benefit of the embryos; e. g., large palpi for the Umioninae,
marsupial water tubes (secondary) and also large palpi for Anodon-
tinae, but, best of all, an adjustment of marsupium near to a special-
ized mantle edge in form of flaps, papillae, tentacles, etc., as
shown in Lampsilinae.

nN

I—Sus-Famity Unioninae Ortmann.

1911a— Unioninae Ortmann. An. Car. Mus., IV, pp. 335-336; 1912b
An. Car. Mus. VIII, pp. 236-277.

ANIMAL CHARACTERS:—Branchial opening rather sparingly
papillose; anal smooth to finely crennulate; supra-anal usually
present separated from anal by very short or moderately long
mantle connection; no tendency to form tubular siphonal openings;
inner laminae of inner gills free from visceral mass; palpi usually
very large and long, marsupium occupying all four gills or by the
two outer ones, when gravid not much swollen, ventral edge
pointed, never bluntly distended and secondary water-tubes
never developed lateral to the ovisacs within; mantle edge antero-
ventrad to branchial opening, smooth; glochidia of the Lampsilis
type, apron-shaped, small to medium, semicircular or semielliptical,
ventral margin rounded, without spines; conglutinates well
formed.

SHELL CHARACTERS:—Forms of shell various, usually thick;
disk smooth to very profusely scuptured; beaks usually scuptured
with concentric or zigzag ridges; hinge teeth very highly developed,
cardinals and laterals never lacking; scars well impressed.

MISCELLANEOUS REMARKS:—The soft anatomy of the species
of this subfamily are rather constant. However, its shell characters

20 NAIADES OF MISSOURI

are so inconstant that this subfamily may be termed a great
group of intergrades. Having very typical hinge teeth and very
closely adhering valves the branchial margins are not well papil-
losed and the soft parts of the different species are more or less
identical. In contrast with the other more modern subfamilies,
Anodontinae and Lampsilinae, a greater differentiation of soft
parts is noted in the latter, due to their more gaping valves
and to a greater adjustment to aeration of the embryos; then,
too, Unioninae differs from either of the two in that its breeding
season is short (tachytictic), being confined to the summer. In
the Untonae the color, form and solidity of the conglutinates can
be considered as of greater systematic value than in the other
sub-groups. It is to be noted that these summer breeders have
the peculiar trait of aborting their conglutinates when they may
be disturbed from their natural beds. The fact of the close,
or even deciduous, mantle connection between the anal and the
supra-anal openings may be a minor character in distinguishing
the genera. The connection between inner laminae of the inner
gills and the visceral mass may also serve in making distinction.
From the fact that there are a great number of variations in shell
character for this sub-family it is necessary to admit several
genera so that there may not be so much opportunity for the same
types of shell to turn up and thus give false impressions of rela-
tionships. It is very striking to note the atavism of the spineless,
subovate glochidium of this sub-family in the fact of its homolo-
gous recurrence under the Lampsilis type. However, this natural
reversion to primitive type in the embryo of the Lampsilinae is
only an indication of the wide gap between the two sub-families
as well as in the fact of its differences of physiological characters
in the adult, such as the discharge of glochidia through the anal
opening for the Unioninae and through the branchial for the
Lampsilinae. However the homologous differences in the soft
parts and hard parts of the two groups are still greater than the
analogous. Why more species of this primitive group should
occur in the more modern region of this state (i. e., N. Mo., the
New Prairies) than in that of the more ancient geologic formation
(i. e., S. Mo.,—the Ozark Uplift)—this is a problem thatthe
author is trying to solve. The unusual variations within the
sub-family especially is another problem that would also be
solved.

NAIADES OF MISSOURI 21

Genus Fusconaia Simpson.

1900b— Fusconaia Simpson, Pr. U. S. Nat. Mus. XXII, p. 784 (as sect.)
1912b—Fusconaia (Simpson) Ortmann, An. Car., Mus., VIII, pp.
240-241.

(Tpye Unio undatus Barnes).

ANIMAL CHARACTERS :—Branchial opening with dense yellow-
ish tentacles; anal smooth; supra-anal separated from anal by
very short connection, laminae of inner gills free from visceral
mass; palpi rather large; all four gills marsupial, ovisacs when
gravid subcylindrical; conglutinates same shape, usually reddish,
subsolid and discharged whole; glochidium subovate, somewhat
small, spineless; colors of soft parts usually brilliant, such as
orange or red.

SHELL CHARACTERS:—Shell roundly quadrate or triangular;
disk smooth; beaks elevated, sculptured with concentric ridges
angled at base of prominent post-umbonal ridge; epidermis
reddish to brown with fine, rather interrupted, rays when young;
hinge teeth well developed; beak cavities deep; nacre white.

MISCELLANEOUS REMARKS:—Dr. Ortmann considers this
genus the most primitive of the Unionidae and limits it to those
species of Simpson’s trigona group that possess subcylindrical
conglutinates and ovisacs, concentric beak sculpture and smooth
disk as the diagnostic features. While the conglutinates of the
Fusconaia species may be reddish, yet they may vary from pale
pink to white due to their development usually. It is to be noted,
however, that when the conglutinates are white all of the anatomy
is also white; when the conglutinates are reddish the soft parts
will be more yellowish. In this state the following groups may
differ morphologically and ecologically as follows:

1. F. undata: swollen, high beaks, mostly greenish—black

BPOSL MAIS Nir ema ee eM el casa TON OF Big Rivers
2. F. trigona: swollen, lower beaks, mostly reddish epider-
GELS PET CE EERE, ast LG ene te), Medium Rivers

3. F. flava: flat, low beaks, always reddish epidermis
Small Rivers
The second group is not found in very typical form in this
State, but is represented by intergrading forms. In fact none of
these Species, representing the above names, are very often found
typical in Missouri, since this State seems to be the home mostly

N
NO

NAIADES OF MISSOURI

for intermediate forms not only for /usconaia, but for other Genera
of this Sub-family, Unzoninae, especially. All Fusconaia of this
State are strictly fluviatile. For the most part the Species of this.
Genus are hermaphroditic, for all localities.

Fusconaia undata (Barnes).
( sPigtoe::*)
PLiaos Megs.\20 Avand Br.
1823— Unio undatus Barnes, Am. Jour. Sci., VI, p. 121, pl., 1V, fig. 4.
1831— Unio trigonus Lea, Tr. Am. Phil. Soc., IV, p. 110, pl XVI, fig. 40.
1900b—Quadrula trigona, Simpson, Proc. U.S. Nat. Mus., XXII, p.,787.
1900—Quadrula undata Walker, Nautilus, XXIV, pp. 5-11 and 16-24,

Plates I and I.
1912b— Fusconia undata (Barnes) Ortmann An. Car. Mus., VIII, p. 241.

ANIMAL CHARACTERS.

NUTRITIVE STRUCTURES—Branchial opening with © short
brownish papillae; anal slightly papillose, separated from supra-
anal by very short,—even deciduous—mantle connection; inner
gills larger, inner laminae free from visceral mass; outer gill
undulate antero-ventrad, palpi moderately large, connected over
half of their length antero-dorsad; most of soft parts yellowish
or cream colored.

REPRODUCTIVE STRUCTURES:—Marsupia formed by all four
gills, when charged not distended, lumen of ovisacs subcylindrical ;
conglutinates same form, light red—even to white—according
to age of embryos; glochidium semicircular, medium size, hinge
line nearly straight, length and height, (0.160 x 0.155mm), about
same.

SHELL CHARACTERS.

EXTERNAL STRUCTURES:—Shell trigonal, thick, heavy anteri-
orly, disk smooth; beaks high, full, pitched slightly beyond
anterior end, sculptured with concentric ridges breaking into
nodules at base of prominent umbonal ridge; dorsal line bowed,
post-ventral line with long gentle incurve; broad shallow valley
in front of post-umbonal ridge; ventral margin bowed in semi-
circular form; epidermis greenish to rusty brown or black or
mingling of both green and black; rest lines furrowed giving an
undulated effect; post-umbonal ridge prominent.

INTERNAL STRUCTURES:—Cardinals single and pyramidal in
right, double and roughly socketed in left; laterals double in

NAIADES OF MISSOURI 23

both valves; scars deeply impressed; beak cavity narrowly deep;
nacre silvery white; male shell usually more compressed than
that of female, but no true dimorphism shown.

Length Width Diameter Um. ra. Locality.
Teas OSs XA Sinn 0.16 (Miss. R., LaGrange, Mo.)

7On xX, O4V xX) Aoniin 0.78 Hat aay. 2
SS) xn 4sy x Laon: Onr7 (Meramec, R., Fern Glen. Mo.)
60 x 55 xX 46mm 0.17 (Osage R., Linn Cr., Mo.)

Juvenile Shells are described as having a light yellowish
brown epidermis with green rays most distinct on anterior slope,
and finely ribbed lines running from beaks to ventral margin
across center of disk.

MISCELLANEOUS REMARKS:—This species was hidden in syno-
nomy for many years until Mr. Bryant Walker (1910b, p. 5)
brought it to light through diligent study. It is found in most
typical form in the Mississippi River and occasionally it may be
found in the Meramec and Osage Rivers where it is to be distin-
guished from F. flava by its swollen high beaks and darker cpi-
dermis. Then, too, this species is determined largely ecologically,
being an inhabitant of the large streams and deep water, for the
most part. In most of the interior streams of the state, undata,
however, is found chiefly in an intermediate, or intergraded,
form with flava. In the whole southwest this species does not
seem to be very near the type as found in the Ohio drainage or
in the Upper Mississippi, especially in Wisconsin where Barnes
secured his type lots. The Des Moines River, Clark Co., Mo.,
has produced rather good types, some shells of which have been
sent to the National Museum by Mr. B. F. Bush and are now
on exhibit there under the number 132, 633. However, none of
these so-called undata types come up to those of the Upper Miss-
issippi. Surber (1913, p. 113) finds fF’. undata in the larval state
to be a gill parasite on the black crappie (Pomoxis sparoides) as
an occasional host. Undata is a tachytictic form, but begins its
breeding very early, bearing glochidia June, July and August
and hence has an unusually long period for a summer breeder.
The writer has observed that during the first part of the breeding
season, when the ova are bright carmine color, that not only the
marsupium but also the nutritive parts—especially the foot are
also a brighter color—chiefly orange—than at the end of the season
when most of the anatomy has a brownish or soiled white color.

24 NAIADES OF MISSOURI

Before maturity the glochidia have been observed to be yeliow-
ish brown and contained in pinkish sacs.

Fusconaia undata trigona (Lea).
(“Little Pigtoe.’’)
Plein Eigse gr A and tb,
1913a—Fusconaia undata trigona (Lea) Ortmann, Pr. Am. Phil. Soc.,
ie No2 Ko:
ANIMAL CHARACTERS.

The nutritive and reproductive structures of this subspecies
are, of course, identical with those of its species.

SHELL CHARACTERS.

Shell more quadrate than that of /. flava, post-umbonal
ridge not so prominent, more solid anteriorly, higher fuller beaks,
epidermis darker. Compared to its typical species it never matures
to be as large, nor as heavy, is not quite so upright, nor as inflated,
has lower beaks and more of a reddish epidermis. The internal
shell structures are identical with those of its species. From the
subspecies, irigonoides, it differs chiefly in being more upright,
not so elongated, nor as large.

Length Height Diameter Locality
GSwiexe 5325) ek Anam (Osage, R., Sagrada, Mo.)
60 Xu N50: x 32mm (ra i Monegaw Springs, Mo.)
Gon xas xX 34mm Gans: ” Warsaw, Mo.)
48.5 X 40 x 26mm ype! ” Tjinn Creek, Mo.)

MISCELLANEOUS REMARKS:—This sub-species is one of the
decided intergrades for F’. undata and flava and is the most common
form in the interior streams of the state—especially in the Osage
where the writer, in a 300 mile survey by boat, ‘made a thorough
study of them to find the interior of shell and soft parts to be
identical with those of the species; however, none of these forms
were found with reddish conglutinates, nor yellowish soft parts.
Probably this whitish colorization was due to the advanced stage
of gravidity in which they happened to be found when they were
encountered between the upper and lower stretches of the river.
at the latter part of July. This variety of undata may be ecolo-
gically determined as a dweller in medium sized rivers, or, if found
in a large river, in medium stream conditions. This is found to
be the case in the Osage, for the more the mouth is approached
the more this form is supplanted by the heavier, more inflated

NAIADES OF MISSOURI 25

and more typical shell of the main species. This subspecies,
however, is more like the type than the trigonoides of Frierson,
the latter being more nearly the flava type and hence might be
well named “¥. undata flava (Raf.)”’

Fusconaia undata trigonoides Frierson, MS.
(‘Big Pigtoe.’’)
Pl. XV—Figs. 30 A—D; Pl. IV, Figs. oa, and gb.
1913—Fusconaia undata trigonoides Frierson MS.—Personal Letter,
February 22, 1913.

ANIMAL CHARACTER:—Soft parts indentical with species.
Glochidium measures 0.180 x 0.165mm; conglutinates white in
glochidial and late embroyonic stages, pink in earlier stages.

SHELL CHARACTERS.

EXTERNAL STRUCTURES:—Shell elongate trigonal, thick,
heavy, very large for the genus; disk without sculpturing except
that rest-lines are somewhat furrowed giving an undulate appear-
ance to growth lines; beaks comparatively low and not placed
so much anteriorly, sculptured with concentric bars breaking into
two or three nodules at base of post-umbonal ridge; post-dorsal
part of shell, bowed, slightly biangulated behind; epidermis
_ Cloth-like, reddish brown to horse bay color, rayed in young.

INTERNAL STRUCTURES:—Identical with those of the species
and other intergrading forms, except that it may vary from a
white to pink nacre.

Length Width Diameter Location

93) ek GO) Xn 42 (Platte R., Dixon Falls, Mo.)
7 OR SOMERS (Osage R., Schell City, Mo.)
SOX eA Ol ext 24! (Osage R., Warsaw, Mo.)

Zo EXe O20 Nexen TA. (Platte R., Garfetsburg, Mo.)

The juvenile indicated by the measurement under the last
number was found lying on its side in the shallow water of a riffle.
It is different from the mature shell in its dark yellow epidermis
marked all over by green rays, also by more prominent umbonal
ridge, more centrally placed and more distinctly sculptured beaks.
The soft parts are all of a bright orange color except the bluish
visceral mass.

This specimen and also the one under the first measurement
of the above list were kindly indentified by Dr. Ortmann as F

26 NAIADES OF MISSOURI

undata rubiginosa (lea) a name which this form might well bear
because of its closer relation with F. flava (Raf.) [=F. rubiginosa
(Lea)]. After a prolonged correspondence among Messrs. Simpson,
Walker and Frierson this rather common and peculiar form was
left to the latter for naming; hence the MS. name herein given.

MISCELLANEOUS REMARKS:—This intergrade is very near
the form, undata-trigona, and differs only in being more elongated,
less upright, more rounded, post-dorsal margin, more reddish
epidermis, lower beaks, and is a larger, heavier shell. Those of
this variety that are found in the Mo. Platte of North Mo. have the
most ponderous shell of any of the /usconata—some reaching
a length of 10oomm while the average length of the species (F.
undata) for the Mississippi only average 60mm. ‘This variety
~ seems to be more of a creek form of Ff. flava and the reason for this
form being larger in the Platte R., a smaller stream, than in the
Osage, the largest tributary of the Missouri in this State, may be
traced as a mere local effect since the shells of other species in the
Mo. Platte are found to be abnormally large. Like most of the
Unioninae this form has a peculiar habit of aborting its conglu-
tinates when taken from its natural bed. The author has been
able to pick out for study the little pink club-shaped conglu-
tinates from whole masses of other white leaf-shaped conglu-
tinates of Ouadrulae or Pleurobemae that would also be aborted
after being collected from the river and placed in a tub or aquarium.
The habits of this form are that of deep and rapid burrowers and
inhabitants of deep water and coarse gravelly bottom. It is found
to be gravid from May until September and sterile for the rest
of the year. A proposed publication by Mr. Frierson on these
puzzling southwestern forms of Fusconaia will, without doubt,
clear up the situation.

Fusconaia flava (Rafinesque.)
(Pigtoe,” ‘‘Red Shell,” ‘‘Red Nose,’ ‘‘Wabash Pigtoe.’’)
Pl~ XV. . Fags. 32 A-——D.
1820— Unio flavus Rafinesque, Monog. Bio. Shells of R. Ohio.
1829— Unio rubiginosa Lea, Tr. Am. Phil. Soc., III, p. 427. Pl. VIII,
A eeTO:
1898—Quadrula rubiginosa Baker, Moll. Chicago. Pt. I. p. 77, Pl.
DGD A ahery gm. DG been Gs
1912—Fusconaia rubiginosa Ortmann, An. Car. Mus., VIII, pp. 241
2427 VPextultc. 4,

NAIADES OF MISSOURI 27

ANIMAL CHARACTERS.

NUTRITIVE STRUCTURES:—Branchial opening with papillae on
inner edge, anal with fine but distinct papillae; supra-anal long
and large with very short connection of mantle edge; gills sharply
pointed behind with wide space between the anterior attachment
to mantle and base of the palpi, inner laminae of the inner gills
entirely free from visceral mass; palpi rather large, subfalcate;
color of soft parts variable, but usually orange yellow especially
the distal end of foot, also mantle edge and adductors, while sterile
gills are brownish.

REPRODUCTIVE STRUCTURES:—Marsupia with crowded septa
dividing the ovisacs parallel to the gill filaments; when charged,
lumen of ovisacs somewhat cylindrical containing club-shaped
conglutinates which are carmine red or pinkish to whitish in
color; glochidia somewhat small, semicircular, spineless, hinge
line nearly straight, about as long as high (0.150 x 0.155mm).

SHELL CHARACTERS.

EXTERNAL STRUCTURES:—Shell trigonal-quadrate, rather
thick, compressed, rather rounded post-dorsad, gently curved
ventrad; disk somewhat undulated by growth lines; beaks not
very high or full, sculptured by concentric ridges breaking into 2
or 3 nodules at base of posterior ridge; this post-umbonal ridge
usually flattened; epidermis yellowish to dark horn color, raved
in well preserved and young shells, eradiate in old.

INTERNAL STRUCTURES:—Cardinals double in both valves;
laterals long, serrated; scars well impressed; beak cavity narrowly
deep; nacre mostly white, sometimes tinged with salmon in beak
and antero-branchial cavities, irridescent.

Length Width Diameter Locality.
650 x) 145) xX° 40mm (St. Francis River, Greensville, Mo.)
Ase ex a ceeX ee Stiri (ees “1 tf 4
50%) xe 40, 3s) 62 4iim (White River, Hollister, Mo.)
BA ee x) 2 7a Xe STO a Chia! th i se)

This latter measurement is that of a somewhat advanced
adolescent shell. However, it shows the juvenile characters of
a flattened post-umbonal ridge, a rounded post-dorsal line and the
very distinct concentric sculpturing on the beaks much more
evidently than in the adult. The most striking characters, that
are absent in the mature shell, are the green rays.

26 NAIADES OF MISSOURI

MISCELLANEOUS REMARKS:—This species is distinguished
mostly from F. undata and the intergrades by its more quadrate
and compressed form of shell, by lower beaks, and less upright
position. F. undata trigonoides is separated from it by possessing
a heavier and more elongated shell with a more prominent post-
umbonal ridge and black epidermis. The White River shells,
indicated in the above measurements, are rather intergrades
for this species and /iebetata and the St. Francis flava are too
inflated to be very typical. Since this State proves to be such
grounds for the inconstant occurence of types, and this species
is so susceptible to intergradation, it is difficult to find a typical
flava, such as found in the Interior Basin east of the Mississippi.
Perhaps its nearest form is in drainage for the south slope of the
Ozarks in this state, although Simpson reports it as having a
general distribution throughout the Mississippi drainage. This
distribution doubtless included its many forms. Simpson further
states that the St. Lawrence River system includes flava. Dr. Sterki
(1898, p. 30) considers this species as occasionally hermaphroditic
by examination of its gonads. Surely this finding can be confirmed
by the forms of Missouri, for it is rarely that it ts even locally a goyo-
chorist. Flava is typically tachytictic being only found gravid
from May until August.

Fusconaia hebetata (Conrad).
Pl. XV ,—Figs. 33A and B.
1854— Unio hebetatus Cortrad., Jl. Ac. N. Sci. Phila. II, p. 296, Pl.
XXVI, Fig. 5; 1888—B. H. Wright, Check List.
1900b—Quadrula hebetata Simpson, Proc. U. S. Nat. Mus., XXII,
De Foz. ‘

ANIMAL CHARACTERS:—The soft parts of a form of F. hebetata,
found in the Osage River, were discovered to be indentical with
those of F. flava.

SHELL CHARACTERS.

EXTERNAL STRUCTURES:—Shell rather orbiculate-quadrate,
thick, moderately inflated, post-umbonal ridge prominent, disk
smooth, beaks flat, and well back from the anterior end post-
dorsal ridge rounded, post-ventral margin gently undulate;
epidermis black with a few faint imbricated rays toward (but
not across) the disk in the middle of the umbonal region.

INTERNAL STRUCTURES:—Cardinals single in right, double

NAIADES OF MISSOURI 29

in left, interdentum deeply gashed in right; laterals double in
left with slight tendency to double in right; umbonal cavity
narrowly deep, scars deep; nacre white to pale pink.

Length Height Diameter Locality.

SS 8S Ol ups Plcyeaten) (Osage River, Linn Creek, Mo.)

MISCELLANEOUS REMARKS:—The above measurement is
that of a moderately compressed shell resembling that of some
typical hebetata shells which are sent to the writer from Alabama
and considered as types by Messrs. Wright, Walker and Simpson.
The latter student (1900b, p. 787) reports the Alabama hebetata as
also found here in Missouri, but no specific locality is given. Since
there seems to be so much confusion concerning this shell of Conrad
with his own cerzna or with JI.ea’s rubida it should be investigated.
Probably it would be found (through longer suites of shells) that
the broad compressed flava of the White River would either be a
form .of Conrad’s hebetata or an unusual flava of Raflnesque, or
perhaps an age-form of the latter. As matters now stand this
species (if it be a good one anywhere) must be listed with some
doubt for Missouri.

Fusconaia ebena (Lea).
(“Nigger Head.’’)

1831— Unio ebena Lea, Trans. Am. Phil. Soc., V. p. 84, pl. IX, fig. 14.
1900b—Quadrula ebenus, Simpson, Proc. U. S. Nat. Mus., XXII, p. 793.
1912b—Fusconaia ebena (Lea) Ortmann, An. Car. Mus., VIII, p. 245.

ANIMAL CHARACTERS.

NuTRITIVE StTRUCTURES:—Branchial opening large with
branched papillae; anal smooth or crenulated; supra-anal large
briefly connected to anal by mantle edge; gills brown outer pointed
anteriorly inner laminae of inner gills free from visceral mass;
palpi moderately large and connected about half of their length
antero-dorsad.

REPRODUCTIVE STRUCTURES:—All four gills marsupial; when
charged scarlet, not distended; before gravidity ovaries carmine
color; glochidium semicircular, spineless, medium size, hinge
line straight but slightly oblique, length and height about equal
(0.160 x 0. 15 mm), conglutinates subcylindrical, bright pink.

SHELL CHARACTERS.

EXTERNAL STRUCTURES:—Shell thick, solid, subrotund, some-

-

30 NAIADES OF MISSOURI

times shows a tendency to bianguation posteriorly; beaks incurved,
projecting forward, sculptured with concentric lines but no sculp-
turing carried out on the disk; rest lines of growth concentric
and furrowed; epidermis satiny horn color.

INTERNAL STRUCTURES:—Cardinals large and massive; lat-
erals long and heavy; interdentum broad; beak cavities deeply
creviced; scars deep; nacre pure white, stippled, irridescent.

Sex Length Height Diameter Um. ra. Locality.

Coe LOS X17 510 Xe OOni nT 0.090 (Miss. R., La Grange, Mo.)
9 O50 Xe) 65), eX 57a 0.100 Cee! 1 uy ee)
Cun 5Ole sn AON cx, asm 0.120 (Pe 22) Hannibal’ Mos)
6 AG). Ss) ah se | Sram O.115 Cre ey a a}

The shell of the juvenile of this last measurment is so round,
and with beaks so drawn up to center of dorsal line that it resembles
that of a Sphaertum. Umbonal sculpturing not very distinct
even in this juvenile. It can always be identified in the early
stages of its juvenility by white spots located post-dorsad on its
shell.

MISCELLANEOUS REMARKS:—The writer, after some years of
extensive collecting from the largest streams of the state, has
failed to find ebena in the interior streams, neither have any Mis-
souri collectors, nor old ‘‘clammers’’ reported it. ‘This shell is
known not only for its greatest commercial value and for its rarity
in general geographical distribution but also for its great abundance
locally. Of course its only home, known so far, is the Mississippi
north of the Missouri River. It is not known why this species
does not occur for this state in those Ozark rivers that bear it in
great abundance in Arkansas not far from the Missouri-Arkansas
line. Sometimes a black shelled Pleurobema pyramidatum or
Fusconaia undata trigono:des may be taken for the ‘‘ Nigger Head”’
(F. ebena), but, from the characteristic cornucopia-form of shell,
together with its deep brown satiny epidermis and regular, con-
centric furrowed rest lines of growth, it should be easily identified.
Frierson reports ebena as a rare shell in Louisiana and Isely (1914,
pp. 1-4) does not report it at all for the Arkansas and Red River
drainages of eastern Oklahoma. Perhaps Call’s account of it (1895,
p. 16) as a common shell, not only for Arkansas, but for all the
larger rivers west of the Mississippi, is more conjectured than
real. Its breeding season has been foune by Wilson and Clark
(1914, p. 42) to extend from May to the middle of July. Surber

NAIADES OF MISSOURI Zi

(1913, p. 104) finds the host that is the specific distributor of this
valuable shell to be a fish known as “‘skipjack’”’ (Pomolobus
chrysochloris).

Genus Amblema Rafinesque.
1820—Amblema Rafinesque, Monograph Biv. Shells of R. Ohio.
1912b—Crenodonta (Schluter) Ortmann, An. Car. Mus., VIII, pp.
245-250.
(Type Unio plicata [Lesneur] Say).

ANIMAL CHARACTERS:—Branchial opening long with few
small arboreal papillae; anal large, very slightly crenulated;
supra-anal separated from anal by very short mantle connection,
sometimes no connection at all; gills large, inner wider and longer,
outer connected high up to mantle antero-ventrad, inner laminae
of inner gills free from visceral mass; palpi long, falcate united
most of their length antero-dorsad; marsupia occupy all four
gills, ovisacs of inner being wider, when gravid ovisacs expand
transversely; conglutinates white, compressed, leaf-like shape,
discharged through anal passage in rather broken or loose masses;
glochidia small, spineless, subovate.

SHELL CHARACTERS:—Shell subquadrate to subtrapezoidal,
thick, beaks more or less elevated, sculptured with concentric
lines slightly angled at the base of the post-umbonal ridge and
disappearing out upon the disk or continued there in a zigzag
pattern of irregular broken pustules, nodules and oblique, indu-
lated or plicated folds, the latter being disposed across the pos-
terior half; hinge teeth heavy and well developed; beak cavities
deep crevices under rather wide interdentum; vein markings
on antero-pallial margin distinct; nacre usually white.

MISCELLANEOUS REMARKS:—It is recognized by students
ot Nazades that this genus needs a thorough revision—especially
as to its shell characters. Like the genus Fusconaia, Amblema is
a group of all sorts of inter-grading and puzzling forms. However,
for this State it is not so much a question of facts regarding a
predominance of these plicated forms for the different faunae as
it is an application of these varieties to the present chaotic no-
menclature for this genus. As nearly as the writer is able to
determine, after a correspondence with students and a thorough
study of literature and actual field conditions, the present status
of affairs would group the species and other allied forms of Amblema

32 NAIADES OF MISSOURI

for North Missouri under the so-called plicata (Say) types, for the
most part; those of Central Missouri under both types of plicata
and the better known undulata (Barnes), and those of Southern
Missourt under undulata. These facts might be accounted for
by the natural physiological adjustment to ecological conditions—
that is to say, the quiet, sluggish, muddy streams of North Missouri
tend to produce a heavy, inflated, rarely plicated shell, mostly
represented by Amb. rariplicata of Deshayes; on the other hand,
the swift, clear water streams of South Missouri have the tendency
to shape up a compressed and multi-plicated shell best represented
by Amb. perplicata quintardi of Cragin, while the intermediate
or combined ecological conditions of Central Missouri give combi-
nations of these two extremes. In the grouping of the members
of this genus there has been much necessary elimination of local
varieties and races and thus types have been adherred to as much
as possible. The arrangement is only submitted as tentative due
to the doubt of the present nomenclatural situation. This problem
may be easily solved if it may be found that the morphology of
shell characters may be traced, in most instances, to ecology. Prob-
ably this solution may be accomplished by studies of closely con-
nected series from the glochidial to the mature shell. Our judgment,
from studies of local conditions in this state, would be that the
obliquely undulated and plicated folds, forming the chief shell
character of this genus, are more developed in swifter current
as a physical adaptation for survival by the way of more permanent
anchorage, etc., just as we may account for the pustulate and
nodulous characters of the shell instead of considering them as
mere characteristic markings. However, when it has been found
that the beak sculpture (the most constant shell character) of Amb.
plicata (Say) and costata (Raf) [=undulatus (Barnes)]| are really
different and that there has been a differentiation from the adole-
scent shells to the mature ones we are compelled to recognize
genetic distinctions in these two species. Yet it seems that it may
be safely stated that two such well defined groups are connected
in all manner of inter-grades through environmental causes such °
as seen in the different ecological provinces of Missouri. It is
found that this genus has a short period breeding season, that the
white, leaf-shaped conglutinates are discharged by the natural
outlet of the anal opening and that these are delivered in broken,
loose masses just as soon as the larvae are mature, or even ejected

NAIADES OF MISSOURI a3

before maturity (‘‘aborted’’) if disturbed. According to recent
studies of Dr. Ortmann and Mr. Frierson Amblema Rafinesque
should supplant all previous names for this genus because Amb.
costata Raf. 1s without doubt Unio undulatus Barnes; hence the
following nomenclature:

(1)—Amblema plicata (Say) 1817=U. plicatus Say.=U. hip-
popea Lea=Quadrula plicata hippopaea Simpson.

(2)—Amblema_ plicata costata (Raf) 1820=U. undulatus
Barnes 1823 =Quadrula undulata Simpson.

(3)—Amblema peruviana (Lamarck) 1819=Quadrula plicata

Simpson.

Note that because of the Law of Priority the local form
(plicata Say) from Lake Erie must be considered unfortunately
as the main species, although other than taxonomic reasons would
not justify the recognition.

Amblema peruviana (Iamarck)
(Ed hreeoRidgey Big Blue Point’).
Pl. XVI,—Figs 35A and B.

1819— Unio peruviana Lamarck, An. Sans. Vert., VI, p. 71., Deshayes,
Aeon VekE. ne CG eG. Vil 1835, p. 53anesG. Cd:) bl 1830, p),607-
1g00b—Quadrula plicata (Say) Simpson, Pr. U. S. Nat. Mus., XII,

p. 767.

- ANIMAL CHARACTERS:—Since this species is simply an Amb.
rariplicata (Des.) with very full, high beaks and with identical
soft parts, except a small difference of form due to a more elongated
shell with deeper umbonal cavities, we would refer our readers
to the description of these characters for rariplicata. Gravid
marsupia have the same structure. Glochidia of peruviana
are found to be semicircular, spineless, medium size, about as
long as high (0.200 x 0.210 mm.)

SHELL CHARACTERS.

EXTERNAL STRUCTURES:—Shell elongate-quadrate with ven-
tral edge rather straight, post-dorsal portion bowed, heavy and
greatly inflated anteriorly, rather compressed posteriorly; beaks
high, full, incurved, well placed forward, sculpture consisting of
concentric lines forming two loops at base of post-umbonal ridge;
undulations four to five, coarse, oblique from ventral margin to
umbonal region across post-umbonal ridge; costae on slopes

34 NAIADES OF MISSOURI

of post-dorsal ridge few, broad, shallowand faint; epidermis leathery
red to black, rarely yellowish or greenish.

INTERNAL STRUCTURES:—Cardinals double in both valves;
laterals single in right, double in left valve; umbonal cavities nar-
rowly deep; muscle scars well impressed; nacre marble white
with blue and old rose tints posteriorly; deep vein mark on antero-
extra pallial border.

Sex Length Height Diameter Localities.

COM Xa OAN weXtuneS Auta (Mississippi R., La Grange, Mo.)
Opry EXrae7/ Aan SS AOS (Osage R., Monegaw Springs, Mo.)
OLA St aX. AO, Xeon (Mississippi R., Hannibal, Mo.)

CH wNele bat Goltelep'd Ceo? (Osage R., Osceola, Mo.)

Juveniles of latter measurement very globose; epidermis
olivaceous with a reddish brown band in center parallel to growth
lines; post umbonal ridge rather prominent; one heavy undulation
at post base with two heavy furrows on either side. The very
greatly inflated beaks of adult shell is doubtless due to the globular
shell of the juveniles.

MISCELLANEOUS REMARKS:—Amblema peruviana (Iam) is
the Quadrula plicata (Say) of authors according to the recent
decision of Mr. Bryant Walker who is making a special study
of original Lamarckian types. Mr. Walker states that Say’s
tvpe of plicata came from Lake Erie and is the form that Lea
describes as hippopaea and that peruviana is a form of the Ohio
shell commonly called plicata but which is really the rar:plicata
Deshayes. ‘This species should perhaps be reduced to the sub-
species, “Amb. rariplicata peruviana (lam); however, because
of its difference from rarzplicata in the possession of full beak
and more globular juvenile shell it is left in specific rank. It is
found in typical form in the Mississippi north of the Missouri,
is scarce but rather typical in the Osage, but is not found at all
in the interior north of the Missouri, River.

Amblema rariplicata (Deshayes)
(‘Ohio Plicata,”*’ “Few Ridge,” Big Blac/Pomra)
PLEX F484 205 Plea recreate
1830— Unio rariplicata Deshayes, Enc. Meth; II, p. 578; An. Sans.
Vert, 2d) eds Vij r835n ph sseco3deed.) lnsnscoupa Gore
ANIMAL CHARACTERS.
NUTRITIVE STRUCTURES:—-Branchial opening very long with
short yellowish papillae; anal slightly crenulate; supra-anal very

NAIADES OF MISSOURI 35

closely—even decidously—connected to anal by mantle con-
nection; inner gills longer and wider—much wider anteriorly,
inner laminae free from the visceral mass; palpi large, connected
for about one-third of their length antero-dorsad; except for its
brownish gills and palpi the soft parts are a soiled white color.

REPRODUCTIVE STRUCTURES :—All four gills marsupial, ovisacs
of inner marsupia more extended transversely, giving the white
conglutinates a leaf-shape; ventral edges pointed; glochidia
medium size, semi-circular, hinge line long and nearly straight,
as long as high, 0.210 mm; conglutinates lanceolate, leaf-like,
discharged in broken masses, white in color.

SHELL CHARACTERS.

EXTERNAL STRUCTURES:—Shell subquadrate, thick, inflated,
posterior end rather rounded; beaks flattened, sculptured concen-
trically with two or three nodulous structures at base of flattened
post-umbonal ridge but disappearing upon the disk; disk with
but few shallow undulations, sometimes entirely smooth and
running obliquely to position of post umbonal ridge; slopes of
post-dorsal ridge rarely costated; epidermis brown or very dark
horn color.

INTERNAL STRUCTURES:—Cardinals massive, scars deep,
umbonal cavity deeply creviced; nacre white with blue, irri-
descent posterior surface.

Sex Length Height Diameter Locality.
Canl2 Om x72 x. 52 TnI —O.169 (Platte R., Dixon Falls,)
ONT20) XS xX 762) —0.230 Ge ” Garretsburg,)
ODS Xe 80" “XOMSI. © 0.215 (Tarkio R., Craig,)
Cuge22) Xe 20) xe 14) —0;220 (Platte R., Agengy Ford,)

Juvenile shell indicated under last measurement is orbicular
in outline, has medium inflation and comparatively high beaks;
however, it does not possess the globose character of peruviana
and its full beaks are soon lost the older it becomes as determined
by a good suite.

MISCELLANEOUS REMARKS:—Amb. rariplicata, as already
explained, is the Ohio shell many authors refer to as the plicatus
of Say, or even as the perplicatus of Conrad. It is to be distin-
guished from the former since that is the Lake Erie form with
full beaks; from the latter, however, rariplicata is not so easy
to distinguish, as its beaks are similar, yet it differs from perplicata
in being more inflated, with less and shallower plications and with

36 NAIADES OF MISSOURI

no tendency toward posterior biangulation. Perplicata, being
more of a southern form, is not found in this state north of the
Missouri, while rarzplicata, a more northern shell, is mostly con-
fined to North Mo., where it is the predominant species of the
Amblemae, yet it is found occasionally in Central Missouri.
Mr. Bryant Walker, who has rescued raripliplicata from the
synonomy of Simpson’s Quadrula plicata, has recognized the
North Missouri “‘ plicata’’ as Deshayes’ shell. The habitat of this
species is that of muddy bottom with a substratum of limestone,
of deep and quiet water and prefers muddy rivers to that of clear
creeks. It is found in the Mo. Platte, Grand R., Big Tarkio and
occasionally in their larger tributaries. It has never been found
in any of the lakes. Its breeding season is very short, having
been found gravid only in June.

Amblema perplicata (Conrad)
(‘‘Blue-Point,”’ ‘“‘ Three-Ridge,”’ ‘‘Round-Lake.’’)
Pig eV I Fees. 37 a aie aie:
1841— Unio perplicatus Conrad, Pr. Ac. N. Sci. Phila., I, p. 19.
1900—Quadrula perplicata Simpson, Proc. U. S. Nat. Mus., XXII,
Toy 17/7fe
1912b—Credononta perplicata Ortmann, An. Car. Mus,. VIII, p. 247-248.
SHELL CHARACTERS.

WXTERNAL STRUCTURES :—vhell ovate, or obliquely, quadrate,
medium in size, moderately inflated, greatest inflation at center
of disk; beaks low concentrically sculptured with two or three
loops at foot of post-umbonal ridge; posterior end of shell biangu-
lated, 5-6 coarse plications across post-half of shell parallel to
antero-postero axis; costae on rounded, post-dorsal ridge few,
broad; epidermis black.

INTERNAL STRUCTURES:—Cardinals double in both valves;
interdentum long and broad; laterals single in right, double in
left; muscle scars deeply impressed; nacre white with posterior
surface bluish to lavender, irridescent.

Sex Length Height Diameter Locality

et BG | ci Velo foe vitshoshool (Osage R., Osceola, Mo.,)
OOOO Xo) MOOMEX eA One (St. Francis R., Greenville, Mo.,)
OPES imme LO TemeXM AS Pash (Osage R., Linn Creek, Mo.,)

CE Om) XRT AEA METIOM Oar ” Warsaw, Mo.)

Many juveniles taken in the Osage average as the above

NAIADES OF MISSOURI : 7,

Warsaw specimen. ‘They are rotund, inflated, epidermis greenish
and approach the spherical form of the juvenile peruviana. Beaks,
even in these young shells, are too eroded to make out the sculp-
tural markings.

MISCELLANEOUS REMARKS:—Since Amb. perplicata is a
Southern species it is only found in this state in typical form in
the south drainage of the Ozark Uplift. Personal collections
made by the writer from the St. Francis are found to compare
well with typical perplicata shells received from Mr. Frierson and
taken from type localities. This species is also sparingly found
in the Osage where its subspecies, quintard: of Cragin is the pre-
dominant form of Amblemae, and from which it is distinguished
by the smaller, more compressed, and much plicated shell of
the latter. Under the description of Amb. rariplicata the dis-
tinguishing features between that species and perplicata have
been mentioned. At first the inclination was to set this species
down in the synonomy of rariplicata from general shell features,
but the few specific differences in shell as well as that of geo-
graphic. range are enough to make it distinct. This species is
tachytictic, being found gravid by Wilson and Clark (1914, p. 42)
from May until July inclusive. The writer examined many through-
out June and July to find none gravid; however, its subspecies
(quintard:) was found gravid during these months and because
of these fact some reason was given that this smaller, compressed
form was only the female of the larger one, just as seen in case of
Plagiola securts or Obovaria retusa.

Amblema perplicata quintardi (Cragin)
(“Little Blue-Point,” ‘‘ Multiplicate.’’)
PLOXVI. Figs. 38 A—D.

1887—Unto quintardi1 Cragin, Bull. Wahb. Coll., II, p. 6; Pilsbry,
Pr. Ac. N. Sci. Phila., 1892, p. 131, pl. VII, figs, 1-3.
1891— Unio pilsbryi Marsh, Nautilus, V. pp. 1 and 2; Nautilus, VII,
NSQse le den figs 7 atid S)
ANIMAL CHARACTERS.

NUTRITIVE CHARACTERS:—Similar to those of the species,
having its anal and supra-anal openings often unconnected by
mantle edges, free laminar edges of inner gills, palpi mostly con-
nected by their edges, and being colored a dirty white or tan;
reproductive structures also rather identical in possessing marsupia

33 NAIADES OF MISSOURI

occupying all four gills, swollen in the center, when gravid, white
when filled with ova, rich brown when charged with glochidia;
conglutinates leaf-like, not solid, easily broken; glochidia semt-
circular, medium in size, hinge line nearly straight, measuring
0.205 x 0.215 mm. Dr. Surber kindly indentifies:—‘‘Like plicata,
but slighlty larger. Easily within the range of variation shown by
this species from different localities.”’

SHELL CHARACTERS.

EXTERNAL STRUCTURES:—Shell obliquely quadrate, small,
moderately compressed, rounded before, usually biangulated
behind; slightly alated; posterior half of disk profusely plicated,
some plicated folds devaricated behind; slopes of post-dorsal
ridge with several upcurved costae; beaks low well placed anteri-
orly, sculptured \in concentric fashion with strong ridges
upcurved posteriorly; epidermis dark reddish brown to black,
without rays.

INTERNAL STRUCTURES:—Cardinals compressed, obliquely
grooved, double in both valves, laterals long, slightly curved;
beak cavities rather deep; nacre dull white.

Sex Length Height Diameter Locality
OES) x) SOW exes AST (Osage R., Proctor, Mo.)
SUMIG Ow EXE eS Sns Ke sone (White R., Hollister Mo.)
OR TOMEx On) Ras asta, (Osage R., Monegaw Springs, Mo.)
int AS eee ky AC waEX ins Hoary Cl) ae habervilles Nios)

These last two measurements are among the smallest juvenile
shells obtained from the Osage where quintardi is so abundant
The writer has examined hundreds of them resulting in this gen-
eral description:—Subovate, slightly longer than high, inflated
(yet diameter never equal to height or length), rather bialated;
beaks flat (dorsal line over umbonal region curved), sculptured
quite well down on disk with three coarse irregular shaped ridges
directed post-ventrad having comparatively deep valleys between
these bars; epidermis brownish yellow; not byssiferous. Dr
Howard kindly comments: ‘‘These juvenile are of the plicata
group of the Osage the exact relationships of which seems to be
undecided.”

MISCELLANEOUS REMARKS:—Surely this subspe®ies is a
decided intergrade of the perplicatus Conrad and costata Rafinesque
(=U. undulatus Barnes). Mr. Walker has referred this abundant
shell for South and Central Missouri to perplicata variety quintardi

NAIADES OF MISSOURI 39

Cragin while Mr. Frierson would assign it to undulata variety Pilsbry
Marsh; however, comparisons of these two forms seem to indicate
that they are so identical as to assign the latter, through rules of
priority, to the synonomy of the former. Dr. Ortmann, who has
examined the anatomy as well as the shell characters of this con-
fusing form, considers it as more like Amblema costata (Raf.) and
suggests the reason why the writer should only find this little
“Blue Point” gravid during a six week’s survey of the Osage
River was that the larger Amblemae were probably males of the
same species although such sex dimorphism has not been observed
in this genus before. Prof. Clark would also assign this form more
to the undulata (Barnes) than to the plicata (Say) group. It has
also been considered as very near undulata variety latecostata (Lea).
Dr. Surber would not refer it to either group. One thing is certain,
that it is not the typical Amb. plicata costata (Raf.) and is far from
either Amb. rariplicata (Des.) or peruviana (Lam). Since there are
few intergrades above or below quintardi and since it is
also such an abundant shell for this state and Kansas it is hoped
that its assignment here settles it fairly well in this genus. The
identical form is common in the White, St. Francis, Black and other
southern streams of the Ozarks as well as in the drainage basins
of the Osage, Gasconade, Meramec and other streams of the north
slope of the Ozark Uplift. However, this sub-species is not found
in North Missouri. Hence its habitat is more that of the swift,
clear-water streams. Its breeding season is found to be the same
as that of its parent species.

Amblema (plicata) costata (Rafinesque)
(‘‘Wash-Board,”’ “‘ Three-Ridge,”’ ‘‘ Blue-Point.’’)
‘‘Flat-Plicate,”’ ‘‘Fluter.’’)

PROVE, Sigs GOs AD.

1820—Amblema costata Rafinesque, Monograph of Biv. Moll. of R.

Ohio.

1823— Unio undulatus Barnes, Am. Jour. Sci. and Arts, rst. ser., VI,
De) 120; tig.) 2).

1900b—Quadrula undulata Simpson, Proc. U. S. Nat. Mus., XXII,
p. 769.

1912b—Crendonta undulata Ortmann, An. Car. Mus., VIII, pp. 246-247.
ANIMAL CHARACTERS

Nutritive structures, as well as the reproductive, are identical
with those of Amb. rariplicata in every respect. Even the glochidia

40 NAIADES OF MISSOURI

are sjmilar, except slightly larger (0.210 x 0.220 mm). Like other
members of this genus there is no trace of brilliant colors of the
soft parts such as red or orange as seen in the Fusconaia or
Alasmidonta.

SHELL CHARACTERS.

EXTERNAL STRUCTURES:—Shell elliptically subquadrate, com-
pressed; rather thick and heavy umbones, not elevated, slighly
inflated, sculptured by five, coarse concentric ridges most pro-
nounced at base of post-umbonal ridge, slighlty alated anteriorly;
dorsal ridge high, with four or five upcurved costae; posterior
half of shell crossed with five or six oblique undulations with
shallow valleys; epidermis reddish brown to yellowish.

INTERNAL STRUCTURE:—Cardinals very heavy, double in
both valves; laterals heavy, serrated; interdentum broad, thick;
beak cavities deep narrow, crevice-like; muscle scars well impressed,
vein markings on extra-antero pallial border; nacre white, often
rusty spotted, with blue irridescence at posterior end.

Sex Length Height Diameter Locality

Gore) xX 7S exoe Onin (Osage R., Schell City, Mo.)

ORE] Gri SUM eae xmas hie (Gasconade R., Gascondy, Mo.)
CPA IEE USEC < MUNG ay (Chariton R., Kern, Mo.)

Juvenile shells have coarse concentric undulations upon the
umbonal region—especially at base of the post-ridge where they
are upcurved; a single broad undulation at the post-ventral
position of shell, a slight alation just anterior to the lunule; color
of epidermis olivaceous.

MISCELLANEOUS REMARKS:—Amblema costata Rafinesque is
without question the Unio undulatus Barnes, but the trinomial
name, Amb. plicata costata (Raf.),is used for taxonomic reasons
as has already been explained under the remarks on this genus
concerning the nomenclature incident to the revival of Rafin-
esque’s ‘‘“Amblema.’’ ‘This species is very seldom seen in typical
form in North Missouri, (never in North-West Missouri) and for
that matter, it is also scarce in Central or South Missouri—but
its actual forms are most abundant of all the Nazad species in this
State south of the Missouri River. Most of the students of Nazades
have returned the results of their studies of the Missour1 Amblemae
indicating a greater prevalence of the ‘undulata’ rather than the
‘“plicata’’ form—especially for the swift clear-water mountain
streams of the South. By actual surveys of some streams of

NAIDAES OF MISSOURI 41

Central Missouri, where ecological conditions are the most diverse
for the State, the authoy has been able to observe the same occur-
rence of the Amblemae as noted by Wilson and Clark in the Cum-
berland River (1914, p. 21) in that the more plicated and less
inflated (undulata) one will be found in upper courses, while the
smoother and more inflated (plicata) one is confined to the lower
portions of the rivers where there is more mud and a weaker
current. On the basis of not only these state-wide observations
but also on these as limited to a single river, we would account
for the existence of these two opposing types of Amblema as due
to ecological rather than to genetic causes. However, as juvenile
shells of two forms are different their origin would also indicate
difference and the matter of their occurrence under certain ecolo-
gical relations might, after all, be simply one of survival. A careful
study of Amb. costata shows it to be a summer breeder, beginning
in May and closing the latter part of July. As this ‘‘undulata”’
group has been understood better taxonomically than the “‘ plicata”’
the geographic distribution of costata has also been better deter-
mined. Simpson reports it (i. e., his QO. undulata (Barnes)) for the
Mississippi basin generally; also for the drainage basins of the
St. Lawrence, the Red River of the North and the Alabama River.
The varieties of this species, however, are reported by many for
the area south and west of the Mississippi River known as the
“South-West,” the fauna of which is included in Central and
South Missouri and bounded on the north by the great faunal
barrier, the Missourt River.

Genus Megalonaias Utterback.
(New Genus.)
Type, Unio heros Say, 1829.

ANIMAL CHARACTERS.

NUTRITIVE STRUCTURES:—Branchial opening very large with
short papillae; anal and supra-anal also-large, almost smooth,
separated by short but distinct mantle connection; inner laminae
of inner gills partly free from visceral mass or sometimes almost
entirely connected; palpi long, enormous; color of soft parts,
tan colored, with gills brownish.

REPRODUCTIVE STRUCTURES:—Marsupia occupying all four
gills, when gravid enormous, padlike, not so distended at ventral

42 NAIADES OF MISSOURI

edge; conglutinates, sole-shaped, brown, rather solid; glochidia
large, ventral margin obliquely rounded, hinge line long.

SHELL CHARACTERS.

Shell large, ponderous, broadly rhomboid, moderately inflated,
post-dorsal ridge alated, sculptured with regular upcurved undu-
lations; post-umbonal ridge broken with coarse plications running
more or less parallel with it; beaks rather low, sculptured with
coarse double looped-corrugations which extend out as nodules at
base of post-ridge and as zigzag ridges all over umbonal region to
upper part of disk; epidermis black; cardinals heavy; laterals
long and straight; interdentum short; beak cavities narrowly
deep; scars very deeply impressed—especially anterior retractor
cicatrix; nacre white to pink.

MISCELLANEOUS REMARKS:—Because of the peculiarities of
heros (Say) as to its animal and shell characters, as well as to its
uniqueness of breeding season it is thought by the author in con-
ference with other students, that this species of Say, very well deserves
rank as the type of a new genus. Although the author has not
examined the animal of boykiniana Lea, triumphans Wright, etc.,
yet, from shell characters, these allied forms would naturally
fall under this new genus, Megalonaias. In all probability crasst-
dens (Lamarck) [=trapezoides (Lea)], which has been grouped
very near heros (Say), may also deserve a special compartment,
according to the recent opinion of Mr. Frierson, who has made
special study of this species abundant beds of which are very
accessible to him; hence because of the difference of shell characters
of crassidens from that of heros (or from any other Nazad shell
in the possession of a ‘‘ ventral scar’’ as pointed out by Mr. Frierson)
this species of ILamarck is not grouped there. Besides crassidens
is not found in Missouri, neither is boykiniana, triumphans and
other conchologically allied forms of M. heros and thus the new
genus will safely stand out for this State with its type, (heros Say),
as the lone representative. Bariosta (Raf.) might be the available
name for our new genus, if crassidens could be found to be congen-
eric with heros, since Kafinesque erected his genus for this species
which he termed ponderosus, but which Mr. Walker, through his
close study of Lamarckan types, says is Lamarck’s crassidens
that ante-dates Lea’s trapezoides as well as Rafinesque’s type.
From the fact that Crenodonta (Schliiter) falls into the synonomy

NAIADES OF MISSOURI 43

of Amblema (Raf.) because of Simpson’s and Ortmann’s treatment,
(preceded by that of Morch in 1853) Schiilter’s name cannot be
used. Thus it may be seen why an original name, ‘‘ MVegalonazas,”’
(etymologically embodying a chief character) is herein submitted.

Megalonaias heros (Say)

(‘‘Giant Heros,” “ Washboard.’’)
VIS wnge POe PL V Aden Migs. 4a Aft,

1829— Unio heros Say, New Harm. Diss., II, No. 19, p. 291.

1831— Unio multiplicatus Lea, Tr. Am. Phil. Soc., IV, p. 70, Pl. IV,
Hg 2k

1900b—Quadrula heros Simpson, Proc. U. S. Nat. Mus., XXII, p. 770.

1912b—Crenodonta heros (Say) Ortmann, An. Car. Mus., VIII., p. 248.

Fic. 2. Megalonaias heros (Say). 9 Diagram of a gravid individual
from Platte River, Garretsburg, showing animal characters
in left valve. Coll. Jan. 25, 1913. (3 nat. size.)

ANIMAL CHARACTERS.

NuTRITIVE STRUCTURES:—Branchial opening very large,
with comparatively few and small papillae branched at their
tips; anal large, very finely dentate on outer edge; supra-anal
immense, slightly but distinctly separated from anal by mantle

A4 . NAIADES OF MISSOURI

connection; anus tentacled: gills very long and large, inner much
wider, inner lamina free from visceral mass for the posterior half
or connected except for a slight slit at posterior end or even entirely
connected; palpi enormous, connected about nine-tenths of their —
length antero-dorsad; soft parts mostly a fleshly-tan, branchial
edges brown with yellowish papillae in incurrent opening, patch
in front of branchial opening chamois-like.

REPRODUCTIVE STRUCTURES:—Marsupia occupying all four
gills; when gravid, enormous purplish pads, obtusely rounded at
ventral edges; ovisacs simple, undivided, some filled with rusty-
brown mucus next to the laminae thus giving the marsupia a
splotched appearance; conglutinates shape of an insole, rather
solid, usually discharged whole, edges with brownish red pigment,
rather thick with no thin transparent portions; glochidia large,
post-ventral border obliquely rounded, hinge line long, nearly
straight, no spines present, very vital, measures 0.280 x 0.340mm."

Fic. 3A. Mature glochidium of M. heros showing peculiar oblique
post-ventral margin from lateral view. (x87—a camera
lucida sketch. Left hand figure.)

Fic. 3B Ventral view of open glochidium of M. heros. (x87—a
camera lucida sketch. Right hand figure.)

SHELL CHARACTERS.

EXTERNAL STRUCTURES:— Shell massive, heavy, subrhom-
boid, post-dorsal ridge rather high slopes of which ribbed with
coarse, upcurved, regular undulations originating from umbonal
region; post umbonal ridge broken with heavy undulations more

t According to Dr. T. Surber, (U.S. B.F. Doc., No. 813, 1915) this glochi-
dium has the greatest variation in size and moreover, he has also found
it parasitic upon the gills of the ‘‘water dog” (Necturus maculosus).

NAIADES OF MISSOURI 45

or less parallel to post-ridges; beaks rather low and full, sculptured
with numerous corrugated or double-looped ridges extending out
as prominent nodules on the post-umbonal-looped ridges and
zigzag, or WM-shaped, ridges on the umbonal region and upper
part of disk; epidermis black, more or less dull color.

INTERNAL STRUCTURES:—Cardinals moderately heavy, double
in both valves; laterals very long, not much curved, interdentum
short, narrow; beak and branchial cavities rather deep; muscle
scar—expecially the progressive impression and that of anterior
retractor—very deep; nacre white (often with rusty spots) varying

to pink.
Sex Length Height Diameter Locality
OW TSO x Lion % e56mm (Platte. R, Dixon Falls.)
St) Hue eM Be eGy Olid (ee ” Garretsburg.)
OMTOOL WE FOUL x | Zi9 *? (Osage R., Warsaw)
ON ig XS 5 MOR 25) jor ( ” ’ Monegaw Springs)
45S 129) UX. Ta.smin) (7°? Warsaw)
Ofer 2 OME SEQUIN LEQ’Sh niin flo et) eh, eLOCLOR)

The young and juvenile shells of the last two _ respec-
tive measurements are very profusely sculptured—no part
of the external surface being smooth—yet no undulations appear
as seen in adult. Beaks low, corrugated; slopes of post-dorsal
ridge finely costated; post-ridge with coarse, apiculated or spurred
nodules; center and anterior of disk covered with irregularly
placed V-shaped ridges and with scattered tubercles; valves
extremely flat; nacre sky blue, irridescent. ‘‘Work up old shells
from the young ones”’ is Mr. Walker’s advice.

MISCELLANEOUS REMARKS:—This most ponderous shell of
the Nazades is typical in North Missouri and the Mississippi,
but the typically massive shell is not found in Central Missouri,
and, so far, it is not reported at all for the southern slope of the
Ozarks in this state. As a rule, heros is only found in the large
rivers; however, in this State the type is found in the Missouri
Platte—a rather small river, while the medium sized one is found
in the largest river of the interior—the Osage—where it assumes
the small form perhaps approaching that of dombeyana Valen-
ciennes. ‘‘Giant heros,’ as this species is often called, is most
frequently found in the deepest depressions of mud bottom with
a substratum of solid limestone. It hardly ever moves from these
situations and perhaps because of this inactivity it accumulates
its heavy shell. Because of the following peculiar characters the

46 NAIADES OF MISSOURI

author sees fit to create a new genus for heros of Say:—
1.—An unusually heavy shell, with zigzag or V-shaped,
sculpturing on upper part of disk and corrugate scupture
on beaks.
2.—A tendency of the inner laminae of the inner gills to
become more or less united with the visceral mass.

3.—The gravid marsupium an enormously distended pad,
colored purplish, or slaty, with reddish splotches here and
there parallel to the septa.

4.—Thick, sole-shaped, subsolid conglutinates with rusty-

brown margins discharged more or less whole with glochi-
dialying all through the conglutinated mass.

5.—A large, vital glochidium with post-ventral margin ob-

liquely rounded.

6.—Breeding season intermediate, or tachytictic with late

season (i. e., bearing glochidia in late winter but being
sterile during the summer.)

From Amblema this peculiar species must be removed on
account of its beak sculpture which is more like that of Quadrula—
especially of the ‘‘Lachrymosa” group, yet it is separated from
the latter chiefly by its ponderous shell and rugose, V-shaped
sculpturing on the umbonal region and upper part of disk. It
has been grouped under Amblema more on account of the oblique
folds on post-half of its shell; however, these plications are, after
all, usually disposed differently with respect to the post-umbonal
ridge and are not so constant and numerous, nor do they appear
so early in the life history of the shell, as in the type for Amblema.
The special reason that a new genus should be built for heros is
on the basis of its unique character of soft parts. No other generic
type of Unioninae (nor of any of the Nazades for that matter)
possesses such peculiarities of form, color or size for its marsupium,
conglutinate or glochidium; and as to its nutritive structures,
none are so eccentric regarding the connection of the inner laminae
to its inner gills. Its idiosyncrasy of breeding habits would not
only give it a special station, aside from all other Nazades so far
known, yet this physiological character may account for its oddity
morphologically. The author has kept an accurate breeding
record of heros throughout the year—especially for the
winter months when other records have been incomplete—to
find it gravid with ova of early embryos in fall and early winter,

NAIADES OF MISSOURI ; 47

with late embryos and immature glochidia in midwinter, and
with mature larvae in late winter but barren from April to August.
Ovulation has been observed for the latter part of August and
unfertilized ova have been found in the ovaries August roth.
Sperm having been found within the visceral mass without being
accompanied by ova for those individuals that possess gills without
the crowded septa of the female proves the sexes distinct and
separate and thus disproves the claim of hermaphroditism for
this species. It is true that during the height of the breeding
season that all individuals found seem to be females but this is
the time when there is greater activity among females; hence,
they may be more in evidence while the males remain inactive
and burrowed from ready accessibility during this season. This
fact may account for the so-called hermaphroditism among other
species. By laboratory tests the writer has kept the glochidia of
this species alive in cold, clear, fresh water exactly thirty days
(five time longer than the life of any other mature glochidia sub-
mitted to this watch-glass test) after being taken from the mother.
This unusual vitality of the larvae is an adaptation to its pro-
longation of breeding season into late winter when they are dis-
charged into the ice-cold water and left to their fate, for it is the
belief of the writer that they are discharged as soon as mature.

Genus Quadrula Rafinesque.

1820—Quadrula Rafinesque, Ann. Gen. Sci. Phys. Brux., p. 305.
1852—Rotundaria Agassiz, Arch. fur, Naturg., p. 48.

(Type, Obliquaria (Quadrula) metanevra (Rafinesque).

ANIMAL CHARACTERS:—Branchial opening large with short
arboreal papillae; anal smooth to finely dentate; supra-anal
very large, briefly and loosely connected to anal by mantle edges;
inner laminae of inner gills free from visceral mass; palpi large,
somewhat sickle-shape; color of soft parts not bright, éxcept for
brownish gills and palpi, tannish or soiled white; marsupia occu-
pying all four gills, when gravid ovisacs swell moderately in center,
ventral edge obtusely pointed; conglutinates white, leaf-like,
sometimes divided at distal ends; glochidia small to medium
in size, subovate, spineless.

SHELL CHARACTERS:-—Shell roundly quadrate, or subrhom-
boidal, occasionally elongate with moderately high beaks sculp-
tured with 3-4 parallel ridges developed on post ridge to nodules;

48 NAIADES OF MISSOURI

disks usually sculptured; epidermis generally dark colored, ray-
less or with greenish splotched paintings; cardinals heavy, double
in both valves, ragged; laterals double in left, single in right;
beak cavities deep, compressed or creviced; shells mostly not
sexually dimorphic.

MISCELLANEOUS REMARKS:—This genus naturally falls into
three groups as follows:—

I. Pustulosa Group.

This group is mostly represented in this State by the northern
and western form, Q. pustulosa schoocraftensis (ea), and is charas-
terized by its greater inflation, smoother, larger and more elongated
shell with beaks drawn back up more toward the center of the
dorsal line; beak sculpture concentric. The actual typical pustu-
losa is rarely, if ever, found in Missouri.

II. ‘‘Lachrymosa’”’ Group.

This is represented in Missouri by Q. quadrula (Raf.) (=lach-
rymosa l,ea), nodulata (Raf.), fragosa (Conrad), aspera (Lea),
verrucosa (Raf.), nobilis (Conrad) and their intergrades, and may
be characterized briefly by a somewhat quadrate or trapezoidal
shell, profusely sculptured disk with tubercles arranged in two
radiating rows from the beaks to ventral margin divided by a
more or less broad radial furrow; beak sculpture double-loop
type.

III. Metanevra Group.

This third group is only represented in this state by Q.
metanevra (Raf.) and cylindrica (Say) and is characterized especi-
ally by its height and coarsely sculptured umbonal ridge in front
of which is a depression but no definite radial furrow and by its
peculiarly triangular greenish splotches; beak sculpture double-
looped or zigzag type.

The genus Quadrula tends toward an unusual intergra-
dation of forms among the above groups in this state and because
of this fact the genus might be more properly treated under various
sub-genera for this catalogue; however, this treatment may be
made unnecessary by the elimination of all the intergrades except
those that possess the nearest approach to types. As to soft
parts, this genus is identical with Amblema but is especially
separated from the latter by the negative shell characters of
oblique folds across the disk. Simpson, who bases much upon
deep beak cavities, as one of the special characters of this genus,

NAIADES OF MISSOURI 49

includes more under this group, that is, the genera, Fusconaza,
Amblema, Megalonatas, Rotundaria, Plethobasus and even some
species of Pleurobema.
Quadrula pustulosa (Lea)!
(‘““Warty-Back,” ““Warty Pigtoe,’”’ “Pimple Back.’’)
PV hi eh igs. areas and: B:.
1831— Unio pustulosus Lea, Tr. Am. Phil. Soc., IV, p. 76, pl. VII,
Tee fe
1834— Unio nodulosus Say., Am. Conch., VI. .
1898—Quadrula pustulosa Baker, Moll. Chicago, Pt. I., p. 86, pl
XXV.

ANIMAL CHARACTERS.

NUTRITIVE STRUCTURES:—-Branchial opening with yellowish
plumed tentacles; anal smooth; sura-anal very closely con-
nected—-even disconnected—by mantle edge; inner lamina of
inner gills free from visceral mass; color of soft parts dingy white;
palpi connected for about one-third of their length.

REPRODUCTIVE STRUCTURES:—AlIll four gills entirely marsu-
pial, septa crowded, ovisacs narrow; conglutinates white, leaf-
like, broken; glochidia large, semi-elliptical, spineless, hinge
line short and evenly curved, measures 0.230 x 0.300mm.

SHELL CHARACTERS.

EXTERNAL STRUCTURES:— Shell ovate-quadrate, higher than
long, post-umbonal ridge almost horizontal, posterior half pustu-
late to smooth, dorsal ridge with nodulous costae; beaks pro-
truding anteriorly sculptured concentrically with upcurved ridges
posteriorly; epidermis rusty brown with somethimes broad green
banded rays diverging from beaks.

INTERNAL STRUCTURES:—Cardinals heavy just under beaks;
interdentum broad, upright; laterals straight, at right angles to
interdentum; umbonal cavity compressed, deep; nacre white.

Sex Length Height Diameter Locality
BAM SSG Se eG ehasbaat (Miss. R., La. Grange, Mo.)
fot 60 x 60 x 38 ” ( ” ” ” ” ” )
eS? Mie Saati skies laa Y ag ya Hannibal i)

No juvenile shells have been obtained for descriptions; this
species is so rare in its typical form for this State that adult shells
have been secured with difficulty.

' The name of this species should read Q. bullata (Raf.) if we accept
Rafinesque’s evident description of it in his Monograph (1820, p. 41).

50 NAIADES OF MISSOURI

MISCELLANEOUS REMARKS:—Typically this species is a small
shell, very upright with beaks protruding extremely anteriorly
and with irregularly arranged pustules over its disk. In this
latter character it is separated from Q. nodulata with which it
is often confused; then too nodulata is not so rotund. Pustulosa
is more typically a southern shell while its variety, schoolcraftensts,
is more of a northern and western form. Its favorite home is clear
water and rather swift streams and is associated with Q. sphae-
rica, refulgens, mortont, etc.,—all of which are not found in Missouri;
on the other hand its northern relative (schoolcraftensis) is more
of alover of mud bottom and sluggish current. It is strange that
this species is not found in South Missouri where its ecological
conditions are most favorable; however, it is not at all common
anywhere in the great South-west. It is occasionally found in
Central Missouri but mostly in varietal forms. The Mississippi
River is the only locality for anything like its type. It should
be a species of wide distribution since its host distributor is the
common crappie (P. annularis).

Quadrula pustulosa schoolcraftensis (Lea).
(‘‘Warty-Back,” “‘ Pimple-Back.’’)
PAV CIS eA oe
1834— Unio schoolcraftensis Lea, Tr. Am. Phil. Soc., V., p. 37, plese
fig. 9.
ANIMAL CHARACTERS.

NUTRITIVE STRUCTURES:—Branchial opening large, low, with
short arboreal papillae; anal obscurely crenulated; supra-anal
closely connected to anal but not deciduous; gills tilted at an
abrupt angle, inner laminae of inner gills entirely free from visceral
mass; palpi unusually long, somewhat curved; except brownish
gills and palps the soft parts are dull whitish or tan.

REPRODUCTIVE STRUCTURES:—All four gills marsupial, septa
crowded, ventral edges pointed and distended slightly in center
when gravid; conglutinates white with thin, transparent spots
arranged transversely in rows; glochidia same in form as the
parent species, but a little larger (0.235 x 0.320).

SHELL CHARACTERS.

EXTERNAL STRUCTURES :—Shell large, subquadrate, ventral mar-
gin gently curved, moderately inflated, thick, heavy; posterior

NAIADES OF MISSOURI 51

half profusely and irregularly pustulate to smooth; beaks rather
high, moderately inflated sculptured concentrically but faintly;
epidermis dark straw to chocolate brown in color.

INTERNAL STRUCTURES:—Cardinals heavy, irregular, double
in each valve: inter-dentum broad, at right angles to laterals;
laterals heavy, double in left, single in right; scars deeply impressed ;
umbonal cavities compressed by deep crevices; nacre usually white,
irridescent especially posteriorly.

Sex Iength Height Diameter Um. ra. Locality
Ci Gmexe a 5 Onn Xr nin 0.300), (Platte sR. Agency;, Mio.)
AG Olen EX 5 Olax | I ZON iy 0.300 (Grand R., Darlington, Mo.)
ORO, Xie Gi 0.295 (Platte R., Claire, Mo.)
Ghee 7 exe) Avex, 1 BY 0.300 (Grand R., Utica, Mo.)

Since schoolcraftensts is one of the greatest occurrence in
individuals for this state, the writer has been able to secure the
largest collection of its adolescent shells than any of the Nazades
in Missouri. The above latter measurement is that of the smallest
one but 1t was without bysst. Its general outline is more elongated
than the mature shell, resembling the adult Q. quadrula, post-
umbonal ridge more prominent, beaks fuller, almost drawn back
to the center of dorsal line, characteristically painted with a
bright, broad, fan-shaped, green ray at base of post ridge within
the original shell area; beak sculpture indistinct, concentric,
broken anteriorly by a radiating furrow directed out on disk.

MISCELLANEOUS REMARKS:—The differences of this variety
from the species has already been mentioned under the description
of the genus. This form was not admitted by Simpson as a race
and is merely referred as ‘“‘a nearly smooth, compressed form of
pustulosa.”’ The varieties of typical pustulosa, indeed, are great—
especially as to disposition of pustules, etc., but this larger more
characteristically quadrate form is so abundant in_the north and
west, where pustulosa-types are rarely found, that it surely deserves
a separation into the subspecific, if not specific class. According
to the figure and description that triangular variety found in
the Ohio River, (that is, Lea’s pernodosa,) might be a synonym of
schoolcraftensis. ‘Taking it all in all this subspecies is purely a
geographical race, but may pass into normal form in a few places,
even in the north and west, such as in the Mississippi River,
Illinois and local points where clear water and swift streams are
found. Schoolcraftensis is a lover of quiet, muddy situations,

2 NAIADES OF MISSOURI

On

where it has developed a heavier, less pustulous shell as we
note in the ecologic results for some shells of Amblemae. This
form is reported also for the St. Lawrence basin as well as through
all the northern part of the Mississippi Valley, even down into the
South-west as far as Kansas and Oklahoma. The writer has been
able to keep a good breeding record for this very acessible form
for Missouri to find it only gravid through June and July.

Quadrula pustulosa asperata (lea).
Pl, COV) nhug ae MAN aad wis.

1861— Unto asperatus Lea, Pr. ac. Nat. Sci. Phila. V, p. 41; Jl. Ac.
Nea Sct Philas Wespaosnobl. Vilkewhise onep

ANIMAL CHARACTERS:—-Soft parts have been examined
afield and found to be identical with those of the parent species.
None were found gravid. All four gills of sterile females were
marsupial in character through the test of finding more crowded
septa.

SHELL CHARACTERS.

EXTERNAL STRUCTURES:—Subtrigonal, very upright, high?
than long, post-umbonal ridge moderately inflated, dorsal line
rather straight, ventral margin abruptly curved, rounded pos-
teriorly, subtruncated anteriorly; beaks well forward and eroded;
tubercles few, disposed on upper part of disk; epidermis reddish
brown to black.

INTERNAL STRUCTURES :—Identical with those of type, pus-
tulosa except perhaps a broader, thinner and more upright
interdentum.

Sex Length Height Diameter Locality

etl AWA Se) MIG) oe) |\tshnaten (Osage R., Warsaw, Mo.)
OLW 5 OLtEX ASN kanes Zien Cae ”” Osceola, Mo.)
CO AG XA Ot Xin ee Te (oe ” Bagnell, Mo.)

MISCELLANEOUS REMARKS:—The form of the above. des-
cription is of rare occurrence in the Osage River, but still the
other form for this state, schoolcraftensis, does not occur much
oftener in this river. According to Mr. Bryant Walker this is
“a western form of Q. pustulosa and if it came from the Coosa
River, Alabama, it would surely be referred to Q. asperata (Lea).”
Ccmparisons to the actual shell from Alabama (Coosa R., Cedar
Fluff) shows it to be almost identical both as to external and
internal features.

NAIADES OF MISSOURI 53

Quadrula quadrula Rafinesque.
(‘‘Maple Leaf,’’ ‘Monkey Face,” ‘Tear Shell.’’)
IOEX, Pte MOO Se ERO VL LEE. S 45, AE.

1820—Quadrula quadrula Rafinesque, An. Gen. Sci. Phys. Brux.
pi BOs.

1828— Unto lacrymosus Lea, Tr. Phil. Soc., III, p.:272, pl. VI, fig. 8.

1831— Unto asperrimus Lea, Tr. Am. Phil. Soc., IV, p. 71, pl. V., fig. 3.

1834— Unio quadrulus Say, Am. Conch, VI.

1898—Quadrula lachrymosa Baker, Moll. Chicago, Pt. I, p. 83, pl.

POV eet) el) higs2).

ANIMAL CHARACTERS.

NUTRITIVE StTRUCTURES:—Branchial opening rather large
with arboreal papillae; anal slightly crenulate; supra-anal very
large closely connected to anal by mantle edges; palpi very long
united about two thirds of their length antero-dorsad and heavily
vein marked; inner laminae of inner gills free from visceral mass;
color of most soft parts tanned flesh color.

REPRODUCTIVE STRUCTURES :—All four gills marsupial; ovisacs
wide in middle transversely, ventral positions being divided,
giving the white conglutinates a double or triple split appearance,
septa thickened at intervals leaving thin transparent elongated
spots arranged regularly and transversely in the conglutinates;
glochidia not found by writer; Dr. Surber reports it as the smallest
of the Quadrulae; color of charged marsupia brown; crenulated
flap on post-dorsal part of foot; probably sexual in function as
only noted in females.

SHELL CHARACTERS.

EXTERNAL STRUCTURES:—Shell medium in size, subquadrate
{o subtrigonal, dorsal ridge more or less alated with costae on
slopes undulated or sulcated post-umbonal ridge prominently
angled set with coarse tubercles, a valley or radial furrow in front
bounded anteriorly by a row of more or less irregularly placed
tubercles on center of inflated disk, presenting the appearance
of drops of melted wax; epidermis varies from olive green to chest
nut brown or even black, in some instances faintly rayed anteriorly
and with continuations of green paintings ventrad to some of the
tubercles; beaks high, full, furrowed, post-obliquely, sculptured
with corrugated, concentric ridges that break into great numbers
of small tubercles out on the umbonal region.

54 NAIADES OF MISSOURI

INTERNAL STRUCTURES:—Cardinals more or less double in
both valves; laterals inclined to double also; umbonal cavities
deep and rounded out; nacre white irridescent.

Sex Length Height Diameter Um. ra. Locality

QO 115 xX 75. X 5Imm x (0.210. (Lake Contrary, St: Joseph, Mia)
Ct OO)! Re OQ A be EN ee x 0.220 (Platte R., Agency Ford)

Ci ON Xe ON anes Soe x 0.350 (Flat Creek, Sedalia, Mo.)

ORIG SiMEXC als Al) ixe, 20) co x 0.325 (Auxvasse R., Fulton, Mo.)

fou Siro x 5 eae ann x 0.3007 (Grand (Re Uitica)

The above measurement is the smallest ever taken by the ;
author. It was discovered stranded on a sandbar, where it was
traced by its tiny furrowed track in the fine wet sand. Although
it had been but few days since its escape from its parasitic life
on the fish, yet it had no byssi. It would seem from this, and many
other instances, that neither the Unioninae nor Anodontinae develop
byssal threads. Three other juveniles found on this same bar
(measuring 11, 13 and 22 millimeters) were also devoid of byssi.
It has been the author’s experience to find juveniles in companies.
The juvenile quadrula has the general appearance of a young
fragosa, having a straw-colored epidermis, very pointed posterior
end, deeply sulcated post-ventral position, full rather double-
apiculated beaks, with corrugated sculpturing and placed almost
in the middle of the dorsal line; tubercles rather folded on anterior
umbonal slopes ridged on post-umbonal slopes and finely ribbed
on post-dorsal slopes.

MISCELLANEOUS REMARKS:—Q. quadrula is represented by
many forms in this state—especially in Central Missouri; how-
ever, the large, heavy form that ranges from Ohio to Nebraska is
rather constant in the drainage basins north of the Missouri
River. It is strange that there should be such a depauperization
of any of these forms in South Mo. ‘This species is found in Arkan-
sas but rather in the aspera form, a small quadrula such as mostly
seen in the Osage system. Mr. Walker thinks that the key for
tracing out the relative ranges of forms might be found in some
ancient drainage system, and varieties, such as found in Missouri,
ought to help solve the question. The inflated, solid and compara-
tively smooth variety of Q. quarula of North Missouri may be
referred to Pratt’s Udio lunulatus (Proc. Dav. Ac. Nat. Sci., I.
1876, p. 167, Pl. XXXI, fig. 1). However, this may simply be
the lacustrine form of the type since the fluviatile forms of North

.

NAIADES OF MISSOURI 55

Missouri approach more the typical quadrula in being more com-
pressed and more tuberculated. Perhaps the most typical quadrula
of Missouri is to be found in the geographic center of the state
where the flatter, thinner and more ‘“‘lachrymosed”’ shell occurs.
As in many of the species of these related genera the intergrades
are so numerous that we can consider only the most striking ones
that may be traced to mere local conditions. The author has
found this species to be the most sensitive to discharge its conglu-
tinates immaturely when disturbed from its-natural bed and then,
too, since conglutinates, spawned in nature, have been examined
to find them containing late embryos it is to be inferred that
maturity may take place outside. Hence we may account for
our difficulty in securing the mature glochidia from the ovisacs
of the mother. The writer has examined hundreds of gravid
quadrula in mid- and late summer only to find every stage of
embryonic development except the glochidial. In this respect
this species resembles Q. verrucosa and the fact that the ovisacs
of each contain unusually large quantities of mucus may have
some association with their eccentric breeding habits. The breed-
ing season of Q. quadrula is from May to August and hence is
tacytictic.

Special attention is given here to a deeply sulcated form of this
species which occurs rather commonly in our North West Missouri
lakes but which may only be a pathologic condition due perhaps,
to parasitic attacks upon the mantle glands that build up the
shell. Three type shells measure as follows:

Sex Length Height Diameter Um. ra. Locality
3 85 x 7O x 57mm 0.485 (Lake Contrary, St. Joseph, Mo.)
Be ae) 55) Xe 54 B-450 iy) * ret tea 1a)
Has) 1X, 38.) x9. 40) a4gsiG ou? s 45 Frm

These measurements show an unusual inflation and extra-
ordinary position of the umbones. If this should be a normal
form it would deserve specific consideration because of the deep
post-dorsal sulcation and also because of the wide, deep radial
furrow in front’ of the prominently angled post-umbonal ridge.
- However, since Mr. Frierson concurs with the author in the belief
that it may only be ‘‘a strange freak”’ after all it would be dismissed
here with only the reference to its photograph (Pl. XVIII, Figs.
46 A and B.)

tn 4
ON

NAIADES OF MISSOURI

Quadrula quadrula contraryensis Utterback.
(Round Maple Leaf.)
Pl. XVIII, Fig’s 47 A and B.

ANIMAL CHARACTERS.

NUTRITIVE STRUCTURES:—Same as that of the parent species,
except for an absence of a supra-anal opening, a difference in
the greater posterior extension of foot and also a general dif-
ference of form of soft parts due to a more rounded shape of
shell.

REPRODUCTIVE STRUCTURES:—Identical with that of the
parent species except for shorter, wider marsupia.

SHELL CHARACTERS.

EXTERNAL STRUCTURES :—Shell medium in size, suborbiculate,
abruptly curved before, broadly rounded behind with very slight
incurvature post-ventrad; well inflated, inclined to globosity;
beaks full, high up on dorsal line (as indicated by the large average
umboidal ratio of 0.495); tubercles few and small, mostly on
umbonal area; post-umbonal ridge rounded, scarcely sculptured ;
sculpturing on beaks corrugated as on parent species; epidermis
olivaceous.

INTERNAL STRUCTURES:—Cardinals different from parent in
being reduced to a single, jagged tooth in right valve; somewhat
double in left; interdentum long, wide, not so deeply gashed in
right valve for the reception of the post-right cardinal; umbonal
cavity deep, basin-like; nacre an unblemished white.

Sex Length Height Diameter Um. ra. Locality
oO 73.5 X 64.5 X 44.0mm 0.495 (Lake Contrary, St. Joseph, Mo.)
@ 76.0 x 66.0 x 45.0 ”’ OLR (CY ” de 24a)
S84. O/4x. PO!) X 85040) Lin NOMS 3 (ak, F # a Bre}
OC ATO, ky. 86:0) X 39-00.) 1 NOsS2Oms oe 49 4 ae 225 ea)

The young shell of the last measurement shows an approach
to the parent shell. The comparatively deep sulcation at the
post-ventral portion of the shell disappears as seen in a shell
series of fairly close connection in ages.

MISCELLANEOUS REMARKS:—The author of this sub-species
is satisfied that he has a sufficient collection of this peculiar shell
taken from different parts of Lake Contrary, St. Joseph, Missouri,
to prove the validity of this form as a variety of that very common,

NAIADES OF MISSOURI ny

heavy shell, that occurs in the Mississippi Valley, North of the
Ohio and also of the Missouri Rivers. The differences in this
upright, rounded shell from its parent are stated in ‘the compara-
tive description. Since students of Nazades have pronounced it
a variety, if found in sufficient numbers, the author concurs by
naming it for its type locality, Lake Contrary, St. Joseph, Mo.
Wherever found in this lake, the bottom is a soft, marly mud,
and the situations are in rather deep water sheltered from wave
“action. The author has discovered a short period breeding season
for contraryensts.

Quadrula nodulata Rafinesque.
(‘Pimple Back,’ ‘‘Warty Back.’’)
PU AVIE, Sitgssi4a7 A and Bb.
1820—Obliquaria nodulata Rafinesque, Bivalves of River Ohio, Ann.
Gen. Sci. Phys. Brux.

1834— Unio pustulatus Lea, Tr. Am. Phil. Soc., p. 79, Pl. VII, fig. 9.

1834— Unio nodulatus Say, Am. Conch., VI.

ANIMAL CHARACTERS:—Nutritive structures absolutely iden-
tical with those of Quad. pustulosa (Lea). The glochidial characters
are the same, except a difference in size, the glochidium of nodulata
being the larger 0.230 x 0.290 mm. However, small differences
in size may not be considered good distinctions as it is the glochi-
dial form that is to be taken into greater account.

SHELL CHARACTERS.

EXTERNAL STRUCTURES:—Shell medium in size, solid, sub-

orbicular, inflated, post-dorsal ridge projected; umbones very
full, high, incurved bearing three or four small corrugated, con-
centric ridges; post-umbonal ridge and central part of disk orna-
mented with two radial rows of small, erect pustules sometimes
terminating with half-tubercles at ventral margins; epidermis
light tan to dark horn.

INTERNAL STRUCTURES:—Identical with pustulosa.

o 48 x 40 x 30 mm _ 0.200 (Miss. R., Hannibal, Mo.)
Oe AS exer aot ke 28I5 O25 On ey yaad ee x ay)
fot) Gye PSC OX i Aly OK nme G2 107 13(

”

” ” ” ” )

Shell of juvenile subglobose, post-umbonal ridge prominent,
post-dorsal ridge short, high; tubercles few in two rows—one on
post-ridge—no radial furrow between; beaks very full, sculptured

58 NAIADES OF MISSOURI

by rather coarse, irregular ridges, extending as tubercles, on the
disk; epidermis yellowish green with alternate bands of brown and
straw color. Interior of shell much like adult except not so broad,
nor as upright, nor as long; nacre white with light blue irridescent
sheen posteriorly.

MISCELLANEOUS REMARKS:—Q. nodulata seems to be only a
globular-shaped Q. quadrula and is more typically a southern
shell; however, it is occasionally met with in the Upper Mississ-
ippi, where it is most found in this State. Mr. B. F. Bush col-
lected some miscellaneous shells from the interior of the state
and donated them to the United States Museum where some
were identified as this species. It is to be distinguished from Q.
pustulosa especially by two regular radiating rows of widely
separated tubercles obliquely arranged from the umbones to the
ventral margin on the posterior half of the disk; then, too, it is
more inflated, is not so upright, has greater umboidal ratio, has
more of an alated dorsal ridge and belongs to the so-called ‘‘ Lach-
rymosa’’ Group, whereas, pustulosa is a member of the first group
of this Genus of which it is the type; hence, the latter is, after
all, not even closely allied. However, there is not much difference
between these two Quadrulae as to the form and size of their
larvae, and as to form of adult shell, it lies nearer to the variety,
contraryensis of Q. quadrula. Surber (1913, p. 113) finds this
species to be a gill parasite upon the crappie (Pomoxis annularis)
as an occasional host. As to its breeding habit, it is tachytictic.

Quadrula fragosa (Conrad).
(“Hickory Nut Shell.’’)
PIX VERT «Bigs: qocX vanad) Y3.
1836— Unto fragosus Conrad, Monog. of Fresh-water Shells, II, p. 12,
Vales higenoe
ANIMAL CHARACTERS.

NUTRITIVE AND REPRODUCTIVE STRUCTURES :—Identical with
Q. quadrula as far as can be determined, with the scanty supply
of material at hand—none of which is in gravid condition. How-
ever, Wilson and Clark (1914, pp. 59 and 60) report it with all
four gills marsupial, thick, pad-like. Glochidium unknown.

SHELL CHARACTERS.
EXTERNAL STRUCTURES:—Shell most quadrate of the Quad-

NAIADES OF MISSOURI 59

rulae, medium in size, greatly inflated, characteristically sulcated
post-ventrad; dorsal ridge prominent, the slopes coarsely cos:
tated; post-umbonal ridge prominent and profusely tubercled,
radial furrow deep and wide, in front of which another row of
rather scattered tubercles extend from the beaks post-ventrad
across the disk; epidermis dark yellowish.
INTERNAL STRUCTURES :—Identical with those of Q. quadrula.

Sex Length Height Diameter Locality
COs mie ex! SON xX) Ms Sint (Miss., R. Hannibal, Mo.)
9 44 x 39 x 18 ” ( ” ” ”” ” )
eae Se xe PEON SCX nO) a (102 R., St. Joseph, Mo.)
Cel Sse me ONS ie aj Pe (Osage R., Schell City, Mo.)

It may be that the juvenile shell measurement of the last
two above is only that of QO. quadrula since all juveniles of the
latter possess the characteristic sulcation at the post-ventral
portion of the shell as well as the profuse costation on the slopes
of the post-dorsal ridge; hence, the inferrence the author would
draw in asserting that Q. fragosa may be an occasional instance
of an overgrown shell of Q. quadrula.

MISCELLANEOUS REMARKS:—This type of Conrad is of rare
occurrence in this State, the Mississippi being the only place
where anything like its type may be found with any degree of
assurance. Abnormal forms of fragosa are seen occasionally in
the headwaters of the Osage. Simpson is not certain about the
distribution of fragosa outside of the Ohio and Tennessee—Cum-
berland systems. It is mainly distinguished from typical Q. quad-
rula by being more squarely quadrate, more inflated and the
upcurved tubercular costae on the rounded post-dorsal ridge
being more pronounced. It differs chiefly from aspera, (the small
Q. quadrula form of the Osage) in not being biangulated pos-
teriorly. It has been found to belong to the short period breeders.

Quadrula aspera (Lea).
(“Little Rough Shell.’’)
Phe XVITE... higs. 400 Avand. B:
1831— Unio asper Lea, Tr. Am. Phil. Soc., IV, p. 85, pl. IX, fig. 15.
ANIMAL CHARACTERS.

NUTRITIVE STRUCTURES:—Branchial opening finely papil-
lose; anal smooth; supra-anal loosely, to deciduously, connected
to anal by mantle edges; inner gills much wider (posteriorly),

50 NAIADES OF MISSOURI

inner laminae of inner gills free from visceral mass; palpi long and
broad; soft parts a light tan. .

REPRODUCTIVE STRUCTURES :—Marsupia identical with those
of QO. quadrula. No gravid forms found.

SHELL CHARACTERS.

EXTERNAL STRUCTURES:—Shell small, subquadrate, biangu-
lated behind, the biangulation pointed ventrad; post-dorsal ridge
costated; post-umbonal ridge prominent, profusely tubercled;
radial furrow rather wide and shallow, bounded in front by a rather
scattered row of sharp tubercles; epidermis blackish.

INTERNAL STRUCTURES:—Identical with those of Q. nobilis
which are somewhat peculiar.

Sex Length Height Diameter Locality
SWS 2 ena Gla) Xu me2 Oat (Osage R., Warsaw, Mo.)
fol 44 x 39 x 27 ’” ( ” ” 9 9? )
OM AON AX Wy SSM hl 2AM a ae (Carat oe ii eae 4)

MISCELLANEOUS REMARKS.—Although this species has only
been found in the Osage basin for this State, yet it is not to say,
a very common shell there. So closely related is this small form
of quadrula to Q. nobilis that a good series of shells may reveal it
as the young of nobilis. Aspera has been considered the southern
form of Q. quadrula and it may be the small: multi-tuberculated
representative of the South-west which is connected geographically
by all forms of intergrades to that large, heavy, smoother repre-
sentative of the North Mississippi Valley.

Quadrula nobilis (Conrad).
("Big Buck Horn,” Maple Veéat.”)
| da BS Aon 8 Atal os iene st

1854— Unto nobilis Conrad. Jl. Acad. Nat. Sci. Phila., II, p. 297,
Pip keV tics novand. a:

ANIMAL CHARACTERS.

NUTRITIVE STRUCTURES:—Branchial opening large with
feathered papillae, anal crenulated, supra-anal without mantle-
connection to anal—hence both openings virtually one, gills
long, rather narrow, inner laminae of inner free only one-half
way, palpi enormous connected two-thirds of their length antero-

NAIADES OF MISSOURI 61

dorsad, color of soft parts tan, for most part, mantle edges at
siphonal openings black, gills and parts above darker tan tha
parts below.

REPRODUCTIVE STRUCTURES :—Only sterile marsupia observed;
all four gills, however, marsupial and same in structure as that
of Q. verrucosa; glochidium not found.

SHELL CHARACTERS.

EXTERNAL STRUCTURES:—Shell roughly pentagonal in gen-
eral outline, heavy, thick, solid, compressed posteriorly, inflated
for one-half of the shell anteriorly, obtusely biangulated behind
with truncation obliquely antero-ventrad, broad, shallow, radial
furrow, post-umbonal ridge flattened and-.sculptured with few
tubercles, area in front of radial furrow irregularly and coarsely
tuberculated, slopes of post-dorsal ridge with low upcurved -
costae, epidermis dark brown, growth lines coarse.

INTERNAL STRUCTURES:—Cardinals and laterals both dis-
tinctly doubled in the two valves, interdentum short, wide,
cut away in right valve for the post-left cardinal, anterior adductor
muscle scars usually drawn to the front, nacre milky white.

Sex Length Height Diameter Locality
OF 8120) Xx 88) exe) 57m (Marais des Cygnes R., Rich Hill,)
CR COn LES NG 0) =X Oly (Osage R., Greenwell Ford)
OES On nse AG Xe 927 85s hae” He 4 Pio)

No juveniles were obtained. The last measurement, is that
of the smallest in the writer’s collection, but shows no real juvenile
characrters, and is more like Q. aspera except for its difference
in posterior biangulation and also in its tuberculation.

MISCELLANEOUS REMARKS:—Simpson (1900b, p. 776) puts
Q. nobilis down in the synonomy of aspera, but later refers it to
Q. verrucosa. However, from studies of its peculiar anatomy and
internal shell structures it may come very near to verrucosa. ‘This
is a rather common species for the Osage where it reaches a larger,
heavier growth of shell than is ever attained by verrucosa. It is
also a broader, shorter shell with great solidity and inflation
anteriorly and also greater compression posteriorly. Novilis is
reported by Isely (1914, p. 4) for the lower Neosho basin. It
likewise appears occasionally in this same drainiage for Missouri
and is also found in the Grand River of North Missouri. Like R.
tuberculata (Raf.), nobilis may be said to have no true supra-anal
opening due to its lack of mantle connection between the anal and

62 NAIADES OF MISSOURI

supra-anal region. This lack of mantle connection is a constant
character in this species, whereas this deciduity is inconstant among
other Quadrulae. The fact of its partial union of the inner laminae
of the inner gills with the visceral mass is also a departure from
the general characters of this genus and a step toward the modern
arrangement. In this latter character nobilis is somewhat like
Megalonaias heros. From the fact that females were found sterile
all through early and mid summer, it may be inferred that its
breeding season is very short and begins early in spring, or like,
heros begins late in the season. Later investigations may
relate this species more closely to Megalonaias for the physiolo-
gical reasons as well as for the morphological.

Quadrula verrucosa Rafinesque.
(Deer Horn,) Back. shorn. 3)
: PL AON EGS 5 ON Neal):

1820— Unio (Obliquaria) verrusoca Rafinesque, Ann. Gen. Phys. Brux.

1823— Unio tuberculata Barnes, Am. Jl. Sci., VI, p. 125, Pl. VII, figs.,
8a; 8b.

1899—Tritogonia tuberculata Simpson, Pr. U. S. Nat. Mus., p. 608.

1912a—Quadrula tuberculata Ortmann, Ann. Car., Mus., p. 254.

ANIMAL CHARACTERS.

.

NUTRITIVE STRUCTURES:—Branchial opening densely set
with arboreal papillae, anal crenulated, supra-anal smooth, very
large, slightly (even deciduously) connected to anal by mantle
edges; gills very long, comparatively narrow, inner broader,
inner lamina of inner gills connected to visceral mass except for
a short distance anteriorly; palpi very long, connected antero-
dorsad for a little more than half their length; color of soft parts,
mostly solid white, gills brown.

SHELL CHARACTERS.

EXTERNAL STRUCTURES:—Shell rather large, elongate, roughly
trapezoid; male shell shorter, more pointed posteriorly and
angled dorsad; female shell much longer, biangulated post-ventrad;
disk profusely tuberculated, the coarser tubercles located ventrad;
post-umbonal ridge prominent and nodulated; slopes of post-
dorsal ridge faintly costated, beaks rather small, apiculated,
sculptured with double-looped, zigzag markings that extend out
. on the disk; epidermis chestnut brown to dark horn color.

NAIADES OF MISSOURI 63

INTERNAL STRUCTURES:—Cardinals heavy, ragged, double in
left usually single in right; laterals long, rather straight and
heavy; beak cavities deep; nacre marble white, occasionly pink,
irridescent posteriorly

Sex Length Width Diameter Locality
OPP 1OOy AX SS) Xie 4S (Grand R., Darlington)
Ses Ox 7 Si xe 4 (Platte R., Agency Ford)
Ce etTOn. Xene5O ux sO (Osage R., Warsaw)
Byles Neon be ut (White R., Hollister)

No juveniles obtained. The last measurement is that of the
youngest verrucosa obtanied. Its beak sculpture and disk are
entirely sculptured with nodules and tubercules. The slope of
the post-dorsal ridge are sculptured with three or four coarse,
costated undulations and with numerous fine costae arranged
dorsad; shell very greatly compressed; nacre bluish.

MISCELLANEOUS REMARKS:—4Q. verrucosa is the most peculiar
species of its genus on account of the sexual dimorphism of tts shell.
For this reason especially, Simpson created a special genus (Trito-
gonia) for it. Some students are inclined to think that Tritogonia
deserves sub-generic rank at any rate, because of its morphological
departure form the typical Quadrula shell. Its soft parts, however,
are so identical with those of the typical Quadrula that there is no
reason for its groupings with any other genus. Even though the
form of the shell may be differnt, yet its conchological parts corre-
late with those of other Quadrulae. Although Rafinesque’s figure
of this species is abomnable, yet an unbiased study of it, together
with that of his good description, would give preference for the
adoption of his verrucosa over that of Barnes’ tuberculata. Like
Q. quadrula, its breeding season is about as eccentric, in that the
mature glochidia are not retained in the marsupia for_any length
of time; hence this accounts for the great difficulty of securing its
larvae for study. Surber was fortunate in securing specimens
with ripe glochidia June roth. The writer would judge from this
record and that of his own (i. e., sterility for the Fall and Winter
months) that this species is tachytictic. Vercucosa has the widest
distribution for this State: however, it varies somewhat in size,
inflation, disk sculpture, nacre-color for the different sections of
the State; e. g., the pink-nacred ones are exclusively confined to
the Southern Missouri streams.

64 NAIADES OF MISSOURI

Quadrula metanevra (Rafinesque).
(‘Maple Leaf,” ‘“‘Monkey-face” “‘Stranger.’’)
Plo XIX, Pgs. (535A and ie

1820—Obliquaria (Quadrula) metanevra Rafinesque, Ann. Gen. Sei.
yeh \WA les Oke, LAL Ory ies in Beal s6(6)-

1834— Unto metanevrus Say, Am. Conch., VI.

1900b—Quadrula metanevra (Raf.) Simpson, Proc. U. S. Nat. Mus.,
SOX 7 740

ANIMAL CHARACTERS.

NUTRITIVE STRUCTURES:—Branchial opening large with short
feathered papillae; anal smooth to finely dentate; supra-anal very
long, open, closely connected by mantle edges to anal; gills
short and wide the anterior connection of outer to mantle far
removed from base of palpi, inner laminae of inner gills free from
visceral mass; palpi long, pointed, connected for one-third of their
length; color of soft parts mostly a dingy white, the only different
color being a straw-yellow of the mantle margin at branchial
opening.

REPRODUCTIVE STRUCTURES:—~All four gills marsupial, septa
and water tubes (ovisacs) well developed, when gravid, marsupia
moderately swollen, ventral margins sharpened; conglutinates
white, broken, compressed, leak-like; glochidia average 0.180 x
o.1g90mm., semi-elliptical, ventral margin rounded, spineless,
medium size, hinge line undulate. ‘

SHELL CHARACTERS.

EXTERNAL STRUCTURES:—Shell roughly pentagonal, alated,
deeply furrowed between dorsal and post-umbonal ridges to
emarginated post-dorsal portion; shallow radial furrow just
in front of coarsely tuberculated and prominent post-umbonal
ridge; disk with smaller, tear-like tubercles scattered all over;
beaks rather apiculated, sculptured by coarse corrugations extend-
ing out on disk; epidermis brownish yellow, pointed by irregular,
downward pointing, green, chevron-like splotches.

INTERNAL STRUCTURES:—Cardinals doubled in both valves;
laterals also doubled, right faintly so; beak cavities deep, com-
pressed; nacre pure white to pale pink.

NAIADES OF MISSOURI 05

Sex Length Height Diameter Locality
CROs ex OOM xe /aO itn (Miss. R., Hannibal )
rapiad MRSS WS RA sus ae oe oyna (Meramec R., Fern Glen )
CLS Ae Exe Ole Kes 5 ria (Osage R., Proctor)
OE SS MEX ee Ouip xen SOM. (ls ” Greenwell Ford)
DAs be Bie Srey eG poovoe! Ga?’ ” Osceola)

Juvenile shell with three nodulous expansions on post-umbonal
ridge, deep furrows between nodules; ligament bright pea green;
epidermis straw-color; slopes of dorsal ridge slightly ribbed;
beaks high upon dorsal line; posterior peculiarly roundly lipped
for the branchial opening.

MISCELLANEOUS REMARKS :—The shell characters of metanevra,
typical of the whole genus, are highly emphasized. The enormous
supra-anal opening and yellow mantle border at the siphonal
opening are characteristic of its soft-parts. This species is well
represented in Central Missouri and in the Des Moines and Miss-
issippi, but is seldom found in North or South Missouri. The
writer has only found it in the Grand River of North Missouri
and while he himself has not found it in South Missouri, yet Mr.
Walker has it in his collection from Black River, Popular Bluff,
Missouri. Simpson (1900b p. 774) reports it for general distri-
bution throughout the Mississippi drainage area except its southern
portion, extending to the Tennessee and Arkansas rivers. Its
favorite habitat is sandy or gravelly shoals and, as its shell responds
to its surroundings, the general form of shell may vary so much
as to make it appear as a different species, or sub-species. Its
breeding season is found to be tachytictic.

Quadrula metanevra wardii (Lea).
(‘““Monkeyface.’’)
Not Figured.

1861— Umo wardu Lea. Pr. Ac. N. Sci. Phila., V, p. 372; Jl. A. C. N.
Cee las Wap ets 7) ele kOe NVi. en 2577)

ANIMAL CHARACTERS:—Identical. with those of its parent
species.
SHELL CHARACTERS.

EXTERNAL CHARACTERS:—Shell more elongated than its
species, comparatively smooth, heavier, more solid, post-umbonal
ridge with an expansion just before reaching basal line; otherwise

66 NAIADES OF MISSOURI

its external and internal shell structures are identical with those of
QO. metanevra.
Sex Length Height Diameter Locality

: OU NS6i ox 4 70) Ox 54am (Des Moines R., Dumas)

MISCELLANEOUS REMARKS:—vhells from the type lot, sent to
the National Museum and now under the label of variety wardi
of Lea, and numbered 134,639, are now in the writer’s collection
through the kindness of the collector, B. F. Bush. However, it is
the opinion of the writer that this form may not deserve a name
since metanevra is subject to so many intergrades due to local con-
ditions. ‘The above comparative description shows its departure
not far from type, besides the form is inconstant.

Quadrula cylindrica (Say).
(Razor Handle,” Cob Shell,” “Rabbit's Foot,”
wspectacley.Case. ®)
PLXTX, ¢ Figs). 5eAcand 5.

1816— Unio cylindricus Say. Nich. Ency., II, Pl. IV, fig. 3.

1819—Unio naviformis Lamarck, An. Sans., Vert. VI, p. 75.

1900b—Quadrula cylindrica (Say) Simpson, Proc. U. S. Nat. Mus.,
OSI pie 77/3).

ANIMAL CHARACTERS.

NUTRITIVE STRUCTURES:—Branchial opening moderately
large with brownish yellow tentacles; anal finely papillose; supra-
anal briefly connected to anal by mantle edge; gills very long and
narrow, outer more narrow anteriorly, inner laminae free from
visceral mass; palpi long, narrow connected one-third of their
length antero-dorsad; color of soft parts peculiar, foot with orange
back-ground striped in black, visceral mass uniorange, mantles
with black pigment especially along the margins at siphonal
openings.

REPRODUCTIVE STRUCTURES:—Only sterile marsupia found,
these with normal structures of Quadrula. Glochidia unknown.

SHELL CHARACTERS.

EXTERNAL STRUCTURES:—Shell rectangular-elongate, length
three times the height, dorsal posterior ridge, long, high, slightly
costated; wide behind, abruptly rounded before; post-umbonal
ridge high, hummocky and pustulate; umbones low, somewhat
sharp pointed, incurved, sculptured by corrugated ridges breaking
into tubercles out on disk; epidermis dark straw painted (as

NAIADES OF MISSOURI 67

in metanevra) with green toothed splotches pointed ventrad.
INTERNAL STRUCTURES:—Cardinals double in both valves,
serrated and irregular; laterals slightly double and very long;
interdentum unusually long; nacre white subject to stain.
Sex Length Height Diameter Um. ra. Locality.
Gros) | Xs “AO xa 2 0.190 (White R., Hollister—)
OP 1OSe x AO) xy ESO 0.190 (Center Cr., Webb City)
OP he xen r 3 Or Xs) 2S 0.200 (St. Francis, Greenville)
CO. Sees) x 260 0.210 (Black R., Williamsville)
MISCELLANEOUS REMARKS;—It is regretted that the descrip-
tion of this interesting species still remains incomplete, from the
fact that no juveniles, nor mature individuals bearing ripe glochidia,
are found yet. Cylindrica is distinctly a southern species and is
not found in North or even Central Missouri and is never found in
the Mississippi north of the mouth of the Missouri. It is a rather
common shell for the White and St. Francis Rivers and from
deposits of shells in Indian graves it has been found to be abundant
in the streams of Southwest Missouri where it is now extinct.
Perhaps the identity of cylindrica is one of the most evident
because of its unique shell and yet it may well be described as an
extremely elongated QO. metanevra. ‘The breeding record kept by
the writer is early embryos August 14 and sterile maruspia August
29; Wilson and Clark (1911, p. 42) record its gravidity for June
17 and July 27 but do not indicate the embryonic stages.

Genus Rotundaria Rafinesque.
(Type Obliquaria [Rotundaria] tuberculata Rafinesque.)

1820—Rotundaria Rafinesque, Monograph of Bivalve Shells of River

Ohio, Ann. Gen. Sci. Phys. Brux.
1900b—Rotundaria (Raf.) Simpson, Proc. U. S. Nat. Mus., XXII,

p. 794 (as subgenus)

ANIMAL CHARACTERS :—Siphonal openings peculiar in possess-
ing no true supra-anal openings; gills short wide, inner much
wider centrally, inner laminae free from visceral mass; palpi
connected about two-thirds of their length antero-dorsad, acuini-
nate postero-ventrad; only outer gills marsupial water tubes
more crowded than in non-marsuplal gills when gravid marsupia
not much distended length-wise through center, ventral edge
pointed; conglutinates white, broken, rather narrowly leaf-like,
or lanceloate; glochidia semi-elliptical, spineless, large, hinge
line short and undulate.

is
SF |

68 NAIADES OF MISSOURI

SHELL CHARACTERS:—Shell rotund, disk sculptured for two-
thirds of posterior part with irregularly placed tubercles, slopes of
post-dorsal ridge regularly costated, some costae somewhat parallel
to umbonal ridge behind; beaks well placed anteriorly, sculptured
profusely with concentrically zigzag lines across two obliquely
posterior ridges being coarser in the valley between; nacre purple;
cardinals heavy, double in left, more inclined to be single in right;
beak cavities deep antero-postero, narrow diametrically, wide
vertically.

MISCELLANEOUS REMARKS:—This genus is unique for its
absence of supra-anal opening, for its limitation of marsupia to
the outer gills and for its peculiar shell structure in the presence
of a well developed sulcus at the post-dorsal part and in its remar-
able beak sculpture. The two species of this Genus are most typically
represented in the Mississippi of this State, but are found to be
more intermediate in form for Central and South Missouri. In
the Gasconade and Osage basins these forms grade into those
that may be referred to Plethobasus cooperianus as far as shell
structure is concerned.

Rotundaria tuberculata (Rafinesque).
(Purple Warty Back; “Red Nigger Head: )))

Pl. XX, Figs. 54° Aland, BS (Pleds ) fags ie
1820—Obliquaria (Rotundaria) tuberculata Rafinesque, Ann. Gen. Sc.
IBEUXs Vip Ose
1898—Quadrula verrucosa Baker, Moll, Chicago, Pt. I, p. 85, pl. XXIII.
1900b—Quadrula tuberculata Simpson, Proc. U. S. Nat. Mus., XXII.

D795:
1912b—Rotundaria tuberculata (Raf.) Ortmann, An. Car. Mus., VIII,
Pp. 258-259. j

ANIMAL CHARACTERS.

NUTRITIVE STRUCTURES:—Branchial opening very large with
few short simple papillae; anal as large as branchial with still
shorter papillae; rectum large, visible, anus slightly tentacled;
gills wide, short, tilted at abrupt angle, inner much wider, inner
laminae free from visceral mass; palpi connected over half of
their length antero-dorsad, pointed postero-ventrad; soft parts
dingy wihite, for most part, gills dark brown biack posteriorly,
foot dark tan.

REPRODUCTIVE STRUCTURES:—Only outer gills marsupial,

NAIADES OF MISSOURI 69

septa closely crowded, when charged distended very little even in

median-longitudinal line, ventral edge not blunt, ovisacs rather

narrow; conglutinates white, narrowly lanceolate, not solid;
glochidia large, spineless, ventral margin rounded, hinge line short,
straight, or nearly so, measures 0.207 x 0.325mm., collected by author,
Aug. 11, 1913, Osage River, Bagnell, Missouri.

SHELL CHARACTERS.

EXTERNAL STRUCTURES:—Shell oval quadrate, medium in
size, compressed, heavy, thick, rounded in front, usually emargi-
nated post-dorsad with radial furrow from this sulcation to beaks,
dorsal ridge rather high with upcurved costae; post-umbonal
ridge rather rounded; posterior half of shell profusely sculptured
with coarse pustules and fine tubercles; umbones low, pitched
considerable anteriorly, sculptured with numerous, heavy, wavy
or corrugated ridges which extend down on upper part of disk;
epidermis brownish red to black.

‘INTERNAL STRUCTURES:—-Cardinals double in left, rather
tripartite in right valve; laterals double in both valves, lower
right lateral rudimentary, scars deep; beak cavities very deep
antero-postero, narrow diametrically, wide vertically, nacre
rich purple, with part within the mantle line a lighter shade,
sometimes whole nacreous surface faded to whitish with pinkish
teeth.

Sex Length Height Diameter U. ra. Locality.

9 80 x 60 x 37mm 0.120 (Meramec R., Fern Glen)
CH MOAMNEK nn 540 \eXcn 2e7E 7 0.135 (Gasconade R., Gascondy)
OR WOS LX PLO2y 1x es ay 2 0.128 (Osage R., Schell City)

The last measurement is that of the smallest juvenile out of
a collection of 156 collected in a space twenty-feet square in the
White River. This place was a quiet retreat of shallow water with
a thin coating of mud over a substratum of limestone. ;

MISCELLANEOUS REMARKS:—The peculiar shell characters
of this species in being suborbicular, heavy, with low corrugated
beaks and the unique anatomical characters in possessing no
supra-anal opening and only outer gills as marsupial are features
especially to be noted. Its distribution in this state is peculiar
in that it is not found at all in the interior northern drainage of
the Mississippi River, and is confined in its typical form more in
the drainage of the south slope of the Ozarks and in the Missouri
portion of the Mississippi while it occurs by intergrades in the

70 NAIADES OF MISSOURI

southern. drainage of the Missouri River. Simpson reports it for
the Mississippi drainage generally. A three hundred mile survey
of the Osage River, beginning at the headwaters, reveals the shell
of this species in all its external form and nacre-color extending to
granifera and even including Pleth. cooperianus. Variation in nacre-
color for this species is remarkable; however, this deviation from the
unipurple nacre of the type may be due to local reaction since it is
most noticed in the Osage below the region of medicinal springs.
Its favorable habitat is that of rocky shoals, but is occasionally
found in deep, quiet water with mud bottom where it acquires a
smoother, heavier and less inflated shell. TShe writer has had the
good fortune to secure, for the first time, several individuals gravid
with mature glochidia. ‘The larva is found to be somewhat smaller
than that of Rk. granifera and with hinge line shorter and straighter;
as to form, and even as to size, it is hardly distinguishable from
granifera when allowance is made for variation in a large series.
This glochidium is figured and described here for the first time (See
Plate I, Fig. 4). It is observed by the writer to be gravid from June
until the middle of August, bearing ripe glochidia mostly about
the middle of July. It is decidedly a short period breeder.

Rotundaria granifera (Lea).
(“Purple Warty Back,” ‘‘Purple Pit.’’)
Pr XIX ies? 55 MAN and 2B.
1838— Unto graniferus Lea, Tr. Am. Phil. Soc., Vi, p. 69, Pl. XIX, fig. 60.
1900b—Quadrula granifera (Lea) Simpson, Proc. U. S. Nat. Mus.,
ROS pe 7O5e

ANIMAL CHARACTERS.

NUTRITIVE STRUCTURES :—Identical with those of Kk. tuber-
culaia in all respects.

REPRODUCTIVE STRUCTURES:—Typical specimens from the
Mississippi show the outer gills marsupial; conglutinates same
color and form as those of R. tuberculata; glochidium measures
0.290 x 0.350mm., being a little larger with more of an undulated
hinge line, but with the same general form.

SHELL CHARACTERS

EXTERNAL STRUCTURES:—Like R. tuberculata except smaller
rotund, upright, alated, inflated,—especially fuller, higher, more
antero-protruding beaks and with more of a rayed character of
epidermis on anterior umbonal slope. Interior of shell identical

NAIADES OF MISSOURI ihe fi

except perhaps shorter laterals arranged at right angles to the
interdentum.

Sex Length Height Diameter Locality
eS eee On enim) UCVSSh Re WwalGrange)
Q 56 x 56 x 34 ” ( ” ” ” )
rot 46 x 46 x 30 ” ( ”) ” ” )
OP 22) eX WOT prekraeTONS 6 (White ”’ Hollister)

The latter measurement is of a juveniles from a lot identified
by Mr. Frierson as approaching granzfera although would perhaps
fall more under tuberculata. However, it meets the test of granifera -
in length and height being about equal and in prominent beaks.
Its beak sculpture consists of numerous, fine concentric corrugations
extending out on disk somewhat like Q. quadrula. In general
shape of shell and dispositition of tubercules it is also like the
latter in this adolescent stage.

MISCELLANEOUS REMARKS:—According to shell measurement,
and with an allowance for eroded beaks, the Osage forms may be
more classed under granifera. A divergence of equality for length
and altitude may indicate and approach to the tuberculata, Lea’s
type, when diameter may be reduced to unity, it measures length
and height the same. On this same basis so many of the Rotun-
dariae of South Missouri would approach more nearly to the
granifera type. Because of its full, projecting beaks, uprightness
of shell and disk sculpture this species has sometimes been
confused with Q. pustulosa and P. coopertanus. However, dis-
tinction can be easily made by comparing to the rich purple nacre
of granifera—a color that is not possessed by either pustulosa or
cooperianus. Its breeding season is found to be the same as that
of tuberculata. Despite their identity of breeding habits, of repro-
ductive and nutritive structures and of internal shell characters
there may be sufficient evidence of difference in external shell
structures to make granifera a good species and thus take it out
of its class as a subspecies of tuberculata, as Simpson had treated
it, and elevate it as Mr. Walker considers.

Genus Plethobasus Simpson.

1900b—Plethobasus Simspon, Proc. U. S. Nat. Mus., XXII, p. 764
(As section).

1912b—Plethobasus (Simpson) Ortmann, An. Car. Mus., VIII, pp.
259-260.

(Type, Unto aesopus Greene).
ANIMAL CHARACTERS:—Anal separated from supra-anal

},

72 NAIADES OF MISSOURI

opening by short mantle connection; gills long, wide anteriorly,
inner laminae of inner gills free from visceral mass; palpi short
and wide; only outer gills marsupial, when gravid the ovisacs
distend but little, giving the conglutinates a lanceolate shape;
conglutinates white, discharged whole; glochidium small, spineless,
subovate or slightly oblique; soft parts orange or sulphur color.

SHELL CHARACTERS:—Shell elongated: to ovate; beaks
moderately high, sculptured by obscurely concentric ridges,
not extending out on disk; epidermis brown to yellow, usually
rayless; beak cavities moderately deep; hinge well formed;
nacre white to pinkish.

As to shell characters this genus resembles both those of
Quadrula—particularly those of the pustulosa group—and also
the genus Rotundaria. Its marsupial characters show an advance
over the genus immediately preceeding. The bright coloration
of its nutritive soft parts and of its ova would suggest some affinity
with the Fusconaia. Dr. Ortmann points out this genus as a con-
necting link between the more primitive Unioninae and those of
the type of the genus Pleurobema and thus elevated Simpson’s
section, Plethobasus, to generic rank, since Simpson recognized
special characters of the type, aesopus, in shallow beak cavities
and outer gills only as marupial. This genus is represented in this
state by aesopus, but doubtfully by cooperianus.

Plethobasus cooperianus (Lea).

(‘Cumberland Pig-toe,’’ ‘‘Warty Pig-toe.’’)
Pl, XX Fags. 57 A and. Be ‘
1834— Unio cooperianus Lea, Tr. Am. Phil. Soc., V., p. 61, pl. VIII,
fig. 21.
ANIMAL CHARACTERS.

NUTRITIVE STRUCTURES:—Branchial opening densely papil-
lose; anal and supra-anal separated by short (even deciduous)
connection; gills rather short, inner gills wider, its laminae free
from visceral mass; color of soft parts bright orange yellow, for
most part.

REPRODUCTIVE STRUCTURES:—Marsupia only occupy outer
gills; when gravid swell moderately in center leaving ventral
edges sharpened; no glochidia found yet; its ova bright yellow,
giving the marsupia a sulphur color.

ae ee
ak

NAIADES OF MISSOURI rié

SHELL CHARACTERS.

EXTERNAL STRUCTURES:—Shell orbicular, to egg-shape in
general outline, disk tuberculated and transversely nodulous
between beaks and ventral margin in front of post-umbonal ridge;
latter flattened, dorsal ridge low, faintly costated; beaks low,
well placed anteriorly; epidermis light-brown to yellowish, some-
what glossy.

INTERNAL STRUCTURES:—Cardinals tripartite in left valve,
rather single in right; interdentum broad, rather doubly gashed
in right valve; laterals double in left and single in right valve;
mantle line high up from ventral margin; nacre whitish, pinkish
(or even bluish) within the mantle line, usually lighter color on
extra-mantle line border.

Sex Length Height Diameter Locality

CH MOOMeS Wars 151X132 (Gasconade R., Gascondy)

Oh aiat Noa pia > gyre. (Osage R., Monegaw Springs)
Cn 7 Oe a OA EX AO Gans ” Warsaw)

MISCELLANEOUS REMARKS :—As this state is out of geographic
range of typical cooperianus it is natural that no real type may be
found in Missouri. However, the writer upon finding a few shells
of the tuberculata (Raf.) type with white and pink nacre submitted
one of the latter to Mr. Walker for his consideration. His com-
ments are:—‘‘A very curious and interesting shell. It has the
shape of Quadrula tuberculata (Raf.) but the nacre of cooperiana
(Lea) and I should call it that, although out of range. I never
heard of tuberculata except with purple nacre.’”’ A white nacred shell
of the same form is considered by Prof. Clark as “‘rather plump,
approaching granifera’’ but that the nacre “suggests cooperiana.”’
Other Missouri collectors have commented upon this strange
departure of R. tuberculata and granifera from type. However,
if it may be proved that this difference of nacre-color is merely
a “fading out’’ due to chemical reaction of mineral water there
would be instead of a true cooperianus in this state a mere local
form of a Rotundaria. The real home of this species is in the
Tennessee—Cumberland system where Wilson and Clark (1914,
pp- 44 and 60) have found it as a summer breeder (a tachytictic
species).

74 NAIADES OF MISSOURI

Plethobasus aesopus (Green).!

(“Bull Head,” ‘“‘Sheep’s Nose,’’ ‘Clear Profit.’’)
PUSUXX, Bagge 50. A Sand ia.
1827— Unio aesopus Green, Cont. Mac. Lyceum, I, p. 46, fig. 3.
1834— Unio cyphia Conrad, New F. W. Shells, p. 68.
1900b—Pleurobema aesopus Simpson, Proc. U. S. Nat. Mus., p. 764.

1912b—Plethobasus aesopus (Green) Ortmann, An. Car. Mus., VIII,
pp. 260-261.

ANIMAL CHARACTERS.

NUTRITIVE STRUCTURES:—Branchial opening densely set
with long and short papillae; anal smooth; supra-anal connected
to anal by short mantle attachment; gills long and sharply pointed
posteriorly, inner gills wider in front, inner laminae free from
visceral mass; palpi short, wide; color of soft parts, peculiar,
mostly orange, the foot, adductors and mantle margins being a
brighter orange.

REPRODUCTIVE STRUCTURES:—Only outer gills marsupial;
ovisacs, when gravid, swell moderately in the center leaving their
unswollen distal ends pointed, thus giving their conglutinates
narrow, lanceolate shape which are solid, red and discharged in
unbroken form; glochidia semicircular, ventral margin obliquely
rounded, hinge line long, medium in size, length slightly greater
than height (0.220 x 0.200mm).

SHELL CHARACTERS.

EXTERNAL STRUCTURES:—Shell triangular, rounder before,
pointed behind, rather heavy; post-umbonal ridge rounded;
umbones high and full, tilted anteriorly, incurved, sculptured
by a deep furrow just posterior to tip of each beak and by a few
coarse concentric ridges and fine radiating lines; disk sculptured
by a row of six or eight, coarse, elongated, undulated or hummocky
tubercles extending from beaks to ventral margin with a broad,
shallow trough between this tubercled row and the post-ridge;
epidermis dark straw to glistening yellowish brown.

INTERNAL STRUCTURES:—Cardinals double in left, single in
right; interdentum narrow; laterals double in left only faintly

' According to Rafinesque’s evident description of Green’s aesopus
in his Monograph of 1820 (p. 39) under the name of Obliquaria cyphya
(U. cyphia) this species should really bear the name now of Plethobasus
cyphius (Raf.) because of priority.

NAIADES OF MISSOURI 75

double in right; umbonal cavity moderately deep; nacre pearly
white, irridescent.

Sex Length Height Diameter Um. ra. Locality

OM 87 ego x Nay 6 —= )).0:070) (Missi, R.,| Hannibal)
Soar x ozs wees4 4 o.230) ((Des, Moines “R), Dumas)
9 55 x 40 x 32 — oo0.180 (Little Blue, Courtney)
ao 33 x 22 x 20 — 0.210 (Des Moines R., Dumas)

This last measurement of a young shell shows great inflation
comparatively. (See Figs. 56 C and D.)

MISCELLANEOUS REMARKS:—This species has a_ general
distribution over the Ohio —- Cumberland system. It is not
uncommon in the Mississippi and Des Moines Rivers, but has
only been found in one interior stream, the Little Blue, Kansas
City, where it was collected by Mr. Bush and donated to the U.S.
National Museum under No. 134,642. Some have found all
four gills of aesopus marsupial, but most observations seem to prove
that only the outer are used as marsupia. The writer has only
observed outer gills as marsupial—even in case of many indivi-
duals with sterile gills. He is able to verify Dr. Ortmann’s obser-
vation of charged marsupia with the ‘‘lilac hue.’”’ Its accidental
host has been found to be ‘‘sauger’’ (S. canadense).

Genus Pleurobema Rafinesque.

1820—Pleurobema Rafinesque, Monograph of Bivalve Shells of River
Ohio, Ann. Gen. Sci. Phys. Brux., p. 313.

1900b—FPleurobema (Raf.) Simpson, Proc. U. S. Nat. Mus., XXII,
Pp. 745 (amended).

(Type, Unio clava Lamarck.)

ANIMAL CHARACTERS:—Anal opening with short mantle
connection to supra-anal; inner gills much longer, inner laminae
free from visceral mass; palpi small very pointed; only outer
gills marsupial; ovisacs distend but little when gravid; conglutin-
ates white, narrowly leaf-like or lanceolate, not broken; glochidium
small, spineless, subovate.

SHELL CHARACTERS:—Shell subtrapezoidal, subquadrate,
rounded or elongated, upright, or, when oblique, with beaks
produced anteriorly; beaks usually rather full and high, sculptured
obscurely with concentric ridges not extending out on the disk;
disk without sculpture; epidermis olivaceous, reddish brown or
even. black, rays more or less present in umbonal region; hinge

76 NAIADES OF MISSOURI

teeth well developed; umbonal cavities moderately deep; nacre
generally whitish or red.

MISCELLANEOUS REMARKS:—The above descriptions of the
anatomy shows the genus to be identical to that of the genus
Plethobasus; but in shell characters there is much difference.
It may well be stated in general terms that Pleurobema resembles
Quadrula as to its nutritive soft parts and Fusconaza as to external
shell structures. However, the Pleurobema shell does not usually
possess such a prominent, angular, and inflated umbonal ridge as
that of the Fusconaia; neither does it possess the yellowish color
of the nutritive anatomy as in the case of Fusconaia. However,
the differences among the species of Pleurobema are well marked
ecological, as well as morphological, ones; i. e., the heavier, more
inflated forms being more as dwellers in the large rivers, and the
smaller, more compressed shells being found in the creeks and
medium sized rivers. From the two following genera Pleurobema
may be easily distinguished by not possessing such an elongate
and straight type of shell.

- The author of this catalogue wishes to gratefully acknowledge
the dedication of a new species of Pleurobema to him under the
authorship of Mr. Frierson. The description and figures of this
new species (Pleu. Utterbackit F.) appear here for the first time,
and, until more data can be secured, concerning its soft parts in
gravid condition, it is placed here tentatively at the close of the
list of Pleruobemae.

Pleurobema obliquum (Lamarck).

(‘‘ Pig-toe,”’ ‘‘White Pig-toe,’’ ‘““Ohio River Pig-toe.’’)
Not figured.
1819— Unio obliqua Lamarck, An. Sans. Vert., VI, p. 72.
1900b—Quadrula obliqua Simpson, Proc. U. S. Nat. Mus., XXII, p. 788.
1912b—Pleurobema obliquum, (Lamarck) Ortmann, An. Car. Mus.,
WAUDL jo), eleva
ANIMAL CHARACTERS:—The soft part of typical obliquum
not having been seen by the author, reference is made to the des-
criptions of the varieties of this species—the anatomy of which
is, of course, identical. Wilson and Clark (1914, p. 61) report this
species as occasionally bearing ova in all four gills and that the
conglutinates have the’appearance of cucumber seeds.
SHELL CHARACTERS:—Shell trigonal, medium in size, emargi-

NAIADES OF MISSOURI bg TATA

nated post-ventrad with radial furrow in front of flattened post-
umbonal ridge; beaks swollen, protruding anteriorly, sculptured
by concentric ridges; epidermis reddish brown to black with rays
originating in umbonal region; cardinals heavy, double in left
single in right valve; laterals double in left, more or less double
in right valve; nacre white.

MISCELLANEOUS REMARKS:—The writer has been unable to
find Pleu. obliquum in typical form anywhere in the state and
claim is only made for it through its various forms and through
Simpson’s report, that it is found in the Mississippi above the
mouth of the Missouri River. Surely there is much need of re-
search chiefly with regard to the geographic facts relating to the
distribution of this species. Most students of geographic distribu-
tion concur in the belief that no true obliquum is found west of the
Mississippi and that it is rarely seen north of the Ohio. Its metrop-
olis is that richest of all centers of mussel faunae, the Cumberland
River, where Wilson and Clark report it as the most abundant of
all the numerous species found there. Briefly stated, obliquum
occurs in this state, but with tts characteristic radial furrow obliterated
and its intergrading forms are very numerous running into each
other in every puzzling way.

Pleurobema obliquum plenum (Lea).
Not figured.
1840— Unio plenus Lea, Tr. Am. Phil. Soc., I, p. 286; Tr. Am. Phil.
Storch WANG by mists t jo Gocco) le CVn ate Xe
1900b—Quadrula plena Simpson, Proc. U. S. Nat. Mus., p. 790.

The writer has not found this species in this state and no
description appears here, since neither soft parts nor shells have
been seen. However, plenum is listed as a variety for Missouri
through the kind report of Mr. Walker that he has it from the
James River, near Springfield, and that it bears the same relation
to obliquum as does also a variety of coccineum found in the same
locality. i

Pleurobema obliquum pyramidatum (Lea).
(“ Pig-toe,”’ ““Pyramid Pig-toe.’’)
PY XX, Figs..58 A and B.
1834— Unto pryramidatus Lea, Tr. Am. Phil. Soc., IV, p. 109, pl. XVI,

fig. 39.
1900b—Quadrula pyramidata Simpson, Proc. U. S. Nat. Mus., XXII,

Pp. 790.

78 NAIADES OF MISSOURI

1912b—Pleurobema pyramidatum (Lea) Ortmann, An. Car. Mus.,
Vig ii: a2iogs

ANIMAL CHARACTERS.

NUTRITIVE STRUCTURES.:—Branchial opening densely papil-
lose; anal finely papillose; anal and supra-anal very closely
connected by mantle edges—sometimes connection deciduous ;—
inner gills broader, longer, inner laminae free from visceral mass;
palpi long and thickened; most of soft parts dirty white, mantle
edges at branchial openings black.

REPRODUCTIVE STRUCTURES:—Only outer gills marsupial;
sterile marsupia with crowded septa, those of male gills very
distinct and more separated; no gravid specimens found.

SHELL CHARACTERS.

EXTERNAL STRUCTURES :—vhell obliquely pyramidal or trap-
ezoidal, very solid and heavy anteriorly; disk smooth; beaks
very full and projecting anteriorly; rather straight dorsad, greatly
curved ventrad, epidermis black.

INTERNAL STRUCTURES :—Cardinals single in right, double in
left valve; laterals double in left, single in right; scars deeply
impressed; beak cavities moderately deep; nacre white, tinged with
blue posteriorly—sometimes pinkish.

Sex Length Height Diameter Locality

of) OG Be LS eine iloyaewat (Osage R., Sagrada)

TOMO Gp eiak= py AGAIAGY pee pita} 7 (Greve ” Warsaw)

OP OB RSs 4 SAN ee EO ae (Meramec R., Fern Glen)
Oo) 27.5 x 26.5) x 1o.Smmmd (Osage Rs Baker)

Juvenile shell thick, almost globular, very smooth; beaks
full but not protruding anteriorly, sculptured with two or three
ridges arranged rather concentrically and breaking into three
coarse tubercles at base of post-umbonal ridge; epidermis reddish
and leather-like with rays on the anterior half of shell; lateral
teeth more inclined to double in right valve than in mature shell;
beak cavities very shallow; nacre solid pink.

MISCELLANEOUS REMARKS:—This pyramidatum is the same
as found in Arkansas and Oklahoma where it is also found unasso-
ciated with typical obliquum. ‘The species, Pleu. pyramidatum
(Lea) and obliquum (Lam.) are most typically represented in the
Tennessee—Cumberland system and the fact of their forms turning
up in the South West (i. e., in the region south of the Missouri and

y
sal

4
P

NAIADES OF MISSOURI 79

west of the Mississippi Rivers) is a question worthy of investi-
gation. This heavy, oblique shell is very easy to identify and
cannot be very well confused with other Pleurobemae. It has been
defined as ‘“‘an overgrown Pleu. clava.”’

Pleurobema obliquum catillus (Conrad).

(“Round Pig-toe,’’ “Pink Pig-toe,” ‘‘Osage Nigger-Head.’’)
PVAAX,) igs. 62° A and B.

1836— Unto catillus Conrad, Monog. III, p. 30, pl. XIII, fig. 2.
ra38—Untzo solidus Wea, Ir. Am. Phil. Soc., VI, Pl. V, fig. (13.

ANIMAL CHARACTERS.

“NUTRITIVE STRUCTURES:—Brachial opening rather large,
with many papillae; anal smooth, separated from supra-anal by
very short mantle connection; gills short and wide, inner the wider,
its inher laminae free from visceral mass; palpi short, wide pointed;
color of soft parts mostly dingy white.

REPRODUCTIVE STRUCTURES:—Outer gills only maruspial,

when gravid brownish, slightly swollen longi-centrad leaving

ventral edges tapering somewhat obtusely; conglutinates white,
formed like seeds of an immature cucumber; glochidium inter-
mediate for catillus and obliquum as to general form, but larger
than either, averaging 0.170 x o.180mm.

SHELL CHARACTERS.

EXTERNAL STRUCTURES:—Shell trapezoidal to subovate,
subglobose, thick ,heavy, medium in size, rounded before, obtusely
rounded behind; disk smooth no radial furrow; beaks high, full,
sculptured by obscure concentric lines; epidermis of red-leather
color, rayed anteriorly.

INTERNAL STRUCTURES:—Cardinals single in right, roughly
double in left; laterals single in right, double in left valve; scars
deeply impressed; beak cavities rather deep; nacre solid pink,
rarely white.

Sex Length Height Diameter Locality

Oo 57-5 X 41 xX 33.0mm (Marais des Cygnes R., Rich Hill)
Sta ier Ss AZ) XU. FAS” Cray ‘i is ‘ ‘5 yy)
CHa ASM Xn AA SOLON (Osage R., Bagnell)

ORNL Ma XG UMD Ole aX NOT oye Cue"? ” Baker)

This last measurement shows this juvenile to be sub-globular.

Its shell is unusually thick with very shallow beak and branchial

80 NAIADES OF MISSOURI

cavities; hinge teeth usually flattened, very wide and heavy;
nacre bright pink; epidermis leathery-red with rays on anterior
part of shell ...

MISCELLANEOUS REMARKS:—This form of catillus is the most
common of the Pleurobemae in the Osage—Gasconade system and
is not found any where else in the state. This “‘solida”’ variety
is characteristic for its small, solid, subglobular shell, with a
more rounded posterior end and less compression for the posterior
half than in typical caiillus. The radial furrow of the type species
(obliqguum) is entirely lost. The only difference between this form
in the two basins (that of the Osage and Gasconade) is in that of
nacre-color—the Osage never varying from pink and the Gasconade
shell always with white-nacre. The almost endless inter-grada-
tions for obliguum and catillus seem to be the general rule rather
than exception, but here in Central Missouri the variety herein
described is predominant. Another form occasionally met with in
the Osage and grading in between this subspecies and catillus is
one that comes near to fulgidus of Lea, but it would not be listed
on account of its rare occurence and doubt whether it should be
really separated from this variety, obliguum catillus. Hundreds
of individuals of this form were examined daily throughout the
entire month of July, when it was in the height of its breeding season,
to find it only gravid (without exception) in its outer gills. It is
found to be tachytictic. Perhaps the best idea can be otbained,
concerning the difference of the Central Missouri catillus from
that of South Missouri, by comparing two average measurements
of mature shells given in the following:

Sex Length Height Diameter Locality
CUS en Ode Exel PANT (White R., Hollister)—S. Mo.
ope Gb sen Ub ben exe} (Osage R., Warsaw)—Cen. Mo.

In both the radial furrow of typical catillus is effaced. The
measurement of the latter removes it so far from the type species
that probably a good species might be made out of it.

Pleurobema obliquum coccineum (Conrad).

(‘‘Pink Pig-toe,”’ ‘““Round Pig-toe,” “Flat Nigger Head.’’)
PL XX EGS Ot CAS Bese sang 1):
1836— Unio coccineus Conrad, Monog. III, p. 29, Pl. XIII, fig. I.

1839—FPleurobema obliquum coccineum (Conrad) Ortmann, Pr. Am.
Ama wehils soc, Wil pp. 2so7—5s00:

¥

NAIADES OF MISSOURI 81

ANIMAL CHARACTERS.

NUTRITIVE CHARACTERS:—Branchial opening with two ranks
of papillae; anal crowded with fine, short papillae; supra-anal
moderately separated from anal; inner gills slightly wider than
outer, inner laminae free from visceral mass; palpi thick and long;
connected antero-dorsad over half of length; color of soft parts
dingy white, for most part.

REPRODUCTIVE STRUCTURES:—Only outer gills marsupial;
when gravid marsupia cream colored, somewhat padiform; conglu-
tinates white, leaf-like, solid; glochidium medium, subovate
spineless, measures 0.150 X 0.155mm.

SHELL CHARACTERS.

EXTERNAL STRUCTURES:—Shell roundly elliptical, thick and
solid anteriorly, moderately thin and compressed for posterior
half; post umbonal ridge flattened; beaks not prominent, nor
protruding anteriorly, sculptured by concentric corrugations;
epidermis reddish brown, rayed anteriorly.

INTERNAL STRUCTURES:—Cardinals double in both valves:
laterals single in right, double in left valve; interdentum wide and
thin; beak cavities shallow; nacre rose pink.

Sex Length Height Diameter Locality
Cal C74 ke 02), Ska 8) (Osage R., Warsaw)
PIA ERS AN Ke BAO be CO a ye? 2)
of! lle) Se Beep og Be: (Cae 2?) Baker)

MISCELLANEOUS REMARKS:—No juveniles of this form are
at hand for description. The writer met with this variety in the
Osage. It can be easily distinguished from the more typical cocci-
neum of South Missouri in not possessing such compression for
the posterior half of shell, in being more elliptical and heavier.
The general outline is that of O. ellipsis. It can be separated from
Pleu. obliquum catillus by this elliptical shape, but its greater
compression (especially posteriorly) and by its thinner, less solid
shell. The writer made an interesting discovery while examining
a gravid individual of this form afield with a (X12) lens to find its
late embryos in rapid rotary motion around one axis. This phe-
nomenon had been observed by the author in Lastena ohiensts.
A breeding record of this form shows it to be a summer breeder

-=

82 NAIADES OF MISSOURI

Pleurobema catillus (Conrad).

(‘‘White Pigtoe,-’’ ‘‘Pink Pig-toe,” ‘Solid Pig-toe.’’)
PY XOX) WEVESCR OA GHG vo:
1836— Unto cattllus Conrad, Monog. III, p. 30, pl. XIII, fig. 2.
1838— Unto solidus Lea, Pr. Am. Phil. Soc., VI; pl. V, fig. 13.
1845—Unto fulgidus Lea, Pr. Am. Phil. Soc., p. 164; Tr. Am. Phil.

SOCH PSSA 8. sp. 1745 Dl Vie eva OL
1900b—Quadrula solida Simpson, Pr. U. S. Nat. Mus., XXII, p. 789.

ANIMAL CHARACTERS.

NUTRITIVE STRUCTURES:—Branchial opening densely papil-
lose; anal finely papillose; supra-anal closely connected to anal;
gills rather long and wide, the inner being wider and longer, inner
laminae free from visceral mass; palpi long and connected about
two-thirds of their length antero-dorsad, soft parts tanned flesh-
color, yellowish in front of branchial opening, papillae blackish.

REPRODUCTIVE STRUCTURES:—Marsupia only occupying outer
gills, ovisacs swollen more centro-lengthwise tapering obtusely
at ventral edges; conglutinates leaf-like, compressed white;
glochidia semicircular, medium in size, hinge line nearly straight;
length and height equal (0.160 x xo.160mm.).

SHELL CHARACTERS.

EXTERNAL STRUCTURES:—Shell subtriangular with obtusely
pointed posterior end, very solid and thick through cardinal
hinge region, ventral line always more curved than dorsal; disk
smooth, post-umbonal ridge flattened; radial furrow in front
rather shallow and wide; beaks full, protruding but not beyond
anterior end; epidermis reddish brown with decided streaks of
green radiating ventrad from umbonal region.

INTERNAL STRUCTURES:—Cardinals heavy, double in both
valves; laterals double in right, single in left valve; interdentum
broad, short and thick; umbonal cavities shallow; nacre salmon
to rosy pink. ,

Sex Length Height Diameter Locality

ly AO2t A Xn COR mOKam nN (White R., Hollister)
OPIS 3X OAM Ao (Black R., Williamsville)
Cun (SO) tex nO3 a xaNeAO (White R., Hollister)

MISCELLANEOUS REMARKS:—Conrad’s catillus (described as
separate from coccineus by the author, but united by Simpson) is

NAIADES OF MISSOURI 83

the solidus of lea and (in the conventional sense) may be called
Pleu. solidum. The latter being antedated, we must use the
former name. ‘This species is rather typically represented in the
Mississippi for Missouri, the mountain streams of South Missouri
and also in the Neosho basin of South West Missouri. No real
types are ever found in Central Missouri and not even forms are
found in North Missouri.. This species is distinguished from
Pleu. coccineum by always being rather swollen and having a
radial furrow more or less expressed. In this latter character
it never reaches the extreme, as seen in obliquum, of the pinched
radial groove terminating in sulcus at the post-ventral margin.
Its breeding record shows it to be tachytictic.

Pleurobema coccineum (Conrad).

(“Flat Nigger-Head,” ‘Pink Pig-toe,”’ “‘Round Pig-toe. ¥
Plesli lectus. 000; \ Pl XX, Fis. (60 Avand B:

1836— Unto coccineus Conrad, Monog., III, p. 29, pl. XIII, fig. I.
1900b—Quadrula coccinea Simpson, Proc. U. S. Nat. Mus., XXII,

pp. 788-789.
1912b—Pleurobema coccineum (Conrad) Ortmann, An. Car. Mus.,
Wena 263)

ANIMAL CHARACTERS.

NUTRITIVE STRUCTURES:—Branchial opening densely set
with papillae; anal with “indistinct crenulations: and papillae;
mantle connection between anal and supra-anal very close; gills
wide, the inner wider and longer, inner laminae free from visceral
mass; palpi long, united two-thirds of their length; color of soft
parts tannish, mantle edge at siphonal openings black.

REPRODUCTIVE STRUCTURES:—Only outer gills marsupial;
when gravid marsupia swell moderately lengthwise in the center;
conglutinates white, thin, leaf-shape, discharged whole; glochidia,
suboval, spineless, medium in size measure 0.150 X 0.150mm.

SHELL CHARACTERS

EXTERNAL STRUCTURES:—Shell subelliptical to subquadrate
varying with age, flat, very much compressed through post half,
greatly inflated (comparatively) anteriorly, dorsal and ventral
margins curved about the same; beaks rather full not very well
placed to the front, sculptured by concentric lines with two or

84 NAIADES OF MISSOURI

three knotty elevations behind; epidermis marked by darker
bands parallel to the growth lines, rayed in young.

INTERNAL STRUCTURES:— Cardinals sharply doubled in both
valves; interdentum cut away in the left valve to receive the
posterior left cardinal; laterals curved, double in left single in
right; umbonal cavity moderately deep; nacre salmon pink to
white.

Sex Length Height Diameter Locality

Oe GON exo. Ol xa et (White R., Hollister)

ey pfctl) NB WHE peewee (St. Francis, Greenville)
OM A 7 ME KNB CON EX Game? (White R., Hollister)

Note that the younger shell is more rounded and squarer,
has more of an olivaceous epidermis with green rays; umbonal
sculpture plainer with three bumps on base of post-ridge; nacre
more pearl bluish.

MISCELLANEOUS REMARKS:—This species (Pleu. coccineum) is
most typically represented in the South and South-west Missouri
drainage systems and, while it is not found at all in North Missouri.
it is only represented occasionally by mere forms in Central Mis-
sourl. It is usually restricted to the smaller streams or to the
headwaters of large rivers. Normally, marsupial characters are
limited to the outer gills only, although this fact has been denied
by some. The writer on one occasion, found this species with all
four gills gravid, but in all other cases the outer gills were only
found functioning as marsupia. In this species and in some other
Pleurobemae, there may be some variabilty in this respect. Coc-
cineum has a short breeding season as determined by the writer’s
breeding record.

Pleurobema missourense (Marsh).

(‘‘Missouri Shell.’’)
Not figured.

1901—Pleurobema Missouriensis Marsh, Nautilus, XV, pp. 74-75.

ANIMAL CHARACTERS.

Not having seen the soft parts of this species the writer can
offer no description. Although the author of missourense gave no
such description, yet the establishment of this species within
the genus Plewrobema must have been inferred from these char-
acters,

er, .
a

NAIADES OF MISSOURI 85

SHELL CHARACTERS.

Through the kindness of Mr. L. S. Frierson the writer was
loaned a shell of this rare species from the original lot, described
by Mr. Marsh and collected by Mr. Elwood Pleas in the Black
River, Popular Bluff, Butler County, Missouri. From the fact
that the writer had but one shell before him, he quotes a more
complete description from the author than can be given without
a series at hand:—‘‘Shell smooth, obliquely triangular, rounded
behind, subbiangular behind, moderately thick, very much
thicker anteriorly, sides somewhat flattened, beaks wide, solid,
incurved; ligament long, light brown; epidermis light brown,
without rays, growth lines numerous, not raised; umbonal slope
wide and rather flat; posterior slope wide, flattened with two
dark inconspicuous lines running from beaks to posterior margin;
beak sculpture unknown; cardinal teeth rather long and solid,
depressed, disposed to be double in both valves, corrugate; lateral
teeth straight, oblique, corrugate; anterior cicatrices distinct,
deep, post cicatrices distinct and well impressed; shell cavity
wide and deep; nacre white.”

The above description was made from four specimens from
young to adult. The young shells are much flatter. The measure-
ment of one of these adult shells is:

Length Width Diameter Locality
66) 0x 1°54 x 26n1m (Black R., Popular Bluff)

MISCELLANEOUS REMARKS:—The author of this species states
that he knows of no described species which closely resembles it.
From the single specimen in hand it seems to be rather intermediate
for P. catillus and coccineum; however, it does not possess the
radial furrow of the former nor the rounded and compressed
posterior half of the latter. The shell of mzssourense compares
well with that of Fusconaia subrotunda and if its soft parts could be
obtained for study it might be found to be a form of the latter
as, it is often difficult to separate the species of Fusconaia and
Pleurobema solely on the basis of shell characters. Even from
character of shell, Frierson would group this species under Fus-
conaia; however, Walker, who considers this a valid species,
would class it near P. estabrookianum (Lea).'

™ More recently (April, 1915) Mr. Walker determines this species as
a Quadrula of the subrotunda groupp (Nautilus XXVIII, Pl. V., figs. 1 and 2).

86 NAIADES OF MISSOURI

Pleurobema Utterbackii Frierson. New Species.

PLY.) tgs. t2 a and.b APL XOX, tes HOw ee)

ANIMAL CHARACTERS.

“NUTRITIVE STRUCTURES:—Branchial opening with many
short antennae; anal very finely crenulated; supra-anal with
short but distinct mantle connection to anal; gills long, much
pointed posteriorly, inner laminae of inner gills free from visceral
mass; palpi wide, short connected about two-thirds of their length
antero-dorsad; color of soft parts mostly a light tan, mantle
edges at siphonal openings blackish, gills of male and sterile female
a darker tan.

“REPRODUCTIVE STRUCTURES:—No gravid females found,
but sterile ones only present outer gills as marsupial; sterile
marsupia wider with more crowded septa than outer gills of male.

SHELL CHARACTERS.

‘EXTERNAL STRUCTURES:—Shell elliptical, somewhat rhom-
boidal; evenly truncate above posteriorly; beaks at one fourth
of their length; epidermis rough, dark reddish brown, faintly
rayed when young; post-slope somewhat biangular and low;
beaks rather strongly corrugate.

“INTERNAL STRUCTURES:—Cardinals teeth roughish, inclined
to be double in both valves; laterals long, medium size; inter-
dentum narrow; muscle scars well marked and separate; cavity
of shell irregular, that of the beaks of medium depth; nacre white,
sometimes pinkish, irridescent behind.

Sex Length Height Diameter Locality

OW 68s 42 xs 126), mim wOWihite River pivollisten)

Gi 65) xe Jans xo iaieds (Jack’s Fork of Current R.)
Cu ESS aX ee 2S eX eA (oui 2 a <3 rs)
OF Pal SOE Xoo 50x me Ole (White R., Hollister)

‘Two juvenile shells are at hand measuring as above. Epider-
mis of latter olive-green, of the former, yellowish, both with
fine rays; nacre of latter bluish, of the former pinkish; beak
sculpture of both roughly corrugate, the three or four coarse ridges
curved up posteriorly into hummocks and directing the apices

* This description of Pleu. Utterbackii is quoted from the M. S. of
Mr. L. S. Frierson and is kindly permitted to be published here,

NAIADES OF MISSOURI 87

of the beaks anteriorly; post-ridge inflated but not so sharply angled
as in juveniles of Fusconaia, nor so greatly rayed; beak sculpture
also different in being more corrugated.

“MISCELLANEOUS REMARKS:—The type shell is from the White
River, Hollister, Missouri, collected by Mr. Utterback of St.
Joseph, Missouri, for whom the species is named. Other specimens
are at hand from contiguous territory. This species might possibly
be the Pleu. argentea--‘‘ pannosa”’ of C. T. Simpson (indicated,
but hardly described, in Proc. Nat. Sci. Phil., r900, p. 82). It is
to be differentiated from the Eastern Tennessee Pleurobema argen-
teum (Lea) with difficulty, having its beaks further in front, and
higher than in argenteum. Specimens have been received under the
heterogeneous names of L. ozarkensis (Call), ellipsiformis (Conrad),
etc. But a series of about a dozen sent by Mr. Utterback from
two or more localities proves the novelty of the form. The appear-
ances of Truncilla and Pleurobema in the mountain streams of
Arkansas and Missouri, together with an undescribed Lampsilis
very close to biangulatus (Lea), is an interesting and remarkable
fact illustrating the power of environmental factors in the family.’’*

Genus Elliptio Rafinesque.

1819—Elliptio Rafinesque, Jour. de Phys. Chim. et His. Nat.

1900b—Elliptio Simpson, Proc. U. S. Nat. Mus., XXII, p. 7oo. (as
section.)

1912b—Elliptio (Raf.) Ortmann, An. Car. Mus., VIII, pp. 265-272.

(Type, Umo [Elliptio] nigra Rafinesque).

ANIMAL CHARACTERS:—Branchial and anal openings large
with many small papillae; mantle connections between anal and
supra-anal short, or moderately so; gills wide, very much round

' Being more doubted by some students that P. Utterbackit may not
be distinct from L. ozarkensis (Call), Mr. Frierson would make this addi-
tional description :—

“Our shell is much more tumid at the beaks, or umbones; it is not furrowed
on the post slope by the siphonal ridges as in ozarkensis; it is thicker;
the anterior muscle scars are distinct, while in ozarkensis they are remarkably
confluent. Our shell is not dimorphic, while, if Call has not confused two
species in one, his species is considerably so. Our shell differs especially
from his figures 1 and 3, less so from fig. 4. Our shell has its whole facies
of a heavier sort than ozarkensis. Our cotypes of the latter, from Mr. Call,
are more inclined towards a Lampsiline structure, as indeed it is placed
by ©; I. Simpson.”

88 NAIADES OF MISSOURI

ventrad, inner wider but not much longer, inner laminae almost
entirely free from visceral mass; palpi medium size; color of soft
parts whitish suffused with black; only outer gills marsupial;
glochidia small, suboval, spineless.

SHELL CHARACTERS:—Shell thick, heavy, subsolid, rhomboid-
ovate, longitudinal axis straight, disk smooth, beaks rather low,
not near anterior end, sculptured with a few fine concentric ridges
angled at the base of the post-umbonal ridge; epidermis brown to
black, faintly rayed or rayless; hinge teeth heavy; nacre varying
from white to deep purple and violet. é ,

MISCELLANEOUS REMARKS:—This genus falls into two groups
for this State. The first group is represented by E. nigra (Raf.)
which possesses a heavy subquadrate of subtrapzoidal type of
shell but with obscure beak sculpture; the second group is repre-
sented by E. dilatata (Raf.) which has more of an elongate, gibbosed
shell with a beak sculpture of thick, heavy, ridges running parallel
to the growth lines. The two other groups of this genus (that is,
beadleianus and complanatus groups) are not found in Missouri,
the former being mostly a representative of some gulf states and
the latter of the immediate Atlantic drainage. Dr. Ortmann
used ‘‘Elliptio’’ as a generic name available for the “ American
Unio”’ and employs the original name, “Unio,” in the sense of
the ‘European Unio’’. The soft parts of this genus being practi-
cally indentical with those of the genera immediately preceding,
the species are indicated entirely on the basis of peculiar shell
characters.

Elliptio nigra Rafinesque.’
(“Hiephant(s War: i: dank)
Pl. XXI, Figs. 64 and 65 A and B.
1820—Unio (Elliptio) nigra Rafinesque, Ann. Gen. Sci. Brux., V,

j0}) ACN Oh, IL PO... UHR, Te, ;
1823— Unio cuneatus Barnes, Am. Jl. Sci., VI, p. 263.

ANIMAL CHARACTERS.
NUTRITIVE STtRUCTURES:—Branchial opening large, well set

1 Simpson (1900 b, p. 706) applied the name ‘‘ Unto crassidens Lamarck”’
to E. nigra Raf., but as previously stated under the description of Mega-
lonaias (IV, p. 124) that close student of Lamarckian types, Mr. Bryant
Walker, has settled the question by pronouncing U. crassidens (1819) as
the so-called U. trapezoides of Lea (1831).

THE NAIADES OF MISSOURI 89

with numerous short papillae; anal opening with small, but very
distinct, papillae; supra-anal briefly but well connected with
anal by mantle edges; gills large, broad, pointed both anteriorly
and posteriorly, inner broader, only slightly longer, than outer,
inner laminae free from visceral mass; palpi moderately large,
connected antero-dorsad, edges curved; color of soft parts dirty
white with mantle edges at siphonal openings blackish and gills
brownish.

REPRODUCTIVE STRUCTURES:—Only outer gills maruspial,
‘when gravid marsupia moderately swollen; conglutinates rather
well developed, leaf like, white; glochidia small, suboval, spineless,
measures 0.130 X 0.150mm.

SHELL CHARACTERS.

EXTERNAL STRUCTURES:—Shell solid, heavy, subinflated, tri- .
angular in outline, post-umbonal ridge prominent; beaks also
prominent sculptured by a few rather obscure ridges subparallel
to growth lines and swollen at the base of post-ridge; disk more or
less smooth; epidermis reddish brown to black often faintly rayed.

INTERNAL STRUCTURES:—Cardinals double in both valves,
heavy; laterals heavy; interdentum long; beak cavities large
not very deep; nacre (for Mo. nigra) only a deep purple—not
variable.

Sex Length Height Diameter Locality
meron Xa (SOn ex) 05 Lite (Miss. R., Hannibal)
fof gI x 61 >< 37 ” ( ” ” ” )

”

meeet 5), Xe 60) xX 47 (Mermamec R., Meramec Highlands)

MISCELLANEOUS REMARKS:—No juveniles, nor young shells
found. This is a rare species for the interior of the state being only
in the Meramec, outside of the Mississippi River. In the latter,
where it is not to say an uncommon shell, it is different from the one
- found in the Ohio by a variation in nacre-color. ~The shell may
show some variation in size and form in the same river, as Wilson
and Clark (1914, p. 42) observed in the Cumberland where it is
short and chunky in the headwaters but is heavier and more
elongate in the lower stretches. Although nigra is essentially a
big river species, yet it is not found in the Osage—the largest
Missouri River tributary. Its occurence in the Meramec carries
it farther west than recorded before. Its breeding record, although
incompletely kept by the writer, shows it to be a tachytictic Unio.

go THE NAIADES OF MISSOURI

Elliptio dilatata (Rafinesque).
(‘‘Lady Finger,” ‘‘Spike,’’ ‘‘ Pistol Grip.’’)
Pl. XXI, Figs. 66 A and B,
1820—Unio (Elliptio) dilatata Rafinesque Monog. of Bivalves of Ohio,
Ann. Gen. Sci. Phys. Brux.

1823— Unio gibbosus Barnes, Am. Jl. Sci., VI, p. 262, pl. XI, fig. 12.

1838—Unio arctior Lea, Tr. Am. Phil. Soc., VI, p. ro, pl. IV, fig. ro.

1912b—Elliptio gibbosus (Barnes) Ortmann, An. Car. Mus., VIII,

a 7 ie
ANIMAL CHARACTERS.

NUTRITIVE STRUCTURES:—Branchial opening small with many
short, blackish papillae; anal with a single row of low papillae;
supra-anal separated from anal by short mantle connection;
gills long and narrow, inner laminae of inner gills free—in some
instances connected about one-fourth of the way anteriorly;
palpi short, wide, connected antero-dorsad about two-thirds of
their length; color of soft parts soiled grayish with area in front
of branchial opening yellowish, pericardianl region invariably
reddish brown.

REPRODUCTIVE STRUCTURES :—Only outer gills are marsupial,
marsupia moderately swollen in center when gravid, dark tan;
conglutinates narrowly lanceolate, always whitish; glochidia
medium size, spineless, hinge line slightly depressed, measure’
0.200 X 0.220mm.

SHELL CHARACTERS.

EXTERNAL STRUCTURES:—Shell elongate-ellipsoid, gibbose,
thick heavy, post-umbonal ridge rounded, inflated; disk smooth;
beaks flattened, coarsely sculptured with five or six wavy ridges
more pronounced behind; epidermis dark brown to horn or
yellowish.

INTERNAL STRUCTURES:—Cardinals rather low, double in
both valves; laterals double in left and inclines to double in right
valve; interdentum very long, cut away in right to receive left
post-cardinal; umbonal cavities rather shallow; however, deeper
in female shell; nacre mostly dark purple, varies from all shades
of purple to salmon and white.

Sex Length Height Diameter Um. ra. Locality
ONT Site OS ANU AsLO 0.260 (Miss. R., Hannibal)
GUL OME 5 ON pXNtsS.O 0.255 (Osage R., Osceola)
On A aun XA 2 OF San MOUS) 0.255 Guba Mt Ke )
CUZ ONES HL LOMAS MnGs5) 0.250 (Niangua R., Hahatonka)

¢

THE NAIADES OF MISSOURI gI

The last two measurements are those of the most adolescent
shells at hand but are not young enough to present much addi-
tional information than can be obtained from the mature shell.

MISCELLANEOUS REMARKS:—This is one of the species of very
wide geographic distribution in United States but is limited in
this state for the interior to those streams south of the Missouri
River where it is met with in a multitude of forms—especially
of the small thin and compressed varieties found in the Ozarkan
streams of South Missouri. In the Osage‘it is found most typically,
aside from the Mississippi which produces the best types of all
Naiad species. The depauperization of this species in size and form
in the mountain streams is evidently due to a swifter current and
hence these dwarfed forms may be merely a local ecologic race
that may not deserve special names; however, two forms in this
state occur often enough to require some little attention.
Dilatata (Raf.) (=gibbosus (Bar.)) is more confused with Ellzp-
saria clintonensis (Simpson) than with any other shell. There is a
difference, however, in the latter possessing capillary rays, and
a broader interdentum, but the best distinction is in the marsupial
structures of the latter that presents a folded appearance, when
gravid. Simpson did not know the difference from shell structures
until he found a gravid clintonensis. While this species is both
lacustrine and fluviatile, yet it is never found in any lake or pond
in this state. The typical dzlataia with white nacre (EF. arctior) is
simply put down in the synonomy. A form like Conrad’s U. arcus
is sometimes found in the Osage but aside from its shortened
dwarfed form of shell it does not even possess enough differentia-
ting characters to give it a varietal place. The writer has found
it to be gravid only from June to August; hence tachytictic.

Elliptio dilatata subgibbosa (Lea).
(‘Little Lady Finger,” ‘‘ Little Spike.’’)

PL XT Rags. 65 A—D
1857— Unto subgibbosus Lea, Pr. Ac. N. Sci. Phila., IX, p.169; 1858,

VikeAceNe Set Phila LV p53s Die Wil sis. 36:
1868— Unio lazarus Sowerby, Conch, Icon., XVI, pl. LX VIII, fig. 348.
ANIMAL CHARACTERS:—Absolutely identical with those of the

parent. No real difference in glochidial characters even.

SHELL CHARACTERS:—Moderately small, short, rather in-
flated, somewhat heavy through the post-ridge, more elliptical,

g2 THE NAIADES OF MISSOURI

-not so pointed posteriorly, older shells tending toward post-dorsal
trunction, dorsal line arched, ventral rather straight, epidermis
brownish; nacre white with pinkish umbonal cavity or solid color.

Sex Length Height Diameter Locality
Qt On Xe BOE | ZOnIIT (Black R., Williamsville)
Gace Spun 26) ok aT (Ags 28 2) )
OUP AOI ES 9 2)3 oh XteO M Gayo? ye 23 )

MISCELLANEOUS REMARKS :— Specimens collected from streams
in Stone County have been sent to the Division of Mollusks in
the National Museum where they were identified as subgibbosus.
It has also been reported from the streams of Texas and Shannon
Counties. It is different from the variety delicatus of Simpson
by being somewhat larger, not so thin-shelled, more arched dorsad,
more pointed both anteriorly and posteriorly, with rather promi-
nent post-umbonal ridge. This variety is rather common in the
Black and St. Francis drainage.

Elliptio dilatata delicata (Simpson).
(“Little Lady Finger.”’)
TID. GENRE RIS Wojely WI 9):
1g00ob— Unio gibbosus delicatus Simpson, Proc. U. S. Nat. Mus., XXII,
p. 704.

ANIMAL CHARACTERS:—Although the anatomy of this variety
is smaller than the parent, yet it is precisely identical. Only sterile
individuals found; however, only outer gills marsupial.

SHELL CHARACTERS:—Shell greatly compressed, very small,
thin, outline evenly elliptical; epidermis brownish red to oliva-
ceous; hinge teeth rather prominent, thin, nacre purple or coppery-
rarely white.

Sex Length Height Diameter Locality
Guns be aXe? Om exon es (White R., Hollister)
ORAS Xa 12 Ae era TT ie (Grek ie f )
fof Pie Moree Wali gh De Toy Care a a )

MISCELLANEOUS REMARKS:—The writer has in his collection
a shell of this subspecies bearing the original label of Mr. Simpson,
the author. The dzlatata shells of the White River compare well to
it. For the same ecologic reason we may account for this small
form in the South Missouri drainage as well as for the occurrence
of subgibbosa. ‘These two forms are not found north of the Ozark
divide, neither is the typical dilatata of Rafinesque found south of
it in this State showing the ready response of the parent species
to different environmental conditions.

THE NAIADES OF MISSOURI 93

Genus Uniomerus Conrad.

1853— Untiomerus Conrad, Proc. Ac. Nat. Sci. Phila, VI, p. 268. (as
genus).

1900b— Untomerus (Conrad) Simpson, Proc. U. S. Nat. Mus., XXII,
Pp. 739 (as section).

(Type, Unio tetralasmus Say).

ANIMAL CHARACTERS:—Both branchial and anal openings
papillose and crenulate; supra-anal closely and loosely connected
to anal; inner laminae of inner gills free from the visceral mass
almost their full length; papli short almost as wide as long; color
of soft parts mostly a soiled white, gills brownish; gills only mar-
supial in outer ones, when gravid rather distended lengthwise
in center, tapering at the ventral edge, ovisacs not divided; septa
wavy; conglutinates white, sole-shaped; glochidia medium in
size, semielliptical, higher than long, hinge line straight.

SHELL . CHARACTERS: — Shell trapezoidal, rather obtusely
pointed behind; disk smooth with the exception of roughened
growth lines; beaks low, sculptured with several coarse concentric
ridges which curve abruptly upward behind where they are
crowded closely together; epidermis rayless, shiny, yellowish
to black; cardinals compressed; laterals nearly straight; nacre
whitish to bluish.

MISCELLANEOUS REMARKS:—Dr. Ortmann elevates Unio-
merus from Simpson’s treatment of it as section mostly because of
the peculiar beak sculpture of its type since this character alone
is a great departure from the Elliptio-shell (See Plate xx1, fig. 69).
Then, too, the shell is thinner, has more of a rayless, vari-colored
polished epidermis and is more elongated with less curved dorsal
or ventral line.

Uniomerus tetralasmus (Say).
(“Pond Horn Shell.’’)

Ph, 2X1, Fees: 60 Ai and -B:

1830— Unio tetralasmus Say, Am. Conch., III, pl. XXIII.
1836— Unto declivis Conrad, Monog., V, p. 45, pl. XXIII, fig. 1.

1839—Unto sayt Ward, (in Tappan). Am. Jl. Sci., XXXV, p. 268,
pl ATL «figs 1,

94 THE NAIADES OF MISSOURI

1912b— Uniomerus tetralasmus (Say) Ortmann, An. Car. Mus., VIII,
pp. 272 and 273.

e
Fic. 4. Uniomerus tetralasma (Say) 9°. Diagram of a gravid individual
from Lost Cr., Amity, showing animal characters in left valve.
Coll] May, 3, 1913. (G7 nate size.)

ANIMAL CHARACTERS.

NUTRITIVE STRUCTURES:—Branchial opening large, set with
numerous papillae; anal finely crenulate on inner edge;
supra-anal large extending to dorsal line, closed from anal by a
moderate mantle connection; gills about the same width, inner
‘onger, inner laminae free from visceral mass for whole length
except for a short distance anteriorly; palpi short and broad,
connected only for one-fourth of their length antero-dorsad;
color of soft parts, for most parts, a dingy white with mantle edge
at siphonal openings blackish, gills brown.

REPRODUCTIVE STRUCTURES:—Marsupia only occupying
outer gills, when charged rather padiform, distended at center,
but not near the ventral edges, ovisacs simple, undivided; con-
glutinates also undivided, white, sole-shaped, with regular thin
transparent areas arranged cross-wise made by the thickening
of the septa at regular intervals; glochidia spatulate, very regular
im outline, hinge line short and straight, medium in size measuring
0.160 x 0.210 mm.

THE NAIADES OF MISSOURI 95

LA
SCAT
. 1
4 at

Fic. 5. Mature closed glochidium of U. tetralasma. (x87)

SHELL CHARACTERS.

EXTERNAL STRUCTURES:—Shell subtrapezoid; post-dorsal
ridge rather high, usually obtusely pointed behind, evenly rounded
in front; disk smooth; beaks low, drawn well back from anterior
end, sculptured with many coarse, concentric, regular ridges
curved up very abruptly behind at base of post-umbonal ridge
where the ridges are drawn closely together; epidermis light
yellow back ground with alternated brown bands running parallel
with the growth lines, or nearly all colored in brown horn with
polished appearance, almost rayless, sometimes faintly rayed
in green on post-umbonal ridge.

INTERNAL STRUCTURES:—Cardinals compressed into rather
blade-like processes; laterals delicate but rather prominent;
interdentum long, thin; umbonal cavities rather shallow; scars
well impressed, nacre light bluish to grayish.

Sex Length Height Diameter Um. ra. Locality
Coy exe 45 Xk) Simm 10.260). (Batterton Pond, Columbia) a
CRS Shc xs UVa Gs got te2? 0.265 (Lost Creek, Amity) NI, urT 45
CBO IRe ANNO X Na DANS 0.260 (Mill Creek, Courtney) ,US ‘ —“gt
(1A Na aidan 7 Jee aL es aR 0.270 (Lost Creek, Amity)

MISCELLANEOUS REMARKS:—U. tetralasma is peculiar ecolo-
gically, as well as morphologically, in that it can become more
quickly established in artificial ponds and lakes than any species.

It is naturally lacustrine, but for some unknown cause it is not .

found in any of our lakes prefering small ponds or quiet creeks
where it is found accompanying Anodonta Danielsi, or Eurynia
subrostrata. From the fact that the writer has not found any
individuals of this species in North Missouri without marsupial
characters he is led to believe that it is locally hermaphroditic at

yan oF

,
ot’
a

PAN

|

96 . THE NAIADES OF MISSOURI

any rate. The writer, too, has had the good fortune to find its
glochidium for the first time and is figured here in this catalogue
for the first (See Text fig. 5). Many were taken from Lost Creek
of the Grand River drainage, May 3d, and also August 5th, most
of which were gravid with glochidia on both occasions. Although
winter observations have not as yet been made, still we would
judge from these two records that this species is not tachytictic
as in most Unioninae. However, like most of the members of this
Sub-Family their conglutinates are ‘‘aborted’’ when removed
from their natural bed. Simpson speaks of this species as being
very susceptible to variation; however, the writer has not noticed
any great variability in this State, where its distribution is rather
wide, and has not seen any varieties worth listing except comptodon,
which has also been reported for Central Missouri by Dr. Britts.

Uniomerus tetralasmus comptodon (Say).
(‘‘Pond Horn Shell.’’)
Not figured.

1832— Unio comptodon Say, An. Conch., V, pl. XIII.

1832— Unto geometricus Lea, Tr. Am. Phil. Soc., V, p. 28, pl. IV, fig. 10.

ANIMAL CHARACTERS are the same as those of the species;
so are also its shell characters except in its outline being more
rhomboid, its epidermis being more of a dull drab—or uni-color
in having more roughened growth lines and a more curved hinge
line.

Sex Length Height Diameter Locality
OT SO xe! AO nea 2s ititn (Grindstone Creek, Maysville)
OF) 775), Xt AO Xe an ty (Lost Creek, Amity)
Cir OSiha X aioe ei Om eas ie ‘ea

MISCELLANEOUS REMARKS:—This variety is often found in
the same bed with the species from which it is discriminated, as
above indicated, by the character of its epidermis. On this super-
ficial basis of epidermis color there are so many intergrades and
for this reason it may be doubted whether this and other recorded
varieties are really worthy of their names. Comptodon was col-
lected by Dr. Britts in Clinton Co., and is now on exhibit in the
Division of Mollusks of the U. S. National Museum under the
number, 150402. According to Henderson (1907, p.87, pl. ii,
figs. 7a and 7b) this variety predominates over the main species
in Colorado. Dr. Scammon (1906, p. 337) reports it for Neosho
County, Kansas. The writer has examined both sterile and gravid

THE NAIADES OF MISSOURI 97

specimens of this form to find it with the same breeding season
as its parent species.

Il—Sups-Famity Anodontinae Ortmann.

1911a—Anodontinae Ortmann, An. Car. Mus., IV, p. 336; 1912b,
An. Car. Mus., VIII, pp. 278-300.

ANIMAL CHARACTERS:—Mantle edge, antero-ventrad to
branchial opening smooth without specialized structures; supra-
anal antero-dorsad to anal opening usually widely separated; no
tendency toward tubular siphonal openings; inner laminae of
inner gill generally free from visceral mass; region just anterior
to pericardium of watery composition; palpi very large; mar-
supia—occupyiug two entire outer gills, when gravid pad-like,
enormous, tissue thickened at edge to permit transverse distention,
two water tubes present on either side of an enclosed central
undivided ovisac and facing outer and inner laminae, these
laminae very thin and delicate rupturing at the slightest scratch;

. glochidia usually large, spadiform, generally longer than high,

with a spine at each ventral tip; no well-defined conglutinates,
but held together in unstable masses by brownish mucus and a
tangle of larval threads.

SHELL CHARACTERS :—Shell thin for the most part; disk usually
without sculpturing; beaks usually coarsely sculptured with con-
centric or double-looped ridges; hinge variable, teeth completely
lacking, or, if present, rudimentary or peculiar; beak cavities not
deep as arule; sexual dimorphism rarely seen.

MISCELLANEOUS REMARKS :—T'he members of this group have
a long period breeding season (bradytictic) due perhaps to their
origin at a time, as Dr. A. E. Ortmann considers, when a possible
shortening of the warm season induced them to retain their embryos
in the marsupia and discharge the glochidia in the spring; hence,
the constant and admirable adaptation of water-tubes for the
aeriation of the embryos in the marsupia while being retained for
that time. This adaptation elevates this group from the primitive
one and places it more among the modern Unionidae. Even on the
basis of shell structure, in that the sculpturing, seen on the disk
of the shells of the Unioninae, is carried back up to the umbona
region where it is almost exclusively confined, there is sufficient
evidence for the more modern grouping. The inability of the
Anodontinae to spread their vavles very wide may account for

98 THE NAIADES OF MISSOURI

the lack of papillae or other specialized structures (as related to
the processes of reproduction) in the region of the branchial open-
ings. Since the species of this group are mostly lacustrine we find
them, of course, mostly distributed in the chain of lakes along the
Missouri River or in the ponds and small sluggish streams of the
interior of the state north of the Missouri River. Compared to
the other sub-families, we do not find so many variations in this
Sub-Family due to the more constant ecological conditions to which
the Anodontine species are remarkably constant—especially as
to reproductive structures, in which respect they differ from those
of the Lampsilinae; however, the Anodontine species are like the
Unionine in the possession of large palpi, whereas those of the
Lampsiline species are small. In all probability the larger palpi
are for reproductive as well as nutritive purposes. It is interesting
to note the recapitulation of the evolution of the whole race of
Natades in some of the individual members of this Sub-Family
in that the coarse sculpturing, noted on the disk of juvenile shells,
is carried back up to the umbones in mature shells—a progression
from the sculptured disk of the more primitive to the smooth
disk of the more modern forms of the adult.

Genus, Symphynota Lea.

1829—Symphynota Lea, Tr. Am. Phil. Soc., III, p. 424.

(Type, Symphynota compressa Lea)

ANIMAL STRUCTURES :—Branchial opening with short papillae;
anal smooth, or finely crenulated; supra-anal larger or smaller
than anal, separated by more or less long mantle connection;
gills bowed ventrad, septa and water-tubes well developed,
inner lamina of inner gills free from visceral mass; marsupium
occupying outer gills, pad-like and with secondary water tubes,
when charged; glochidia large, spadiform, spined, hinge line
undulate; palpi sickle-like united for one-half of their length
anterio-dorsad; color of soft parts usually yellowish.

SHELL CHARACTERS:—Shell elliptical to oval, compressed,
smooth except for costae sometimes on posterior dorsal ridge;’
beak sculpture double looped, or sinuate-concentric; cardinals
always present; laterals imperfect, or even absent; nacre white
or bluish. :

MISCELLANEOUS REMARKS:—The shell characters of Symphy-
nota would relate it more closely to the more primitive group than

-_

THE NAIADES OF MISSOURI 99

any of the Anodontinae on account of its sculpturing on the pos-
terior dorsal ridge, the costae there being somewhat similar to
those on the shell of some Amblemae or Quadrulae. Simpson
treated this genus under three sub-genera and while the shell
characters may greatly differ, yet, the animal characters are so
constant and the known species are so few to retain this subgeneric
treatment. The type, S. compressa (Lea), is not found in this
state—not even in the Mississippi River. Only two species of
this genus, S. complanata (Barnes) and costata (Rafinesque), are
found in Missouri and they are not widely distributed, the former
being confined mostly to the north and the latter to the south
part of the state.

Symphynota complanata (Barnes).

(“Heel Spitter,’”’ “‘Hackle Back,’ ‘Hatchet Back,’’ ‘‘ Pan-cake.’’)
Pl. XXII, Figs. 70 A and B.
1823—Alasmodonta complanata Barnes, Amer. Jour. Sci. and Arts,
D2 7 Ose Dis Oude fice 21

1900b—Symphynota complanata (Batnes) Simpson, Proc. U. S. Nat.
.Mus., XXII, pp. 665-666.

ANIMAL CHARACTERS.

NUTRITIVE STRUCTURES:—Branchial opening thickly set
with short papillae; anal finely dentate; anus of intestine fringed
with three or four papillae; supra-anal large, mantle connection
widely separating it from anal; inner gills, wider than outer,
inner laminae free except briefly, anteriorly; marsupia occupy
entire outer gills, truncated along ventral margin when charged,
Ovisacs not divided; glochidium very large, spined, hinge line
undulate measures 0.310 x 0.320mm; most of soft parts yellowish,
gills rusty color when gravid.

SHELL CHARACTERS.

EXTERNAL STRUCTURES:—Usually rhomboidal, compressed;
alae high, marked with a few upcurved costae; disk smooth:
beaks low, sculptured with coarse double-looped ridges; epidermis
of young shell reddish with brown rays; of old specimens, brown
to black.

INTERNAL STRUCTURES:—Cardinals single in right, double in
left valve; laterals faintly double in both valves; umbonal cavity
shallow; nacre bluish to satiny white with marginal ribbon of

100 THE NAIADES OF MISSOURI

lavender; sexual dimorphism not very distinct; the biangular
character climed for posterior end of male shell not constant.
Sex Length Height Diameter Um. ra. Locality

OME7ON RnlOS. 2oxi a2 ii Os2'6 (Big Mud Lake)
Cun Sie SOS yest 0.26 (Platte R.)
ORO IE) OS.) ae eOu i 0.20 (Gs ee)
OES BA OS we IStueR eS ie 0.20 (102. River)

The juvenile shell is very flat, a very beautiful wine-colored
epidermis marked with bright brown rays: beaks are coarse,
marked with the characteristic sculpturing of adult shell except
the later bars are down on the upper part of the disk; nacre bluish.

- MISCELLANEOUS REMARKS:—This species is both fluviatile
and lacustrine for this state. Observation of aquarium specimens
discharging sperm proves this species a gonochorist—a character
this is opposite to the congeneric species and type of this group,
compressa Lea. ‘The author has also observed this species to be
gravid with glochidia from November to April and, in most
instances, has noted early and late embryos mingled with the
glochidia in the same individual at the same time. ‘This species
is very common in North Missouri where it grows very large in
the lakes, but is uncommon and dwarfed in Central Missouri and
is not found at all in the clear, swift water-streams of South Mis-
souri. Complanata is so distinct from other alated forms that there
should be no confusion. It differs from Proptera alata (Say) in
that the latter is dimorphic more inflated and has a purple nacre.
There is such difference between this species and the type (S.
compressa) that it may well deserve its subgeneric name, Plerosygna
Raf. (1813), that Simpson applied.

Symphynota costata (Rafinesque).

(‘Fluted Shell,’’ ‘““Squaw Foot,’’ ‘“‘Sand Mussel.’’)
Ply XXER Figs 77 pA.
1820—Alasmidonta costata Rafinesque, Ann. Gen. Sci. Brux., p. 318,
PIN PX, fig 15.16
1823—Alasmidonta rugosa Barnes, Am. Jour. Sci. and Arts, p. 278,
oly DG OEMS rhea ye
1900b—Symphynoia costata (Raf), Simpson, Proc. Nat. Mus., XXII,
p. 665.
ANIMAL CHARACTERS.

NUTRITIVE STRUCTURES:—Anal opening slightly crenulated
on inner margin; supra-anal moderately separated from anal;

SS be

THE NAIADES OF MISSOURI IOI

inner gills larger, much wider anteriorly, inner lamina free from
visceral mass nearly whole length; palpi not large, triangular,
united partly anterio-dorsad.

REPRODUCTIVE STRUCTURES:—Marsupium typically Anodon-
tine; glochidium next to largest on record (0.380 x 0.390mm)
wider than long, hinge line undulate; soft parts yellow; marsu-
pium, however, rich brown when charged.

SHELL CHARACTERS.

EXTERNAL STRUCTURES:—Shell moderately large, thin to
moderately thick, elongate, compressed (especially in male),
posterior end bi-angulate, costae on slopes of post-dorsal ridge;
disk without sculpturing; umbones peculiarly marked with four
coarsely mingled concentric and double-looped bars; epidermis
from light horn-color to dark chestnut in old specimens, greenish
and rayed in young.

INTERNAL STRUCTURES:—Cardinals single in right, rather
tripartite in left valve and interdentum deeply notched; laterals
almost obliterated; nacre deep rich cream in umbonal cavity,
while lavender and b ue on pallial border, often whole nacreous
surface yellowish or ferruginous due to a distomid infection to
which this species is so susceptible.

SHELL MEASUREMENTS.

Sex Length Height Diameter Um. ra. Locality

9 116 x 85 x 44mm 0.370 (Gascondy, Mo., Gasconade R.)
Gi AG) ae UNS ae hind 0.280 (Black R., Williamsville, Mo.)
ORT OOM Se Geen, Bee 0.275 (Miss. R., LaGrange, Mo.)

Tish exe Aw Ker 2A Nh TOL2eO.) (Sta branciseR. Greenville)

MISCELLANEOUS REMARKS:—S. costata is found in sandy and
muddy situations, is a deep burrower and very active. With this
habitat and physiological characters it is strange that it should
not be found at all in the sluggish muddy streams of North Mis-
souri and very rarely in Central Missouri where the streams are
intermediate Tor clearness and current. Perhaps this species has
the most variegated nacre of any Navzad shell. It is a very common
species in the clear and rapid streams of the Ozark Plateau and
Center where its shell is duller epidermis than those of the Miss-
issippi. (See Pl. xxi, Figs.71 A—F.) This compression and plica-
tion are due, doubtless, to swifter current and more rocky bottom.

102 THE NAIADES OF MISSOURI

Its general distribution is for the St. Lawrence drainage and in the
Mississippi as far south as Texas. This species can be easily
identified and distinguished from other shells by rugose or ribbed
structure on the abrupt slopes of the post-dorsal ridge, by its
peculiar deep socket just underneath the beak, by its compara-
tively unridged laterals, but, most of all, by its very characteristic
compound beak sculpturing. Because of these very striking shell
characters it may deserve the subgeneric treatment of Simpson
(1900b p. 664) who gave this species the name Symphynota (Las-
migona) costata (Raf.) Dr. Ortmann and Mr. Frierson think this
subgenus, Lasmigona, really deserves generic rank. ‘The author
has found the breeding season of costata to extend from August
until May with eggs and early embryos for late summer and fall
and glochidia for winter and spring.

Genus Arcidens Simpson
1900b—Arcidens Simpson, Proc. U. S. Nat. Mus., XXII, p. 661.

(Type Alasmidonta confragosa Say).

ANIMAL CHARACTERS.

Branchial opening densely set with papillae; anal finely
serrated; supra-anal long with short mantle connection to anal;
inner gills wider in front than outer, inner laminae of inner gills
free; palpi large, united two-thirds of their length antero-dorsad;
marsupium Anodontine both in external and internal structures;
glochidium spined, large, hinge line undulate.

SHELL CHARACTERS.

Shell somewhat rhomboidal, inflated with rather high full
beaks; disk and beaks profusely sculptured, the latter coarsely
double-looped, the spinuous tuberculed loopes extending in two
diverging rows upon the disk; the former with oblique folds on the
post-ventrad part with pustulated expansions along the post-
umbonal ridge; cardinals present but only traces of laterals are
seen; nacre white.

This genus is represented in this state by few individuals
and while the only species of this genus, known so far, is both
fluviatile and Jacustrine it is more often found in quiet creeks,
head waters of rivers or in other lacustrine conditions of the rivers,
such as the pond-like stretches, sloughs, bayous, etc.

THE NAIADES OF MISSOURI 103

Arcidens confragosus (Say).

(“Black Pocket-Book,”’ “‘Black Pocket,’’ ‘‘Rock Shell,’’
“Rock Pocket-Book.’’)

Pl. XXII, Figs. 72 A and B.

1829—Alasmodonta confragosus Say, N. Harm. Dis., II, p. 339.

1888— Margaritana confragosa B. H. Wright, Check List.

1900b—Arcidens confragosus (Say) Simpson, Proc. U. S. Nat. Mus.
SX ip. Oo2™

ANIMAL CHARACTERS.

NUTRITIVE STRUCTURES:—Branchial opening large, with few
papillae; anal with tiny papillae on inner edge; supra-anal very
long, connected antero-dorsad two-thirds of length; inner gills
somewhat wider, inner laminae free from visceral mass; color
of gills and palpi brown, all other soft parts soiled white and chamois
like.

REPRODUCTIVE STRUCTURES:—Marsupium occupying only
outer gills, light brown when sterile, spotted and vertically striated
when gravid with early embryos, padiform and dark brown when
gravid with ripe glochidia; internal structure of gravid marsu-
pium typically Anodontine; glochidium of specimen from Platte
River, Missouri, (0.353 x 0.350mm.) but possessing same shape,
i. e., subtriangular, with undulate hinge line.

SHELL CHARACTERS.

EXTERNAL STRUCTURES :—Shell subrhomboid, inflated, roughly
sculptured with apiculated tubercles in umbonal region, ribbed
tubercles on post-umbonal ridge, coarse undulations across post-
ventrad part of disk, slopes of post-dorsal ridge sub-costated;
beaks full, high, corrugated; epidermis brown to black in adult,
greenish mingled with black in youth.

INTERNAL STRUCTURES:—Cardinals single in right valve,
double in left, the posterior one being long, serrated and placed
just under the beak in place of the interdentum; laterals, faint in
both vales; scars rather well impressed; umbonal cavity somewhat
deep; nacre bluish to white with sky-blue border.

Sex Length Width Diameter Um. ra Locality

OOS x G7 nef Se mim Orson NCPlatte Re Mio.)
TOD OS KP RAS. ali 0.34 (L. Contrary, Mo.)
CURLS eee ANS Xe SiS 0.31 (Osage R., Mo.)
ASwex) MSS), X*4ae.5.,'7° 20:30 Gor Pie a)

104 THE NAIADES OF MISSOURI

The latter measurement is that of a juvenile taken in a cutoff
slough at Warsaw, Mo. Like that of other juveniles of this species,
its supra-anal opening is found to be rudimentary—a mere furrow—
and the gills are specked with minute black pigmented spots.
Its shell is more rhomboidal than older; also two rows (five in a
row) of ribbed tubercles; more prominent, coarse undulations not
so distinct, nor horozontal; more zigzag sculpturing on disk;
epidermis more blue-greenish; alae more costated; nacre more
irridescent and bluish in beak cavities and with a brighter lavender
ribbon around the margins.

MISCELLANEOUS REMARKS:—Arc. confragosus is peculiar in
its shell structure by its profuse subspiny sculpturing on disk and
beaks, its coarse tubercles—especially on umbonal ridge being
smooth dorsad and ribbed ventrad and by its postero-cardinal of
left valve being long, coarsely serrate and in place of interdentum.
In many characters this shell is like that of of Arkansia wheeleri
W. and O., but differs in not having well developed laterals and
in having more profuse and prominent sculpturing. Confragosus is
fond of quiet water and muddy bottoms; thus it is ‘more lacustrine
and when fluviatile it is found in creeks or in the head waters and
bayous of the large streams. It has a general distribution from
western Indiana to Iowa. Simpson reports it as most abundant in
Illinois and is also generally found in the Mississippi and in the
states adjoining, although it is, by no means, a common shell
anywhere. It is a rare species even for North and Central Missouri
where there are more lacustrine conditions and is not found at all
in South Missouri. The author has found it gravid with active
glochidia the latter part of January and with late embryos in the
middle of March and great numbers were examined daily during
July and August to find it sterile; thus it is bradytictic.

}
Genus, Lastena Rafinesque.

1820—Lastena Rafinesque, Ann. Gen. Sci. Phys. Brux., p. 316.
1853—Leptodea (Raf.) Conrad, Pr. Ac. N. Sci. Phila., p. 262.

ANIMAL CHARACTERS:—Branchial opening narrow, upcurved,
papillose, anal smooth, supra-anal short, widely separated from
anal; gills long, tapering posteriorly, outerand inner gills about
the same size; inner laminae of inner gills free from visceral mass;
palpi subfalcate; color of most exposed soft parts orange, rest of
soft parts tan-colored and soiled white; marsupia, rusty color

THE NAIADES OF MISSOURI . 105

when charged, ventral edges distended, water canals present;
no specialized structure of mantle edge antero-ventrad to branchial
opening; glochidium large, broadly spadiform, spined, hinge
line straight.

SHELL CHARACTERS :—Shell thin, subalated, smooth on disk:
beaks flat, sculptured with four or five rather double-looped ridges;
epidermis smooth, polished, rayed in green in the region of the
post-umbonal ridge; hinge teeth absent; scars faint, confluent;
nacre bluish.

In this state this genus is represented by the two species,
Las. ohiensis (Raf.) and suborbiculata (Say)—the latter not having
been completely described hitherto. The author has had conve-
nient access to large beds of suborbiculata and has been fortunate
in securing specimens gravid with embryos in all stages and with
mature glochidia. Neither has the latter been figured nor des-
cribed before. Because of the fact that the marsupium of subor-
biculata is more like that of Arcidens and that of ohiensis closer to
Anodonta we would group the latter as more modern; then, too,
the hermaphroditism and longer breeding season of ohiensis
would also indicate an advance in being able to perpetuate the
race.

Lastena suborbiculata (Say).
(“Suborb,”’ ‘‘ Heel-splitter.’’)
Eh hoe) toa: Pi IX Foe..1o; Pl. XXII, Figs. 73 AD.

1831—Anodonta suborbiculata Say, New Harm. Diss. (Newspaper
form); Am. Conch. I, No. II, 1831 (Later date), p. XI.

1867—Anodon suborbiculatus Sowerby, Conch. Icon., XVII, Pl. V, fig. 11,
LY;

ANIMAL CHARACTERS.

NUTRITIVE STRUCTURES:—Branchial opening comparatively
small, upward curved with many fine orange colored papillae;
anal also directed upward, smooth with Y-shaped yellow markings;
supra-anal long, far removed from anal by mantle connections;
inner gills wider but very little longer than outer, inner laminae
of inner gills not connected to visceral mass; palpi rather long,
united antero-dorsad about one-third of their length; pericardinal
region very large, watery, pinkish-brown in color; foot, long,
thin, deep orange in color, adductors also orange, yellowish re-
tractors and protractors visible through the watery, transparent

106 THE NAIADES OF MISSOURI

soft parts; gills olivaceous; patch in front of branchial opening
light tan or chamois-like; cerebral ganglia bright orange spots
external and on top of foot antero-ventrad to palps.

te

\
AT \ . \ \
i, bt \ \ ‘ ANN SN YY \ \ \\\) \\ ws
A or nie
CY BNO ASINI\
\ i i, N \ F

Nl bails

" Me

Fic. 6. Lastena suborbiculata (Say) 9. Diagram of a gravid individual
from Lake Contrary, St. Joseph, showing animal characters
in left valve. (34 nat. size.)

REPRODUCTIVE STRUCTURES:—Marsupia when sterile, dark
tan with crowded septa, tissue of ventral edge thickened, occupying
outer gills only; when gravid, russet, with heavy septa more widely
separated, distinct, veining enormously pad-like, greatly dis-
tended and faintly scalloped ventrad, longitudinal line, near and
parallel to the ventral margin, indicating terminations of gill
filaments; water canals next to thin laminae on either side of an
undivided central ovisac which is closed at the base; no sexual
specialization on margin of mantle antero-ventral to branchial
opening (thickened edges here have nutritive function of siphonal
contraction); glochidium spined, very large, broadly spadiform,
hinge line straight, longer than high, (0.325 x 0.320mm.) glochidial
shell russet color, bluish spots for the adductors; no conglutinates

ra
4

THE NAIADES OF MISSOURI 107

but glochidia are held together in loose masses by brownish mucus
and coiled larval threads.

EtGae7 = Mature closed glochidium of L. suborbiculata. (x87.)
SHELL CHARACTERS.

EXTERNAL STRUCTURES:—Shell subround, or suborbicular,
thin, compressed, rounded before, bowed ventrad, pointed behind,
suleated post-dorsad, alated, dorsal line from apex of wing to an-
terior end, straight and at an angle of 45 degrees; disk smooth;
beaks flattened, sculptured with coarse wavy bars, intermediate
ones bow-shaped and arched toward apex, latter double-apiculated
‘with smaller tubercles just ventrad, later bars subundulate on
upper disk and running more or less parallel with growth lines;
epidermis polished, straw colored in young. light brown-born in
old; rayed all over with green capillary lines and one or two
broad bluish-green bands from beak to extreme posterior point
of shell; growth lines raised and undulated showing through on
nacreous surface.

INTERNAL STRUCTURES:—Cardinals and laterals entirely
lacking; anterior adductor muscle scars two comparatively deep
elongated triangular areas, progressive impressions most distinct;
other cicatrices very faint, confluent, mantle line broken by
minute ridges; umbonal cavity shallow; nacre whitish, bluish
' or coppery, irridescent.

Sex Length With Diameter Um. ra. Locality
O@res) X 130) xX (67mm “O:200)) (Lower ©: Contrary; ‘St- Joseph)
eS On ek Dis X) 14o.2? 0.270 (Upper LV. Contrary, 7’ yen a)
OP AT Xe Sp LX LA 0.260 (Sugar Lake, Armour, Mo.)
Si EVRY Oe ic Ms Ca ae 0.250 (L. Contrary, St. Joseph, Mo.)

The latter measurement is that of the smallest juvenile of
this species out of a collection of a little over a hundred of these
delicate shells. This one was without byssi and doubt is expressed

108 THE NAIADES OF MISSOURI

as to whether any of the lacustrine Anodontinae are byssiferous,
since the quiet water of the lake would perhaps make these threads
unnecessary. The specimen above measured has a very thin,.
papery shell, almost transparent; ground-glass-like inside view,
yellow-horn color outside appearance, beautifully rayed in green
especially on post-umbonal slope. In life the heart beat could be
detected through the thin shell and the alimentary tract traced;
the heart beat 28 times per minute, regular but feeble, while that
of an adult was only twenty-two times per minute, irregular but
strong.

MISCELLANEOUS REMARKS:—This species is espécially charac-
teristic for the shape of its shell being not variable, but somewhat
like an ordinary dinner piate as to form and size; also the very
distinct progressive impressions are somewhat characteristic.
Its shell is the largest in outline of any of the Nazades, although it
is not heavy,—even with its soft parts. Its meat has been tested
through Domestic Science to be of great food value. Except for
greater inflation, in case of the female shell, no real sex dimorphism
can be detected. ‘The author has noted more of a greenish granular
appearance for the outer gills of the male. The fact that the writer
has discovered, from aquarium observations, individuals discharg-
ing sperm on two occasions disproves that wt 1s hermaphroditic. For
reference one of these males was killed and preserved in the act
of discharging its sperm.

This discharge of sperm made the water milky and when
examined by a high-power (X385) lens it was observed to be the
flagellated sperm in cysts rolling about through the water like the
colonial Protozoa. ‘Then, too, the simple test that not all indiv-
duals have the crowded septa of the outer gills disproves that all have
marsupial characters of these gills. Thus hermaphroditism can not
be applied to this genus Lastena, as a general character, 1f this species
is to remain with it. This is the first description of the animal of
this species that has been drawn up and the author has been the first
to report 1ts mature glochidium which in general shape is about like
that of A. grandis having about the same shape with the same
straight hinge line, but being smaller. The glochidium is very
active, having been observed to snap fifteen times per minute.
The habitat of suborbiculata is that of black sand and mud bottoms
in deep quiet water, is a rare shell in general distribution, but,
when found, is abundant. Simpson reports it for Nebraska, Iowa,

if ne

-

co

THE NAIADES OF MISSOURI ‘ 109

Illinois, and Louisiana. Dr. W. S. Strode reports it as very large
typical and abundant in Illinois and the fact of its southern range
to Louisiana (as reported by Mr. Frierson) is interesting. Although
this mussel is very susceptible to the attacks of the parasite,
Atax, its shell is hardly ever distorted for that reason; neither
is the shell hardly ever eroded or injured by chemical reaction.
An accurate breeding record, kept by the writer, shows it to be a
long period; breeder, but not so long or continuous as that of Las.
ohiensis (=imbecillis.) It is found to be with early and late embryos
from September to December, and mature and immature glochidia
from December to March, but sterile for the remaining months.

Lastena ohiensis Rafinesque.
( Paper, Pond) Shell:’”)
PLOT, egsi57 4 Aland B,
1820—Lastena ohtensis Rafinesque, Ann. Gen. Sci. Brux., V, p. 316.

1829-—A nodonta imbecillis Say, N. Narm. Diss. II, p. 355.

ANIMAL CHARACTERS.

NUTRITIVE STRUCTURES:—Branchial opening with yellowish
tentacles pointed upward, anal narrow, smooth supra-anal small,
far removed from anal; outer and inner gills about the same size,
inner laminae free from visceral mass; palpi long, sickle-shaped,
united antero-dorsad about two-thirds of its length; foot, adductors
branchial opening region orange color, rest of soft parts tannish
or dirty white.

REPRODUCTIVE STRUCTURES:—Marsupia rusty brown and
pad-like with water-tubes and undivided ovisacs when gravid;
mantle edge antero-ventrad smooth without sexual specialization;
glochidium golden russet, broadly spadiform, spined, hingle line
straight, longer than high (0.310 x 0.zg0mm.); no conglutinates;
glochidia enmeshed in a tangle of larval threads.

SHELL CHARACTERS.
EXTERNAL STRUCTURES:—Shell subelliptical and subcylin-

drical, thin, inflated, slightly alated; disk smooth, shinning;

beaks flush with dorsal line sculptured with coarse looped bars,
later ones being finely tuberculated, apex doubly apiculated;
epidermis grass green, to olive with post umbonal slope marked
by two or three bluish parallel rays.

INTERNAL STRUCTURES:—Teeth entirely lacking; muscle

IIlO THE NAIADES OF MISSOURI

scars faintly impressed, confluent; branchial cavities large; nacre
pearl blue.

Sex Length Height Diameter Um.ra. Locality
® 698 x 4o "x 39mm x 0.320 (Gud Wake, Kenmoor, Mo)
O63) “x 1625 x an 7) xvore4ol (Lower Lakes St. Joseph as\las)
Q@ 61 x 28 x 35” x 0.360 (Spring Lake, Monegaw Spgs. Mo.)
Cue 2i5eiex | lor ox 2 2 xO. 3808 (vitid: Walken. Elallsae om)

The latter juveniles of the last measurement has the least
diameter that the author has ever examined. It was discovered in
very active locomotion in shallow water along the lake beach and
wonder was expressed how such a compressed shell could contain
enough musculature for such vitality. Its beak sculpture presents
two apiculations at the apex of the umbone surrounded by rather
wavy or looped bars extending low to the disk. So thin were the
valves and soft parts that when studied with the lens the heart
action could be observed through the shell when held up to the
light. ‘The characteristic green rays, extending parallel along the
post umbonal ridge area, are more pronounced here than in the
adult shell.

MISCELLANEOUS REMARKS:—The vitality of ohiensis of the
embryos in the active rotary motion is seldom seen in the Nazades.
This motion was observed to take place around one axis from
right to left in very rapid rotation. Mr. L. S. Frierson states that
he has seen the glochidium taken from the mother and so suffici-
ently metamorphosed as to turn its shell up from a glass slide
through an angle of 180 degrees.* The fact, too, of this species
being normally lermaphoroditic gives it a character possessed
by few Nazades. The adult shell is also so peculiar that there is
no need for confusion in making identification. The nearest to
it in general form and color is Lasmonos leptodon, yet it can be
easily distinguished from this distant relative by the beak sculp-
ture and hinge. Its suppressed umbones flush with the dorsal
line, making “‘beakless beaks,’’ are perhaps its recognition marks.
It is a lover of quiet, shallow water and muddy bottoms and for
this reason is distinctly lacustrine. ‘The author has found it in

* Dr. A. D. Howard has lately discovered Lastena ohiensis as also non-
parasitic in its glochidial life and accounts for its distribution through the
buoyancy of its juvenile shell as a compsensatory provision for the loss of
the usual means of distribution by fishes. (Science, N. S., XL, pp. 353-
355, Sept. 4, 1914).

“
=

THE NAIADES OF MISSOURI Hata

the main body of rivers but in such cases there was always some
slough, bayou, or lake near by from which its light shell may have
been carried over in time of flood. This species has a general
distribution over the Mississippi and St. Lawrence basins. In
this state it is confined to the lake district of N. W. Missouri,
and in the lacustrine conditions of Central and South West Mis-
souri. Its breeding season seems to be continuous for the year,
or at least there is a very short interim of sterility. The author
examined it nearly every month of the year to find it gravid and
that, for the most part, with mature (active) glochidia. The
“eye spots,’’ mentioned by Simpson, as characteristic marks on
the mantle edge at the branchial opening, have not been observed
by the writer. Because of its Anodonta-like marsupia, but more
on account of its physiological characters, in being a hermaphrodite
with an almost continuous breeding season, this species should be
assigned to a little higher position in the genus than suborbiculata. The
fact that Rafinesque used ohzensis as the type for his genus Lastena
and also because of such departure in anatomical and concholo-
gical features from those of the genus Anodonta for ohiensis and
its nearest ally, suborbiculata, this genus Lastena should now be
employed for these two species of this State.

Genus, Anodonta Lamarck.
1799—Anodonta Lamarck, Prodrome Class. Cogq., p. 87.
1817—Anodontes Cuvier, Regne. An., II, p. 472.

(Type, Mytilus cygneus Linnaeus).

ANIMAL CHARACTERS:—Branchial opening with yellowish
papillae, anal smooth to slightly crennulated; supra-anal generally
small, removed from anal by long mantle connection; inner lamina
of inner gills free from one-half to entire length; palpi usually long
and large; only outer gills marsupial, when marsupia are gravid,
ventral edge distends and secondary water-tubes appear, ovisacs
simple, undivided, dark brown when gravid with mature glochidia;
no conglutinates formed; glochidia large, brownish, spined,
spadiform.

SHELL CHARACTERS:—Shell elliptical, inflated, thin, slightly
alated; disk smooth; beaks full high, sculpturing distinct, double-
looped, angled upward centrally; epidermis polished, brightly
colored; hinge teeth completely lacking.

No genus is so susceptible to so many mutations, yet it is

112 THE NAIADES OF MISSOURI

really only represented in this state by A. grandis and Danielsit.
However, the latter, even may only be a creek form of grandis.
A few other species, reported for this state under this genus, have
doubtless received their names without deserving them and hence
wil] only receive passing notice. The members of this group being
lacustrine, they are limited more to the lake distinct in Northwest
Missour:, to that portion of Central Missouri where lakes, ponds
and sloughs abound, and to the Mississippi Lowlands of South-
east Missouri. Very few Anodontae are reported for South Missouri
where lacustrine conditions are rare.

Anodonta grandis Say.
(‘‘Floater.’’)
PIO VT OF go) D5. VP OX Ds Haesee7 5 AG er ee

1829—Anodonta grandis Say, N. Harm. Diss., II., p. 341.
1852—Anodonta opaca Lea, Rr. Am. Phil. Soc., X, p. 285, pl. XXV,
fig. 46.

ANIMAL CHARACTERS.

NUTRITIVE STRUCTURES:—Branchial opening with rather
long yellowish papillae; anal directed upward, smooth; supra-
anal separated from anal by long mantle connection, small, almost
closed in some instances; inner gills wider and longer, inner laminae
entirely free from visceral moss; palpi very large united antero-
dorsad about one-half of their length; anterior portion of peri-
cardial region thick and watery; color of gills usually dark brown,
mantle edge at siphonal openings blackish, palpi cream to purplish,
remaining parts mostly tan or soiled white.

REPRODUCTIVE STRUCTURES:—Marsupium occupying outer
gills only, when gravid pad-like, distended at ventral edge, secon-
ary water canals present, undivided ovisacs in center, laminae
very delicate rupturing at slight touch; sterile marsupia thick-
ened at edges to allow for distention; glochidium largest on record,
(0.400 x 0.395mm.), spadiform, spined, russet color, straight
hinge line; no conglutinates, glochidia held in loose mosses by
brownish mucus and tangles of crinkled larval threads.

SHELL CHARACTERS.

EXTERNAL STRUCTURES:—Shell subovate, large, greatly in-
flated especially in umbonal region, subalated, subsolid anteriorly,

¢?
-

THE NAIADES OF MISSOURI 113

rounded before, pointed behind; disk unsculptured; beaks full,
apices recurved, sculptured by several coarse irregular double-
looped ridges the loops being more or less nodulous; epidermis
glossy, varied in color from brown-horn to green, growth lines
rather undulated. ;

INTERNAL STRUCTURES:—Hinge teeth completely lacking;
muscle scars not well impressed, progressive impressions most
evident; umbonal cavities large and deep especially in female
shell; nacre variable naturally from whitish, or bluish to coppery
or even to salmon chocolate or brick-red, irridescent. Probably
the latter colors. are more pathologic than normal.

Sex Length Width Diameter Um. ra. Locality
9 215 x 118 x 84mm—o.360—(Mud Lake, Kenmoor, Mo.)
@ 155 x 80 x 66 ”’ —o.285—(L. Contrary, St. Joseph, Mo.)
@ 105 x 63 x 50 ’’ —o.380—(’’ oe Me iB 325)
ORTON. XiweT 4x 5. °° =—0.300-—-(7! - 4 y a)

Several of these juvenile shells of A. grandis (the latter measure-
ment being the smallest) were found in one spot on the west
beach of Lake Contrary. These juvenile shells were indentified
by Dr. A. D. Howard of the U. S. Fisheries, Biological Station,
Fairport, Iowa, where experimental rearing of these species from
the glochidium has been made and a series of shells have been.
obtained all the way from its larval to its independent and mature
life. At the end of the fifth year it is identical with that of Lea’s
opaca. ‘The juvenile of the above measurement is very thin and
papery almost transparent, is coarsely sculptured even on its
disk—the bars being decidedly double-looped with a re-entering
angle between the nodulous loops terminating at the tip of the
umbone in two minute conical tubercles. It is especially to be
noted that single laterals are faintly seen in each valve of this
juvenile shell; also double right and single left cardinals may be
seen with a (x12) lens.

‘MISCELLANEOUS REMARKS:—Perhaps no species of Nazades
is so polymorphic as A. grandis. Probably these mutations are
only z6ogeographical expressions of its shell which seems to respond
most readily to every change in ecological relations. Its pliable
juvenile shell may be so shaped by its environment as to give
rise to its many varietal forms. By choice grandis is lacustrine
under which conditions its shell is typically inflated, shorter and
thinner; if subjected even to the mild fluviatile action of a creek

114 THE NAIADES OF MISSOURI

it becomes thicker and more compressed and more elongated.
Its changes are so great at different ages that many names have
given it for this reason; doubtless A. opaca, stewartiana, leonensts,
elc., are mere synonyms for this reason. Because of parasitism,
pounding of the surf, etc., this species is found in many pathologic
forms in our lakes; a common one being that of a shell deeply
suleated at the post-ventral point and another with its shell
extremely truncated post-dorsad. To the latter A. footiana and
perhaps A.dakotana, may be referred. A.salmonia may also be
assigned to a grandis-form that has a blistered salmon-colored
nacre due to a distomid infection. A. grandis has a general distri-
bution all over the Mississippi drainage, also in the St. Lawrence
drainage and that of the Red River of the North. In this State it
is found in most of its forms in the chain of lakes, “cutoffs,”
sloughs and bayous along the Missouri River and quiet, muddy
creeks of the north and central portions. It has only been rarely
reported for the Ozark Center or Plateau. The soft parts of the
half-grown grandis (A. opaca) are found by Domestic Science
tests to be very edible. A strict breeding record, kept by the author,
shows this species to be gravid with glochidia from December
until March and sterile from this month on to September; there-
fore it is a long period breeder and its larvae are the largest and
most- active known, contracting from ten to fifteen times per
minute. The species which follow in description under this genus
are only believed to be as mere forms of grandis and only receive
separate notice because of their original report for this state,
under these names,—and are so grouped for sake of conformity
to other writers.

Anodonta dakotana Frierson.
(‘Dakota Shell,’’ “Short Nose.’’)
Pl. XXIV, Figs..77 A and B.

1914—Anodonta dakota Frierson MS.

ANIMAL CHARACTERS:—With the exception of shorter, wider
gills, due to the shape of shell, the nutritive and reproductive
structures of this species (if it be one) are identical with those of
A. grandis. Its marsupium, in gravidity, is exactly the same;
so are its glochidia in form and size (0.400 x 0.395mm.).

SHELL CHARACTERS:—Shell subrhomboidal, short, obese,
abruptly truncated behind and, with the exception of not being

a

al

THE NAIADES OF MISSOURI 115

flat on the center of the disc, it may not be the typical dakota of
Frierson. In other respects the shell structures are identical
with those of A. grandis. ;

Sex Length Width Diameter Locality

ORAL kee 71 Oy Xa AS (L. Contrary, St. Joseph, Mo.)
fot To8 x 73 x 49 ” (Ly. ” ” ” ” )

MISCELLANEOUS REMARKS:—This truncated form may only
be the result of a local reaction on grandis as it is not often found
in very quiet water but in the more disturbed water near the
shore, yet its occurrence in such a constant shell-form is so common
in our Missouri lakes that it would be safe to assign it to the defi-
nite species herein referred, or at least its subspecies. Dr.Ortmann
thinks this form may bear the same relation to our western lakes
as A. benedicits (a form of grandis-footiana) does to Lake Erie
where it is grown close to the shore in the surf.

_ Anodonta corpulenta Cooper.
(“Big Floater,’ “Slop Bucket.’’)

Not figured.

1834—Anodonta corpulenta Cooper, App. to Narrative, Exp. Miss. R.
to ot. LL) p.'154.-—B. W. Wright Check List, 1888.

ANIMAL CHARACTERS :—The nutritive and reproductive struct-
ures are identical with those of A. grandis; however, its glochi-
dium is different in shape and size, having an irregular, undulate,
hinge line with length and depth equal (0.350 x 0.350mm.).

SHELL CHARACTERS:—With the exception of a shorter,
wider, more inflated shell and also of more recurved beaks the
shell is the same as that of A. grandis.

MISCELLANEOUS REMARKS:—Some students of Nazades are
inclined to call corpulenta an “overgrown grandis.’ However, its
smaller, but most of all, its differently formed glochidium would
separate it from grandis since nothing is so constant as glochidial
characters. This form is reported as rather common in the sloughs
and lakes along the Mississippi in this state; yet it is not found
in the lakes of North-west Missouri. Simpson reports it for the
Missouri river (1900b, p. 646) but is not specific about the locality
and states that it has a general distribution for the upper Mississ-
ippi River east to Indiana and south to Texas where it may be
replaced by A. stewartiana. Dr. Surber (1913, p. 106, Pl. XXIX,
fig. 1) has found this species to be an occasional fin-parasite upon

Va

116 THE NAIADES OF MISSOURI

the same host as that for Fusconaia ebena. Its breeding season
is the same as that of A. grandis.

Anodonta Danielsii Lea.
(‘‘Daniel’s Shell.’’)
PDS XUV eres MO) Aa aM jist.
1858—Anodonta daniels Lea, Proc. Ac. N. Sci. Phila., III, p. 113;
JIA INS Set Phila. 186091; p3365, el) Wecili fice too:
1859—Anodonta texasensts Lea, Proc. Ac. N. Sci. Phila; p. 113; Jl.
AcoIN. Sci.) Phila, 1860p. 1366) PL ei ios om.

ANIMAL CHARACTERS:—Branchial opening wide, densely
papillose, anal smooth, supra-anal small, far removed from anal by
mantle connection; palpi large, united two-third of their length
antero-dorsad; inner laminae of inner gills free from visceral sac.

REPRODUCTIVE CHARACTERS:—Marsupia occupying outer
gills, when charged pad-like, ventral edge blunt, greenish poster-
iorly, rest rusty brown; glochidia not found so far.

SHELL CHARACTERS.

EXTERNAL STRUCTURES:—Shell subelliptical, moderately
large, subsolid; disk smooth; beaks rather low, sculptured with
coarse double loops radiating from the beaks; epidermis dark
horn with areas of green between the dark lines of growth.

INTERNAL STRUCTURES:—No teeth; scars faint; umbonal
cavity shallow; nacre pearly-blue to light salmon with bluish
border.

Sex Length Width Diameter Um.ra. Locality
@ 115 X 55 xX 40mm—o.304—(Lost Creek, Amity, Mo.)
o 180 x 65 x 42 ’’ —o.290—(Tarkio R., Craig, Mo.)
@ 82 x 42 x 30 ”’ —o.268—(Flat Cr., Sedalia, Mo.)
OV S5Or ik FON kelp, i022 SO—— (a 7 + Bore Nt)

The last measurement is that of the smallest and youngest
Danielsi1 that has been obtained. It is a beautiful grass-green
shell with a single brown band running parallel with the growth
lines. Its beak sculpture is the most distinct of any in the writer’s
collection and is typically Anodontine. Its soft parts are tannish
and the outer gills are plainly marsupial.

MISCELLANEOUS REMARKS:—This species is a rather common
creek form of grandis. It is especially characterized by a more
elongated, compressed and smaller shell. As a rule its shell is
also thicker and its epidermis takes on more of a greenish color

a erat eae

r
-™

THE NAIADES OF MISSOURI ELT

with alternate brownish bands. It is striking to note such a close
likeness of its shell to that of Uniomerus tetralasma with which
it often accompanied in our muddy, sluggish creeks of North
Missouri. Of course it can be distinguished from the latter by
its very different umbonal sculpturing and by the absence of
teeth. Mr. Bryant Walker very kindly identified this species
and stated that the shells were more compressed than those from
Oklahoma and Kansas and that he had practically the same shells
in his collection from South-west Missouri under the names of
Anodonta texasensis Lea, but, being a doubtful species, it may
equal to Danielsi, or at any rate the latter has priority. Hence,
we are placing A. texasensis in the synonomy of this species. Simp-
son treats texasensis as very near Danielsi: and, although he had
only a young, broken shell from Lea’s collection for study, yet he
is very doubtful about the validity of it as a species and thinks
it may only be a mere variety of grands after all.

Anodonta Bealei Lea.
(‘‘Beale’s Shell.’’)
Not figured.
1863—Anodonta bealet Lea, Pr. Ac. N. Sci. Phila., VII, p. 194; Teh
Ncw Nescie Phila, VAvis66, p26, Pl IS ifien a5,

The writer, not having seen this species, would infer from
Lea’s figure that it is the same as A. Danielsii, or near. Through
the kindness of Dr. Dall, curator of the Divison of Mollusks for
the U. S. National Museum, report was made that Dr. John H.
Britts, (deceased), a well-known conchologist of this state, collected
shells of A. Beale: from the Grand River, Henry County, Missouri
and sent them to the National Museum where they are now
deposited under the numbers, 150,392 and 150,391. Simpson
states the geographic distribution of this species from Texas to
Kansas.

Genus, Anodontoides Simpson.

1898a—Anodontopsis Simpson (in Baker), Tr. St. Louis Ac. Sci.,
WAOGE jopeGoy
1898b—A nodontoides Simpson (in Baker), Moll. Chicago, p. 72.

ANIMAL CHARACTERS.

“An mal with marsupium occupying the outer and sometimes
the four leaves of the branchiae, ovules more numerous in the

118 THE NAIADES OF MISSOURI

outer, the whole pad-like; gills large, inner semi-circular, free
from the abdominal sac or united with it; branchial opening
large with many small, papillae; anal with well developed papil-

lae.”” (Simpson.

SHELL CHARACTERS.

EXTERNAL STRUCTURES:—Shell sub-elliptical inflated, thin;
disk smooth; beaks somewhat full with distinct beak sculpture
consisting of concentric ridges upcurved behind; epidermis dark
brown, polished, sometimes rayed; hinge-teeth lacking, or merest
rudiments, scars shallow; nacre bluish white.

Dr. Ortmann considers this genus pratically an Anodon with
concentric beak sculpture and as a good connecting link for Ano-
donia and Alasmidonta. ‘The only species of this genus, ferussact-
anus, is only represented along the Mississippi of this state where
it is a rare shell. Unfortunately the soft parts, have not been
secured for description. The glochidia of the species and sub-
species (subcylindricus) of this genus have the same shape and
measure 0.32 and 0.33mm. respectively—height and length being
equal.

Anodontoides ferussacianus (Lea).
(‘‘Ferussac’s Shell.’’)
Pl: ITI, Fags, 7a—Ssa.

1834—Anodonta ferussaciana Lea, Tr. Am. Phil. Soc. V, p. 45, pl.
Wile io eeTse

1898—Anodontoides ferussacianus (Lea) Baker, Moll. Chicago,
J2Ate aes 195 Ap IN INOs aolee Hey Wie sie! 2:

ANIMAL CHARACTERS.

According to Dr. Ortmann (1g1r2b, p. 294) the anatomy of
this species is essentially that of Anodonta and differs only in the
shorter mantle connection between the anal and supra-anal and
in the anal being distinctly papillose. The glochidia (Ortmann
1811b, pl. 89, fig. 12) are described as rather small (0.320 x 0.320
mim.) for the subfamily, subtriangular and spined.

SHELL CHARACTERS.

EXTERNAL STRUCTURES:—Shell subelliptical, thin, inflated,
medium in size, post-umbonal ridge rather faint; compressed
with distinct, regular, concentric ridges bent up behind and api-
culated at the apices; epidermis brownish to bluish-green, some-

THE NAIADES OF MISSOURI 119

times rayed; hinge teeth rudimentray, usually lacking; muscle
sears faint, confluent; nacre whitish or pearl blue.
Length Width Diameter Um. ra. Locality
48 | X!°20 “xX 4 18——0.280— (Miss. Ru, Hannibal’, » Mo))
47 X 28 x 20—0.2850-(Miss. R., Hannibal, Mo.)

MISCELLANEOUS REMARKS:—Probably this species can be
best characterized by its medium sized, sub-elliptical shell with
its concentric, umbonal sculpturing, polished olive-green or
brownish epidermis and slightly incurved hinge in front. of beaks.
A. ferussacianus is only known to occur for a certainty in the
Mississippi of this state. Old, eroded shells from the Niangua
River, Camden, Co., and from Casteel Creek, Clinton Co., have
structures of this species more than anything else, but the identi-
fication is too doubtful for much consideration. The shell of
this species is like that of Strophitus, but differs in beak sculpture;
it also differs from some similar shells of Anodonta by the incurved
anterior hinge to the beaks and by a compressed post-dorsal
portion of shell back of a slight posterior ridge. Ortmann (1921b,
pp. 293-294) denies that all four of its gills are marsupial, and
Simpson, who claims to have found embryos in all four gills does
not class this species under his Tetragenae (i. e., those that have
all four gills marsupial) because its characters of shell and nutri-
tive soft parts seem to agree better with his Homogenae (Unios
with only outer gills marsupial.) This species is generally distri-
buted throughout the Mississippi drainage, the St. Lawrence
system and that of the Red River of the North. The subspecies
only occur in the St. Lawrence drainage.

Genus Alasmidonta Say.

1818—Alasmidonta Say, Jl. Ac. N. Sci. Phila., I., p. 459.
1840— Uniopsis Swainson, Tr. on Mal., p. 382.

ANIMAL CHARACTERS.

Mantle connection between anal and supra-anal openings
moderately long; inner laminae of inner gills free from visceral
mass, or, more or less connected to it; outer gills only marsupial;
when charged, distended at ventral edges, water canals facing
laminae present, central ovisacs undivided; no conglutinates,
embryos held in mucus masses; glochidium large, spined, sub-
triangular, hinge line straight, or nearly so.

120 THE NAIADES OF MISSOURI

SHELL CHARACTERS.

Shell subquadrate to subtrapezoidal, thin, inflated; disk
smooth; beaks heavily sculptured with irregular concentric bars—
the later ones being more or less undulate; epidermis olivaceous to
burnt orange with broken rays; cardinals present, laterals reduced;
beak and branchial cavities deep; nacre white to pearl blue.

The characters of the shell of this genus—especially in its,
coarse concentric beak-sculpture—shows that it is somewhat
primitive, yet the tendency of the union of the inner laminae of
the inner gills with the visceral mass in an indication of progress
in structure. The two species that represent Alasmidonta for this
State are not found in the interior north of the Missouri River.

Alasmidonta calceolus (Lea).
(‘Slipper Shell.’’)
Pl. XXIV, Figs. 79 A—D.

1830— Unio calceola Lea, Tr. Am. Phil. Soc., III, p. 265, pl. III. Fig. 1
1898—Alasmodonta deltoidea Baker, Moll. Chicago, Pb. I., p. 63,

PI AVely fies to Valet ce aS
1900b—Alasmidonta calceola (Lea) Simpson, U. S. Proc. Nat. Mus..

XXII, p. 668.

ANIMAL CHARACTERS.

NUTRITIVE STRUCTURES:—Siphonal openings large, mantle
edges with regular blocks of black; gills of medium size, inner
laminae partly united with visceral mass; palpi rather long,
tongue shaped; most of soft parts light yellowish.

REPRODUCTIVE STRUCTURES:—Marsupium pad-like and
brownish when charged, water-canal present; glochidium large,
spined, spadiform, longer than high, hinge line straight.

SHELL CHARACTERS.

EXTERNAL STRUCTURES:—Shell small, slipper-shaped or sub-
trapezoidal, obtusely angular behind, post-umboidal ridge rounded;
disk smooth;- beaks high, pointed, with coarse concentric sculp-
turing consisting of four or five bars sharply bent in behind;
epidermis yellowish or olivaceous with wavy double rays on and
parallel to the post umbonal ridge.

INTERNAL STRUCTURES:—Cardinals single and conical in
right valve, double in left with post tooth saddle-shaped; laterals
mere thickened hinge line; nacre white.

THE NAIADES OF MISSOURI 120

Sex Length Width Diameter Locality
Osh dee on 2) —OWnite RR. . iollister, Mio.)
o 26 x 18 x 10 ” —(Jack’s Fork, Shannon Co.)

9 18 x Ir x 7.5mm—(Jack’s Fork, Shannon Co.)

The latter is a juvenile, tawny in color, with beak sculpture
extending well out upon the disk in undulated bars, showing
here, as in so many of the Anodontinae, that in the adolescent
shell there is more of tendency toward disk sculpture in the indi-
vidual, just as seen in the primitive shell of the whole race of

‘Natades.

MISCELLANEOUS REMARKS:——This species is easily identified
by its small shell (being never much more than an inch and one-
half long), by its slipper-shape and by its coarse concentric sculp-
turing. It is a great burrower and, although it may be abundant,
it may escape notice because of this habit. For this state calceolus
is only found in the streams of the south slope of the Ozarks where
it is found in company with its nearest relative Alas. marginata,
and is found in greatest numbers in Jack’s Fork of the Current
River, Shannon County. It is found rather common in the streams
of Arkansas, and has a general distribution in the Ohio, Tennessee
and Cumberland Rivers; also the Lower and Middle St. Lawrence
systems. Being found with mature glochidia in late Fall it can
be classed as bradytictic.

Alasmidonta marginata Say.
(“Nigger Toe,’’ ‘Elk Toe.’’)
Pl XXIV, Figs. 75 A and B.

1819—Alasmidonta marginata Say, Nich. Inc., No. 1.
1843—Alasmidonta corrugata DeKay, Zool. of N. Y., Pt. 5, p. 198
PIV fic aso:

ANIMAL CHARACTERS.

NUTRITIVE STTRUCTURES:—Branchial opening densely papil-
lose; anal with fine papillae; supra-anal moderately separated
from anal, mantle-edges marked with squarish black blocks at
regular intervals; outer gills wider than inner; inner lamina of
inner gills connected with visceral mass; palpi very long and
united for one-half of their length antero-dorsad; foot very long
and powerful, orange colored; other parts tannish colored.

REPRODUCTIVE CHARACTERS :—Marsupium with wavy crowded
septa when sterile; greatly distended when gravid, bluish with

122 THE NAIADES OF MISSOURI

late embryos, brown with glochidia, ventral edge trucated, water
canals on either side of undivided ovisacs; glochidia large, spined,
spadiform, hinge line undulate, height greater than length (0.350
x 0.300mm.).

SHELL CHARACTERS.

EXTERIOR STRUCTURES:—Shell subrhomboidal, inflated—
extremely so along the sharply angled, post-umbonal ridge; post
dorsal ridge low with broad gentle slopes finely costated; disk
smooth; beaks long fuJl, sculptured with heavy concentric bars,
the later ones undulated low almost to disk; epidermis smooth,
polished, with spotted, greenish rays from anterior portion of shell
to posterior ridge.

INTERIOR STRUCTURES :—Cardinals single in each valve, inter-
dentum displaced by saddle-shaped tooth in left valve; laterals
reduced to rounded edges; muscle cicatrices faint; shell cavity
deep; nacre whitish to pearl. blue and pinkish.

Sex Length Width Diameter Locality
9 75 x 40 xX 34 mm—(Gasconade, R., Gascondy, Mo.)
fot 60 x 31 x 24 ” —( ” ” ” ” )
OO 166) x35) x 9 245 ee Jiack’siHork, Shannons Cons\ion)
ONa a5 uss SOT Shey OTe S) em (ee ak iy a #3 * )

The juvenile of this last measurement presents the same
sculpturing as in the juvenile calceolus except that the bars are
somewhat more elongated in marginata and are really lower and
coarser extending down well on the disk.

MISCELLANEOUS REMARKS:—It has been well known by
Pilsbry and Fox that this western shell is not the Alasmidonta
truncata Wright, mentioned by Simpson. This species is easily
recognized by its post inflated shell making the post - dorsal portion
almost truncated and also by its extremely coarse beak sculpture.
Its very long narrow foot extension is a notable physiological
character. It delights in sandy, pebbly situations. The muddy
waters of North Missouri is not conducive to its distribution
there and is very rare in the Osage basin; however, it is rather a
common shell in the Gasconade where it reaches its greatest per-
fection and is commonly distributed throughout the mountain
streams of the south. Occasionally marginata is found in the Miss-
issippi north of the Missouri River. The author has records of

etl

THE NAIADES OF MISSOURI 123

its breeding season for August through to December, a sufficient
record to know that it is a long period breeder (bradytictic.)

Genus, Strophitus Rafinesque.

1820—Strophitus Rafinesque, Ann. Gen. Sci. Phys. Brux., p. 316
1852—Uniopsis Agassiz, Arch. fur Naturg., p. 49.

(Type, Anodonta undulata Say).

ANIMAL CHARACTERS:—Branchial opening densely papillose;
anal papillose or crenulate; mantle connection between anal and
supra-anal not Jong and bordered by square, black spots; inner
gills larger, inner laminae free from, or united to, the viscera]
mass; palpi united antero-dorsal for most of their length; color
of soft parts variable but with the tendency to have certain parts
(such as foot, adductors, mantle edge at branchial opening) orange
in color; marsupium peculiar, consisting of ovisacs divided into
many compartments at right angles to the laminae; conglutinates
short, solid cords, (termed placentulae by Ortmann.)

SHELL CHARACTERS:—Shell, subrhomboid to subelliptical,
subsolid, inflated, with low post-umbonal ridge; disk smooth;
beaks rather full, sculptured with rather heavy concentric bars
upcurved behind; epidermis rayed or rayless, polished; hinge
teeth mere rudiments, sometimes entirely absent.

Because of the great specialization in marsupial structure,
the tendency of the inner lamina of the inner gill to become con-
nected to the visceral mass and also because of a more developed
hinge, this genus is the highest of the Anodontinae. It is represented
in this State only by S. edentulus.

Strophitus edentulus (Say.)

(““Squaw-Foot,”’ ‘‘Creeper.’’)

Pl. XXIV, Figs. 80 A—D.
1820—Alasmodonta edentula Say, New Harm Diss., II, No. 22, p. 340.
1888——Anodonta shafferiana B. W. Wright, Check List.

1900b—Strophitus edentulus (Say) Simpson, U. S. Proc. Nat. Mus.,
XXII, pp. 616-618.

ANIMAL CHARACTERS.

NUTRITIVE STRUCTURES:—Branchial opening doubly papil-
lose; anal with inner edge crenulated, supra-anal moderately

31)

124 THE NAIADES OF MISSOURI

connected to anal, mantle edge here blocked in black at regular
intervals; inner gills much wider and longer than outer, inner
laminae connected about one-half way; palpi united almost to
their tips antero-dorsad; color of foot, palpi and adductors orange,
variable with age.

REPRODUCTIVE STRUCTURES:—Marsupia occupying outer gills
with secondary water tubes, ventral edges distended when gravid,
ovisacs occupied by several other smaller sacs arranged crosswise
facing the outer and inner laminae in which small, solid white
cords (placentulae), containing the ova or two to ten larvae, are
situated; glochidia large, spined, spadiform, hinge line straight,
length greater than height, (0.35x0.285 min).

SHELL CHARACTERS.

EXTERNAL STRUCTURES:—Elongate-ovate, moderately solid,
inflated, post-umbonal ridge usually rounded; female shell more
obtusely (or biangulated) posteriorly than male; umbones rather
full sculptured by two or three very coarse, wavy concentric
ridges abruptly bent up behind; disk not sculptured; epidermis
usually a glossy brown, sometimes marked by bright green rays,
especially in young shells.

INTERNAL STRUCTURES:—Cardinals almost obliterated, more
pronounced in left valve, where it is rounded and placed just
under the beaks; laterals and interdentum lacking; umbonal
cavities deeper in female shell; nacre variable from solid salmon
or white, to cream or pearl-blue color.

Sex Length Width Diameter Um. ra. Locality

@ 95 xX (55) x» 38——n1m—o.3460—(Marais desiCysnesuke
Rich Hill, Mo.,)

oO 77.5 X 45.5 X 27 —mm—o.4z30 (Osage Ro, Linn Cry)

O34) ex 20) x4) mo egioe (oz Re Wiyjecu evo)

OO 4t X! 24° X1375—-mim——o.2435-5 (Grand Re Darlington)

The last two measurements are those of the only shells of eden-
tulus jound in the interior north of the Missouri: River and these are
juveniles. Unlike most adolescent shells of this species, both shells
are uni-colored except for a single brownish band parallel with
the growth lines near the ventral margin on a back-ground of
yellowish-green; hinge teeth and beak sculpture typically stro-
phitus; nacre of both about the same; shell thin and transluscent.

MISCELLANEOUS REMARKS:—S. edentulus is rather easily
recognized even through casual observation by its somewhat

a

THE NAIADES OF MISSOURI I

No
n

inflated elliptical shape with the beak sculpture or coarse concen-
tric bars bent up behind, but, most of all, by its very peculiar
marsupial characters which are an adaption to its eccentric habit
of independent metamorphosis. This and Lastena ohiensis are
the only species on record so far that do not normally possess a
fish host for the metamorphosis of its larva. This species is not
so particular about its habitat and hence it has one of the widest

' distributions of any species in the United States. It is strange

that it should not have a wide distribution throughout the State.
It is almost unknown for the interior of North and Northwest
Missouri, and is perhaps best represented in numbers and typical
form in the Osage basin. Its sub-species, pavonius Lea (which,
at best, is perhaps only a color-variant) is not found in this State.
The shell of this species is exceedingly variable, for this State,
as to its shape, size and thickness, but these variations are only
individual characteristics or deviations due to special local condi-
tions. The author has found the breeding season of edentulus
to be about as long and over-lapping as that of Lasmonos fragilis;
however, there was a short interim noted in most individuals about
the middle of July when there was more or less sterility. Because
of the great vitality and nonparastic life of the larvae and also because
of its constancy in breeding season, we might conclude the reasons
for its prolificacy and wide geographic distribution; we might
conclude, too, that its distribution may be due also to a dependent
life as well upon fishes of those larvae that have been observed
to escape from the extruded placentula, and, as some students
have advanced, the buoyancy of the placentula, bearing the juve-
niles, may be the greatest cause for the wide distribution.

Sub-family Lampsilinae Ortmann.

1911a—Lampsilinae Ortmann, An. Car. Mus., IV, pp. 337-338; 1912b,
An. Car. Mus., VIII, pp. 300-360.

ANIMAL CHARACTERS:—Mantle edge antero-ventrad to bran-
chial opening of the female with special structures, such as papillae,
flaps, etc., siphonal openings with tendency to become tubular;
supra-anal separated from anal by a mantle connection of medium
length; inner laminae of inner gills generally connected with
the visceral mass throughout; palpi medium to small; mar-
supium occupying only the outer gills, or parts of the latter, situated
in their posterior portion as a rule; when sterile an extra thickness

{26 THE NAIADES OF MISSOURI

of tissue on the ventral border to permit a bulging out; when
gravid ovisacs are undivided internally, and distal ends are extended
beyond the original edge externally; glochidia of both Propter«
(“ax-head”’) and Lampsilis (‘‘apron-form’’) types, varying mucl.
in shape an size; conglutinates white, undivided at their distal
ends, discharged more or less broken through the thin ventral
edges of the ovasacs; color of soft parts modest, never so bright
with tinges of yellow or red as seen in the other sub-families,
Unioninae and Anodontinae.

SHELL CHARACTERS:—Shell rounded, sub-elliptical or elon-
gated; beak sculpture generally obscure, when present usually
the double looped type, rarely concentric; epidermis rarely dull,
usually with bright color markings; hinge teeth rarely reduced,
generally complete with well developed teeth; sex. dimorphism
of shell in most cases well expressed by a truncated or blunted
posterior end, by an expanded post-ventral portion, ete.

MISCELLANEOUS REMARKS:—With regard to marsupial
structure the Missouri Lampsilinae naturally fall into three groups.
All these agree, however, in the extension of the membranes
beyond the ventral edge of the marsupium when gravid; hence
this distention tends to make the membranes thinner so that
osmosis may be facilitated. To aid further in this osmotic action,
there is a tendency in the three following types to draw the mar-
supium back toward the branchial opening where there is the
greatest amount of aération due to the action of papillae, car-
uncles, flaps, ete. :

1. Lllipsarta-Group. Marsupium most primitive in that
the whole outer gill is occupied; yet advantage is secured for the
aération of the embryos in rendering the ventral edges thin by
distention and in throwing the marsupia into folds, thus increasing
the surface for greater exposure to the water currents. The only
representative in this state is FE. clintonensis (Simpson). ;

2. Obliquaria—Cyprogenia—Group. Number of ovisacs re-
duced, but each greatly enlarged and elongated and placed at the
greatest vantage point for oxygenation of the embryos. This
group is represented in Missouri by only two species, Obliquaria
reflexa (Raf.) and Cyprogenia Aberti (Conrad). The former has
its few large ovisacs drawn back beyond the middle of the gill,
while the latter has its ovisacs slightly in front of the middle of
the gill, but extremely elongated into upward coiled spirals.

f

THE NAIADES OF MISSOURI 27,

3. Proptera—Lampsilis-Group. -In this division the best
adaptation for the proper respiration of the embryos is secured
by situating the numerous, dilated ovisacs in a more or less kidney-
shaped marsupium near to the branchial opening where the
postero-ventral margin of the mantle is set with papillae, flaps,
etc. The first members of this group have this mantle edge only
slightly crenulate and lamellate, while beyond the genus, Pro-
tera, is the culmination of the modern structure in the arrange-
ment of the inner edge with papillae or flaps close to, or remote
from, the outer edge. This group is represented by about thirty
species in this State.

It may be added that the Lampsilinae are dissimilar to the
Unioninae in their breeding season in that practically- all the
species are long period breeders (bradytictic), but that the glochi-
dia of these two sub-families are similar in form and in being spine-
less. It is especially to be noted that the members of these two
sub-families have developed perfect hinges in the adult shell,
whereas those of Anodontinae possessing glochidia with spines
have defective hinges. We should also note that the Lampsilinae
are able to spread their valves far apart—a habit which may
have some relation to the differentiation of their mantle margins
in admitting greater incurrents of water—while the Unioninae
and Anodontinae show a primitive character in being unable to
force their valves far apart and accordingly in not developing
stronger papillae and more extended mantle edges at their siphonal
openings—a defect that may be somewhat counterbalanced by
the delvelopment of larger palpi than is very often seen in the
Lampsilinae. It may be stated further that there is not such
intergradation of forms in this sub-family as seen among the
Untioninae, or even as noticed among the Anodontinae as there
seems to be more distinctness and fixity of characters among the
several genera, especially as seen in the marsupial structures
upon which a good key is built.

Genus Ellipsaria Rafinesque.

1820—Ellipsaria Rafinesque, Monog. Biv. Shells of R. Ohio., Ann.
Gen. Sci. Phys.
1900b—Ptychobranchus Simpson, Proc. Ac. N. Sci. Phila., p. 79.

(Type, Ellipsaria fasciolaris Rafinesque 1820= phaseolus
Hildreth, 1828).

128 THE NAIADES OF MISSOURI

ANIMAL CHARACTERS:—Branchial opening with papillae;
anal separated from supra-anal by short mantle connection but never
lacking; inner laminae of inner gills, more or-less free from vis-
ceral mass; palpi very small, connected about one-fourth of
their length; color of soft parts mostly whitish with mantle edge
black along the siphonal openings; marsupium occupying whole
outer gill with a number of folds; ventral edge, when gravid,
presenting a beaded appearance; glochidia medium in, size,
subovate; conglutinates white, solid, subcylindrical.

SHELL CHARACTERS:— Shell subelliptic rather elongate, arched -
dorsad, disk smooth; beaks low, sculpturing indistinct, finely
concentric, later bars, however, somewhat double-looped; epi-
dermis yellowish to olivaceous, painted with capillary-like rays
forming interrupted squarish spots; hinge teeth well formed,
branchial] impression of female shell very distinct, nacre white
to pearl blue.

MISCELLANEOUS REMARKS:—This most primitive genus of
Lampstlinae, like those of Anodontinae and some genera of Union-
tnae, uses the whole outer gill as a marsupium but shows modern
character in the special structure of folding. Ellipsaria is only
represented in this State (and perhaps only for the whole South- _
west) by E. clintonensis Simpson. Since the shell of this species
is about the same form as that of dilatata (Raf.) it is often confused
with this species of Elliptio from which is widely separated by a
sub-family. The real test of distinction between these two species
is concerning the marsupial characters; hence we see here an
instance of shell characters as a poor guide for discrimination
even for species of very distant relation.

Ellipsaria clintonensis (Simpson.)
(‘Kidney Shell.’’)
Pl, XOGV,, Pigs. Sig Avandeia:

1900a—Ptychobranchus clintonensis Simpson, Pr. Acad. Nat. Sci.
Phila. Pt L p: 79, plo Vey fig. ae T9OOb), Proce Upon Nate yiice
XML, p. 613.

1906—Ptychobranchus clintonense (Simpson) Scammon, Sci. Bull,

Winivay Keansey lide spy ieirop

ANIMAL CHARACTERS :—Identical with those of the type for
this genus as to its nutritive structures and also as to the repro-

THE NAIADES OF MISSOURI 129

ductive as far as able to determine from sterile material that is
only at hand. Glochidia not known.

SHELL CHARACTERS.

EXTERNAL STRUCTURES:—Shell elongate - elliptical moder-
ately inflated, obtusely rounded before, pointed behind, dorsal
line acurate, ventral with a slight long upward curve; disk smooth:
post-umbonal ridge rounded; beaks low, faintly sculptured con-
centrically across two radiating ridges; epidermis olive green or
- yellowish rayed with capillary lines, some arranged in bundles.

INTERNAL STRUCTURES:—Cardinals double in both valves,
post-cardinal of right valve rudimentary; interdentum long,
rather narrow, notched; scars well impressed; beak cavity shallow
branchial, however, large with deep impression in female shell;
nacre white to pearl blue.

Sex Length Height Diameter Locality
@ 95 x 50 x 28 ——(Spring R., Webb City)
ORES Gm xen 4A exe 25) Wihite Re MEvollisten)
So 85 xX 45 xX 24 ——(Jack’s Rork, Shannon Co.)
ORNIGOs Xe BONY Xb 1725 (White R., Hollister)

This last specimen being young and well preserved shows
the fine characteristic rays more distinctly and while the beak
sculpture would show more distinctly than in older shells yet it
is even obscure here and does not add anything to the above
description of the external shell structures.

MISCELLANELUS REMARKS:—Before Simpson had _ studied
the soft parts of this species he had considered it as FE. dilatata
(=U. gibbosus); however, its peculiar marsupial characters would
not only discriminate, but also its different beak sculpture and
dissimilar hinge. The beak sculpture of dilatata is one of the most
emphatic among the Nazades while that of this species is one of
the most obscure; besides the interdentum of the former is broader
and thicker while the branchial impression of clintonensis dis-
tinguishes it from all other species outside of its genus. ‘This
species lies very close to its fellow, facsiolaris, and it is considered
by some as merely a variety of it, but perhaps it is a good species
on account the lack of the splotched rays and larger, heavier,
thicker shell of the type for Ellipisaria.' Clintonensis is abundant

‘Recent studies by Dr. Ortmann and Mr. Frierson have resulted in
the positive conclusion that the Unio occidentalis Conrad (Monog., VII,

130 THE NAIADES OF MISSOURI

locally in the White, Black, and Neosho River basins. Simpson
reports it for the Red River, Arkansas; Prof. Isely and Rev.
Wheeler also report it for Arkansas and Oklahoma. Thus it seems
to have supplanted fasciolarsis (=phaseolus) of the Tennessee
drainage for the Southwest.

Genus Obliquaria Rafinesque.

1830—Obliquaria Rafinesque, Ann. Gen. Sci. Phys. Brux., p. 301.
1900b, Simpson, p. 610.

(Type Obliquaria reflexa Rafinesque.)

ANIMAL CHARACTERS:—Branchial opening large with papillae;
anal crenulated; supra-anal high with moderately short mantle
connection to anal; inner laminae of inner gills free from the
visceral mass except for a short distance anteriorly; palpi short
and small; soft parts grayish; marsupium occupying only outer
gills and consisting of 5-7 ovisacs placed posterior to the center
of the gill and when gravid extending far beyond the edge of sterile
marsupium; glochidia medium in size, semicircular, hinge-line
with a slight up-curve in centre; conglutinates large, white,
club-shaped, glochidia scattered all through the conglutinated
mass.

SHELL CHARACTERS:—Shel] medium in size, thick roundly
trigonal, inflated; disk of one valve with row of large knob-like
nodules running from beaks centrally ventrad and alternating
with the knobs on the other valve; beaks sculptured with two
or three concentric bars which, although heavy, are not well
defined; epidermis greenish-yellow to brown with paintings of
numerous interrupted rays; cardinals prominent and ragged;
laterals short nearly straight; beak and branchial cavities not
very deep; nacre white; female shell smaller and slightly inflated
post-ventrad.

MISCELLANEOUS REMARKS:—O. reflexa is the type and only
member of this genus known thus far and is one of the most easily
identifiable of all the Lampsilinae not only in its most unique
marsupium, but also in the knobbed sculpture of its disk. The
sex dimorphism of the shell for this type is rather peculiar as

1836, pl. XXXVI, fig. 23) is the Pty. clintonense Simpson (1900-a and b)
and hence this species, whose type locality 1s the Current River, Missourt,
should be:—Ellipsaria occidentalis (Conrad),

a

THE NAIADES OF MISSOURI 131

described above and is not often seen among the Nazades. In
that there are not such advantages for the aération of the embryos
and also a greater reduction in the number of ovisacs as seen in
most other genera of this sub-family, this genus is given a primitive
grouping here. However, in the reduction of the number of ovisacs
a compensation is made in the enlargement and elongation. ‘This
genus has a rather wide distribution over the northern and central
parts of the state, but is entirely absent from the drainage of the
south slope of the Ozarks.

Obliquaria reflexa Rafinesque.
(‘‘Horny-Back,” ‘“’Three-Horned Warty-Back.’’)
Plo XXV, Figs. 62 A—F.

1820—Obliquaria (Quadrula) reflexa Rafinesque, Ann. Gen. Sci. Phys.,
p. 306; Chenu. Bib. Conch., 1st ser., III, 1845, p. 19.

1823— Unio cornutus Barnes, Am. Jl. Sci., VI, p. 122, pl. IV, fig. 5.

1900b—Obliquaria reflexa (Raf.) Simpson, Proc. U. S. Nat. Mus.,
XXII, p. 611; Ortmann 1912b—An. Car. Mus., VIII, pp. 310-312.

ANIMAL CHARACTERS.

~ NUTRITIVE STRUCTURES:— Branchial opening large with light
colored papillae on a black back-ground; anal crenulated; supra-
ana] rather large and briefly connected to anal; inner laminae of
inner gills free except for a short distance anteriorly; palpi small,
wide, short, connected for one-half of their length antero-dorsad;
color of soft parts grayish or dirty white, mantle edges at branchial
opening black, branchial papillae and inner margin of anal opening
yellowish, gills of male and sterile female tan-color.
REPRODUCTIVE STRUCTURES:—Only outer gills marsupial,
when sterile, the ovisacs not extending below edge of gill, when
gravid larger and greatly elongated beyond the original edge,
Ovisacs 5-7 in number, large, club-shaped, curved post-ventrad,
glochidia scattered throughout the conglutinated mass; conglu-
tinates club-shaped, solid, white, discharged whole; glochidia
semi-circular, medium in size, hinge line slightly curved upward
in middle, measures 0.225 x 0.235mm.

SHELL CHARACTERS.

EXTERNAL STRUCTURES:—Shell sub-trigonal, heavy and thick
anteriorly, post-dorsal line rounded; slightly incurved post-

132 THE NAIADES OF MISSOURI

ventrad in male, slightly swollen in female; whole shell medium
in size, small but more inflated; disk from beaks to central-ventral
edge sculptured with a row of a few large knobbed tubercles,
those of one valve alternating with the knobs of the other; post-
umbonal ridge with corrugations; epidermis yellowish-green to
dark brown.

INTERNAL STRUCTURES:—Cardinals upright, jagged; laterals
short, nearly straight at right angles to a rather broad interdentum
beak and branchial cavities moderately deep; nacre a pure,
stippled white.

Sex Length Height Diameter Locality
oe GIA SONG eae | Sassen) (Platte R., Platte R. Station)

OF 55) X45) x) sOmm——— (Miaraiswdesi@yones eAthol)
Oo 35 xX-26 x 17mm——/(Platte R., Dixon Falls)

Q@ 20 xX I5 x I2mm——(Miss. R., Hannibal)

et! MAXEY SS TIS 5% 9.5mm——(Crows Fork, Fulton)

The last two are measurements of juveniles of widely different
locality under far different ecological conditions, although the
shell characters are not very much different. The former shows
more of a rayed olivaceous epidermis and the latter a plain straw
color. The Mississippi juvenile, being more typical as in case of
most shells, is described here:—Shell sub-trigonal, valves inequi-
lateral with two knobs on one side and one on the other, darker
green epidermis below the knobs, rayed with interrupted V-
markings, beak sculpture irregular concentric undulations extend-
ing out on disk; nacre white, slightly tinged with pink.

MISCELLANEOUS REMARKS:—Both as to structure of shell and
nutritive soft parts O. reflexa is rather primitive, but as to marsupial
characters it naturally falls under the lower groups of the Lampst-
linae. In North Missouri reflexa reaches a very large growth while
in Central Missouri it averages only about one-half the size; for
the two faunae this variation applies to many other species. Since
Drs. Lefevre and Curtis (1912, pp. 137-and 138) have called
attention to the eccentric breeding habits and glochidial behavior
of reflexa the writer has followed up the breeding period rather
closely to find that it is gravid with early and Jate embryos, also
with glochidia, during June, July and August, but is sterile for
late Fall and mid-Winter, thus showing that this species has a
short period of gravidity,—a different reproductive habit from

4
THE NAIADES OF MISSOURI 133

that of most Lampsilinae. ‘The fact that the mature glochidia
will not leave the conglutinated form after being extrued by the
mother and because of the fact, too, that artificial infection of
fish cannot be induced with its glochidia would lead to believe
that its metamophosis may take place without parasitism.

Genus Cyprogenia Agassiz.

1852—Cyprogenia Agassiz, Arch. fur Naturg., p. 47; 1900b, Simpson,
p. 609.

(Type, Unio trroratus Lea.)

ANIMAL CHARACTERS :—Branchial opening with short papillae;
anal finely crenulate; supra-anal closely connected to anal;
mantle edge antero-ventrad to branchial opening with fine crenu-
lations for a short distance; inner laminae of inner gills free from
visceral mass except at anterior end; palpi very small, pointed,
very wide gap between them and anterior attachment of outer
gills; marsupium consisting of 5-7 ovisacs anterior to center of
outer gills, when gravid ovisacs immensely elongated and coiled
post-dorsad; conglutinates white, very long and solid, subcylin-
drical; glochidia semicircular, medium in size, ventral margin
obliquely rounded, hinge line long and slightly upcurved.

SHELL CHARACTERS:—Shell roundly triangular, subinflated;
disk with peculiar nodulat structure; beaks more or less prominent,
sculpture obscure; epidermis olive, painted with mottled rays;
hinge complete; beak cavities rather deep.

MISCELLANEOUS REMARKS:—The type of Cyprogenia, irrorata‘
(Lea), is not found in Missouri being entirely displaced by C.
Aberta (Conrad). The variety of trrorata pusilla of Simpson, is so
doubtfully reported for the St. Francis River that it is not listed
here. Simpson is of the opinion that all C. crrorata, reported for
the localities west of the Mississippi, are really C. Abertt. As to
soft parts there is a similarity to those of Obliquaria; however,
the slight differentiation of the mantle border antero-ventrad to
branchial opening and also its uniquely coiled and extremely
elongated ovisacs would rank it above.

’ From Rafinesque’s evident description and figures (Ann. Gen. Sci.
Brux., V, 1820, p. 312, pl. LX XXII, figs. 4, 5) we should make C. ?rrorata
(Lea) a synonym for C. stegaria (Raf.)

134 THE NAIADES OF MISSOURI

Cyprogenia Aberti (Conrad.)
(“Young Fan-Tail.’’)
Pl. XXV, Figs. 83 A and B.
1850—Unio aberta Conrad, Pr. Ac) Nat. Sci. Phila Vi) pe tosuc5sas
ipSAcsyNat= sc Lila ps 2osn pl exe Vales Te
1885— Unio popenot Call, Bull, Washb. Col., I, p. 49, pl. II.

1900b—Cyprogenia abertt (Conrad)! Simpson, Proc. U. S. Nat. Mus.,
XXII, p. 610.

ANIMAL CHARACTERS.

NUTRITIVE STRUCTURES:—Branchial opening with many
short papillae; anal with finely crenulated inner edge; supra-
anal separated from anal by short mantle connection; mantle
edge antero-ventrad to branchial opening slightly crenulate;
gills short, wide, inner wider than outer, inner laminae free from
visceral mass, except for a short distance anteriorly; palpi very
small, connected about one-half of their distance antero-dorsad;
color of soft parts dirty white, except for the black, squarish mott-
lings of the mantle edges around the supra-anal opening.

REPRODUCTIVE STRUCTURES:—Marsupium formed by five
to seven ovisacs originating from the edge of the outer gills antero-
ventrad and extremely elongated posteriorily into a coil; conglu-
tinates white, very long, solid, club-shaped; glochidia unkown.

SHELL CHARACTERS.

EXTERNAL STRUCTURES:— Shell sub-triangular, compressed;
beaks rather pointed, sculpturing obscure; post umbonal ridge
prominent with a hummocky expansion middle-ways for the
female shell, not so sculptured in male; radial furrow rounded
moderately wide; dorsal ridge faintly ribbed; disk entirely
rugose; epidermis brownish yellow with numerous banded rays
marked with mosaics of green mottlings of various patterns of
geometric designs.

INTERNAL STRUCTURES:—Cardinals double in each valve;
laterals double in left, single in right; interdentum long; beak
cavities deep; nacre bluish, irridescent.

Sex Length Height Diameter Locality

Cue 4 2a kG on ONS (St. Francis R., Greenville
QIAGAO XG anG2 sd OO (White R., Hollister)

Chee Bi eS 3 Oy Beers Qs s “

OS YO) ee IZ) WSS LiNIt-(0) (ears :

THE NAIADES OF MISSOURI 135

Although the shell of the last measurement is young and well
preserved, yet the beak sculpture does not even present anything
very distinct. The beaks are pointed, incurved and two-ridged,—
one ridge radiating off to the posterior and the other to the anterior
umbonal slope. The shell in this stage resembles that of young
P. securis from a dorsal view. The soft parts of this specimen
show that its marsupial characters consist of seven sterile ovisacs
originating just in front of the middle part of outer gill curved
backward toward the branchial opening.

MISCELLANEOUS REMARKS:—C. Abertt is a rather common
little shell in the White, Black and Neosho basins of this State.
It is distinguished from C. zrrorata by not being so rounded,
nor so solid, rugose and ridged parallel to growth lines. It is not
to say a variable shell, yet the writer has noted some with such a
truncated posterior end as to suggest an approach to zrrorata,
or is probably the C. Aberti lamarckiana (lea) reported for the
Black River, Missouri. Specimens taken from Indian mounds
in Southwest Missouri show great preservation although deposited
some centuries ago. As they were placed in these graves for “‘food”’
to the departed spirit”’ (as was the burial custom of the aborigines)
in greater quantities than other mussel shells it is evident that this
species was prized above all others for its food qualities. It can
be determined that the live mussels were deposited since dried
muscular tissue is still adhering to the muscle scars.

Cyprogenia Aberti lamarckiana (Lea).
(Not figured, nor described.)

1852— Unio lamarckianus Lea ,Tr. Am. Phil. Soc., X, p. 266, pl. XVII,
fig. 20.

This sub-species is simply listed for this State through a report
of it by Mr. Elwood Pleas to the U. S. National Museum, where
it is now on exhibit under the number, 124,630—and also through
a recent report of it for the Black River, Popular Bluff, Missouri,
by Mr. Walker who has received it in this same collection of Mr.
Pleas, a part of which lot was sent to the Washington Museum.
No data is at hand for illustration or description.

i36 THE NAIADES OF MISSOURI

Genus Obovaria Rafinesque.
1819—Obovaria Rafinesque, J. de Phys. Chim. Hist. Nat., p. 426.
(Type, Unio retusa Lamarck.)

ANIMAL CHARACTERS:—Branchial and anal opening both
papillose; supra-anal large, crenulated; mantle margin antero-
ventrad to branchial opening slightly specialized with lamellae
or crenulations; inner gills twice the width of outer, inner laminae
entirely connected to visceral mass; palpi small, far removed from
anterior end of outer gills; color of soft parts soiled white; mar-
supium consisting of many ovisacs originating from posterior
half of outer gills and extending far below the ventral edge; con-
glutinates poorly developed, embryos being held in rather loose
masses; glochidia somewhat large, semielliptical, spineless, hinge
line undulate.

SHELL CHARACTERS:—Shell rounded or ovate, inflated,
height, greater than length; post-umbonal ridge not distinct,
disk smooth; beaks prominent, sculptured with a few indistinct,
concentric, sinuate bars; epidermis brown with faint rays.

MISCELLANEOUS REMARKS:—AlIthough this genus is another
one of the primitive types of Lampsilinae, yet the differentiation
of the mantle border antero-ventrad to the branchial opening and
the tendency of the marsupium to assume the reniform shape
and to acquire a position near the opening of the incoming currents
all show and approach to the more modern groups. According
to Dr. Ortmann the sub-genera of this genus, as fixed by Simpson,
are well deflned enough to be retained.

Thus we have the following grouping :—
1.—Sub-Genus Obovaria (sens. strict.)
Shell upright, oval, rather solid; beaks drawn up more
toward the middle of the dorsal line; cardinals mostly normal.
Type, O. retusa (Lamarck.)
2.—Sub-Genus Pseudo6dn Simpson (1900b, p. 601).
Shell oblique, elliptical, solid, thick; beaks protruding
anteriorly; cardinals subparallel to laterals.
Type, O. ellipsis (Lea)
From the above diagnoses it may seem that division is made
on the shell characters, the soft parts being identical,—even in
marsupial and glochidial characters. However, this Genus is

THE NAIADES OF MISSOURI 137

only represented in this State by ellipsis and that in a limited
distribution both in the geographical and individualistic sense.

Obovaria (Pseudo6n) ellipsis (Lea).
(‘Missouri Nigger-Head,”’ “‘Egg Shell,” “Hickory Nut.’’)
PIZXXY, Fogs. 64.A and B.

1828— Unio ellipsis Lea, Tr. Am. Phil. Soc., III, p. 268, pl. IV, fig. 4.
-1900b—Obovaria ellipsis (ea) Simpson, Proc. U. S. Nat. Mus.; rg912b,
Oremann,, Car. Mus, Vill pp» 323-324.

ANIMAL CHARACTERS.

NUTRITIVE STRUCTURES:—Branchial opening small. with
two-ranked papillae; anal finely papillose; supra-anal crenulated
(a rare character) not well connected to anal; mantle border
just antero-ventrad to branchial opening with crowded papillae
or crenulations extending one-third of the way towards center
of ventral margin; gills very wide, both blunt and pointed poster-
iorly, inner laminae of inner gills entirely connected to visceral
mass; palpi rather small, connected about one-half of their length
antero-dorsad; foot pinkish, mantle edge dark in region of siphonal
openings, rest of soft parts dirty white.

REPRODUCTIVE STRUCTURES:—Marsupium occupying pos-
terior portion of outer gills, rather kidney-shaped, consisting of
several ovisacs, twenty-five or thirty which, when gravid, extend
far below the original edge, pigmented purplish ventrad; conglu-
tinates white, not well formed, ova and glochidia discharged in
rather loose masses;' glochidium medium in size, semi-elliptic,
rather short and straight, measures 0.210 x 0.265mm.

SHELL STRUCTURES.

EXTERNAL STRUCTURES:—Shell sub-elliptical, rather oblique,
very: solid, thick, heavy; ventral margin more rounded than
dorsal; disk smooth; no post-umbonal ridge; rest lines of growth
very distinct; beaks projecting anteriorly, rather prominent,
sculpturing indistinct; epidermis yellowish-horn color with green
rays in young shell.

INTERNAL STRUCTURES:—Cardinals very heavy, nearly par-
allel to laterals with right post-cardinal converged dorsad and
rounded up from a broad V-shaped gutter; interdentum broad,
thick, right deeply gashed; beak cavities not very deep; nacre
white.

138 THE NAIADES OF MISSOURI

Sex Length Height Diameter Locality

OE SON Ex. f Olle eX EA AF (Grand River, Sumner)

Coe 0} PEXoMNS 5) lEXaI SO (Mississippi River, Hannibal)
OR OS) XuMall Xe wea (Osage River, Warsaw)

Cy i BOne x PQA SON ans (Mississippi River, Hannibal)
OVD REX. 2ON Kee) ( a ah si )

Beaks of these specimens of the last two measurements very
full, rounded, poorly sculptured although not eroded; more
inflated (comparatively) than adult shell; epidermis olive with
profuse paintings of green rays so as to give the appearance of
olive green; post-ventral edge of shell more obliquely rounded
than in adult; nacre pearl blue.

MISCELLANEOUS REMARKS:—From shell characters there is
no real sex dimorphism except a little greater inflation in the
female, but not only a less crowded arrangement of septa is seen
in gills of the male but there is a more intense black pigmentation
in the region of the branchial opening. The crenulated supra-anal
opening is surely a unique character and may indicate a conversion
of thts opening into the anal. The bare connection between the two
openings would also indicate this merging. Although of rare
occurrence ellipsis reaches its greatest perfection for the interior
in the Grand River of North Missouri. It is found occasionally
in the Osage Basin, but never develops a shell as large, heavy
or bright as found in the Grand or in the Mississippi. This fact
of difference in size, color and solidity for the shells of these different
mussel faunae applies to most other species as well. Scammon
(1906, p. 306) reports this species as very active with strong
musculature and that he has traced this species for fifty yards
by its furrow in the Kansas River. This species is bradytictic.

Genus Nephronaias Crosse and Fischer.

1893—Nephronaias Crosse and Fischer, Miss. Sci., Pt. 7, II, p. 556;
1g00b, Simpson, Proc. U. S. Nat. Mus., XXII, p. 591.

(Type, Unio plicatulus Charpentier.)

ANIMAL CHARACTERS:—Identical with those of Obovaria—
even in glochidial characters.

SHELL CHARACTERS:—Shell rounded to sub-elliptic and
elongate, usually compressed; posterior ridge rather indistinct,
beaks not near the anterior end, sculpture poorly developed,—
consists of a few faint double-looped bars; epidermis greenish

ve ~~

THE NAIADES OF MISSOURI 139

to yellowish, generally with very distinct green rays; sex dimor-
phism of shell not well shown.

MISCELLANEOUS REMARKS:—This genus is set aside solely
on shell characters. The sub-genus, Pseudoon, serves as a good
connecting link between Obovaria and WNephronaias. Chiefly
because of the lack of much specialization of the mantle border
antero-ventrad to the branchial opening Unio ligamentina (1am.)
is taken out of Simpson’s grouping of it as a Lampsilis. In this
State this genus is best represented by N. ligamentina and ellipsi-
formis (Lea).

Nephronaias ligamentina (Lamarck). (
Pl. XXV, Fugs:'85A°and B.

1819— Unio ligamentina Lamarck, An. San. Vert., VI, p. 72.

1900—Lampsilis igamentina Simpson, Proc. U. S. Nat. Mus., XXII,
P-. 539.

1912b—Nephronaias ligamentina (Lam.) Ortmann, An. Car. Mus.,
Vibe pes 25:

ANIMAL CHARACTERS.

NUTRITIVE CHARACTERS :—Branchial opening large with strong
papillae; anal distinctly crenulated; supra-anal rather small,
well separated from anal by thick mantle connection; gills very
large, inner laminae of inner gills entirely connected to visceral
mass; palpi very large, wide and pointed; color of soft parts
dingy white for most part, however, post-mantle edge brownish.

REPRODUCTIVE STRUCTURES:—Marsupia occupying most of
outer gills, consisting of about sixty ovisacs well separated by
thick septa, when gravid extending far below original edge of
sterile marsupium, making a longitudinal line; mantle edge
antero-ventrad to branchial opening with twenty-five or thirty
low denticulations; conglutinates white, broad, leaf-like, solid
when ova are present, cohesion lost when mature glochidia are
developed; glochidia semi-elliptical, spineless, large, hinge line
undulate, measures 0.220 x 0.260mm.

SHELL CHARACTERS.

EXTERNAL STRUCTURES:—Shell rather evenly eliptical, solid,
moderately inflated, beaks rather low, sculpture consisting of
several fine, wavy, concentric lines most pronounced at foot of
posterior and anterior slopes; disk smooth; epidermis brown or
yellowish with broad, dark-green rays.

ss

140 THE NAIADES OF MISSOURI

INTERNAL STRUCTURES:—Cardinals rather stumpy and stout;
interdentum rather short and cut away; laterals very strong;
nacre white with stippled effect—a very valuable shell com-
mercially for this reason.

Sex Length Height Diameter Locality
OM nmoe xs) (6O8" ex, 744-5 1m (Marais des Cygnes, Rich Hill)

CL On mnexy OS see Xe Alse S nrlnin (Meramec R., Meramec Highlands)
OMT OOM 1508 9 Xo ez Olli (Osage R., Osceola)
Ce sXe 20) wexe s LOFOMt (Gasconade R., Gascondy)

THEY Se) RS 8 Ao rerven (St. Francis R., Greenville)

BaShex OX 3.0mm (St. Francis R., Greenvile).

These last two measurements are those of two byssiferous
juveniles identified by Dr. Howard and Prof. Clark. At first the
writer was inclined to call them L. luteola chiefly on the grounds
that both were found clinging by their byssi to a costata shell in
a bed where luteola predominated; however, this identification
was excluded on the basis of the presence of anterior rays and a
difference of umbonal sculpture being less prominent with the
ridges more broken in case of juvenile ligamentina as shown in
these two specimens. The byssus is attached to the upper posterior
part of the foot although it extends out antero-ventrad between
the valves. In the smaller juveniles the bysuss is about 120mm
long, in the larger 135mm. Both bear dense papillae on both bran-
chial and anal openings. Anterior end of outer gills lifted up very
high above the palpi, gills dark tan-color; branchial papillae rusty
red; epidermis yellowish with bright broad green rays—mostly
placed anteriorly.

MISCELLANEOUS REMARKS:—While JN. ligamentina may have
the widest general distribution of the North American Nazades,
yet it 7s not found anywhere in the interior of this State north of the
Missouri River. However, it is the most common of species in
the Mississippi, the Des Moines and in all the interior drainage
south of the Missouri. It is not inclined to vary much from the
typical ligamentina of Lamarck; however, the Osage River con-
tains some forms that are somewhat puzzling due to ecological
conditions that erode the epidermis and distort the shell of this
species (and of other characteristically rayed species, for that mat-
ter), but these are of rare occurrence in the Osage from the center of
its course to its mouth. As mentioned elsewhere this local effect
may be traced to the chemical reaction of the mineral water of
the springs’ region. There are no species it may be confused with

THE NAIADES OF MISSOURI I4I

except N. ellipsi formis when the former is young. However, the
more elliptic shell with broader, straighter rays would serve as
the main distinguishing features. Surber (1913, p. 109) has found
that its glochidium is a gill parasite upon the white bass (K.
chrysops) as a natural host. Breeding records have been care-
fully kept for this species, especially for commercial reasons, to
find that it is typically bradytictic.

Nephronaias ligamentina gibba (Simpson).
1900b—Lampsilis ligamentinus gibbus Simpson, Proc. U. S. Nat. Mus
XXII,p. 540.
(“Southern Mucket,” ‘‘ Yellow Mucket.’’)

ANIMAL CHARACTERS:—Identical with those of the parent
species, except, of course, in short gills and other modified parts
due to a shorter shell. The glochidia are the same.

SHELL CHARACTERS :—Shell “peculiarly short, humped form”’
(Simpson); thicker, heavier more inflated with more roughened
growth lines and more of a yellowish epidermis than the parent
shell.

Sex Length Height Diameter Locality
Sy AOS ex OO! ke onim (Osage R., Monegaw Springs)
2 SO) x 464) x” Aomm CAS “Linn ‘Creek)

” ””

O89) xe HO eX) .3onim ( Bagnell)

MISCELLANEOUS REMARKS:—Gibba seems to be a rather .
common variety throughout the southern range of the species
and is expecially characterized by the short, stout, ‘‘humped”’
form of shell. Perhaps it bears the same relation to its species as
dakotana Frierson does to grandis Say. The writer’s experience
in the study of the form of ligamentina while on a 300-mile float
down the Osage was that it was difficult to ascertain the point
of separation between the species and the variety, gibba, so imper-
ceptibly do they grade into each other. This form is met with in
drainage of the Ozark Center as well—especially in the Black
River.

Nephronaias ellipsiformis (Conrad).
(‘‘ Ellipse.’’)
Pl. XXV, Figs. 86 A—D.

1836— Unto ellipsiformis Conrad, Monog. VIII, p. 60, pl. XXXIV, fig. I.

1845— Unto spatulatus Lea, Proc. Am. Phil. Soc., IV, p. 164.

1898—Lampsilis spatulatus Baker, Moll. Chicago, Pt. I, p. 106, pl
KOPNet ss apl. EMM atie..2,

"142 THE NAIADES OF MISSOURI

1900b—Lampsilis ellipsiformis Simpson, Proc. U. S. Nat. Mus., XXTI,
DP. 557-
ANIMAL CHARACTERS.

NUTRITIVE STRUCTURES:—Branchial opening with numerous
yellowish papillae; anal very finely papillose; supra-anal small,
high, closely but distinctly connected to anal; gills large, pointed
even in the marsupial ones; inner laminae of inner gills connected
entirely to visceral mass; palpi sickle-shaped; color of soft parts
the usual dirty white with posterior mantle edges blackened.

REPRODUCTIVE STRUCTURES:—Marsupium occupying posterior
half of outer gills, consisting of about twenty ovisacs separated by
thick septa, when gravid extending below the original edge of sterile
marsupium, tips pigmented with bluish, beaded spots; mantle
edge antero-ventrad to branchial opening with papillae terminating
in rather fine crenulations centrad-ventrad; conglutinates and
glochidia unknown.

EXTERNAL STRUCTURES:—Shell small, elliptical, dorsal and
ventral lines about the same curviture; post-umbonal ridge rather
rounded; beaks very low, usually eroded, even in the youngest
shells, thus sculpture not seen; epidermis brownish-yellow with
bright waved rays all over disk; no sculpturing on disk; shells
somewhat sexually dimorphic, the female being rather swollen
post-ventrad.

INTERNAL STRUCTURES.—Cardinals strong, upright; inter-
dentum large and thick; laterals short, stout, very slightly curved;
beak cavities shallow; nacre white, sometimes with slight pinkish -
tinge and teeth rusty-red.

Sex Length Height Diameter Locality
of HO Se el Se wa iarion (Gasconade R., Gascondy)
O43 x 128 2x or smi (Osage R., Warsaw)
VTi oe WG oko a Sisahan (See. Proctor)
OPER a Dice Ap) oon 7.5mm (Niangua R., Hahatonka)

MISCELLANEOUS REMARKS:—This little striped shell is common
throughout Central Missouri, but is never found anywhere in the
interior north of the Missouri River and is rare in the southern
drainage. Its shell may sometimes be taken for young N. liga-
mentina; however, the adult shells of these species are nothing alike.
The anatomy of both are very similar; however, the inner mantle
edge antero-ventrad to branchial opening is more specialized and
indicates a step in advance. Hundreds of females were examined

THE NAIADES OF MISSOURI 143

daily throughout July and the first two weeks of August to find
them sterile in every case. Since Wilson and Clark (1912, p. 48)
report it gravid for an earlier date this incomplete breeding would
indicate that it is bradytictic.

Nephronaias ellipsiformis venusta (Lea).

Not figured.

1838— Unto venustus Lea, Tr. Am. Phil. Soc., VI, pl. II, fig. 4.

1900b—Lampsilis venustus Simpson, Proc. U. S. Nat. Mus., XXII,
p- 543.

ANIMAL CHARACTERS:—Entirely identical with those of the
species both as to nutritive and reproductive structures. No glo-
chidia have been found.

SHELL CHARACTERS:—Also identical with the typical ellipsi-
formis-shell except for a smal) guttered furrow just antero-parallel
to post umbonal-ridge of shell. he male shell of this sub-species
is also more pointed posteriorly than the male type species.

Sex Length Height Diameter Locality
SO) 3s By) eh Briton (Niangua R., Hahatonka)
Oss. xara xo? omit (Wy eras & 4g )

MISCELLANEOUS REMARKS:—The writer heartily agrees with
Mr. Walker that venusta is ‘very closely related to ellipsiformis
and also with Mr. Frierson’s opinion, that it is only a form of
ellapsiformis. ‘The type locality for U. venustus of Lea is Potosi,
Washington County, Missouri, and belongs to the Meramec River
basin. Simpson (1g900b, p. 543) only reports it for that locality.
Since then Rev. Wheeler has reported it for Arkansas; so has
Wilson and Meek (1912. p. 19.). The writer has only found it
in the Niangua River. Having such limited distribution and such
lack of discriminating features from N. ellipsiformis there should
be no hesitancy in naming venusta as a variety. From N. pleasii
this subspecies differs by a ticker, heavier, more coarsely rayed
and more of a tawny clolored shell.

Nephronaias Pleasii (Marsh).
(“Bleeding Tooth,’”’ ‘Pleas’ Shell.’’)
Pl. XXV, Figs. A—D.
1891— Unio pleasit Marsh, ‘‘The Observer’’ (a newspaper), II, May;
Nautilus, V. p. 2.
1900b—Lampsilis pleasit Simpson Pr. U.S. Nat. Mus., XXII, p. 557.

ANIMAL CHARACTERS :—No females have been secured by the

144 THE NAIADES OF MISSOURI

writer; however, the nutritive structures of the males are identical
with those of N. ligamentina and ellipsiformis.

SHELL CHARACTERS.

EXTERNAL STRUCTURES:—Shell sub-elliptical, rather thin,
smooth, somewhat compressed, rounded before, obtusely angular
behind; beaks rather low, scuJptured by three or four fine shaped
undulations; epidermis brown polished horn, with numerous green
capillary rays, disposed mostly posteriorly and showing through
the thin sheJl on the inside.

INTERNAL STRUCTURES:—Cardinals small, single in right,
double in left valve, erect and parallel with laterals; left inter-
dentum cut away for post-cardinal tooth; beak cavities rather
shallow; nacre bluish, coppery or salmon in umbonal cavity.

Sex Length Height Diameter Locality

ofl PM Be exe erlin Pog aoe \ioabol (White R., Hollister)
of SES SS VSS Utes imalinal (Cre Ma a )
of i XO) | Se aS. Ese) ike). soolieal (James R., Galena)

MISCELLANEOUS REMARKS:—According to Mr. Marsh this
shel] bears some resemblance to Unio spatulatus Lea (i. e., U
ellipstformis Conrad), but differs chiefly in being thinner, smaller
and more compressed. It is like venusta in that the female shell
is deeply emarginate or constricted in front of post-umbonal ridge
as the writer determines from the author’s description (1891, p. 2).
This species was dedicated to Mr. Elwood Pleas of Indiana who
collected this Species, together with many other rare Species,
from South Missouri. It was also collected by Mr. S. M. Godbey
at Morrisville, Polk Co., Missouri, who sent it to the National
Museum where it is now recorded under the number, 132634.
The writer found pleasii as a rather common shell in the White
River, this State.

Nephronaias ozarkensis (Call).
(‘‘The Ozark Shell.’’)
(Not figured.)

1887— Unio ozarkensis Call, Pr. U. S. Nat. Mus., X, p. 498, pl. XX VII;
1895, Dr AcwSct.. st. loms) Vi lGipp 23-345 nels oovidilile
1900b—Lampsilis ozarkensis Simpson, Pr. U. S. Nat. Mus., XXII,
P: 557- ;

ANIMAL CHARACTERS:—Reference to rough field notes show

THE NAIADES OF MISSOURI - 145

that the soft parts are those of Nephronaias. The shell was
identified later as ozarkensis of Call.

SHELL CHARACTERS.

EXTERNAL STRUCTURES :—Shell sub-elliptical, smooth, rather
compressed; post-umbonal slope somewhat biangulate by siphonal
ridges; beaks not prominent, sculptured by three fine undulations;
epidermis brownish-yellow or olive with numerous fine green
rays over central portion of disk; sexually dimophic.

INTERNAL STRUCTURES:—Cardinals tend to double in both
valves, laterals rather short, slightly curved; nacre usual'y white,
sometimes salmon or pink, irridescent; muscle scars confluent.

Sex Length Height Diameter Locality
O55 .0k _ 135.0) X12 (Jack’s Fork, Current R.)
CRS ARS Xe 27 exe 1582 (Jack’s Fork, Current R.)

MISCELLANEOUS REMARKS:—The latter measurement is that
of Call’s taken for a shell from the same locality (which is one of
the type localities of ozarkensis) as for the shell of the first measure-
ment which is now in the hands of the writer through the kindness
of Mr. B. F. Bush, but which is now too much damaged through
shipment for figuring. Its shell is very much like that of N. pleasii
as to general outline, but is a little thicker and has a different
nacre and epidermis. Forms of this Species reported by Meek
and Clark (1912, p. 18) for the White River drainage and described
as like “a very elongated Quadrula coccinea’”’ and also identified
by Mr. Walker as ‘“‘Pleurobemae rather than species of Lamp-
stlis’’ are doubtless only Pleurobemae utterbackit of Frierson.
Definite assignment to the latter may be made for shells received
from the White River, Hollister, Missouri, under the name of
ozarkensis with the note:—‘‘although not having Lampsiline
beak sculpture.’’ The reader is invited to compare descriptions
and illustrations of Neph. ozarkensis and Pleu. utterbackit and note
that the shell of the former does not possess such tumid beaks,
nor such a furrowed post-slope, nor such distinct muscle scars,
and its shell has its whole facies of a thinner, lighter character,
thus being more inclined to a Lampsiline structure.

Genus Amygdalonaias Crosse and Fischer.

1893—Amygdalonaias Crosse and Fischer, Jour de Conch., pp. 31-32;
1900b,—Simpson, Proc. U. S. Nat. Mus., XXII, p. 604 (as subgenus for
Plagiola).

146 ; THE NAIADES OF MISSOURI

(Type, Unio cognatus Lea.)

ANIMAL CHARACTERS:—Anal opening crenulated; supra-
anal widely separated from anal; inner laminae of inner gills con-
nected to visceral mass except for a small posterior slit; palpi
small; marsupia consisting of several ovisacs at posterior half
of outer gill that acutely tapers; conglutinates white, undivided;
glochidia smalJlest of all Nazades.

SHELL CHARACTERS:—Shell among the smallest, roundly
triangular, inflated, flattened on post-dorsal slopes; post-umbonal
ridge sharply anguJar; disk smooth; beak rather full, sculptured
with a few ridges, the latter ones being rather definitely double
looped; epidermis greenish to yellowish with characteristic paint-
ings of green arrow-marked rays; female shell slightly more
inflated post-ventrad; hinge teeth delicate; nacre usually white.

MISCELLANEOUS REMARKS:—Although this genus stands
very close to Obovaria and Nephronaias, having essentially identical
structures of soft parts, yet it deserves this compartment on account
of its unique form, size and color markings of shell and especially
upon its glochidial characters, being the smallest on record. The
only two members of this genus are represented in this State by
A. donaciformis (Lea) in North Missouri and by truncata (Raf.)
in Central Missouri. The latter is never found north of the Missouri
River and the former is rarely ever found in Central Missouri;
neither have been found by the writer in South Missouri. The
Osage River bears many intergrades for these two species.

Amygdalonaias donaciformis (Lea).
(‘‘Fawn’s Foot,” “ Deer-Toe,” “Zigzag.’’)
PEUX AV, Figs. 80; A).
1828—Unio donactformis Lea, Tr. Am. Phil. Soc., 111, p. 267, pl.
TVs Sigs" 3)
1820— Unio zigzag Lea, Tr. Am. Phil. Soc., III, p. 440, p. XII, fig. 19.

1898—FPlagiola donactformis Baker, Moll. Chicago, Pt. I, p. 92, pl.
XIII, fig, 4; 1900b, Simpson, Proc. U. S. Nat. Mus., XXII, p. 605.

ANIMAL CHARACTERS.

NUTRITIVE STRUCTURES:—Branchial opening small with
numerous papillae; anal indistinctly crenulated; supra-anal
separated by a long and thick mantle connection to anal; inner
laminae connected to visceral mass except for a narrow slit

THE NAIADES OF MISSOURI 147

anteriorly; palpi small, connected one-half of their length antero-
dorsad; color of soft parts dirty white except for blackish mantle
edge at siphonal openings.

REPRODUCTIVE STRUCTURES:—Marsupia rather low on post-
ventral portion of outer gills; when gravid the numerous distinct
ovisacs extend below the original edge of gill; glochidia smallest
on record, measuring 0.600 x 0.063 min., semicircular, spineless,
hinge line short, very slightly undulated; conglutinates white, loosely
connected when glochidia mature.

SHELL CHARACTERS.

EXTERNAL STRUCTURES:— Shell very small, compressed,
rounded before, pointed high- behind; post-umbonal ridge rather
prominent; disk smooth; beaks rather full sculptured by five
upward angled bars extending out as finer concentric lines in later
bars; epidermis green or olivaceous, painted with radiating green
rays of zigzag or arrow-marks; female shell inflated post-ventrad.

INTERNAL STRUCTURES:—Cardinals double in left, single in
right valve, compressed, high and ragged; interdentum narrow;
laterals single in right, faintly double in left; nacre pearl blue
or white. rarely pink.

Sex Length Height Diameter Locality
GY ee Koy Se aah (Grand R., Gallatin)
OM ame xe 2 oe Xe eS (Platte R., Dixon Falls)
OF sgh 58" NO SO Geared (ae ” Agency Ford)
oe 4 x Sa5 0X 9.5mm (Grand R., Darlington)
OW Rr iele sx GAMO} >< Alasprambaol. Ce ” Chillicothe)

The last two are among the smallest juveniles in the writer’s
collection. The smaJlest meets with the following description :—
Post-umbonal ridge sharply angled; beaks prominent, well up
toward middle of dorsal line, sculptured by five early bars bowed
upward in the center, the latter ones being rather fine, concentric;
epidermis green with costa-like paintings on the post-dorsal
ridge; disk with two rows of zigzag paintings parallel to the growth
lines. Four juveniles of this species were found in the Osage
clinging to one byssal thread, but unfortunately they were lost.

MISCELLANEOUS REMARKS:—Typical donaciformis may be
easily distinguished from Amyg. truncata in possessing a smaller
shell, more painted, thinner, less inflated, more dorsally ridged,
and is more of an inhabitant of quiet water with mud-sand bottom.
Donactformis is more supplanted in Central Missouri by truncata

148 THE NAIADES OF MISSOURI

(Raf.), but, as stated before, it takes the place of the latter wholly
in North Missouri. The North Missouri Grand River bears dona-
ciformis in its most typical form. ‘The writer finds this species
most colonial in their habits, and has been able to find many of
them nearly every month of the year, but has not found any
gravid during the winter. The earliest date for the bearing of
glochidia is June 19th. No previous public record has ever been
made of this unique glochidium. From the above data it may be
inferred that it is not bradytictic as is mostly the breeding habit
of the Lampsilinae. ‘This little mussel] is also eccentric in that while
in the parasitic stage it develops an adult shell five times the size
of the glochidial one. Surber (1913, p. 109) finds that its specific
distributor is ‘““Sheep’s Head” (A. grunniens).

Amygdalonaias truncata (Rafinesque).
(‘‘ Deer-Foot,”’ or ‘‘ Deer-Toe.’’)
XXV, Bag: 88 A and..B.

1820— Unio truncata Rafinesque, Ann. Gen. Sci. Phys. Brux.

1831— Unto elegans Lea, Am. Phil. Soc., IV, p. 83., pl. fig. 13.

1898—Plagiola elegans Baker, Moll. Chicago, Pr. I, p. 91, pl. XXI,
fig. 1; 1900b, Simpson, Pr. U. S. Nat. Mus., XXII, p. 604.

1912b—A mygdalonaias elegans (Lea) Ortmann, An. Car. Mus., XXII,
D, 328.

ANIMAL CHARACTERS.

NUTRITIVE STRUCTURES :—Identical with those of donaciformis.

REPRODUCTIVE STRUCTURES:—Branchial mantle margin a
little more thickened with slight crenulations than in donactformis;
glochidia a little larger, measuring 0.060 x 0.070 mm—otherwise
these structures are identical with those of donaciformits.

SHELL STRUCTURES.

EXTERNAL STRUCTURES:—Shell short, roundly triangular,
inflated; post-umbonal ridge sharply angulated from beaks to
posterior point of shell; disk smooth; beaks rather prominent,
sculptured with a few fine ridges more or less double-looped or
sinuated; epidermis yellowish, brownish or even grreenish with
beautiful paintings of green broken by arrow-marked rays; no
sex dimorphism of shell, both sexes being rather swollen post-
ventrad.

INTERNAL STRUCTURES:—With the exception of a deeper and

~~

THE NAIADES OF MISSOURI 149

more rounded out branchial cavity and somewhat coarser cardinals
these structures are identical with those of donaciformis.

Sex Length Height Diameter Locality

i 50) xX) 365 x 925) mm (Osage R., Linn Creek)

OM ABE Xd 9 34y Xeon? Sy afr) (Gasconade R., Gascondy)
OF oe Xe ON 7a Tint (Osage R., Schell City)

eS Taek 27) ke LOLs mien ae iy 2S Proctor)

MISCELLANEOUS REMARKS:—As pointed out under the des-
cription of donaciformis, truncata is as distinct when typical as
its only con-generic ally—especially in its broadly truncated shell
post-dorsad. Neither is truncata so sexually dimorphic; however,
the male shell is unusually more elongated and pointed posteriorly
and has less inflation. Both sexes have their shells rather expanded
post-ventrad. ‘This species is rarely found in South Missouri,
(the writer not having made personal collections of it there at all)
although it is really more of a southern species than donaciformis.
It is not to say very typical in the Osage or Gasconade basins
where there are many intergrades for it and its ally, but reaches
its greatest perfection in the Mississippi. The breeding habits
of this species is the same as that of donaciformis as far as records
show.

Genus Plagiola Rafinesque.

1819—Plagiola Rafinesque, J. de Phys. Chim. Hist. Nat., p. 426;
1852, Agassiz, Arch, Fur Nat., p. 48, (redefined); 1g00b, Simpson, Pr.
U.S. Nat. Mus., XXII, p. 603.

(Type, Unio securis Wea.)

ANIMAL CHARACTERS:—Anal opening smooth, connected to
supra-anal by close mantle attachment; inner laminae of inner
gills free or partly connected to visceral mass; gills brownish—
all other soft parts tannish; marsupium rather reniform consisting
of 40-50 well defined ovisacs; conglutinates lanceolate, not very
solid; glochidium spatulate, very much higher than long, spineless,
very large.

SHELL CHARACTERS:—Shell sub-triangular, solid, not greatly
inflated, with square cornered post-umbonal ridge and flat post-
dorsad; disk smooth; beaks pointed, rather high, sculptured
with faint double-looped ridges; epidermis yellow with broken
rays; cardinals low and jagged; laterals rather stout, straight or
slightly curved; nacre white.

MISCELLANEOUS REMARKS:—The chief characteristic of this

i50 THE NAIADES OF MISSOURI

genus is in its peculiar shell and glochidial characters. As to its
animal characters it is essentially that of Obovaria and Amyg-
dalonatas. Because of its spatulate and higher-than-long glocidia
there is ‘“‘a transition,’ as Dr. Ortmann aptly puts it, “toward
the glochidia of the Proptera-type,’’ which has essentially the same
hinge line and rounded ventral margin, but with different post-
terior and anterior ends.

‘

Plagiola securis (Lea).
(Buttery):
Pi. LT, Pigs. .5a—oo.
1829— Unio securis Lea, Tr. Am. Phil. Soc., III, p. 437, pl. XI, fig. 17.
1834— Unio lineolata Say, Am. Conch., VI.
1900b—Plagiola securis (ea) Simpson, Proc. U. S. Nat. Mus., XXII,
p. 603.
ANIMAL CHARACTERS.

NUTRITIVE CHARACTERS:—Branchial opening rather small
with numerous papillae; anal crenulated; supra-anal very large
closely, but definitely connected by mantle edges to anal; anus
tentacled; inner laminae of inner gills free about three-fourths
of their length from the visceral mass; palpi large, connected
one-third of their length antero-dorsad; color of soft parts tan,
or cream color with gills brownish and papillae yellowish.

REPRODUCTIVE STRUCTURES:—Marsupium composed of about
twenty-five ovisacs placed in the posterior half of outer gill; mantle
border antero-ventrad to branchial opening with about fifteen
very low, irregularly placed papillae; marsupium when charged
with ripe glochidia color of brown sugar, somewhat kidney shaped;
conglutinates not very solid; glochidia subelliptic or spatulate
hinge line very short, ventral margin round, spineless, much higher
than long (0.230 x .330mm).

SHELL CHARACTERS.

EXTERNAL STRUCTURES :—Shell sub-triangular, not very much
inflated, compressed in umbonal region, truncated narrowly post-
dorsad; disk more or less smooth; beaks somewhat pointed
and directed anteriorly, sculptured with a few fine concentric

! This name, as employed by Say, was really preoccupied by Rafinesque
in his Monograph of 1820 and hence through priority this species should

bear the name Plagiola lineolata (Raf.) in spite of the fact that Simpson
considered this as one of the many ‘‘indeterminates’’ of Rafinesque.

THE NAIADES OF MISSOURI 151

and indistinctly double-looped ridges; post-umbonal ridge square
cornered from beaks to post-extreme; epidermis yellowish or light
brown painted with rays broken into square or lunate blotches;
female shell smaller, thicker, shorter and more inflated than male.
INTERNAL STRUCTURES:—Cardinals rather low, ragged the
the right one having four vertical subparallel ridges; interdentum
broad; laterals stout, rather long and sharply inclined; beak
cavities, moderately deep; nacre silvery white, irridescent.
Sex Length Height Diameter Locality
CHS Ol Xe One Xo es a TL Tia (Merame R., Meramec Highlands)
Ch GK Fy Ea Be poahael (Marais des Cygnes, Athol)
ON Oy Se eye So giehaalon (Miss. R., Hannibal)
Cee one Xe 30m Xe Toman (ee ” LaGrange)
MISCELLANEOUS REMARKS:—P. securis being more of a
marine type of shell than fresh water renders it worthy of the
creation of a genus. The young shell is like that of an ‘‘exquisite
shell from the sea-shore,’’ so narrowly flattened is it post-dorsal
portion of shell, so delicately painted with broken lunate rays
and so arched forward are its compressed and pointed umbones.
This species is not found at all in the interior north of the Missouri
River; neither is it found in Southwest Missouri. It is rather
common in the Osage, Gasconade and Meramec though not very
typical as a rule. The most perfect securis is the Mississippi.
The writer found this species from the Mississippi bearing ripe
glochidia June 22nd; Wilson and Clark (1914, p. 52) found the
Cumberland securis in the same gravidity June 3-16. Dr. Ortmann
finding it gravid in late fall again fixes its breeding season as
normally bradytictic.

Genus Lasmonos Rafinesque.

1820—Lasmonos Rafinesque, Monograph, Ann. Gen. Sci. Phys. Brux.
1911b—FParaptera Ortmann, Mem. Car, Mus., IV pp. 331, 334, 338.

(Type, Lasmonos fragilis Rafinesque.)

ANIMAL CHARACTERS:—Siphonal openings large inclined to
be tubular; supra-anal high, well separated from anal; inner
laminae of inner gills entirely connected to visceral mass; palpi
free their whole length post-dorsad, color of soft parts grayish with
yellowish papillae on blackened mantle edge or branchial opening;
marsupium kidney-shaped, consisting of several ovisacs occupying
posterior part of outer gills; conglutinates white, leaf-like, not

152 THE NAIADES OF MISSOURI

very solid; glochidia very small, sub-ovate; spineless, hinge
line short, slightly curved.

' SHELL CHARACTERS:—Shell thin, sub-elliptical, alated, com-
pressed; post-umbonal ridge lacking; disk smooth; unbones
low marked with fine concentric lines followed by later double-
looped bars; epidermis glistening tawny, rayed; sex-dimorphism
shown in wider more blunt vertically at posterior end of female
shell; hinge teeth reduced to rudiments.

MISCELLANEOUS REMARKS:—This genus is also constructed
on the basis of characters relating to shell and glochidia rather
than to anatomical structures. On basis of glochidial characters
alone it classes with Amygdalonaias; however its shell characters
throw it near to the genus Proptera. Lasmonos is represented
in this State by its type (which is the commonest shell in North
Missouri) and by simpsoni Feriss. The latter is grouped here
tentatively until its soft parts are studied as its shell characters
more closely relate it to the type of this genus than to any other.
The species, Leptodea leptodon Rafinesque, is perhaps congeneric
here and much depends upon its marsupial and glochidial characters,
which are as yet unknown; however, the writer has not been
fortunate enough to secure live specimens of this species (not
even dead shells) in this State, but, because of the use Rafinesque
made of it, we are concerned here for nomenclatural reasons,
for should it be found to be really congeneric with fragilis, aside from
its several shell characters, the generic name, Leptodea, would take
preference to the one herein used.

Lasmonos fragilis Rafinesque.
(‘‘Paper Shell,” “‘Razor Back.’’)
Pl. 1X, Fie: 10,0 Pl. XOGVE, igs, 90 Ae
1820—Lasmonos fragilis Rafinesque, Mono. Biv. of Ohio.
1823— Unio gracilis Barnes, Am. Jl. Sci., VI, p. 274.
1861— Unio dolosus Wea, Jl. Phil. Ac., V, p. 75.
1900b—Lampsilis gracilis Simpson, Pr. U. S. Nat. Mus., XXII, p. 573
1912b—Paraptera gracilis Ortmann, An. Car. Mus., VIII, p. 331.

ANIMAL CHARACTERS.
NUTRITIVE STRUCTURES:—Branchial opening round, with
spreading, yellowish tentacles; anal slightly crenulated, with thick-

ened edges and normal diaphragm; supra-anal long, extending to
dorsal ala, usually closed; mantles parallel] at edges, dark colored

oy,
—
a,

THE NAIADES OF MISSOURi 153

and thickened on edges of siphonal openings, white patch at base
of branchial papillae, crenulated along border in front of branchial
opening, post-ventral region of mantle darker than that of female;
palpi united only at base, very long in old specimens; foot large,
powerful, very extensile; gills dark tan, pointed posteriorly, inner
gills longer and broader than outer, inner laminae of inner gills
entirely connected to visceral mass.

REPRODUCTIVE STRUCTURES:—Marsupia occupying posterior
part of outer gill, reniform, consisting of about forty, leaf-like
ovisacs and, when gravid, extending beyond original edge of gills,
the extreme thickness of tissue here allowing the bulging out
until glochidia escape through the ruptured edge; conglutinates
white, elongate, leaf-shape, not very solid, usually surrounded with
brick-red matter; glochidia among the very smallest (0.085mm.
by 0.075mm.) belonging to the Lampsilis type (i. e., semi-elliptical,
ventral margin rounded, gaping, hookless, short hinge line which
is slightly undulate.)

SHELL CHARACTERS.

EXTERNAL STRUCTURES:—Shell medium in size, thin, alate,
posterior end of female shell blunt; beaks compressed, marked
with three or four wrinkles arranged in a double loop ending with
two or three rather nodulous elevations at the base of the post-
umbonal slope; epidermis straw color with bright green rays in
young and well preserved specimens.

INTERNAL STRUCTURE:—Cardinal teeth very weak, single in
each valve; lateral teeth more solid, long, lamellar, elevated, no
interdentum; muscle scars faint, retractor large and peculiarly
placed; beak cavity shallow; nacre pearl-blue with the usual
characteristic pink on the posterior portion.

Sex Length Width Diameter Um. ra. Locality
Oe BOO) SrA Ol S23 0.250 (Perche Cr., Columbia)
AOR e Xa 70. Sond Ol2To) (Grande Re, Utica)
OF 74 x 38 xX 26 o275 (Platte R., Agency Ford)
OPO Xen 37 Xl D5 0.283 (102 R., St. Joseph)
25 Sell) xk 655 O-200) (Osage ik: ‘Colley’s: Hord)

BYSSIFEROUS JUVENILE:—The latter measurement is taken
from a juvenile collected in the Osage River, Colley’s Ford Mo..
July 15, 1913. It possessed a bysuss t60mm. long and was attached

154 THE NALADES OF MISSOURI

to a plicate shell. This byssal thread was so strong that it pulled
off with some difficulty and was split in three strands near its
base, each being marked by a muscilaginous substance. The
umbonal markings of this flat straw-colored juvenile shell consists
of four broadly inverted V-shaped ridges the rear line being finer,
longer and closer together, extending down the posterior umbonal
ridge.

MISCELLANEOUS REMARKS:—L. fragilis is distinctly a river
form for this State, although we would naturally think that this
alated and thin-shelled species would be established in the lakes
and other quiet waters of Northwest Missouri, especially where
it predominates the streams. Breeding records for this species
show that it may bear glochidia every month of the year except
for a few weeks in mid-summer; hence, a very long period breeder.
It was found in August distending its ovisacs with water preparatory
to ovulation. Only two other species possess smaller glochidia—
those of Amygdalonajas donaciformis (Lea) and A. elegans (Lea)
with which fragzlis is closely related; however, external characters
of shell alone—especially as to size and form—show no close con-
nection. Fragilis may be distinguished from other similar alated
forms by its peculiar yellow surface, marked by brown horn-colored
restlines, depressed umbones, green rays in young and broadly
elliptical outline in old specimens, if their alae are lost as is often
the case. ‘Through special cooking tests the writer has found
out that nearly all the soft parts of this species is very edible.
It is also economically important in producing pearls, since it is
easily parasitized. No mussel is more active and as it anchors
itself so firmly it is often extracted from its bed with great
difficulty. the straw-colored and green rayed juveniles are easily
located, not so much by color as by their ‘‘tracks’’ since they are
the most active crawlers. This species is the most abundant in the
One-Hundred-and-Two, Platte, Grand, Tarkio, Osage—in fact all
the streams of Northwest and Central Missouri as determined by
personal collections. It is poorly developed in the Osage and is not
found at all further South in the clear-water streams of the Ozarks.
Simpson reports it for the Missouri River, but I think he means
only for the tributaries of the Missouri as no mussel life is actually
reported in the main stream of this River throughout the State.
Its general distribution is for the entire Mississippi River drainage;

a

a ae

ou eg i” a ll alia

vy

THE NAIADES OF MISSOURI 155

St. Lawrence system; Red River of the North; Eastern Texas

and Cumberland River. a 5, :

Lasmonos simpsoni (Ferriss).
(Simpson’s Shell.)
PIX Ve ages: “on Anand. B:
1900—Lampsilis sumpsont Ferriss, Nautilus, xiv, p. 38.

ANIMAL CHARACTERS unknown to writer.

SHELL CHARACTERS.

EXTERNAL STRUCTURES:—Shell subovate, elongated, sub-
solid, narrowly rounded in front, broadly rounded behind, some-
what alated; disk smooth; beaks low, sculptured by ridges some-
what corrugated and nodulous; epidermis tawny with green rays
with rather roughened growth lines; hinge line evenly curved.

INTERNAL STRUCTURES:—Cardinals reduced to mere stumpy
rudiments; laterals single in right, very faintly double in left
valve; anterior scars rather deep, posterior shallow; nacre bluish
shaded with violet, copper or pink.

Sex Length Height Diameter Locality
3 78 x 46 x 28mm. (White R., Hollister)
Cage fsOrex. DOM Ce aaa 4 Sie ae)

MISCELLANEOUS REMARKS:—No juveniles, nor young shells,
have been obtained by the writer in this State. However, Mr.
Ferriss, the author, has obtained a good suite from Spring River,
Hardy, Arkansas, and has described the young shells as possessing
an epidermis with green rays and ‘“‘coppery beaks,’’ a well marked
post-umbonal ridge and low but distinct beaks with coarse corru-
gations. The author of this species, groups it between Lasmonos
fragilis and leptodon. From the former it may be distinguished
by a thicker more elongated shell, by more reduced hinge teeth
and less varigated nacre and from the latter by being more inflated,
wider, thicker, not so pointed posteriorly and with fewer rays.
Hence its place can be fairly well determined conchcologically.
Future studies of its marsupial and glochidial characters of this
species, as well as that of leptodon (=S. teniussimus Lea), may
classify it far differently, since shell characters are too liable for-
parallelism and convergence as true bases of classification.

156 THE NAIADES OF MISSOURI

Lasmonos leptodon? (Rafinesque).
Not Figured.

1820—Unio (Leptodea) leptodon Rafinesque, Ann. Gen. Sci. Phys.
Brake pi 205 eel Lae Kee

1829—Symphynota tenuissima Lea, Tr. Am. Phil. Soc., III, p. 435,
Plt XI, Fig. 27.

This species is listed here on the strength of reports of its
occurrence in the Mississippi and Neosho Rivers of this State.
From a shell, (measuring 58x31x14mm.), received from Michigan
through exchange, the author is able to make comparisons and thus
concur with the general assumption that it should group under
Lasmonos. However, superficial observations would group it
near Lastena ohiensis, but presence of hinge teeth, although not
well developed, and also different beak sculpture would sufficiently
separate it. Surely the “clear water streams’ of South Missouri
may also yield specimens of this species since the same rivers that
reach up into Missouri are reported to bear it in Arkansas. Scam-
mon (1906, pp. 304 and 305) reports it for Kansas and Simpson
describes its general range for the upper Mississippi drainage
south to the Tennessee River and for Southern Michigan.’

Genus Proptera Rafinesque.

1819—Proptera Rafinesque, Monog. An. Gen. Sci. Phys. Brux.;—1900b,
Simpson, Pr. U.S. Nat. Mus., XXII, p. 566, (as sub genus); 1912b, Ortmann,
An. Car. Mitch, ills i322).

(Type, Unio alatus Say)

ANIMAL CHARACTERS :>—Branchial opening with dense papillae;
anal crenulated; supra-anal small, moderately closely connected
to anal; inner laminae entirely connected to visceral mass; palpi
only slightly antero-dorsad; marsupia reniform occupying pos-
terior part of outer gills, consisting of several ovisacs; conglu-
tinates not solid, broken; glochidium ax-head or celt-shape,
usually armed with two spines at each corner of ventral edge of
each valve; mantle border antero-ventrad to branchial opening
slightly lamellar with crenulations only.

SHELL, CHARACTERS:—Shell subelliptic or subovate, solid to
thin, strongly alated post-dorsad; disk smooth; hinge fairly well

‘ The presence of L. /eptodon in Missouri need not be so questionable

now because of A. A. Hinkley’s recent report of it in the James River at
Galena this State. (Dec. 23, 1915, Pr. U. S. Nat. Mus., Vol. 49. p. 588.)

g
-

9%
15

THE NAIADES OF MISSOURI 7

d-veloped; beaks low, sculptured by the early bars of fine con-
centric arrangement and later one of double-looped type—some-
times rather nodulous at base of post ridge; sexually dimorphic,
the female shell being wider posteriorly by the expansion of the
post-ventrad edge of shell.

MISCELLANEOUS REMARKS:—With the exception of unique
glochidium and more developed hinge this genus stands with
Lasmonos. Proptera is represented in this state by the four species:
alata, which is found mostly in Central Mo., purpurata which
only occurs in South Mo., laevissima which is mostly restricted
to North Mo., and capax which is entirely confined to the Miss-
issippi River. The last named species has not been definitely
settled within any genus before on account of a lack of an exact
determination concerning the morphology of its animal. The
extreme inflation of the capax shell, as compared to the compressed-
type of the other members of this genus, wouJd seem to shut it
out, but glochidial and marsupial characters (besides its similar
beak sculpture) are by far more reliable affinities. All the members
of this most sharply defined genus are long period breeders.

Proptera alata (Say).
(“Razor Back,’’ ‘‘Rudder Back,” ‘‘Hatchet Back,”’
ean alee: *”)
lel View oes) prer a:

1816— Unto alatus Say, Nich, Encyc., II, pl. IV, fig. 2.
1898—Lampsilis alatus Baker, Moll. Chicago, Pt. I, p. 97, pl. XVIII.
1912b—Proptera alata (Say) Ortmann, An. Car. Mus., VIII, p. 333.

ANIMAL CHARACTERS.

NUTRITIVE STRUCTURES :—Branchialand anal openings inclined
to tubular structure, branchial upcurved, small with numerous
papillae; anal smooth thick edges; supra-anal large thick and
close mantle connection to anal; inner laminae of inner gills
entirely connected to visceral mass; palpi about as wide as long,
connected about one-half of their length antero-dorsad; color
of soft part tan-flesh color with dark mantle edges and orange
colored cerebral ganglion.

REPRODUCTIVE STRUCTURES :—Marsupia large, occupying pos-
terior half of outer gills, consisting of large ovisacs sulcated ventrad
mantle edge antero-ventrad to branchial opening lamelar with

158 THE NAI‘DES OF MISSOURI

Fic. 8. Proptera alata (Say) 2. Diagram of a gravid individual from
Platte River, Agency Ford, showing animal characters in left
valve. Coll. June 7, 1913. (34 Nat. size.)

crenulations; conglutinates large, broken with ova or glochidia
all through the mass; glochidia large, ax-head shape, with ay
at each ventral corner of shell (0.220 x 0.380 mm.).

Fic. 9a. Lateral yiew of mature Fic. 9b. Anterior view of open
glochidium of P. alata. (x87.) glochidium of P, alata, (x87.)

£

ree S

e .7
Fe

THE NAIADES OF MISSOURI 159

SHELL CHARACTERS.

EXTERNAL STRUCTURES:—Shell large broadly elliptical, solid
alated post-dorsad; somewhat inflated at middle of disk, beaks
low sculptured concentrically and also double-looped; disk not
sculptured; epidermis usually black-reddish with broad rays in
young specimens; female shelJs blunt, or even truncate, vertically
for its posterior end.

INTERNAL STRUCTURES:—Cardinals erect-double in both
valves; laterals also double placed at an upward angle; beak
cavities moderately deep; nacre usually purple.

Sex Length Height Diameter Locality
OR TsO xl 1 ox OAS (Platte, R., Dixon Falls)
Ch aS Olin Savill eke 5 3-0 (are Platte City?)

Oar TSee x5, kl 33KO (@eage R., Warsaw)
OMS 2inexe V54 3X) 21650 (Grand R., Utica)
MISCELLANEOUS REMARKS:—This species is most typical in

North Missouri; the shell is thinner, smaller and rather dwarfed
in Central Missouri and is wholly lacking in South Missouri
drainage. The writer has only found alata lacustrine on one
occasion, but that may have been due to accidental translocation.
Breeding records show it to be bradytictic. The writer has observed
that most marsupia of this species, when gravid with ripe glochidia,
have purplish blotched marsupia; this character, however, is
rather inconstant. Alata has a general distribution throughout
the Mississippi and St. Lawrence River basins.

Proptera purpurata (Lamarck).
(Purple Shell,” “Purply,”’ “Buttermilk Shell,’’ Red Shell.’’)
Pl. XXVI, Figs. 92 A—D.

1819— Unio purpurata Lamack, An. Sans, Vert., VI, p. 71.

1900b—Lampsilis purpuratus Smpson, Pr. U. S. Nat. Mus., XXII,
p. 568. ‘

1912b—-Proptera purpurata (lam.) Ortmann, An. Car. Mus., VIII,
Pp. 234.

ANIMAL CHARACTERS.
NUTRITIVE CHARACTERS :—Identical with those of alata.
REPRODUCTIVE STRUCTURES:—Marsupium consists of twenty

. ovisacs placed in posterior half of outer gills; glochidia (according

to Lea) ax-head shape—no measurement given.
SHELL CHARACTERS.
EXTERNAL STRUCTURES:—Shell large, rather elongate—ellip-

i

160 THE NAIADES OF MISSOURI

tical, inflated; disk smooth; beaks high and full; post dorsal
ridge somewhat alated; post umbonal ridge biangulated; epidermis
glossy black.

INTERNAL STRUCTURES:—Cardinals double in both valve;
laterals prominent, blade-like; umbonal and branchial cavities
deep and rounded out; nacre rich purple.

Sex Length Height Diameter Locality

el EXO) NGG) Sek Eaantiont (White R., Hollister)
OD 255 exe Ome xe 2 A Atm Gees ’” Forsyth)
Cu Sen Sans OlNeXe me Oni ( ” Hollister)
GON Se) A gp SS eyasaobenl (ae a 4p )

MIscELLANEOUS REMARKS :—The young shells of P. purpurata
are thin and fragile but later become thick and solid; resembling
alata in form and nacre but is more so alated not compressed.
This shell only appears in the White and Neosho River basins
and is one of the few not found in the Mississippi. Its favorite
habitat is deep water and mud bottoms. It is hoped its glochidium
may be verified and more proportionate measurements given
than Lea was able to record.

Proptera laevissima (Lea).

(“Paper Shell,” “Double Wing.”’)
Pl. EX, Pigs? to-and 20; (Pl. XOXViS Rigs: Of Ae

1830—Symphynota laevissima Lea, Tr. Am Phil Soc., III, p. 444,
ole OIUOLS saver aes.
1900b—Lampsilis laevissima Simpson, Pr. U. S. Nat. Mus., XXII,

Bs, 574.
1912b—Proptera laevissima (Lea) Ortmann, An. Car. Mus., VIII,

psi3g44
ANIMAL CHARACTERS

NUTRITIVE STRUCTURES:—Branchial and anal openings very
tubular, directed away from each other; anal smooth; supra-anal
high, well separated from anal by mantle connection; inner
laminae of inner gills entirely connected to visceral mass; palpi
broader than long, connected about one-half of the length antero-
dorsad; color of soft parts a modest tan, except for mantle edges
at siphonal openings and the area over nephridium.

REPRODUCTIVE STRUCTURES:—Marsupium large, kidney-
shaped occupying over half of posterior part of outer gills and
consisting 50-60 narrow ovisacs somewhat distended transversely

34°

THE NAIADES OF MISSOURI 161

and very much so ventrad from original edge of sterile marsupium,
ventral tips of ovisacs teat-like, not colored; conglutinates white,
discharged in broken disintegrated masses; glochidium 'ax-head
shape or celtiform, small with spine-like structures measuring
0.100 X 0.155mm; branchial mantle edge thickened, lamellar, but
without palpilae.

SHELL CHARACTERS.

EXTERNAL STRUCTURES:— Shell elliptical compressed, thin,
bialated, post-ala being drawn near to the beaks in definite lobes
of growth, sometimes curved laterally; disk without any sculpture:
post-umbonal ridge absent, female shell swollen post-ventrad:
epidermis brown-glistening horn-color with faint rays and areas
of indigo blue especially on post wing; beaks low, suppressed
sculptured with a few fine concentric lines and a row of three small
tubercles on line with a post-ridge.

INTERNAL STRUCTURES:—Cardinals thin, erect, double in
right, single in left valve, laterals rather reduced; scars somewhat
faintly impressed; beak and branchial cavities rather shallow;
nacre solid purple.

Sex Length Height Diameter Locality
CHens5O) LOS) x eA THM 102 R., St. Joseph)
Go 145 90 39mm Mud Lake, Kenmoor)

(
x x (

Ch agp oe Gl So's, Mesut (Platte, R., Agency Ford)
Si x (

OR AT ae 12mm Lake Contrary, St. Joseph)

The last measurement of a juvenile—the youngest and smallest
Naiad shell ever found gravid by the writer. Its glochidia were
normal. Many of these juveniles are in the writer’s cabinet,
having been collected in ‘nests’? from L. Contrary for the most
part. The shells are like those of ground glass in color and trans-
luscent both externally and internally. Beaks are rather apicu-
lated and marked by rather coarse concentric ridges with three
teat-like tubercles arranged in a row on line with post-ridge, resemb-
ling juvenile beak sculpture of Lasmonos.

MISCELLANEOUS REMARKS:—This species may represent the
critical transition period from the primitive to the actual modern
forms. Its glochidium is not a true Proptera form in not possessing
typical spines at the ventral corners of its valves. Coker and
Surber (1911, pp. 179-182) have pointed out its metamorphosis in
the parasitic life as eccentric in that the glochidium remains

162 THE NAIADES OF MISSOURI

intact as a saddle over the beginning of its adult shell. No species,
perhaps, has such tubular development of mantle edges for the
branchial and anal openings. In this state its distribution is
peculiar, being almost exclusively found in North Missouri and
never in South Missouri. It is often found in company with
alata from which it can be separated on account of thick shell and
coarser epidermis of the latter. It may be mentioned here that
laevissima shows the highest modern development of the stphonal
openings, 1. e., into the actual tubular form. (See Plate IX). This
Species is distinctly bradytictic.

Proptera capax (Green).
(‘Pocket Book,’ ‘‘Swell Shell.’’)
Pl XX Vip Rigs: oF (A andr:

1832— Unio capax Green, Cab. Nat. leis, UL, jel. Belox
1899—Lampsilis capax Smith, Bull U.S. Fish Com., p. 291, pl. LX XIV.

ANIMAL CHARACTERS.

NUTRITIVE STRUCTURES:—Branchial opening with rusty red
papillae arranged in two ranks; anal finely crenulated; supra-anal
large with two large tentacular siructures on each mantle edge; inner
laminae of inner gills entirely connected; palpi rounded antero-
ventrad, connected antero-dorsad two-thirds of their length;
color of soft parts tanish, mantle edge antero-ventrad, reddish-
brown.

REPRODUCTIVE STRUCTURES:—Marsupium occupying the
greater posterior part of the outer gill, consisting of about fifty
small ovisacs distended transversely when gravid, and being also
distended at the distal ends the ovisacs presenting teat-like
appearance; no mantle flap antero-ventrad to branchial opening,
nor any specialization except for a thickening of the mantle edge;
conglutinates not solid, white; glochidium ax-head or hatchet-
shape in form, spined, rather small, 0.105 x 0.185mm.

SHELL CHARACTERS.

EXTERNAL STRUCTURES:—Shell rather globose, extremely
inflated; disk smooth; beaks extremely full, round, high, sculp-
tured with single tubercles on incurved tips surrounded by fine
concentric ridges looped into two or three small tubercular mark-
ings at very base of post ridge; epidermis smooth, polished,

E
.
'

wr

THE NAIADES OF MISSOURI 163

brown horn-color, sometimes with yellowish narrow bands parallel
to growth lines, rayless. ,

INTERNAL STRUCTURES:—Cardinals double in right, slightly
so in left valve and arranged parallel with laterals; interdentum
short; laterals single in right, double posteriorly in left valve;
beak and branchial cavities very deep and large, basin - like;
nacre white with light rosy pink in branchial cavities, border light
bluish.

Sex Length Height Diameter Locality

Cen TON eka 82k we OS iia tnd (Mississippi R.,Hanibal)
OF Jo50° X75) x “O6mm (ope au one Ss)
OF 66.9= 50) Xx) 42mm (onary Way Grange)

MISCELLANEOUS REMARKS:—Capax has the most inflated
shell of the Nazades, yet because of the fact that it is rayless and
has no sex dimorphism, nor furrowed beak sculpture, nor pure
white nacre of L. ventricosa it must be removed far from the latter
although its immensely inflated shell would superficially class it
near ventricosa. Its great inflation is not any greater, however,
than that of the relative inflation of the /aevissima shell in the last
stage of its parasitic life. Most of all, anatomical material kept
by the writer, shows no mantle flap (PI. XX VI, fig. 93 B) as seen
in L. ventricosa, nor as to be noted in any Lampszilis, and the mantle
edge antero-ventrad to the branchial opening is not even as much
specialized as in laevissima, or alata; hence its place perhaps
should precede /acvissima, at least, but is placed last in the group-
ing under this genus on account of its most peculiarly inflated
shell which may show an advance over the other species that show
the other extreme in possessing a compressed shell in their adult
life. Capax is very rare shell for this State. It has a rather limited
geographical distribution over the whole country; however, Simp-
son reports it as abundant locally, yet the writer’s experience in
collecting it for in the Mississippi is that it is rare even there and
it was considered a stroke of good fortune to secure glochidially
gravid material showing proptera characters.

Genus Carunculina Simpson.
(Type, Unto parvus Barnes.)

1898—Carunculina Simpson (in Baker, p. 109, as section).
1900b—Carunculina Simpson. Proc. U. S. Nat. Mus., XXII, p. 563.
(as subgenus); 1912b, Ortmann, Car. Mus., VIII, p. 337 (as subgenus).

ANIMAL CHARACTERS:—Branchial opening small with rather

164 THE NAIADES OF MISSOURI

large papillae; anal smooth, supra-anal] large, closely connected
to anal; inner laminae of inner gills free, more or less, from the
visceral mass; palpi small, connected half of their length antero-
dorsad; marsupia formed by a few large ovisacs occupying pos-
terior part of outer gills, reniform; branchial edge with a papillose
caruncle; conglutinates solid, white, club-shaped, glochidia medium
in size, semi-elliptic.

SHELL CHARACTERS:—ohell very small, elliptic, rounded
before, rather thick, disk smooth; beaks low, coarsely sculptured
by regular concentric bars upcurved behind; epidermis dark
cloth-like.

MISCELLANEOUS REMARKS:—This is a good genus as now
considered by Dr. Ortmann who treated it at first (1912, p. 337) as
a subgenus for Lurynia, but even then he was inclined to consider
it as merely conventional whether we use it generically or sub-
generically. Carunculina is remarkable for its smaJlest sized shells,
for its unique beak sculpture and for its peculiarly specialized
mantle edge antero-ventrad to the branchial opening. It is well
represented in this State by the typé, parva, and although the
writer has not personally collected tecxasensis and glans yet these
two have been reported in such manner that they can be definitely
listed.

Carunculina parva (Barnes).
(‘‘Liliput Shell.’’)
PITT bee 6c: Plow xc V EE Bigs Osan
1823— Unto parvus Barnes, Am. Jl. Sci., VI, pl. XIII, fig. 18 (outline).
1900b—Lampsilis parvus Simpson, Pr. U. S. Nat. Mus., XXII, p. 564.
1912b—Eyrynia (Carunculina) parva.-Ortmann, An. Car. Mus., VIII
p. 338.
ANIMAL CHARACTERS.

NUTRITIVE STRUCTURES:— Branchial small, directed upward,
with few but large papillae; anal also pointed upward, smooth,
supra-anal present, closely but definitely connected by mantle
edge; inner laminae of inner gills usually free from visceral mass
about one-half of their length; palpi comparatively large, connected
antero-dorsad about two-thirds of their length; color of soft parts
tan-color except for a blackish or reddish border to mantle at
branchial] opening.

REPRODUCTIVE STRUCTURES:—Marsupia kidney-shaped, con-

on hall odie

THE NAIADES OF MISSOURI 165

sisting of twenty ovisacs, well marked, occupying posterior half
of outer gills, somewhat distended transversely and also at distal
ends below the original] line of sterile marsupium; border of mantle
antero-ventrad to branchial opening greatly specialized into a
double row of red papillae terminating in a knobbed caruncle,
which, under (x87) lens, is cellular—each cell being hexagonal in
shape; conglutinates white, discharged whole, club-shaped,
glochidia medium in size, sub-elliptical, hinge line straight, spineless,
measures 0.175 xX 0.100.

SHELL CHARACTERS.

EXTERNAL STRUCTURES:—Shell very small, rather thick,
elliptical, rounded before, disk without sculpture; beaks low with
six coarse regular, parallel bars evenly curved up at foot of post-
ridge region; epidermis brownish to reddish or olivaceous, cloth-
like female shells broader posterior ends made by more swollen
post ventral portion, males with pointed shells.

Sex Length Height Diameter Locality

Pes oexue2 sey Xu noMmm: (lake Contrary, st. joseph—)
Cie ae ee Xeni «(Ponds Coltimbia))

225 ees ex ms mimn(Wowemly-«Contrary,, ot. Joseph)
* 145 x 8.5 x 5.3mm (Singleton Lake, Halls)

oy

We sxs Ors). Eom. ( ” is A)

The writer obtained about forty juveniles, within the range
of the last two measurements, in shallow clear water along the
northwest shore of Singleton Lake. They were confined to a small
space and were traced here and there among a maze of tiny tracks.
These juvenile shells differ from the adult by a thinner shell, more
pointed posteriorly, a more greenish epidermis, more compressed,
and by a coarser beak sculpture which, although arranged the same
in its concentric bars curved up posteriorly, yet they extend down
well on the center of the disk. (See Pl. III, fig. 8c).

MISCELLANEOUS REMARKS:—The writer is able to bear out the
statements of Drs. Sterki and Orimann that parva is locally herma-
phroditic. In the past three years, hundreds have been collected
in nearly all the Northwest Missouri lakes and streams, but not
a single one has been found without the marsupial character of
gills and the sexually dimorphic female shell. However, the male
and female shells appear in Central Missouri. In all specimens

* This symbol (*) would indicate hermaphroditism here.

166 THE NAIADES OF MISSOURI

for this State the writer finds the supra-anal opening present.
Its presence has been doubted by some other writers. This pygmied
mussel has great vitality. The writer records thirty-eight heart
beats per minute—among the most rapid of the Nazades. It is
one of the most active in its locomotion. Its breeding season show
it to be bradytictic. The writer has been fortunate to secure parva’s
glochidium and make more of a definite study than has been recorded
since Lea left his studies. (Obs. XIII, 1874, pl. X XI, fig. 2.)

Carunculina texasensis (Lea).
(“Texas Shell.’’)
Not figured.

1857—Unio texasensis Lea, Pr. Ac. Nat. Sci. Phila., p. 84; Jl. Ac.
NEScil vive, 18608 p. 3504 ple Sites maAe

1862— Unio bealei Lea, Jl. Ac. N. Sci., V., p. 204, pl. XXX, fig. 273.

1912b—Eurynia (Carunculina) texasensis Ortmann, An. Car. Mus.,
Villice p33:

ANIMAL CHARACTERS:— The writer not having seen the
soft parts of this species quotes Simpson’s description :—‘“‘ Animal
with marsupium consisting of a few large ovisacs (8 to 13); inner
gills wholly, or in part, free from the abdominal sac; female
often having a well developed caruncle on the mantle below the
branchial opening.”’

SHELL CHARACTERS.

EXTERNAL STRUCTURES:—Shell small, rather thick, subin-
flated, smooth, rounded before, pointed post-dorsad; post-
umbonal fidge rather prominent, especially in the female shell,
which is shorter, more inflated and not so pointed posteriorly;
epidermis a dark slaty color with one or two whitish rest lines;
beaks low with coarse concentric bars upcurved at base of post-
ridge.

INTERNAL STRUCTURES:—Cardinals double in right, faintly
so in left valve; laterals single in both; interdentum lacking;
beak and branchial cavities rather shallow and irridescent pos-
teriorly.

Sex Length Height Diameter Locality
S45 ik 240 ex ems mmm ve oste Creeks sevanntay)
OV i237 x. 20) ox) 112 rom a(Wosty Creeks a Aunty)

MISCELLANEOUS REMARKS:—Comparison to some types of

texasensis from Wimberly Lake, Texas, assures the writer that

THE NAIADES OF MISSOURI 167

the specimens of the above measurements are a near approach,
at least, to this species. However, this species is listed for Mo.
more on the strength of Mr. Simpson’s report of it for Harrison
County, Missouri. where the famous author of the ‘‘Synopsis
of the Naiades’”’ used to reside. He states that texasensis ranges
north into northern Missouri, southern Illinois and Indiana.
This species is a good one and should be shut out of the synonomy
of parva especially because its posterior end of shell is never
evenly rounded, nor is its epidermis as cloth-like and nacre as
white as that of parva. The sex dimorphism, too, is different,
as determined by the above description of shell.

Carunculina glans (Lea).
(“Little Purple.’’)
(Not figured.)

1834-—Unio glans Lea, Tr. Am. Phil. ‘Soc.,, p. 82, Pl. VIII, fig. 12,
Ohisaes, 10863) ip. 4.02)

1900b—Lampsilis glans Simpson, Pr. U. S. Nat. Mus. XXII, p. 565.

1912b—Eurynia (Carunculina) glans Ortmann, An. Car. Mus., VIII,
Pp- 339.

ANIMAL AND SHELL CHARACTERS:—Since the writer has not
secured any actual shells or soft parts for this species the descrip-
tions of these parts do not appear here.

MISCELLANEOUS REMARKS:—The writer would also lay
claim to this species for Missouri from Simpson’s report of it
for the White River, and also from a few scattered reports of it
through some local collectors for the Elk River and other Southern
Missouri streams. From Lea’s description (Obs. X., 1863, pp.
402 and 4o5) and also from Wilson and Clark’s (1912, p. 48)
this species falls under this genus. From shells received by the
writer in exchange it would seem to be more nearly like a young
P. purpurata. It is distinguished from C. parva in being a wider,
shorter, thicker, heavier and more polished shell and also in
possessing a prominent post-umbonal ridge and a coppery and
purple nacre.

Genus Eurynia Rafinesque.
(Type, Unio recta, Lamarck.)
18120—Eurynia Rafinesque Monog., Ann. Gen. Sci Phys. Brux.;

1900b, Simpson, Pr. U. S. Nat. Mus., XXII, p. 534 (as section); 1912b,
Ortmann An. Car. Mus., VIII, p. 336 (as genus).

168 THE NAIADES OF MISSOURI

ANIMAL CHARACTERS:—Siphonal openings well formed;
inner laminae of inner gills usually entirely connected to the
visceral mass; in male no specialization, but in female the inner
edge of mantle antero-ventrad to branchial opening always with
well developed papillae, or short tentacles which often extend to
the central of ventral edge; marsupium reniform, swollen, con-
sisting of many ovisacs occupying posterior part of outer gill
and ventral edges beaded in white or black pigment when gravid;
conglutinates white, not very solid; glochidia large or medium
in size, semi-elliptical.

MISCELLANEOUS REMARKS:—The special structures on the
mantle antero-ventrad to the branchial opening would group
this genus among the highest of the Lampsilinae from the fact
that the aération of the embryos is well secured through such
specialization. Especially because of the number, form and
arrangement of the papillae two sub-genera may be marked out.
In the following description when the specialized mantle edge is
discussed the female is considered.

Sub-genus Micromya Agassiz.

(Type, Unio fabalis Lea.)

1852—Micromya Agassiz, Arch. fiir Nat., p. 57; 1912b, Ortmann,
iMag (Coney IGG, WADUL ios 243357 .

ANIMAL CHARACTERS:— Mantle edge antero-ventrad to bran-
chial opening specialized by papillae, both regular and irregular,
arranged rather widely separated in a single row but never
extending to the middle of the ventral margin; inner laminae of
inner gills entirely connected, or more or less free.

SHELL CHARACTERS :—Shell sub-elliptical, small or medium in
size; beak sculpture rather double*looped-or distinctly sinuate
with the posterior sinuation rather open.

MIscELLANEOUS REMARKS:—This sub-genus is represented
in this state by three species—all found only in the Ozarks.
The type fabalis of Lea of Micromya is not found anywhere in
Missouri. The essential distinction between the two sub-genera,
Micromya and Eurynia (sens. strict.) is in the less extensive and
less crowded arrangement of the papillae on the inner edge of the
mantle antero-ventrad to branchial opening in the former.

THE NAIADES OF MISSOURI ’ 169

Eurynia (Micromya) lienosa (Conrad.)
(‘Little Spectacle Case.’’)
Pie eV, Vhags. 00 “AD:

1834— Unio lienosus Conrad, An.,Jl. Sci., XXV, p. 339, pl. 1, fig. 4.

1900b—Lampsilis lienosus Simpson, Pr. U.S. Nat. Mus., XXII, p. 547.

1912b—Eurynia (Micromya) lienosa (Conrad) Ortmann, An. Car.
Mus., VIII, pp. 340 and 341.

ANIMAL CHARACTERS.

NUTRITIVE STRUCTURES:—Branchial opening with two-ranks
of papillae; anal crenulated; supra-anal high, small, closely
connected by mantle edges to anal; inner laminae of inner gills
more or less free from the visceral mass; palpi subfalcate connected
antero-dorsad about one-half of their length; color of soft parts
soiled white except mantle edge of siphonal area blackish, gills
brownish.

REPRODUCTIVE STRUCTURES:—Marsupium kidney-shaped,
restricted to posterior half of outer gill, consisting of twenty-five
distinct ovisacs, which, when gravid, distend transversely in middle
and ventrad as white beadlike bodies; inner mantle edge of females
antero-ventrad to branchial opening with eight to ten conical
tentacles rather wide apart and reaching a little over half way
centrad-ventrad; conglutinates large, club-shaped; glochidia large,
subovate, measuring 0.220 x Oo. 270 mm.

SHELL CHARACTERS.

EXTERNAL STRUCTURES:—Shell small, elliptical, moderately
inflated, thick; post-umbonal ridge rounded; disk smooth; umbones
low sculptured with inverted V-shapes; epidermis reddish brown
with dark banded rays; female shell expanded post-ventrad, male
rather biangulated behind.

INTERNAL STRUCTURES :—Cardinals double in left, single in
right valve; laterals also double in left, single in right; inter-
dentum lacking; beak cavities moderately deep; nacre purplish
with old gold and copper-color in branchial cavity.

Sex Length Height Diameter Locality
OF Sa Ex) SOME, | TLS min (Black R., Williamsville)
C5 0m. x 920, x) zoom ON anaes e )
GAS s20 5X) Bee OU IT Oreste si )
Oe 20mm xual Se Xa Omnth Cy ae “a )

170 THE NAIADES OF MISSOURI

MISCELLANEOUS REMARKS:—In the young shell of the last
measurement the beaks were sculptured with inverted V-shaped
ridges similar to that of subrostrata. This species is only found
in the Black River for this State. Rev. Wheeler considers lzenosa
as intergrading with nigerrima and while the two are usually found
in the same locality yet nzgerrima is more likely to occur as a
creek form. ‘The writer obtained some gravid August 29 with late
embryos. The young one of the above measurement was gravid
and, as preserved, shows many characters like that of subrostrata
but can be separated on account of an insufficient development of
mantle edge antero-ventrad to branchial opening.

Eurynia (Micromya) iris (Lea.)
(‘Rainbow Shell.’’)
Pl XOX VA ies 07 Ae ana abr

1830— Unia iris Lea, Tr. Am. Phil. Soc., III, p. 439, pl. IX, fig. 18.

1898—Lampsilis iris Baker, Moll. Chicago, Pt. I., p. 105, pl. XIII,
jig, LR *jolle DSCIOW, ine ee

1912b—Eurynia (Micromya) iris (Lea) Ortmann, An. Car. Mus.,
Vii pe pe 34n ands3 42"

ANIMAL CHARACTERS.

NUTRITIVE STRUCTURES:—Branchial opening densely papil-
lose; anal crenulated;. supra-anal large, closely connected to
visceral mass; palpi small, one-half connected antero-dorsad;
color of soft parts dark tan with posterior part of gills and mantle
blackish.

REPRODUCTIVE STRUCTURES :—Marsupia composed of twenty
closely crowded ovisacs occupying post-half of outer gills; inner
mantle edge fringed with eight or ten papillae, the most anterior
ones reaching well toward the center of ventral edge where they
are larger, postero-curved and terminating in small low papillae
near the branchial opening—alJl rather wide apart; glochidia
rather large, subovate measuring 0.240 x 0.300 mm.

SHELL CHARACTERS.

EXTERNAL STRUCTURES:—Shell small, elongate-elliptic, thin,
dorsal line slightly curved, ventral straight; compressed anteriorly
inflated in center of post-umbonal ridge; beaks pointed but low,
sculptured by seven or eight double-ooped ridges; epidermis

_—=

2
é THE NAIADES OF MISSOURI 171
smooth reddish-brown with bright green rays arranged all over
its shell.
INTERNAL STRUCTURES:—Cardinals double in both valves,
laterals double in left, single in right; beak cavities rather shallow;
nacre white or Jight bluish.

Sex Length Height Diameter Locality
Sth IGG pan Dia Se" ai Sheateal (Jack’s Fork of Current R.)
OR SS). on oh or SLOT. (White R., Hollister)
Oeil we OGG SS | inianbaa (Black R., Williamsville)
Ct! "Be G6 AA os BEpaalion (Jack’s Fork of Current R.)

The last measurement is that of a young shell that shows a
beak sculpture of a profusely double-looped or corrugated ridges
the latest one being the strongest and running down quite low on
the disk.

MISCELLANEOUS REMARKS:—For this State iris is strictly
a southern shell, being only found in the White and Black River
basins. Perhaps this pretty little shell is much more common
than supposed, since it is so liable to escape observation due to
its minuteness of size yet its bright green rays of uneroded shells
make it rather conscpiuous in clear shallow water. It has been
found to be bradytictic.

Eurynia (Micromya) brevicula (Call).
(“Broken Rays,’ ‘“Soul-of-Wit.’’)
Pl. XXVII; Figs. 96 A—D.

1887— Unio breviculus Call, Pr. U. S. Nat. Mus., X, p. 499, pl. XXVIII;
dit Acr Soci ot Wows, Vall, (1895) sp.6, pl. XUV:
1900b—Lampsilis breviculus Simpson, Pr. U. S. Nat. Mus., XXII,
P-. 533.
ANIMAL CHARACTERS.

NUTRITIVE CHARACTERS:—Branchial opening densely papil-
lose; anal crenulated; supra-anal large, high, well separated from
anal with thick, spotted mantle edges; inner laminae of inner
gills not free from visceral mass; palpi rather large, connected by
their edges one fourth of their length antero-dorsad.

REPRODUCTIVE STRUCTURES:—Marsupium rather kidney-
shaped consisting of ten or fifteen ovisacs well separated, with
bluish ventral border and each ovisac presenting a beaded appear-
ance of black pigmented spots; in female mantle border antero-
ventrad to branchial opening with a flap-like structure bearing eight

eg f%e THE NAIADES OF MISSOURI

or ten papillae terminiating toward the center of ventral border
with longer finger-like tentacles; glochidium unknown, but is
identical doubtless with that of its sub-species, Brittsz.

SHELL CHARACTERS.

EXTERNAL STRUCTURES:—ochell elliptical, medium in size,
usually rather thin, evenly rounded before; post-umbonal ridge
not present; beaks large but low sculptured by six inverted V-
shaped ridges with their apices pointing toward the tips of the
beaks and with the posterior ridges extending out as longer and more
oblique rows at the base of the post-ridge region; epidermis smooth,
shiny, straw-color with coarse broken rays most pronounced
posteriorly.

INTERNAL STRUCTURES:—Cardinals erect, double in left,
single in right valve; interdentum narrow; laterals double in
left, single in right, blade-like; beak cavities rather deep and base-
like; nacre bluish or whitish with tinge of pink in umbonal cavities.

Sex Length Height Diameter Locality
Cr OAe xe AON xX, 27) Semin —— (WW lnite eee liis ter)
OPS Syke UA Xveizeds San = (Foe . ; )
OF 5 ox ido ex 230 mm— (2? a 44 )
ef) YM} SES eats) soa (7 mt eu )

MISCELLANEOUS REMARKS:—This species is strictly a 5S.
Mo. shell and its sub-species is only found in Central Missouri.
Some of the South Missouri streams bear brevicula that almost
approach Sritts1; however, brevicula is a rather common shell in
the streams of the south slope of the Ozarks, where it is typical.
Young shells of this species are very thin, while the adult shells
become very thick comparatively. Perhaps this species exhibits
sexual dimorphism more than any of this genus. The female had
a much broader, shorter more inflated shell than the male; the
latter being more or less biangulated behind. The slightly long
incurved post-ventral portion of the female shell is very charac-
teristic. Gravid females are unknown. SGrevicula is the largest,
most emphatic member of the Micromya group.

Eurynia (Micromya) brevicula Brittsi (Simpson).
( Britts’ “Shell-’’)
PIV XXV IT» Figs? gov A nang sB*

1900a—Lampsilis brittsi Simpson, Pr. Ac. Nat. Sci. Phila., p. 76, pl.
Vie, figs andt2 1600) \b, “Uo Nate Nise tne ee Sms aise

———_

THE NAIADES OF MISSOURI 173

ANIMAL CHARACTERS.

NUTRITIVE STRUCTURES :—Branchial opening large with large
yellowish papillae; anal crenulated; supra-anal moderately
separated from anal by distinct mantle connection; gills wide, the
inner slightly longer and wider, the inner laminae connected with
the visceral mass their entire length; palpi wide and large, united
one fourth of their length antero-dorsad; color of soft parts tan-
color except foot which is more yellowish and mantle edge which is
black for the siphonal openings.

REPRODUCTIVE STRUCTURES:>—Marsupia wide, more or less
reniform, consisting of about a dozen large distinct ovisacs, dis-
tended, when gravid, transversely in center and along the ventral
edge into black pigmented beads at the distal ends; conglutinates
white, rather club-shaped; glochidia moderately large, semt-elliptical,
hinge line slightly oblique and undulate measuring 0.250X0.305 mm.;
mantle edge antero-ventrad to branchial opening with a flap
extending toward the center of ventral margin with about ten
papillae beginning rather low at edge of branchial opening and
ending with tentacular processes at end.

SHELL CHARACTERS.

EXTERNAL STRUCTURES :—Shell medium in size, thick to thin,
subelliptical; post-umbonal ridge lacking; beaks large but low-
sculptured by six inverted V-shaped ridges the posterior ones
being longer and thrown more or less obliquely across post-umbonal
slope; disk without sculpture; male shell rounded before, rounded
and more or less biangulated behind; female shell very deeply and
widely sulcated at the post-ventral margin of shell and is less
elliptic in general outline, also thicker and more inflated than
male shell; epidermis yellow to olivaceous with broad, widely
separated rays of interrupted lunate or V- pane splotches—all
covering the whole shell.

INTERNAL STRUCTURES:—Cardinals stout, double in left,
single in right valve; interdentum long, narrow; laterals short
somewhat curved reaching far back; beak and branchial cavities
rather deep and basin-like; scars well impressed; nacre white,
pinkish and irridescent posteriorly.

Sex Length Height Diameter Locality
9 64 x 40 x 27mm—(Niangua se Hahatonka )
O55 0x 36 x 25mm—( a )
Ou AO Sa 2A oe aaa —— (1 27 a ie )

174 THE NAIADES OF MISSOURI

The peculiarity of the shell of this sub-species (as well as that
of the species) is that the younger the shell the very much thinner.
It is also more brilliantly tawny and green rayed.

MISCELLANEOUS REMARKS:—Surely this form of brevicula,
found by the writer in its type locality, Niangua River, has enough
peculiar characters to entitle it to a good species, as Simpson had
first considered it. Its special characteristic is the very wide, deep
emargination in the female shell at its post-ventral margin. How-
ever, it is almost identical with its parent species as to its soft parts.
Its tentacled lamellar-like flap on the mantle edge antero-ventrad
to the branchial opening is somewhat like that of ventricosa and
hence might be grouped under the Lamp. luteola group; however,
the smaller papillae along the posterior end of the flap (or rather
thickened mantle edge) would class it more as an Eurynia. Brittst
is to be distinguished from its parent by the greater post-ventral
sulcus (Fig. 99), which extends in as a rather deep radial furrow
for a short distance forming the greatest inflation of the shell in
front of this. It also differs in shell characters from the female
species (brevicula) in not being so broad posteriorly and not as
rounded post-dorsad. Dr. Britts collected the originals from
Niangua River and sent them to Simpson for naming; hence the
consequent name of this species. Cotypes (now in the hands of
the writer and illustrated herewith) collected from almost the same
point in the Niangua show a decided difference from cotypes of
Call’s brevicula many of which are now in the writer’s collection,
through the kindness of Mr. B. F. Bush, one of the most active
students and collectors of Nazad shells now living in this State.
This sub-species is bradytictic as inferred from the writer’s brief
breeding record. He has had the good fortune to collect the glo-
chidia of this form for the first time. In all probability this glochi-
dium is the same as that of Call’s brevicula. However, its breeding
season seems to be a little different as the writer collected many
of the species only a day or two later to find them all sterile.

Sub-Genus Eurynia (Sens. Strict.) Rafinesque.
1912b—Eurynia (as sub-genus), Ortmann, An. Car. Mus., VIII, p. 338.
(Type, Unio recta Lamarck.)
ANIMAL CHARACTERS:—Differs from those of Micromya in
the structure of its rough mantle edge antero-ventrad to branchial
opening being more differentiated into a greater number and longer

a
i
THE NAIADES OF MISSOURI 175

row of papillae on the inner edge extending down quite to the
central part of the ventral edge. ‘These papillae are often quite
tentacular and are rather regular and uniform in shape and size
and are never widely separated as in case of the Micromya mantle
edge of this anterior branchial border. Its inner laminae of the
inner gills are usually entirely connected with the visceral mass;
however, a small hole is sometimes left at the posterior end post-
dorsad to foot.

SHELL CHARACTERS:—In shell characters there are no great
distinctions to be considered as a group since the chief distinguish-
ing characteristic is in the post-mantle edge as above discussed.
Its beak sculpturing is identical with that of the Mzcromya shell
being sinuated or double-looped, the posterior loops being more
or less broken behind.

This group of Eurynia is represented in this State by E. (E)
subrostrata and recta, both having rather wide distribution.

Eurynia (Eurynia) subrostrata (Say).
(“Common Pond-Mussel,”’ ‘ Lilliputian.’’)
Pl. XXVII; Figs. ro1 A—D.

1831— Unio subrostratus Say, New Harm. Digs.

1850— Unio mississippiensis Conrad, Jl. Ac. N. Sci. Phila., 1, p. 277,
ple XOXOKOVIIIE, fie T1.

1868— Unio topekensis Lea, Pr. Acad. Nat. Sci. Phila., XII, p. 144.

1900b—Lanpsilis subrostratus Simpson, Pr. U. S. Nat. Mus., XXII,
Pp. 546.

1912b—Eurynia (Eurynia) subrostrata (Say), Ortmann, An. Car. Mus.,
Wie pa s44.

ANIMAL CHARACTERS.

NUTRITIVE STRUCTURES :—Branchial opening narrowly papil-
lose; anal finely papillose supra-anal separated from anal by a
rather short mantle connection; inner laminae of inner gills con-
nected to visceral mass; palpi rather small and connected antero-
dorsad about one-fourth of its length; color of soft parts grayish
with mantle edge along siphonal region blackish.

REPRODUCTIVE STRUCTURES:—Marsupia kidney (or rather)
fan-shaped, consisting of twenty large, well defined ovisacs, dis-
tended, when gravid, at ventral edge thus giving the congluti-
nates a club-like shape; ventral tips of ovisacs beaded bearing
bluish pigment with glochidia scattered throughout the sacs;

’
: ;

176 THE NAIADES OF MISSOURI

glochidia rather large, semi-elliptical, spineless, regularly rounded
ventrad, hinge-line straight, measures 0.270 x 0.330 mm.; mantle
edge antero-ventrad to branchial opening in female with numerous
regular papillae extending quite down to the central part of ventral
border.

SHELL CHARACTERS.

EXTERNAL STRUCTURES:—Shell small to medium in size,
rather elongate-elliptic, thin, compressed; post-umbonal ridge
rounded; female shell very wide and blunt posteriorly, male
pointed and narrow; umbones low, sculptured by eight or ten
coarse, regular, inverted V-shaped ridges with the apices pointed
toward tips of beaks, the posterior ridges longer and more disposed
obliquely across base of post-ridge; disk without sculpturing;
epidermis brown to black with many rays disposed posteriorly
and showing through on the nacreous surface.

INTERNAL STRUCTURES:—Cardinals double in both valves,
rather thin and erect; laterals thin, double in both valves; scars
rather well impressed; beak and branchial cavities rather deep
and hollowed out; nacre white to light bluish irridescent posteriorly.

Sex Length: Height Diameter Locality
Oo 62 xX 27 xX 21.5mm-—(Flat Creek, Sedalia).
9 65 x 36 x 25.5mm—(Hinkston Creek, Columbia)
oo 50 x 28 x 15.5mm—(Lost Creek, Amity)
Q@ 36 x 18 x 13.5mm—(Flat Creek, Sedalia)

This last measurement is for one that has preserved soft parts
and although it is very young and small yet it is gravid with normal
glochidia. Its beak sculpture is very distinct as shown above in
the description of shell character.

MISCELLANEOUS REMARKS:—Subrosirata is a creek and pond
shell, but in spite of this lacustrine disposition it is never found in
any of the North West Missouri lakes Like U. tetralasma it
adjusts itself easily and quickly to artificial ponds and channels.
It is never found in large rivers nor swift streams. It has a general
distribution over the State, especially in the ponds and quiet
creeks of Central part. Simpson gives it a general distribution over
the entire Mississippi drainage north of about latitude 41°. The
breeding season of subrostrata is a long one. Its glochidia seem to
be very constant in size for widely separated localities. Compari-
sons have been made of glochidia from mussels of Central Missouri

aS 9 en si

THE NAIADES OF MISSOURI 177,

sculptured by fine concentric ridges disposed somewhat like that of
with those from the Mississippi to find them precisely identical in
every respect.

Eurynia (Eurynia) recta (lamarck).'
(‘‘Spectacle-Case,”’ ‘‘Black Sand Shell.’’)
PEE VI rihaes. LO0n A)
1819— Unio recta Lamarck, An. Sans. Vert., VI, p. 74.

1823—Unto praelongus Barnes, Am. Jl. Sci., 1st ser., VII, p. 261, fig. 11.
t900b—Lampsilis rectus Simpson, Pr. U. S. Nat. Mus., XXII, pp.

544-545. .
1912b—Eurynia (Eurynia) recta (Lam.) Ortmann, An. Car. Mus.,
WABDLS TOR eye

ANIMAL CHARACTERS.

NUTRITIVE STRUCTURES :—Branchial opening with numerous
papillae; anal finely crenulate; supra-anal separated from anal
by moderate mantle connection; inner laminae of inner gills con-
nected to visceral mass; palpi small, almost-entirely free along
their antero-posterior edges; color of soft parts grayish with its
posterior mantle border blackish or reddish brown.

REPRODUCTIVE STRUCTURES:— Marsupium rather kidney-
shaped consisting of fifty large ovisacs extending below the original
ventral line into thickened, cream-colored, cone-shaped beads
when gravid; ova lying in irregular masses within the sacs; mantle
edge antero-ventrad to branchial opening specialized with very
great number of large, densely crowded papillae extending entirely
to the center of the ventral edge; conglutinates white, glochidia
rather medium in size, semi-elliptical, spineless, rounded ventral
edge, hinge line undulated, measure 0.220 x 0.280 mm.

SHELL CHARACTERS.

EXTERNAL STRUCTURES :—Elongate-elliptic, heavy, rather
thick, large; female shell broader and more blunt posteriorly than
male; no post-umbonal ridge; disk smooth; beaks large, low
sculptured by fine concentric ridges disposed somewhat like that of

1 This Species is the most generally distributed of the Lampsilinae.
(See accompanying Map (Plate X XIX) for three other generally distributed
Species; viz., Cumberlandia monodonta (Say) as representative of Margart-
tanidae, Quadrula verrucosa (Raf.) of Unioninae and Strophitus edentulus
(Say) of Anodontinae.

178 THE NAIADES OF MISSOURI

subrostrata; epidermis black, glossy, rayed with broad reddish
stripes.

INTERNAL STRUCTURES:—Cardinals very long and _ stout,
double in both valves; laterals long, somewhat pointed in male, °
more or less horizontal in female; nacre usually rich purple but is
variable to white, or the two colors may be present for the same.
individual.

Sex Length Height Diameter Locality
Oo 125 xX 53 xX 31mm—(Black R., Williamsville)
9 109 x 48 x 30mm—(Osage R., Osceola)
o& 96 xX 40 x 25mm—(Gasconade, Gascondy)
@ 78 x 30 x 18mm—(White R., Hollister)

MISCELLANEOUS REMARKS:—No juvenile shells are at hand.
Adolescent shells of recta are even difficult to obtain. Recta is not
a variable shell for this state; even in nacre-color it is rather
constant—being more purple in Central Missouri and white in
South and Southwest Missouri streams. This species has one of
the widest distributions in the state; however, it is seldom found in
the North Missouri streams. It is strictly fluviatile. According
to Simpson it has a very general distribution over the United
States, although it is not very ‘common in its individual occurrence
anywhere. The predominance of one sex over another in this
species for the same stream is more noticed than in any other.
Probably this occurrence is due more to breeding season than to
any other cause. The writer notes from his own record, and that
of others, that this species is bradytictic.

Surber (1913, p. 109) finds that the occasional host for recta
to be the sunfish (L. pallidus).

Genus Lampsilis Rafinesque.
1820—Lampsilis Rafinesque, Monog., Ann. Gen. Sci. Phys.
Brux. p. 298; 1900b, Simpson, Pr. U. S. Nat. Mus., XXII, p. 526.
(Type, Unio ovatus Say.)

ANIMAL CHARACTERS :—Branchial and anal opening papillose;
supra-anal not very large, separated from the anal by a moderate
connection; inner laminae of inner gills connected to the visceral
mass, sometimes a small hole is left post-dorsad of foot; marsupium
usually kidney-shaped, distended, consisting of many ovisacs
which are distinct, extended. below original edge of sterile marsu-

~ ee

THE NAIADES OF MISSOURI 179

pium when gravid into blunt, pigmeted beads; mantle edge double
posteriorly, the inner one antero-ventrad to branchial opening
developed into a ribboned flap usually produced into a tentacled
lobe at its end located about the lowest post-ventral point; con-
glutinate not solid; glochidia rather large, subelliptic.

SHELL CHARACTERS:— Shell elliptical to ovate; disk smooth;
beaks sculptured by the sinuate or double-looped type, sometimes
with a tendency of the posterior loop to become broken; epidermis
usually smooth, thin and shiny often brilliantly rayed. Hinge
with two cardinals and two laterals in left and two cardinals and
one lateral in the right valve; female shell with an inflation at
the post-ventral region of shell just over the marsupia.

MISCELLANEOUS REMARKS:—The differentiation of the mantle
antero-ventrad to branchial opening into a flap marks this genus
as among the highest of the Lampsilinae. ‘This flap is so developed
with tentacles and papillae that it is often extended externally
and waved to and fro so as to produce almost the best possible
aération for the embyros. This genus is represented in this State
by five species which have a good general distribution.

Lampsilis anodontoides (Lea).'
(“Yellow Sand Shell,” ‘‘Lady’s Finger.’’)
Pom hi apis ke Asand Bria JX V LIT? Kigs.102 A).

1834— Unio anodontoides Lea, Tr. Am. Phil. Soc., IV, p. 81, pl. VIII,
fig. It.

1834— Unto teres Say, Am. Conch,. VI; 1820, Rafinesque, Monog.

1898—Lampstlis anodontoides Baker, Moll Chicago, Pt. I, p. 100,
plo exe figs or

ANIMAL CHARACTERS.

NUTRITIVE STRUCTURES:—Branchial opening rather small
directed upward; anal crenulated; supra-anal high well separated
by mantle edges from anal; inner laminae of inner gills connected
to visceral mass; palpi long, falcate, connected for one-half of
their length antero-dorsad; color of soft parts grayish except
brownish red mantle border at branchial opening.

‘From Rafinesque’s evident description of this Species in the Suppli-
ment to his Monograph of 1820 under Unio teres (Elliptio teres) Lea’s name,
as given here by Simpson, (1900b, p. 543,) should stand as a synonym for
Lampsilis teres (Raf.).

180 THE NAIADES OF MISSOURI

REPRODUCTIVE STRUCTURES:—Marsupium rather reniform
occupying over posterior half of outer gills and consisting of sixty-
five ovisacs well separated, when gravid extending below original
ventral edge of sterile marsupia; inner mantle edge antero-ventrad
to branchial opening a specialized flap reaching down to lowest
point of the post-ventral part of shell where it is developed into a
tentacular lobe; conglutinates white, sole-shaped, not very solid,
glochidia medium in size, sub-elliptical, spineless, hinge line rather
short, evenly curved, measuring 0.185 x 0.210 mm.

SHELL CHARACTERS.

EXTERNAL STRUCTURES:—dhell elongate-elliptic, medium in
size, subsolid, disk smooth; umbones large, but not full, sculpture
by five or six double looped or sickle-shaped ridges most pronounced
and opened at base of post-umbonal slope; epidermis straw-color
(usually without much display of rays) smooth, polished; female
shell much produced at the post-ventral edge of shell and continued
upward as a marsupiual inflation for a short distance; male shell
pointed posteriorly.

INTERNAL STRUCTURES :—Cardinals prominent, serrate, double
in right valve, single in left; beak and branchial cavities rather
deep and basin-like; nacre satin-white, irridescent posteriorly.

Sex Length Height Diameter Locality
G@ 120 xX 60 xX 45mm—(Chariton R.; Kern)
@ 100 x 50 x 38mm—(Miss. R., Hannibal)
50 xX 23 xX 16mm—(Grand R., Darlington)
12h 5 eax (So de 5mm—(Grand R., Utica)

The last measurement was that of one of the smallest juveniles
obtained by the writer. It has a black border to its shell and a
short byssus extending from between the valves at ventral portion
of shell.

MicELLANEOUS REMARKS:— Even in the juvenile anodon-
toides there is some difference from that of the fallaciosa shell
in that there are not as evident. The main distinction between
the adult shells of these two species is that ‘of fallaciosa is bril-
liantly rayed, is smaller, has more reddish beaks and is a dweller
in muddy creeks, sloughs and lakes while anodontoides loves sandy
situations of swifter water and develops a large, thick shell, rayless,
unicolored epidermis and is a most active mussel. When perfect
(as it is found in the Chariton and Mississippi Rivers) it is one of

— =

THE NAIADES OF MISSOURI 181

the most beautiful shells. It is strange that it shoud not be found
anywhere in the Ozarks as it seems to be a mussell that rather
prefers swift current. Yet as that is an unglaciated region without
much sand, to which it is partial, we may account for its absence
there in part. It is entirely supplanted in the Osage by fallaciosa.
From the writer’s breeding record for this species it is bradytictic.

Lampsilis fallaciosa Smith.
(Slough Sand Stell,”” ‘Creeper.)”
Pl Vik rags. 16 Avand B.

1899—Lampsilis fallaciosa Smith, Bull. U. S. Fish., p. 291, pl. LX XIX;
Ig00a, Simpson, Pr. Ac. N. Sci. Phila., p. 74, pl. II, fig. 5.

ANIMAL CHARACTERS:—lIdentical with L. anodontoides in
every respect, except perhaps in glochidial characters.

SHELL CHARACTERS:—Differs from anodontoides in possessing
a smaller, lighter, thinner shell; a more prominent post-umbonal
ridge; more pronounced beak sculpture; pinkish nacre in umbonal
cavity; bright yellowish, or olivaceous epidermis with bright
green rays all over shell—especially on the posterior slope; rusty
red color often for umbonal region; a sulcus often seen just anterior
to the post-ventral edge and extending a short distance up on the
shell as a radial furrow.

Sex Length Height Diameter Locality
Oe G49 kn 4 ox.) 28) tim——(hower Lb. Contrary, St. Joseph)
O64 x2 30) xe 2 ini —— (Chariton R= Kern)
ONT Ode SEX Nam x 21 mm—(Miss. R., Hannibal)
51.5 X 24.5 X 15 mm—(Osage R., Warsaw)
UA eX 7.5 X 5.5mm—(Grand R., Chillicothe)

The last measurement is that of a juvenile identified by Dr.
Howard. Its beaks are sculptured by two or three subparallel
ridges at the base of the post umbonal slope and a few very faint
tubercles at the base of the anterior umbonal slope. Anterior end
of the shell is greatly produced as noted in most juvenile shells
of any species. Note the very small inflation in the above measure-
ment. It is strange that this shell at this stage of its life should be
practically rayless while the rayed character of the adult shell is
its chief feature.

MISCELLANEOUS REMARKS:—Fallaciosa may have developed
from anodontoides for ecological reasons. ‘This little striped shell

182 THE NAIADES OF MISSOURI

is a dweller along the edges of muddy streams or in ponded stretches
of the rivers and prefers lacustrine situations. For that reason it
is commonly known as “Slough Sand Shell,’ and ‘‘ Creeper.”
Mr. Walker makes the assertion that typically these two species
are very distinct, but that it is frequently difficult to name indi-
vidual specimens so given are they to intergrading. The fact, too,
that both forms are found in the same stream (as in the Chariton
R., for instance) and apparently entirely distinct would go to show
that they are specifically distinct. Besides Surber (1912, p. 5)
states a difference in size of glochidia, those of fallaciosa being
larger (0.200 x 0.240 mm.) than those of anodontoides (0.185 x
o.210mm.).

Surber (1913 p. 107) also reports that this species (fallaciosa)
has for its fish host the crappie (P. platorhynchus) its glochidium
being a gill parasite.

Lampsilis Higginsii (Lea).
(“Higgin’s Shell.’’)
Pl XXVIII, Figs. 105A and 1b.

1857—Unto higginsu Lea, Pr. Ac. N. Sci. Phila., TX, p. 84.

1900b—Lampsilis higginsit Simpson, Pr. U. S. Nat. Mus., XXII, p. 540.

ANIMAL, CHARACTERS :—As only dead shells of this species have
been secured by the writer .no description of the soft parts can
appear here. Surber (1912 p. 9) reports its glochidium as sub-
elliptic, spineless, with hinge line short and measures 0.210 x
0.260 mm.

SHELL CHARACTERS.

EXTERNAL STRUCTURES :—Shell very thick; male sub-elliptic;
female subrhomboid with posterior end vertically truncate; beaks
very large, rounded, full, sculpture unknown; epidermis brownish-
red with rays.

INTERNAL STRUCTURES:—Cardinals large, erect; laterals
straight in female; slightly curved in male shell; interdentum wide,
thick; beak cavities deep; scars deep; nacre rosy pink to salmon.

Sex Length Height Diameter Locality
o 86 x 63 x 45mm—(Mississippi R., Hannibal)
9 68 x 50 x 38mm—( e a a )

o 85 x 48 x 48mm—( z ” Louisiana)

THE NAIADES OF MISSOURI 183

MISCELLANEOUS REMARKS:—According to Simpson this is a
puzzling species that closely resembles O. ellipsis in outline and
its great posterior truncation and post-ventral inflation of the
female shell would seem to be characteristic enough to make it a
good species. Male shells obtained from the Mississippi River
of this State, in the hands of the writer, look more like N. ligamen-
tina than anything else, yet its cardinals are more stumpy, is a
thicker heavier shell and has a rosy nacre. This State is within
its range, as its distribution is from Iowa to Kansas. Surber reports
“Sauger’’ (S. canadense) as its fish host.

Lampsilis Powellii (Lea).
(‘‘Powell’s Shell.’’)
Not figured.

1852— Unio powellit Lea, Pr. Am. Phil. Soc., V., p. 252; Tr. Am. Phil.
NOC. Xe pA270, pl) LX, figs 25.

This species is listed for Missouri through a report by Mr.
Frierson from a collection made by F. A. Sampson for the Elk
River, McDonald Co., this State. Since no specimens are at hand
the writer can give no description except that for the shell quoted
from Scammon (1906, pp. 288 and 289).

SHELL CHARACTERS.

EXTERNAL STRUCTURES :—‘‘Shell large, rather thin, elliptical
in outline, neither inflated nor compressed. Anterior margin almost
circularly rounded; ventral margin gently and evenly bowed;
posterior margin rounded, biangulated; dorsal margin rather long
and straight. Umboidal ratio in specimens examined, 0.20.,
umbones rather flattened. Anterior and lateral slopes flattened
and rounded; posterior slope very slightly excavated and marked
with two radial lines. Epidermis smooth and generally shining,
olive-brown. Ligament long and rather thick.

INTERNAL STRUCTURES:—‘ Pseudo cardinals small, serrate,
rather bluntly pointed, single in right valve and double in left.
Laterals long, slightly curved, lamellar. Interdentum long, narrow,
rounded. Anterior adductor cicatrix well impressed, large, much
longer than wide; posterior scars large, very slighly impressed,
confluent. Dorsal cicatrices on the lower surface of the interdentum.
Pallial line well impressed in its one-half and crenulate. Cavity

i84 THE NAIADES OF MISSOURI

of beaks deep, of the shell moderately deep. Nacre white, decidedly
irridescent posteriorly.”

Dr. Scammon reports Powellii as a very rare shell for Kansas,
being found in only one locality, Spring River, Baxter Springs,
and further states that this species may be distinguished from
L. luteola, its nearest ally in local waters, by the smaller and less

pointed cardinals and the thinner, squarer and less inflated shell. -

Simpson states that Powelli is also found in Salina and Clinton,
Arkansas, and in Guadaloupe River, Texas. The fact that Mr.
Simpson found this rare shell in the Neosho basin of this State
its range is more determined.

Lampsilis luteola (Lamarck).
(‘Fat Mucket.’’)
1 ODS WAI MIE TORS IOS. ell

1819— Unio luteola Lamarck, His. Sans. Vert., VI, p. 79.
1898—Lampsilis luteola Baker, Mol. Chicago, Pt. I, p. 103, pl. XI,
ideey ieee G0) (4) POON ithe sem

ANIMAL CHARACTERS.

NUTRITIVE STRUCTURES:—Branchial opening large with
numerous papillae; anal slightly crenulated; supra-anal well
separated by thick mantle connection; inner laminae of inner
gills connected to visceral mass; palpi short, wide; color of soft
parts dingy white, mantle border blackened posteriorly.

REPRODUCTIVE STRUCTURES:—Mantle edge antero-ventrad to
branchial opening with long spotted flap at the end of which are
two or three finger like tentacles and about midway an eye spot
appears; marsupium large, kidney-shape, consisting of numerous
distinct ovisacs that hang down toward the mantle flap in beaded
rows; conglutinates white, large, subsolid; glochidium rather
large (uniformly smaller for lacustrine /uteola), subelliptic, spineless,
measuring 0.250 xX 0.290mm.

SHELL CHARACTERS.

EXTERNAL STRUCTURES:—Shell broadly elliptic, narrowly

rounded before, broadly rounded behind; female shell greatly
inflated, rather truncated posteriorly expanded post-ventrad, male
shell pointed posteriorly; disk smooth; umbones large but low,

aa

ae BY
TE

THE NAIADES OF MISSOURI 185

Sculpture faint consisting of fine broad, inverted V-shaped lines with
the apices pointing toward tips of beaks; epidermis yellowish
or olivaceous with widely separated and interrupted rays.

INTERNAL STRUCTURES:—Cardinals double in left, single in
tight; laterals doubled the same; nacre white.

Sex Length Height Diameter Locality

@ 110 x 65 x 48mm—(Flat Creek, Sedalia)

oO 130 9x 68 x 48imm—( -” ee Ae)

Q@ 82 x 46 x 30mm—(Black R., Williamsville)
Oo 54 xX 30 xX I17mm—(White R., Hollister)

MISCELLANEOUS REMARKS:—Although L. luteola is considered
as having the greatest geographical distribution over all United
States yet (strange to say!) it has limited distribution in Missouri.
It is not found at all in North Missouri, occurs very sparingly for
Central Missouri, (especially in the Osage basin) and is not at all
typical for South Missouri. The best types are found in Crow’s
Fork, Fulton, and in Flat Creek, Sedalia, where the female shells
attain enormous size and thickness—the typical “Fat Mucket,”’
as it is known on the market. Surber finds that the glochidia of
luteola attain a larger size in the fluviatile forms (1912, p. 4) and
thinks that the larger size of the river form may be correlated with
the larva. Lwuteola is bradytictic.

Lampsilis luteola rosacea (DeKay).
(“Rosy Mucket.’’)
PLT Vile Bags 104g vAnand. B.

1843— Unio rosaceus DeKay, Zool. of New York, V., p. 192, pl. XXXIV,
figs. 355 and 356.
1900b—Lampsilis luteolus rosaceus (DeKay) Simpson, Pr. U. S. Nat.
CWS 2 OSSD UR Sor, GeeiG i
ANIMAL CHARACTERS:—No soft parts have been seen but in
all probability identical with those of the parent.
SHELL CHARACTERS :—Identical in all respects with the parent
species except in its solid pink nacre.
Sex Length Height Diameter Locality
oOo 125 X 72 xX 49mm—(White R., Hollister)
9 90 x 52 x 37mm—(Black R., Williamsville)
MISCELLANEOUS REMARKS:—A cotype from a lot of pink-
nacred shells collected by the writer in the White and Black

7.

186 THE NAIADES OF MISSOURI

Rivers was pronounced by Mr. Frierson as rosacea DeKay but not
exactly the author's shell from the St. Lawrence. Mr. Walker
comments :—‘‘I do not remember of ever having seen a red-nacred
luteola from the southwest. The Great Lakes form, rosacea DeKay,
is typically red or rather pink.”

Lampsilis reeviana (Lea).
(““Reeve’s Shell.’’)
Not figured nor described.
1852— Unto reevianus lea, Tr. Am. Phil. Soc., X, p. 272, pl. XX, fig. 28.

This species is catalogued through a report of it for Clinton,
Missouri. The writer has not found it; hence no figure nor descrip-
tion appears here. Simpson reports this throughout the South-
west and hence the locality of this State, from which Mr. Walker
reports as having received his reeviana shell, is within the range.

Lampsilis ventricosa (Barnes).*
(“Pocket Book.’’)
Pl. XXVIII, Figs. 106 A—D.

1823— Unto ventricosus Barnes, Am. Jl. Sci., VI, p. 267, pl. XIII,
fig. 14. (in outline).
1900b—Lampsilis ventricosus Simpson, Pr. U. S. Nat. Mus., XXII, p.
Bil.
ANIMAL CHARACTERS.

NUTRITIVE STRUCTURES:—Branchial and anal opening papil-
lose; supra-anal large, closely connected to anal; inner laminae
of inner gills connected to visceral mass; palpi connected about
two-thirds of their length antero-dorsad, color of soft parts whitish
except foot which is pinkish and gills of male and sterile female
which are light brown, gravid marsupium darker brown, edged
in blue and black.

REPRODUCTIVE STRUCTURES :—Marsupium kidney-shaped con-

‘ According to Vanatta, l. c., (T915, p. 551), Lampsilis ventricosus
Bar. (1823) of Simpson’s Synopsis, p. 526, should read Lampsilis cardium
Raf. since this Species is unquestionably the Lampsilis cardium (Unio
cardium) of Rafinesque’s Monograph (1820), p. 298, No. 14, Pl. 80, Figs.
16, 17, 18 and 19, as now identified from Types in the A. N. S. P. Coll.,
INO: 20), 210:

THE NAIADES OF MISSOURI 187

sisting of thirty large ovisacs distended, when gravid, at their
distal ends into bulging beads drawn down near to mantle flap
which is a long, wide, ragged ribbon that bears eye spots and
extends to bend of the post-ventral curve of the shell; congluti-
nates white, discharged in unbroken masses; glochidia medium
in Size, semi-elliptic, with rather straight hinge line; measuring
0.205 X 0.255mm.

SHELL CHARACTERS.

EXTERNAL STRUCTURES:—Shell of female sub-rhomboidal
greatly inflated, swollen post-ventrad, male sub-elliptic not so
inflated; narrowly rounded before, disk smooth, without sculpture;
beaks very full, very much inflated, sculptured by four coarse
sub-parallel bars with rounded furrows between; epidermis thin,
smooth, polished, yellowish, bluish olivaceous or even terra
cotta, with broad brilliant green, or blue-green rays all over shell;
post-umbonal ridge prominent but not angled.

INTERNAL STRUCTURES :—Cardinals prominent, serrate, rather
curved; laterals erect blade-like; beak cavities very deep and
basin-like; nacre pure marble white, sometimes inclined to pink.

Sex Length Height Diameter Locality
@ 100 x 65 x 45mm-—(Gasconade R., Gascondy)

o 90 x 65 x 42mm—(Black R., Williamsville)
Lions 2Ontsa s 2oimimn—— (Osa re Re Osceola)
@ 55 xX 39 xX 26mm—(Miss., R., La Grange)

The -young shells are very bright colored. ‘The specimen
of the last measurement has a blue epidermis with bright blue-
green stripes. Its beak sculpture is very plain and eroded in curved
beaks showing as above described. No juveniles obtained.

MISCELLANEOUS REMARKS:—Young shells look much like
multiradiata but can be distinguished from the latter by the presence
of post-umbonal ridge and by not possessing so many finer rays.
The adult shell is told from that of ovata by not possessing the
sharp cornered post-ridge, larger shell and more peculiar rays.
Aside from these two related shells ventricosa is unique. Multira-
diata and ovata are not found in Missouri. Ventricosa is also very
peculiar in the structure of its soft parts—especially in the great
development of the mantle flap that characterizes the genus
Lampsilis. ‘The writer has observed these flaps extended and in
action both in the aquarium and in nature. Three have been seen

}
. /
A

188 THE NAIADES OF MISSOURI

spawning, at which time the mother buries her shell in the sand
up to the siphonal openings, the flaps are waved to and fro exposing
the ventral edges of the ovisacs through the branchial opening
while ever now and then sole-shaped conglutinates emerge from
the anal opening by convulsive jerks. With the eye spots showing
at the base and the fringed flaps rhythmatically waving one is
fascinated. Ventricosa is found to be typically bradytictic. The
geographic distribution for Missouri is wide; however, it is of
rare occurrence in the streams of North Missouri—never found in
Northwest Missouri. South of the Missouri it is one of the com-
monest of shells.

‘ Lampsilis ventricosa satura (Lea).
(‘‘Plain Pocket Book.’’)
PL SOV IER oh vgs. 07 eA ab.

1852— Unio satur Lea, Pr. Am. Phil. Soc., V., p. 252; Tr. Am. Phil.
SoCs Xe DSS eu D ZO sm plano Ville atigee oe

1900b—Lampsilis ventricosus satur (Lea) Simpson, Pr. U. S. Nat. Mus.
> OO. joR Sis

ANIMAL CHARACTERS :—lIdentical in every way to the parent
species.

SHELL CHARACTERS:—Also identical to the species except in
its uni-coloration of epidermis which is rather a dark-brownish.
All shells collected by the writer for this State are also smaller
when mature.

Sex Length Height Diameter Locality
@ 88 x 55 x 45mm—(Black R., Williamsville)
So 75 xX 54 x 42mm—(White R-, Hollister)

MISCELLANEOUS REMARKS:—This subspecies is only found
in the Southwest. For this State it is definitely reported by Mr.
Walker for the Black River., Popular Bluff. The writer collected
some of these forms of ventricosa from the same stream a few miles
north. The Black is a metropolis for ventricosa where it is found
in all forms, since this species is hable to intergrading—satura
being one of these intergradations. Yet its rayless character (like
that of capax) would make it worthy of a name.

“Ts

THE NAIADES OF MISSOURI 189

Genus Truncilla Rafinesque.

(Type, Truncilla triqueter Rafinesque).
1819—Truncilla Rafinesque, Jl. de Phys. Chim. et Hist. Nat. pp. 427.

ANIMAL CHARACTERS:—Branchial opening densely set with
papillae; anal crenulated; supra-anal well separated from the anal

‘by a definite mantle connection; inner laminae of inner gills

entirely connected with the visceral mass; outer gills greatly
tapering anteriorly; palpi very small, post-dorsal margins entirely
free; color of soft parts grayish, posterior margins of mantle black.
Marsupia kidney-shaped, distended transversely as well as ventrad
when gravid; formed by many ovisacs that occupy the posterior
section of outer gill and extend down from the ventral edge of the
original sterile gill in blunt, beaded unpigmented structures in
state of gravidity; conglutinates not solid; glochidium medium
in size, semicircular, hinge line very long, length about the same
as height; post-ventral edge of marsupium doubled, the inner
edge remote from outer forming a peculiar compartment as the
highest specialization for the respiration of the embryos.

SHELL CHARACTERS:—Female shell very distinct from that
of male, with a strong inflation or projection (marsupial expansion)
in the post-ventral region which so changes its position and form
that it assumes very many strange shapes; male shell not so
modified post-ventrad, however, nodulous expansions do appear
in some species; shell of either sex small, usually narrowly rounded
in front much thicker anteriorly; beaks rather full, comparatively
large, sculptured by double-looped ridges, usually obscure; epi-
dermis yellowish or brownish, rayed with numerous fine green
lines; cardinals and laterals usually single (or faintly double) in
right valve, double in left; branchial cavity deep, basin-like;
nacre white or bluish.

MISCELLANEOUS REMARKS:—This remarkable genus is the
most modern due to the best possible adaptation to reproduction
both as to the morphology of shell and soft parts. This correlation
of the physiology to the morphology is best seen in the greatest
specialization of the reproductive structures of the animal. Recog-
nizing that the most recent classification of the Unionidae is based
primarily upon the modification of the marsupium and that the
genus Truncilla has carried out this sexual differention to the

“190 THE NAIADES OF MISSOURI

greatest extent, Walker (1910c pp. 75-81) gives us the following
systematic arrangement of Truncillae on the basis of reproduction:

1.—Perplexa—Group.—Marsupial expansion occupies the
whole post-ventral area of shell.

2.—Triquetra—Group.—Marsupial expansion formed by the
inflation of the post-umbonal ridge.

3.—Foliata—Group.—Marsupial expansion anterior to post-
umbonal ridge and more or less separated from it.

These groups may in turn be subdivided because of the different
forms and shifting position of the sexual expansion. The first and
third groups are represented in this State by two new species,
discovered by the writer in South Missouri streams, and their
novelty acknowledged by Mr. Frierson of Frierson, Louisiana.

Truncilla Curtisii Frierson and Utterback. New Species.
(“ Curtis’ Shell.’’)
Pl. VI, Figs. trga-d; Pl. XXVIII, Figs. to9 A—D.

ANIMAL CHARACTERS.

NUTRITIVE STRUCTUTES:—Branchial opening densely bordered
with papillae; anal crenulated; supra-anal high, rather small,
separated from anal by moderately short mantle connection,
mantle border here spotted; inner laminae of inner gills entirely
connected to visceral mass; palpi very small connected only by
their anterior base which is remote from the anterior attachment
of pointed outer gill; color of soft parts grayish except the blackish
mantle edge at siphonal openings.

REPRODUCTIVE STRUCTURES:— Marsupium very _ broad,
rounded ventrad, kidney-shaped, ovisacs several, distinct occupy-
ing posterior half of outer gills and distended into beaded, unpig-
mented structures along ventral edge when gravid; conglutinates
broken masses; glochidia unknown as only specimens gravid
with early embryos have been obtained; inner mantle edge of
female antero-ventrad to branchial opening drawn in toward the
interior of shell forming a chamber.

SHELL CHARACTERS OF FEMALE:—Obvate, lacks flattened
area of the disc, slightly emarginated just below post dorsal line;
epidermis cloth-like, brownish-yellow, finely and obscurely radiate

THE NAIADES OF MISSOURI Ig!

all over; nacre white; the antero-extra pallial layer remarkably
thickened; anterior muscle scars deep, the posterior lightly im-
pressed and confluent; the pallial line reflected upward and inward
in the post-half; cardinals double in each valve, small, high,
accuminate, sulcate; sexual expansion thin, swollen, slightly
radiately and concentrically ridged, denticulate on edge.

SHELL CHARACTERS OF MALE:—Shell much the smaller of
the two (so far as noticed); rounded before, sinuous below, widely
biangular behind, flattened over the umbones and to the post-
base; post ridge widely double.

Beaks of both sexes remarkably heavily ridged, inclined to be
doubly looped, but obsately so in front, ridges heavy behind
running downwards and backwards to the umbonal ridge. The
earlier growth of the shell when looked at through a lens resembles
in a striking way a diminutive Amblema plicata (Say.)

Sex Length Height Diameter Locality
9 33 x 23 #x 4r5 mm—(White R., Hollister, Mo.)
So 22.5 X 19.5 x 13.5mm—(White R., Holilster, Mo.)
9 265 x 18.5 x 14 mm—(White R., Hollister, Mo.)

MISCELLANEOUS REMARKS:—The position of this interesting
species is exactly between capsaeformis Lea and biemargiatus
Lea. From capsaeformis our species differs in the sexual enlarge-
ment being of the same general body color and in being more
expanded or swollen in the middle and therefore not so regularly
fan-shaped as in capsaeformis and our shell is not so regularly
rounded behind. From biemarginata our species may be differen-
tiated by its lack of pronounced angles and ridges of the former
and by our species being much smaller and thinner and from its
general almost solid piece color. Our species differs most remarkably
in the heavy beak sculpture. From deviatus Anthony our shell
similarly differs in color; and the sexual swelling is not so far
protruded behind. A specimen of deviatus, recently procured,
shows this species to have beaks nearly as heavily corrugate as
our species and not, as Anthony supposed, nearly smooth as in
capsaeformis. ‘The presence of a form so intimately resembling
those of the East Tennessee mountain streams in Missouri is of
great interest.

The shell was taken by the co-author, W. I. Utterback, in
the White River, Hollister, Mo., Aug. 26, 1913, and is named in
honor of Dr. W. C. Curtis of the Department of Zoology, Univer-

192 THE NAIADES OF MISSOURI

sity of Missouri. The type shells, which are line-drawn and also
photographed herewith, are now in the possession of Mr.
Utterback.

Truncilla Lefevrei' Utterback. New Species.
(‘‘Lefevre’s Shell.’’)
PLO Vie. Fees. 13+ @——a° Pl XX Ve ves shOdeiet ae

ANIMAL CHARACTERS.

NUTRITIVE STRUCTURES:—Branchial opening thickly papil-
lose; anal crenulated; supra-anal moderately connected to anal;
outer gills shorter and only half as wide as inner gill, inner laminae
entirely connected to visceral mass; outer gills drawn up high
and pointed anteriorly forming wide gap between palpi and
anterior attachment; palpi small, free their whole dorsal length;
color of soft parts dingy white with squarish, blotched mantle
edge around anal and supra-anal openings and solid blackish
border at branchial opening.

REPRODUCTIVE STRUCTURES:—Marsupium formed by several
ovisacs arranged in a kidney-shape, which, when gravid, extend
down to the edge of inner gills forming a plain beaded border
on the ventral edge; inner mantle edge anterior-ventrad to bran-
chial opening drawn over into the interior of shell forming a com-
partment evidently as a water reservoir; no conglutinates nor
glochidia observed.

SHELL CHARACTERS.

EXTERNAL STRUCTURES:—Shell small, narrowly rounded
before, solid anteriorly, thin posteriorly; general shape of both
sexes ovate-trigonal; epidermis brownish-yellow, smooth, with
fine, continuous rays; beaks rather large, full, too eroded to make

TAs may have been noted, the author has departed from the accepted
Code of Nomenclature on Naiades in so far as to employ the initial capital
for all names of those Species and Sub-Species derived from the names of
persons when used substantively in both their respective binomial and
trinomial forms. Although this action may seem somewhat presumptuous,
yet the departure is surely justifiable on the grounds of efforts to be more
consistent with clearness as to the nominal derivation and especially with
the Latin and Greek etymology or diction. In this regard the suggestion
of the Editor has been followed and reference would be made to his comments
on ‘‘ Proper Publication’? (Am. Mid. Nat., Vol. IV., No. 3, pp. 95 and 96).

Se

THE NAIADES OF MISSOURI 193

out sculpture. Female shell broader posteriorly, marsupial expan-
ston formed post-ventrad, above basal line just anterior to post-
umbonal ridge and bounded ventrad by a furrowed rest line. Male
shell more trigonal in shape with post-umbonal ridge rather
biangulated and with a very slight radial furrow in front; dorsal
ridge rather prominent.

Internal structure of both sexes about the same except a
higher mantle line in the female shell; cardinals double in both
valves; laterals single in right, double in left; branchial cavities
deeply basin-like; nacre blue with a tinge of yellow in the bran-
chial cavity, irridescent posteriorly.

Sex Length Height Diameter Locality
Q@ 32 xX 21 x i15mm—(Black River, Williamsville)
Oo 26.5 x 18 x 14mm—(Black River, Williamsville)

MISCELLANEOUS REMARKS:—Although this rare Species has
been found only in one locality yet a sufficient suite of shells was
secured to establish its novelty. One specimen was obtained
gravid with ova, yet it was sufficiently, although briefly, described
afield before it was lost as often results in a rush of field work.
At first the author was inclined to call this Species 7. triquetra,
but comparisons to actual shells of typical triquetra show that it
is placed in the third group of 7runcilla which is characterized by
the marsupial expansion formed by the inflation just anterior
to the post-umbonal ridge not extending below the basal line
and in which group triquetra is not classed. Lefevrer differs from the
arcaeformis of Lea in not possessing a radial depression in front
of the post-dorsal ridge and in not having such a prominently
curved post-umbonal ridge and also in not possessing such coarse
hinge teeth. This new and most modern Species is dedicated to Dr.
George Lefevre of the Department of Zoology in the University of
Missouri. The discovery of this new Species from the Black River,

- Williamsville, Missouri, and also of the new Truncilla, Curtisi1 Frier-

son and Utterback, from the White River, Hollister, this State, and,

being the only completely described Truncillae west of the Mississ-

ippi, it seems fitting that these should bear the names of the two

associate authors and instructors who have contributed so much to

the science of the Nazades in their monumental work, ‘‘ Studies on

the Reproduction and Artificial Propagation of Fresh-Water Mussels.”
(THE Enp).

194 THE NAIADES OF MISSOURI

BIBLIOGRAPHY.

1898b—Baker, F. C——The Mollusca of Chicago Area. The Pelecypoda.
(Nat. Hist. Survey of the Chicago Acad. of Sci., Bull. No. 3, Pt. 1.

1890—Brooks, W. K.—Handbook of Invertebrate Zoology for Laboratories
and Seaside Work. (Boston, Mass., Pub. Co.).

1885—Call, R. E.—A Geographic Catalogue of the UNIONIDAE of the Miss-
issippi Valley. (Bull. Des. Moines Acad. Sci.; I, pp. 5-57.)

1895—Call, R. E.—A Study of the UNronrDaAk of Arkansas with Incidental
Reference to their Distribution in the Mississippi Valley. (Tr.
St. Louis Acad. Sci., VII, No. 1, pp. 1-65, 21 plates).

1912—Coker, Robt. E.—Mussel Resources of the Holston and Clinch Rivers
of Eastern Tennessee. (From Notes of Investigation Taken by
J. F. Boepple). U.S. B. F., Doc. No. 765.

1914—Coker, Robt. E.—Protection of the Fresh-water Mussels. (U.S. B.
F., Doc. No. 793, pp. 1-23 with plates I and II).

1892—Dall, W. H.—Instructions for Collecting and Other Useful Hints,
for the Conchologist. (Pt. G. Bull. U. S. Mus., No. 39).

1899—Frierson, L. S—VThe Unronipagk of DeSoto Parish, Louisiana.
(Reprint from Gulf Fauna and Flora., Bull., I, No. 1.)

1901—Frierson, L: S—A New Unio from Texas. (Naut., 15, pp. 75-76).

1904—Frierson, L. S.—Observations on the Genus QuUADRULA (Naut. 17,
joys Meee batel secs).

1911—Frierson, L. S—-A Comparison of the UNIONIDAE of the Sabine
Rivers (Naut., XXIV, pp. 134-136).

1914—Frierson, L. S—Remarks on Classification of UNIONIDAE. (Naut.,

XXVIII, pp. 6-8.)

1900—Ferriss, J. H—A New Arkansas Species (Lampsilts Simpsont) (Natt.
DOW fois Ne

1912—Hannibal, Harold—A Synopsis of the Recent and Tertiary Fresh-
water Mollusca of the California Province. (Proc. Mala. Soc.
Lon, | pp. 112—166, Pt. Ll? pp. 167-211, Pt. ir):

1907—Henderson, Junius—Mollusca of Colorado. (Pt. 11, pp. 77-96, Plates
I and II, Univer. Sci. Ser.).

1915—Hinkley, A. A..— New Fresh-water Shells from the Ozark Mountains.

(Proc. U. S. Nat. Mus., XLIX, pp. 587-589.)

1912—Howard, A. D.—The Catfish as a Host for Fresh-water Mussels.
(Reprint Tr. Am. Fish. Soc.).

1911—Isely, F. B.—Preliminary Note on the Ecology of the Early Juvenile
Life of the UNIONIDAE. (Biol. Bull., XX, pp. 79-80).

1914—Isely, F. B.—Mussel Streams of Eastern Oklahoma. (U. S. B. F.,
Ec. Cir., No. 9).

1913—Israel, Von W.—Biologie der Europaischen Susswasser-muscheln
(Herausgeben vom Thuringer Lehrerverein fur Naturjkunde).

1815-1843—-Lamarck, J. B. de—Histore Naturelle des Animeaux sans
Vertebres. (7 vols. Paris, 1815-1822; 2nd ed., 10 vols., Paris,
1835-1843).

THE NAIADES OF MISSOURI 195

1831—Lea, Isaac—Observations on the NarapkEs. (Tr. Am. Phil. Soc.,
pp. 63-121; 1834, pp. 23-119).

1838—Lea, Isaac—Description of New Fresh-water and Land Shells.
(Tr. Am. Phil. Soc., pp. 1-154; 1842, pp. 163-252).

1852—Lea, Isaac—Description of New Species of the Family UNIONIDAE.
(icy Am Phill Soc. pp. 252-204).

1862—Lea, Isaac—Description of Ten UNIoNIDAE of United States. (Pr.
Acad. Nat. Sci. Phila., pp. 168 and 169).

1912—Lefevre, Geo. and Curtis, W. C.—Studies on the Reproduction and
Artificial Propagation of Fresh-water Mussels. (U. S. B. F.,
OOK DOG INO. 750).

1906—Lindahl, Josua—Orthography of the Names of the NarapEs. (Jl.

: Cinn. N. Hist. Soc. XX, No. 5, pp. 235-243).

1891—Marsh, W. A.—A Description of Two Species of Unio From Arkansas
(U. Pilsbry and Pleasit) (Naut., V, pp. 1-2; 1892, VI, pp. 1-2:
TSOS Ville: clea leah:

1901— Marsh, W. A.—Description of a New Unio from Missouri. (P. mis-
Sourensis, n. sp.) (Naut., XV, pp. 74-75).

1912—Meek, S. E., and H. Walton Clark—The Mussels of the Big Buffalo
Fork of White River, Arkansas. (U.S. B. F., Doc. No. 759).

1909—Ortmann, A. E.—The Breeding Season of UNIONIDAE in Pennsyl
vania. (Naut., XXII, pp. 99-103).

I9gt1a—Ortmann, A. E.—The Anatomical Structure of Certain Exotic
NataDES Compared with that of the North American Forms.
(Naut., XXIV, pp. 103-108, 114-120, 127-131).

1911b—Ortmann, A. E.—A Monography of the NatapEs of Pennsylvania.
(Mem. Car. Mus., IV, pp. 279-339).

1912b—Ortmann, A. E.—Notes upon the Families and Genera of the
NAIADES. (Reprint An. Car. Mus., VIII, pp. 222-365).

1891b—Pilsbry, H. A.—Critical Notes on Eastern Texas UNIONIDAE. (Naut.,
We PP 74577)

1901— Pilsbry and Fox. On Alasmidonta marginata. (Naut. 15, pp. 16 and

: 47).

1906—Pilsbry and Ferriss—Mollusca of Ozarkian Fauna. (Pr. Acad. Nat.
Sci. Phil., pp. 529-567).

1878—Pratt, W. H.—The Shell Beds of the Vicinity of Davenport, Iowa.
(Pr. Dav. Acad., pp. 156-162).

1820-1831—-Rafinesque, C. S—Monographie des Coquilles Bivalves
Fluviatiles de la Riverie Ohio. (Ann. Gen. Sci. Phys. Brux.,
V, pp. 287-322).

1829—Say, Thomas—Description of Some New Terrestrial and Fluviatile
Shells of North America. (New Harm. Diss., II, pp. 229; et
seq. ad interim, 1829-1831).

1830—Say, Thomas—American Conchology; or Description of the Shells
of North America. (New Harmony, Ind.).

1906—Scammon, R. E.—The UNIoNIDAE of Kansas, Part I, (Kan. Univer.
Sci. Bull., III, pp. 279-373.).

196 THE NAIADES OF MISSOURI

1913—Shira, A. F.—The Mussel Fisheries of Caddo Lake and the Cypress
and Sulphur Rivers of Texas and Louisiana. (U.S. B. F. Econ.
CitseNOntO))s

1895—Simpson, C. T.—The Classification and Geographic Distribution of
the Pearly Fresh-water Mussels. (Pr. U. S. Nat. Mus., XVIII,
PP. 295-344).

1900a—Simpson, C. T.—New and Unfigured UNronipak. (Pr. Acad. N.
N. Sci. Phil., Vol. 52, pp. 74-86). <

1900b—Simpson, C. T.—Synopsis of the NaraDEs or Pearly Fresh-water
Mussels. (Pr. U. S. Nat. Mus., XXII, pp. 501-1044).

1901—Simpson, C. T.—On the Classification of the UNIONIDAE. (Naut.,
XV, pp. 72-82).

1898—Smith, H. M.—The Mussel Fishery and Pearl Button Industry of

the Mississippi River. (Bull. U. S. Fish Com., pp. 289-314, 31 plates).

1891—Sterki, V.—A Byssus in Unto. (Naut., V, pp. 73-74).

1898—Sterki, V.—Some Observations on the Genital Organs of UNIONIDAE
with Reference to their Classification, (Naut., 12, pp. 18-32).

1903—Sterki, V.—Notes on the UNIONIDAE and their Classification. (Am.
Natural., 37, pp. 103-113).

1907—Sterki, V.—A Preliminaty Catalogue of the Land and Fresh-water
Mollusea of Ohio. (Pr. Ohio Acad. Sci., IV, Pt. 8).

1910—Sterki, V.—Common or Vernacular Names for Mussels. (Naut.,
XXIV, pp. 16 and 16).

1891a—Strode, W. S.—Mollusks of Thompson Lake, Illinois. (Naut., IV,

PP.. 133-134).
1891b—Strode, W. S.—Mollusks of Spoon River, Illinois. (Naut., V., pp.
61-64).

1896—Strode, W. S.—The Size of Mussels. (Naut., IX, pp. 115 and 116).
1912—Surber, T.—Identification of the Glochidia of Fresh-water Mussels.
GUEZS Baek Dock Non 77a).
1913—Surber, IT.—Notes on the Natural Hosts of Fresh-water Mussels.
(QUI SoBe Ik, Webb) OO Ey INOS 77/3).
1914—Utterback, W. I.—Mussel Resources of Missouri. (U. S. B. F.,
Econ. Cir., No. 10, pp. 1-6).
1916a—Utterback, W. I.,—Breeding Record of Missouri Mussels. (Naut.,
XOGXE No: 2, pp: 13-20.)
1910—Vanatta, E. G.—UNIONIDAE of Southeastern Arkansas and North-
eastern Louisiana. (Naut., XXIII, Jan., pp. 102-104).
1916—Vanatta, E. G.,, Rafinesque’s Types of Unio. (Proc. Acad. Nat.
Sci. Phila., pp. 549-559.)
1898—Walker, Bryant—The. Distribution of the UNIONIDAE in Michigan.
(Mich. Ac. Sci., March).
1910 —Walker, Bryant—The Distribution of Margaritanidae margaritifera
in North America. (Pr. Mala. Soc. of Lon., Vol. 9)
1900b— Walker, Bryant—On the Validity of Unio undatus Barnes. (Naut.,
pp. 6-10, 16-24).

re

THE NAIADES OF MISSOURI x

1910b—Walker, Bryant—Notes on TRUNCILLA, with Key to the Species.
(Naut., 24, pp. 75-81).

1912a—Wilson, Charles B. and H. Walton Clark—The Mussel Fauna of the
Kankakee Basin. (U. S. B. F. Bull., No. 758).

1912b—Wilson, C. B. and H. Walton Clark—The Mussel Fauna of the
Maumee River. (U.S. B. F. Bull., No. 757).

1912— Wilson, C. B. and E. Danglade—The Mussels of Central and Northern
Minnesota: (U.S. BF: Beon. Cir, No.3): ©

1914—Wilson, C. B. and H. Walton Clark—The Mussels of the Cumber-
land River and its Tributaries. (U. S. B. F., Doc. No. 781).

1883—Witter, F. M:.—The Mollusks of Muscatine County (Iowa) and
Vicinity. (Muscatine Pub. Co.).

1888—Wright, B. H.—Check List of North America and other Fresh-water

Bivalves. (Dore and Cook Pubs., Portland, Ore.).

1898—Wright, B. H.—New Varieties of UNIONIDAE. (Naut., XI, pp.
ag.)

1902— Wright, B. H. and Bryant Walker—Check List of the North American,
NaIaDES. (Detroit Pub. Co.). . °

ERRATA. af

(For Reprints of Utterback on The Naiades of Missouri.)

.Some errors have been due partly to improper and insufficient correc-
tions of the MS. which originally followed Lindahl’s ‘‘Orthography of the
Names of Nazades,’’—an article that adheres strictly to the International
Code. The following immediate errata for page 3 applies to all other like
mistakes made in using capitals for the Greek and Roman names of Species
and Sub-Species when used adjectively. On the other hand, through oversight
in some instances, small initials have crept in for the substantive form when
capitals were intended despite ‘‘Canon VIII’ as adopted in the generally
accepted Code of Nomenclature. (See foot-note for Truncilla Lefevret,
page 192). Most of the other errors are the typographical mistakes that
usually escape even the most careful proof-reading.

Page 3, line 23, for ‘“‘Lamarckiana’’ read ‘‘lamarckiana’’; line 24,
for ‘‘ Reeviana’’ read “‘reeviana.”’

Page 7, line to, for “marsupial”? read ‘“‘marsupia’’; line 40, for
‘* Magnonatas’’ read ‘‘ Megalonaias’’; line 44, for ‘‘ Schoolcraftensis’’ read
‘ 44
“* schoolcraftensis.”’

Page 8, line 16, for “‘ Cooperianus’’ read ‘‘cooperianus.’

Page g, line 7, for ‘“Genus XII” read ‘‘Genus XIII’’; line 19, for
“ Ferussacianus”’ read ‘‘ferussacianus’’; line 29, for ‘“‘Genus VXII”’
read ‘‘Genus XVII’’.

Page 10, line 39, for “‘texensts’’ read ‘‘ texasensis.”’

—

‘

198 THE NAIADES OF MISSOURI

Page 11, line 12, for ‘‘ Curtist’’ read ‘‘ Curtisii’’ (This latter inflection
really should occur for all Latinized substantives derived from names of
persons terminated by a consonant).

Page 19, line 25, insert ‘‘inner’’ before ‘‘usually.”’

Page 20, line 11, for ‘‘ Untonae’’ read ‘‘ Unionidae’’; line 18, for
“The connection’’ read ‘‘the usual disconnection.’’

Page 21, line 32, for “‘ F. trigona”’ read ‘‘ F. undata trigona’’.

Page 22, line 4, omit comma after ‘‘hermaphroditic’’; line 12, for
swblates dvand ts (read Plates) ljandelnh.

Page 29, line 21, insert next line below this reference:—‘‘ Pl. XV..,
Figs. 34A and B”’.

Page 33, line 19, insert comma after ‘“‘p. 71”’

Page 36, line 6, for ‘‘raripliplicata”’ read ‘‘rariplicata”’

Page 37, line 24, for “‘these fact” read “‘this fact’’; line 27, for
“quintardt”’ read ‘‘Quintardiit (All other errors regarding Quintardii
read as corrected here).

Page 44, for Text-Fig. 3 A transpose ‘““AN” and ‘“‘PO”’. -

Page 45, line 9, for “‘expecially’’ read “‘especially’’; line 20, between
“very” and “‘profusely”’ insert ‘“compressed and’’.

Page 46, line 3, for ‘“‘scupture’’ read ‘“‘sculpture’’; line 13, separate
‘‘glochidia’’ and ‘“‘lying’’; insert next line below:—‘‘7.—No undulations
in juvenile and adolescent shell asin Amblemae”’. .

Page 48, line 10, for ‘‘charasterized”’ read “‘characterized’’.

Page 49, line 4, for all statements of ‘‘Quadrula pustulosa (Lea)”’
read ‘‘Quardrula bullata (Raf.)’’ as mentioned in the Foot-note for this page.

Page 54, line 38, for “‘ Udio”’ read “‘ Unto’’.

Page 55, line 22, for ‘“‘tacytictic”’ read ‘‘tachytictic”’.

Page 61, line 2, for “‘tha”’ read “‘than’”’.

Page 65, line 28, for ‘“‘wardiu”’ read ‘‘Wardiw’’ (All other errors
regarding the capitalization of ‘‘ Wardii’’ read as corrected here).

Page 67, line 35, insert comma after ‘‘marsupial’’.

Page 68, line 37, for ‘‘wiite’’ read ‘‘white’’.

Page 73, line 17, for “‘state’’ read ‘‘State’’ (AIl other errors in the
use of this word when its antedecedent is geographic, e. g., ‘‘ Missouri,”
correct as read here).

Page 76, line 25, for ‘‘ Pleruobemae’’ read ‘‘ Pleurobemae’’.

Page 80, line 39, omit ‘‘Am.”’

Page 81, line 30, between ‘‘catillus’’ and ‘“‘by”’ insert ‘‘not only”
and between “‘but”’ and ‘‘its”’ insert ‘‘also by’”’; line 35, between “‘had”’
and “‘been”’ insert “‘also”’.

Page 84, line 18, for period use a comma after ‘‘ North Missouri’’.

Page 85, line 2, of Foot-note for ‘‘groupp’”’ read ‘‘group”’.

Page 88, line 13, for the first word, “of” read “‘or’; line 21, for
“used”? read use”’. ;

Page 93, line ro, for “‘papli” read ‘“‘palpi”’.

Page 94, in Text-Fig. 4, for ‘‘M’”’ on inher gill read “‘I”’.

Page 97, line 36, for ‘‘umbona”’ read ‘“‘umbonal’’; line 39, for
“vavles”’ read ‘‘valves’’.

‘

‘

THE NAIADES OF MISSOURI 199

Page 100, line 2, for ‘‘climed’’ read ‘“‘claimed’”’; line 27, for ‘‘ Ptero-
sygna”’ read “‘ Pterosyna’’.

Page 101, line rg, for ‘‘bue”’ read ‘‘blue’”’.

Page 103, line 27, for the adverb. ‘‘ventrad’”’ read as adjective,
“ventral’’.

Page 104, line 33, insert next line below:—‘‘ (Type, Lastena ohiensis
Rijs) 9 line 30, Separate, outer and “and “7.

Page 105, line 26, for ‘“‘p.’’ read ‘‘Pl.’’; line 36, for ‘‘ pericardinal”’
read “ pericardial’’. A

Page 106, line 10, omit comma after ‘“‘distinct’’ and supply after
at veining ee

Page 107, in Text-Fig. 7, transpose ‘‘AN’’ and ‘‘PO”’.

Page 111, line 33, for ‘‘brownsih”’ read ‘‘brownish-yellow”’.

Pagemnn2, sine 22.0fOm . moss reads mass’. \line» a3, fon “mlosses’ ”
read ‘‘masses’’.

Page 117, line 35, insert next line below:—‘‘(Type, Anodonta ferus-
saciana Lea)”’

Page 118, line 6, omit “External Structuies’’; line 18, add ‘‘about’’
after “‘being’’. Y

Page 119, line 30, insert next line below:—‘‘(Alasmidonta undulata
Dy) ieee

Page 122, line 26, for ‘““known” read “‘shown’’.

Page 124, line 10, before ‘‘containing’”’ insert ‘‘each’’ and for comma

use semi-colon after ‘‘larvae’’ and also omit ‘‘are’’; line 11, omit ‘‘situ-
ated’: line 12, for ‘“‘min’”’ read “‘mm’’; line 16, for “‘obtusely”’ read
OD tiHSCis ve

Page 129, line 34, for ‘‘facsiolaris’’ read ‘‘fasciolaris’’; as indicated
in Foot-note for this page, for all statements of ‘‘ Eliipsaria clintonensis
(Simpson)”’ read “ Ellipsaria occidentalis (Conrad)’’.

Page 130, line 7, for period after ‘“‘p. 301’’ use semi-colon.

Page 132, line 8, use semi-colon after ‘“‘interdentum’’.

Page 133, line 22, for ‘‘nodulat’”’ read ‘‘nodulated’’.

Page 136, line 2, for “‘J”’ read ‘“‘Jl.’’; line 16, omit comma after
“height’’.

Page 143, line 30, for ‘‘pleasit”’ read ‘‘ Peasi1’’; (do. page 144, line
29; do. page 145, line 20); line 32, for ‘‘clolored”’ read ‘‘colored”’.

Page 145, line 26, for ‘‘ utterbackit’’ read ‘‘ Utterbackii’’; (do. line 31).

Page 148, line 18, insert ““IX’’ after ‘‘pl’’.

Page 152, line 15, for ‘‘stmpsoni”’ read ‘‘Simpsoni”’; (do. page 155,
line 3).

Page 153, line 38, for ““bysuss’’ read ‘‘byssus’’.

Page 155, line 34, for ‘‘teniussimus”’ read ‘‘tenutssimus’’.

Page 159, line 28, for ‘‘Lamack”’ read ‘‘ Lamarck’’.

Page 160, line 14, for ‘‘more’’ read ‘‘not”’ and for ‘‘not”’ read “‘nor’’.

Page 163, line 34, for “‘ proptera”’ read “‘ Proptzra’’.

Page 164, line 20, for ‘‘tecxasensis’’ read ‘‘texasensis"’.

Page 168, line 6, for ‘‘central’’ read ‘‘center’’; after line 10 supply
the following deletion from text :—

200

THE NAIADES OF MISSOURI

SHELL CHARACTERS:—Shell elliptical, small or medium, beak sculp-

ture rather double-looped or distinctly sinuate with posterior sinuation
somewhat open.

ERRATA.
(PratEs I—X XVIII.)

Pl. I, Fig. 2, for “‘vavel’’ read “‘valve’’.

Pl. II, Fig. 5a, Supply label 4, i. e., ‘Extreme dorsal point.”’

Pl. V, Fig. 12b,) for “‘ Utierbacki”’ read ““ Uiterbacki”’; do. Pl. XX,
Figs. 63 A—D.

Pl. VI, Figs. 14 a—d, for “Curtisz” read “ Curtis’; do. Pl. XXVIII,

Figs. 109 A—D.

Fig.

Pl. IX, Fig. 19, After ‘feeding’? supply comma and “‘respiring”’.

Pl. XIII, Fig. 26, Supply ‘‘-Hundred” after “‘One;”’ do. Pl. XXVI.
90.

Pl. XVI, Figs. 38 A—D, for ‘‘Quintardi” read ‘‘ Quintardii’’.

Pl. XIX, Fig 52, for ‘‘cylindirca”’ read “cylindrica”.

Pl. XXV, Fig. 81, for ‘‘clintonesnsis’’ read ‘‘clintonensis’’.

Pl. XXVIII, Fig. 107, for ‘‘ventricoas’’ read ‘‘ventricosa”’

The Naiaves of Missouri

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PLATEXXIX

Key to the Mussel Faunce of Missouri.
cia)

sh, turbid, mud bottom;(Coingi dental Morphology |p hrel
Smooth in
OR’ tssoyR FAUNA, -Sssouri R. Southern
boundry ,= hysiography) Level or roll-
ing pralries,Lower stream conditions;(Co-
dental Cheracgers), : 4
iti ostly lacus: .
a S;Or GLACIAL pains
a; (roe L000 PLAINS, auperated
2.-CENTRAL Mi SsouR! FAUNA, -Ozack Crest South-
ern houndry,= Warcgrophy) (catactacetal
opograp an rogra ; (Foincidenta
characters), ussels ore ys kPornel ,Com-
Ltive-Modern.
b=OLD PRAIRIES, gr CUESTA PLAINS.
ZARK DRAINAGE: [Nai dgeograph «fEcolog Streams Swift
fear, rock bot omi(Cainercl ntal Morphatoyy) shell most
small, rou Compressed
NTRAL MisSOURI FAUNA,-North Slope of
Ozark Uplift ~Mo.R. Northern boundry
. “OZARK BORDER (Lower HEN é
.~ OZARK PLATEAU (Gasconade Basin).
©.-OZARK CENTER (Meramec Basin ).
5.-SourH MiSsourt FAUNA, ~Ozark Crest north-
ern boundry , ~(Physiog raphy) Dissected
Uplift, Upper Stream Condi fons; (Coinei
dentol Characters) ‘ant, mo d=
e ost | ‘i
+-OZARK BORDER (9.W,Mo.,-Neosho Basin),
OZARK PLATEAU(White River Basin)
© =O7ARK CENTER(Black River BaSin).
ApttississiPP: Flood PLAINS and Low

LANDS(S.E.Mo., Dep wented Eu
set Founa). oI ia a the

on€ Indicated merck are

t distingt because
overt xtinct Musgse,
due te the excessive loess ond

other alluvia in the waters of
these regions.

reenvi!
Set
“aby

Physiographic Features after Marbut)

Sub=Family III LAMPSILINAE:—
differentiated with
special ovisacs mostly arranged post-
eriorily near the post-ventral mantle
margin specialized with crenulations,
papillae, etce.; only outer gills marsu-

Marsupium

pial; glochidium Lampsilis Type;
bradvtictic.
Proptera Type

(Intermediate to
modern form) of
glochidium: Axe-
head shape, spin-
ed-spineless.

;

The Spineless
glochidia are fol-
lowed inthe adult
life by perfect
and compbiete
hinge teeth.

Lampsilis type, (Modern—
Form) of glochidium —Suboval—
subelliptic, spineless.

This reversion of the modern form
of glochidium to that of the primi-
tive very strikingly shows that ata-
vism characteristic of the principles
of evolution.

As Based On

Reproductive

Characters
i]

Sub=Family Il ANODONTINAE:—

Marsupium differentiated with lat-
eral water tubes when gravid; post-
ventral mantle margin undifferenti-
ated; alNour gills marsupial; gloch-
idium Anodonta Type; bradytictic.

| yj iN
} 7 » Ga
vAAD S| 2 » -

Anodonta Type
(Intermediate
Form) of glochid-
ium: Subtriangu-
spined, fol-
lowed in adult by

incom plete
teeth.
oe |

lar,

hinge

Sub = Family |
UNIONINAE : —
Undifferentiated
marsupium and
post-ventral
mantle margin;
all four (or outer)

—Primitive
gills marsupial;
tachytictic spe-
cies; glochidia
Lampsilis Type.

MARGARITANIDAE:—

Marsupium more primitive than
that of Family II; post-ventral
mantle margin undifferentiated; all
four gills marsupial; glochidium
Lampsilis Type; tachytictic

Family |

WILLIAM IRVIN UTTERBACK, B.S., A. M.

Bachelor of Science, (B.S.), Wabash College, Crawferds-
ville, Indiana; Class 1901

Master of Arts, (A. M.), University of Missouri, Colum-
bia, Mo.; Class 1915. The author submits this
catalogue (‘‘The Naiades of Missouri’’)

to Missouri University as a
Master's Thesis

EXPLANATION OF PLATES.

Plates I—IV, VII and VIII are intended to be a further elucidation
of the text, especially as to shell structures. Plates III and IV are compara-
tive representations of the beak sculpture and marsupial characters of the
three Sub-Families. Plates V and VI are careful drawings of new species
described and figured for the first time. Plate IX shows physiological
relations while Plates X—XIV show the ecologic. Plates XV—XXVIII
are photographs of shells representing about one-half natural size, arranged
in progressive order of classification, and, in most cases, the shell structures
of the exterior are shown by the left valve and of the interior by the right.

EXPLANATION OF PLATE I.

Fig. 1.—External structure of left valve of Rotundaria tuberculata

Rafinesque, 2 (Nat. size).
1.—Anterior end.
2.—Posterior end.
3.—Ventral side.
4.—Dorsal side.
s5.—Antero-ventral side.
6.—Antero-dorsal side.
7.—Post-dorsal section.
8.—Post-ventral section.
9.—Nodule.

10.— Tubercle-— Umbonal region.
11.—Center of disk.

12.—Lunule.

13.—Beak, or umbone.

14.—Ala, or dorsal ridge.
15.—Costae.— Dorsal slope.
16.—Post-umbonal ridge.
17.—Rest lines of growth.
18.—Minor lines of growth.

Fig. 2.—Internal structure of right vavel of R. tuberculata (Raf.) @

(Nat. size.)

1.—Epidermis.

2.—Outer nacreous zone.
3.—Middle nacreous zone.
4.—Inner nacreous zone.

5.—Vein marks.

6.—Retractor muscle scar.
7.—Post, add. mus. scar.
8.—Anterior adductor muscle scar.

g9.—Branchial cavity.
10.—IL,unular hinge.
11.—Cardinal tooth.
12.—Hinge tooth.
13.—Interdentum.
14.—Hinge ligament.
15.—Beak cavitiy.
16.—Ala, or wing.

17.—Beak showing sculpture.
Fig. 3a.—Lateral view of juvenile R. tuberculata showing sculpturing
of beak extending out on disk. (Nat. size).
Fig. 3b.—Dorsal view of juvenile R. tuberculata showing beak sculpture.
(Nat. size.)
Fig. 4.—Right side of
(nov. glochidium) showing :—

closed glochidium (X87) of R. tuberculata

1.—Anterior end.
2.—Posterior end.
3.—Dorsal, or hinge line.
4.—Ventral margin.

5.—Center of disk.
6.—Adductor muscle.
7.—Posterior adductor.
8.—Pericardial area.

PAE Ele UTTERBACK ON NAIADES OF MISSOURI

EXPLANATION OF PLATE II.

Fig. 5a.—External structures of left valve of Plagiola securis (lea)—
Male shell reduced one-fourth from natural adult size.

1.—Extreme ventral point. 3-4.—Post-dorsal section.

2.—Extreme anterior point. 5.—Minor lines of growth.

3.—Extreme posterior point. 6.—Rest lines of growth.
1-2.—Antero-ventral section. 7.—Lunule.
1-3.—Post-ventral section. 8.—Beak or umbone.
2-4.—Antero-dorsal section. 9.—Post-dorsal truncation.

10.—Broken rays.

Fig. 5b.—Internal view of right valve of P. securis. & Same reduction
as in Fig. 5a.

Fig. 6a.—External view of left valve of P. securis. Female shell reduced
one-fourth from natural adult size. Same age as adult. Comparison to male
shell of Fig. 5a. denoted by dotted outline.

Fig. 6b.—Internal structures of right valve of P. securis. 9. Same
reduction as in Fig. 6a.

1.—Ventral margin. 8.—Beak cavity.
2.—Epidermis. 9.—Interdentum.
3.—Mantle line. 10.— Beak.

4.—Vein marks. 11.—Hinge ligament.
5.—Ant. retractor mus. scar. 12.—Hinge tooth.
6.—Ant. adductor mus. scar. 13.—Protractor mus. scar.

7.—Cardinal tooth. 14.—Post add. mus. scar.

PEATE (TT, UTTERBACK ON NAIADES OF MISSOURI

EXPLANATION OF PLATE III.

Fig. 7a.—External structures of Anodontotdes ferussacianus (Lea). 92
(Nat. size). i

1.—Ventral extremity. 6.—Rest lines of growth.
2.—Dorsal extremity. 7.—Beak.
3.—Anterior extremity. 8.—Post-dorsal ridge.

' 4.—Posterior extremity. 9.—Post-umbonal ridge.

5.—Minor lines of growth.
Fig. 7b.—Internal structures of shell of A. ferussacianus. 9.

1.—Ventral extremity. 6.—Mantle line.
2.—Dorsal extremity. 7.—Ant. add. scar.
3.—-Anterior extremity. 8.—Post. add. scar.
4.—Posterior extremity. 9.—Beak cavity.
5.—Rest lines of growth showing 10.—Apex of beak.

through shell.
Fig. 8a.— Dorsal view of A. ferussacianus shell showing Anodontine beak

sculpture.
Fig. 8b.—Dorsal view of P. coccineum shell showing Unionine beak

sculpture.
Fig. 8c.—Dorsal view of E. (C.) parva shell showing Lampsiline beak

sculpture.

PLATE ITI, UTTERBACK ON NAIADES OF MISSOURI

EXPLANATION OF PLATE IV.

Fig. 9a.—Right gills of Fusconata undata trigonoides Frierson, showing
both marsupial,— a Unitonine character.

Fig. 9b.—Diagrammatic, vertical section of a Unionine ovisac at
ventral margin.

Fig. roa.—Right gills of Lastena suborbiculata (Say) showing entire
outer one marsupial,—an Anodontine character.

Fig. 1ob.—Diagram of Anodontine ovisac showing lateral water tubes
as provision for aeration of embryos.

Fig. 11a.—Right gills of Proptera alata (Say) showing only posterior
portion of outer one marsupial,—a Lampsiline character.

Fig. 11b.—Diagram of Lampsiline ovisac, showing rupture of ventral
edge to allow escape of glochidia.

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UTTERBACK ON NAIADES OF MISSOURI

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S geoe E a ie to pan eet

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EXPLANATION OF PLATE V.
(Drawings by G. T. Kline.)

.

Fig. r2a.—External view of left valve of a new species, Pleu
Utterbackwt Frierson. o’ (Nat. size.) .
Fig. 12b—Internal view of right valve of P. Utterbacki. 9%

‘
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a PA»
4 :
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fi :
a 5
i
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ks 7 Fat
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Fig. 12a.

Fig. 12b.

PLATE V, UTTERBACK ON NAIADES OF MISSOURI

EXPLANATION OF PLATE VI.
(Drawings by G. T. Kline.)

Fig. 13a.—External view of left valve of a new species, Truncilla
Lefevret Utterback.o (Nat. size.)

Fig. 13b.—Internal view of right valve of T. Lefevret. if

Fig.13c.—External view of left valve of 7. Lefevrer. 9°

Fig. 13d.—Internal view of right valve of T. Lefevret. 9

Fig. 14a.—External view of left valve of a new species, Jruncilla
Curtist Frierson and Utterback. ™ (Nat. size).

Fig. 14b—Internal view of right valve of T. Curtist. o

Fig. 14c.—External view of left valve of T. Curtist. 9

Fig. 14d.—Internal view of right valve of 7. Curtist. 9

Jenies, iil SUNS

Fig. 14b. Fig. 14d.

PLATE VI. UTTERBACK ON NAIADES OF MISSOURI

EXPLANATION OF PLATE VII.

Fig. 15.—Anodonta grandis Say 9—Actual longi-section of the vis-
ceral mass showing entire alimentary tract, protractor muscle and other
animal structures in left valve. (34 Nat. size).

Fig. 16.—Megalonaias heros (Say) Q Photograph of gravid specimen
showing animal structure in left valve. (34 Nat. size).

EXPLANATION OF PLATE VIII.

Fig. 17A.—Lampsilis anodontoides (Lea), o—Extenal view of right
valve. (34 Nat. size).

Fig. 17B.—L. anodontoides. s&—Internal view of left valve.

Fig. 18A.—Lampsilis fallaciosa (Smith) Simpson. 9—External view
of right valve. (34 Nat. size).

Fig. 18B.—L. fallaciosa. 9—Dorsal view showing Lampsiline beak
sculpture.

UTTERBACK ON NAIADES OF MISSOURI

EXPLANATION OF PLATE IX.

Fig. 19.—Posterior views of live mussels in aquarium showing ‘‘siphens’’
open in act of feeding and discharging wastes. Reading from left to right
are:—One P. laevissima &, L. fragilis 9 (next three) and L. suborbiculata 9
(two at extreme right). Young of L. fragilis (lateral view) and Q. quadrula
(umbonal view) lie in front.

Fig. 20—Continued aquarium view showing narrowly open “‘siphons’”’
of A. rariplicata on the left and the extremely extended “siphons” of: P.
laevissima o& on the right (lateral view).

Tee ae

¢ ee S a
SOS at aaa

ones

Ra aa

PLATE IX,

UTTERBACK ON NAIADES OF MISSOURI

AM Ye 7 oa 1 a =i :
vhs Pt oe a :
mri oly : n
0) Ga: } ¢ 7 ud, ‘
‘ toes ae Wp:
, te Sea, eT ey eta
. hn i am
a ® 7-4) oe
n a : eae 0 fie
i a rie be i
; “I 4
¢# L 4 \
, ‘
,

EXPLANATION OF PLATE X.

Fig. 21.—Platte River below a small falls showing a quiet, sheltet
“pocket”? where juveniles and small species of mitiseels: congregate in gr
numbers. Note dead shells on the rocky bar. ;

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UTTERBACK ON NAIADES OF MISSOURI

Fig. 22.—Limestone cliffs and mussel bed at the foot above
Abundance of lime in the water here contribt

Falls, Platte River.

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the unusual Brew of shell. ‘

Fig. 23.—‘‘Fishing’’ for mussels in the West Bayou of wate
St. Joseph. A garden rake is used in deep water, but hand, a

ever possible, is the most successful.

‘EXPLANATION OF PLATE XI.

PLATE UTTERBACK ON NAIADES OF MISSOURI

a

EXPLANATION OF PLATE XII.

Fig. 24.—Beach of a North-West Missouri Lake showing th
sight of a pile of cleaned mussel shells made by a musk-rat after fe:
the soft parts. These ravages, as well as the receding of the
greatly to deplete the mussel beds. ° “

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PLATE XII. UTTERBACK ON NAIADES OF MISSOURI

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EXPLANATION OF PLATE XIII.

Fig. 25.—Lake Contrary, (St. Joseph),—the home of the Ano
especially Lastena suborbiculata. Although originally the wee of tHe

Hie baea pie
Fig. 26.—One-and—Two River, oe Mill.—Above the: Prey

mussel fauna is different, due to the limitation of the range of certait
as distributors of mussel life in the parasitic stage.

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PLATE XIII, UTTERBACK ON NAIADES OF MISSOURI

EXPLANATION OF) PLATE 2XtVieq, ) ne

Fig. 27.—Shells in situ (above and to right of hat) embec
along Beck’s Slough, St. Joseph. This shows a former mussel |

there.

PEATE XLV. UTTERBACK ON NAIADES OF MISSOURI

EXPLANATION OF PLATE XV.

Fig’s. 28—A and B Cumberlandia monodonta (Say) 9, Miss. R.,
LaGrange.

Fig’s. 29 A and B.—Fusconaia undata (Barnes) 9, Miss. R., Hannibal

Fig’s. 30 A and B.—Adult F. undata trigonoides Frierson MS. ©
Platte R., Agency Ford.

Fig’s. 30 C and D.—Juvenile of trigonoides.

Fig’s 31 A and B.—F. undata trigona (Lea) 2, Osage R., Warsaw.

Fig’s. 32 A and B.—Adult F. flava (Raf.) o|, White R., Hollister

Fig’s 32 C and D.—Young of flava.

Fig’s 33 A. and B.—F. hebetata (Conrad) 9, Osage R., Warsaw

Fig’s 34 A and B.—F. ebena (Lea) 9, Miss. R., LaGrange.

PLATE XV. UTTERBACK ON NAIADES OF MISSOURI

EXPLANATION OF PLATE XVI.

Fig’s 35 A and B.—Amblema peruviana (Lamarck) 9, Osage R.,
Osceola.

Fig’s 36 A and B.—A. rariplicata (Deshayes) 9, Platte R., Dixon Falls.

Fig’s 36 C and D.—A. rariplicata (Des) o', Tarkio R., Craig.

Fig’s 37 A and B.—-A. perplicata (Conrad) 9, St. Francis R., Greenville.

Fig’s 38 A and B—A. perplicata Quintardi (Cragin) 9, White R.,
Hollister.

Fig’s 38 C and D.—A. perplicata Quintardi (Cragin) 9, Osage R .
Froctor.

Fig’s 39 A and B.—A. plicata costata (Raf.) o, Chariton R., Kern

Fig’s 39 C and D.—Juvenile of costata—Same locality as adult.

PLATE XVI. UTTERBACK ON NAIADES OF MISSOURI

EXPLANATION OF PLATE XVII.

Fig’s 40 A and B.—Adult Megalonaias heros (Say) @, Platte R.

Garretsburg.
Fig’s 40 C and D.—Juvenile heros, Osage R., Monegaw Springs.

Fig’s 40 EK and F.—Young heros, Osage R., Warsaw.

Fig’s 41 A and B.—Quadrula pustulosa (Lea) 9, Miss. R., Hannibal.

Fig’s 42 A and B.—Adult Q. pustulosa schoolcraftensis (lea) 9, Platte
R., Claire.

Fig’s 42 C and D.—Young schoolcraftensis.—Same locality as adult.

Fig’s 43 A and B.—(Q. pustulosa asperata (Lea) o&, Osage R., Bagnell.

Fig’s 44 A and B.—Q. nodulata (Raf.) o&, Miss. R., Hannibal.

MISSOURI

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EXPLANATION OF PILATE XVIII.

Fig’s 45 A and B.—Q. quadrula (Raf.) 9, Lake Contrary, St. Joseph.

Fig’s 45 C and D.—Q. quadrula &. Same locality as female.

Fig’s 45 EH and F.—(Q. quadrulao, Flat Cr., Sedalia.

Fig’s 46 A and B.-Q. quadrula 9, I. Contrary.—A common pathologic
shell found in the N. W. Mo. Lakes.

Fig’s 47 A and B.—Q. quadrula contraryensis Utterback @, L. Con
trary.—A new variety.

Fig’s 48 A and B.—(Q. fragosa (Conrad) 9, Miss. R., Hannibal.

Fig’s 49 A and B.—(Q. aspera (Lea) 9, Osage R., Warsaw.

PEATE, X VILL. UTTERBACK ON NAIADES OF MISSOURI

EXPLANATION,.OF PLATE XIX.

Fig’s. 50 A and B.—(Q. verrucosa (Raf.) o&, Grand R., Darlington.

Fig’s 50 C and D.—Young Q. verrucosa (Raf.) 9, White R., Hollister.

Fig’s 51. A and B.—@Q. nobilis (Conrad) 92, Marais des Cygnes R.,
Rich Hill.

Fig’s 52 A and B.—(. cylindirca (Say) 9, Black R., Williamsville.

Fig’s 53 A and B.—Q. metanevra (Raf.) o&, Meramec R., Meramec
Highlands. :

Fig’s-54 A and B.—Rotundaria tuberculata (Raf.) 9, Osage R., Schell
Citeyx

Fig’s 55 A and B.—R. granifera (Lea) 9, Miss. R., LaGrange.

PLATE XIX. UTTERBACK ON NAIADES OF MISSOURI

EXPLANATION OF PLATE XX.

Fig’s 56 A and B.—Plethobasus aesopus (Green) 9, Des Moines R.,
Dumas.

Fig’s 56 C and D.—Juvenile of P. aesopus.—Same locality as adult.

Fig’s 57 A and B.—P. cooperianus (lea) 9, Gascondy.

Fig’s 58 A and B.—Pleurobema obliquum pyramidatum (Lea) 2,
Osage R., Baker, Mo.

Fig’s 59 A and B.—P. catillus (Conrad) 9, Black R., Williamsville.

Fig’s 60 A and B.—P. coccineum (Conr.) ?, White R., Hollister.

Fig’s 61 A and B.—P. obliquum coccineum (Conr.) 9, Osage R., Warsaw.

Fig’s 61 C and D—Young P. obliquum coccineum (Conr.).—Same

locality as adult.
Fig’s 62 A and B.—P. obliquum catillus (Conr.) 2, Osage R., Colley’s

Ford.
Fig’s 63 A and B.—P. Utterbacki Frierson (n. sp.) 9, White R., Hollister.
Fig’s 63 C and D.—P. Utterbacki F. o&, Jack’s Fork of the Current R.

PEATE XX, UTTERBACK ON NAIADES OF MISSOURI

EXPLANATION OF PLATE XXI.

Fig’s 64 A and B.—Elliptio nigra (Raf.) o, Meramec R., Meramec
Highlands.

Fig’s 65 A and B.—E. nigra (Raf.) 2, Miss., Hannibal.

Fig’s 66 A and B.—E. dilatata (Raf.) 9, Osage R., Osceola.

Fig’s 67 A and B.—E. dilatata delicata (Simpson) 9, White R., Hollister.

Fig’s 67 C and D.—E. dilatata delicata (Simp.) ©, Black R., Williams-
ville.

Fig’s 68 A and B.—E. dilatata subgibbosa (Lea) 9, Black R., Williams-
ville.

Fig’s 68 C and D.—E. dilatata subgibbosa (ea) &, Black R., Williams-
ville.

Fig’s 69 A and B.—Uniomerus tetralasma (Say) 9, Batterton Pond,
Columbia.

PLATE XXI UTTERBACK ON NAIADES OF MISSOURI.

EXPLANATION OF PLATE XXII.

Fig’s 70 A and B.—Symphynota complanata (Barnes) 2, Big
Lake, Kenmoor.
Hie’s 171 JA and eB: Oana costata (Raf.) 2, Black

Williamsville. : Me
Fig’s 71 C and D.—S. costata (Raf.) a, Gasconade R., Gascondy. fe
Fig’s 71 E and F.—S. costata (Raf.) 9, Miss. R., Hannibal.
Fig’s 72 A and _B.—Arcidens confragosa (Say) °, Marais des

R., Papinsville.

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PLATE XX

BXPLANATION: OF PLATE) XX

Fig’s 73 A and B.—Lastena suborbiculata (Say) 9, Lower Lake Cont
St. Joseph. abe
Fig’s 73 C—F.—Juveniles of L. suborbiculatan—Upper L. Contrary
Note the coarse Anodontine beak sculpture which reaches well down on t
disk. ;

PLATE XXIII. UTTERBACK ON NAIADES OF MISSOURI

EXPLANATION OF PLATE XXIV.

Fig’s 76 A and B—Anodonta Danielsii Lea 2, Lost Cr., Amity.

Fig’s 77 A and B.—A. dakotana Frierson 9, L. Contrary, St. Joseph.

Fig’s 78 A and B.—Alasmidonta marginata Say 9, Gasconade R
Gascondy. :

Fig’s 79 A and B.—A. calceolus (Lea) 9, Jack’s Fork, Current R.

Fig’s 79 C and D.—A. calceolus, &, White R., Branson.

Fig’s 80 A and B.—Strophitus edentulus (Say) 2, Osage R., Linn Cr

Fig’s 80 C and -D.—S. edentulus &, White R., Branson.

PLATE XXIV. UTTERBACK ON NAIADES OF MISSOURI

EXPLANATION OF PLATE XXV.

Fig’s 81 A and B.—Ellipsaria clintonesnsis (Simpson) 9, White R.,

Hollister.

Fig’s 82 A and B.—Obliquaria reflexa Raf. o', Platte R., Platte R. Sta.

Fig’s 82 C and D.,—O. reflexa Raf.- 9, Osage R., Monegaw Springs.

Fig’s 82 E and F.—Juvenile reflexa—Crow’s Fork, Fulton.

Fig’s 83 A and B.—Cyprogenia Aberti (Conrad) 9, St. Francis R.,
Greenville.

Fig’s 84 A and B.—QObovaria (Pseudoon) eltipsis (Lea) 9, Grand R.,
Sumner. .

Fig’s 85 A and B.—Nephronaias ligamentina (1,amarck) 9, Meramec
R., Fern Glen.

Fig’s 86 A and B.—N. ellisiformis (Conrad) o, Osage R., Warsaw.

Fig’s 86 C and D.—N. ellipsiformis (Con.) 9, Niangua R., Hahatonka.

-Fig’s 87 A and B—N. Pleast (Marsh) 9, White R., Branson.

Fig’s 87 C and D.—N. Pleasiti (Marsh) «&, White R., Branson.

Fig’s 88 A and B—Amygdalonaias truncata (Raf.) &, Osage R., Schell
Citiyae Vio:

Fig’s 89 A and B.—A. donactformis (Lea) o&, Grand R., Gallatin.

Fig’s 89 C and D.—A. donaciformis (Lea) 9, One-and—Two R., St.
Joseph.

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PEATE XX V,

EXPLANATION-OF PEATE Sacer

Fig’s 90 A and B.—Lasmonos fragilis (Raf.) 9°, One-and—Two River,
St. Joseph. Fig. 90 B is the photograph of the animal in the left valve
showing the gravid marsupium.

Fig’s 90 C and DZ. frags (Raf.) of} Platte Ry Ageney Wore

Fig. 90 D.—A photograph of soft parts in left valve.

Fig’s. gt A and B.—Lasmonos Simpsoni (Ferriss) 9, White R., Branson.

Fig’s 92—A and B—Proptera purpurata (Lamarck) o', White R.,
Forsyth.

Fig’s 92 C and D—Proptera purpuraia (lamarck) 9, White R.,
Forsyth.

Fig’s 93 A and B.—Prop. capax (Green) 9, Miss. R., Hannibal. Fig.
93b shows photograph of animal with gravid marsupium. Note non-speciali-
zed post-ventral mantle margin.

Fig’s 94 A and B.—Pvop. laevissima (Lea) 9, Mud Lake, Kenmoor.

. Fig’s 94 C and D.—Juveniles of /aevissima, L. Contrary, St. Joseph.

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EXPLANATION OF PLATE XXVII.

Fig’s 96 A and B. —Burynia cone pore (cakenaneh J, B
Wile goes aa

Fig’s 97 A and B. Ae (Mi) aris: (eal) “2 W nite Re, Hollister, ae
Bigs 98 A and B.—E (M.) brevicula (Call) &, White R., Branson.

LORE ae
Fig’s roo A and B.—E. (Eurynia) recta aaa o, Osage R., ¢
Fig’s 100 C and Doe (E.) recta ope Q, Meramec R., I

Highlands.

Fig’s ror A and B. —FE. (E.) subrostrata (Say) o&, Lost Cr.,
Fig’s 101 C and D.—E. (E.) subrostrata (Say) 9, Flat Cr., ee ia.

PEATE Xe VL. _ UTTERBACK ON NAIADES OF MISSOURI

EXPLANATION OF PLATE XXVIII. ~_

Fig’s 102 A and B.—Lampsilis anodontoides (Lea) &, Chariton R., Kern. |
Fig’s 102 C and D.—L. anodontoides (Lea) 9, Chariton R., Kern.
Fig’s 103 A and B.—L. luteola (Lamarck) o’, Black R., Williamsville.
Fig’s 103 C and D.—L. luteola (Lam.) 9, Black R., Williamsville.
Fig’s 103 E and F.— Young L. /uteola (Lam.) &; Black R., Williamsville.
Fig’s 104 A and B.—L. luteola rosacea (Dekay) ©, White R., Branson.
Fig’s 105 A and B.—L. Higgins (Lea) 9, Miss. R., Hannibal.
Fig’s 106 A and B.—L. ventricosa (Barnes) o’, Black R., Williamsville.
Fig’s 106 C and D.—L. ventricosa (Barnes) 9, Miss. R., Hannibal. |
Fig’s 107 A and B.—L. ventricoas satura (Lea) 9. White R., Hollister. 5
Fig’s 108 A and B.—Truncilla Lefevrei Utterback 9, Black R.,
Williamsville.
Fig’s 108.C and D.—T. Lefevrei Utterback o’, Black R., Williamsville,
Fig’s 109 A and B.—Truncilla curtisi Frierson and Utterback 9°,
White R., Hollister.
Fig’s 109 C and D.—T. Curtiss F. and U. o, White R., Hollister.

PLATE XX Vili. UTTERBACK ON NAIADES OF MISSOURI

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