Skip to main content

Full text of "The Naiades of Missouri"

See other formats























I Amer. Midland Nat., Vol. k, no. 3, PP. ^+1-53 May 191^ 

II Amer. Midland Na.t., Vol. U, no. U; 97-152 July 191^ 
III Amer. Midland Nat. Vol. k, no. 5; l8l-20^ Sept 191^ 

IV Amer. Midland Nat. Vol. U, no. 6; 2^U-273 Nov. 191^ 

V Amer. Midland Nat. Vol. U, no. 7; 311-327 Jan 19l£ 

VI Amer. Midland Nat. Vol. U, no. 8; 339-35^ Feb 19l£ 

VII Amer. Midland Nat. Vol. h, no. 9; 387-^00 May I916 

VIII Amer. Midland Nat. Vol. k, no. 10; U32-U60* July I916 

Note that there are two completely different (type 
set) errata printings because of page references, etc. 



The Naiades of Missouri 

William I. Utterback, B.S., A.M., 

Author of "Mussel Resources of Missouri," (1914), and "Breeding 
Record of Missouri Mussels," (1916a). 

Reprinted from The American Midland Naturalist, Vol. IV., 

Nos. 1 — 10, with Plates I— XXIX. 


University Press 

Notre Dame, 




{Plates i — xxviii.) New Series. 


After some years of intensive studies in the field, library and 
laboratory an attempt is made to give a catalogued account of 
the Naiadss, 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 Naiades 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 mar-supial characters, has been carefully followed 
in this work. The many changes in the nomenclature of this 
catalogue from that of the vSimpsonian system are due especially 
to the recognition of Lindahl's orthographic modification and of 
the wise scheme of taxonomy for the Naiades 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 


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. vSince 
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 vStudies Afield" 
for the years 19 13 and 19 14, 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 swifter, become more swollen and heavier shells further down 
stream 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), 
0. quadriila (Raf.), P. UUerhackii Frierson, 7?. tuberculata (Raf.), 
U. tetralasma (Say), Las. suhorbiculata (Say), Prop, capax (Green), 


Eur. (M.) brevicula (Call), T. Ciirtisi Frierson and Utterback, 
and T. Lefevrei 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 respectivelv made 
of the studies of juveniles and glochidia. Likewise, 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 Zoogeograpiiic 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 (Lea), Plevi. plenum (Lea), Lamp. 
Reeviana (Lea) and Lamp. PowellH (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, hianfiulata (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 
Zoology, 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. E. Scammon, author of "Kansas 


Unionidae." For other personal help while attending the Uni- 
versity thankful acknowledgements are due to Dr. R. I,. 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. vSampson, author of the 
"MoUusca 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 vState. 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 vState, viz:— Messrs. C. T. vSimpson, W. A. Marsh, 
Elwood Pleas and Dr. John H. Britts; also to those students of 
Naiades for the nearest surrounding vStates 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 L. vS. 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 Naiades as well as for his 
special information concerning the Southwest forms. Through 


very pleasant and extensive cocrespondence 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 vState 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 
harrier^ 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 vState 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 diflferent 


physiographic provinces because of their different ecological 
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; h = Mo. and Miss. R's (Proper); c = Ozark Uplift. 
I.— NORTH MISSOURI = Primitive Mussel Fauna. 

I. a — New Prairies, or Glacial Plains. (N. and N.W.Mo.) 
i.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. 
i.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 vSpccies and Sub-Species, Hsted under the following 
general Key to the Missouri Naiades, arc 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 mostlv 

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, vSub-I'amilics and Generic Groups. These characters 
arc indicated under the lettering in the Scheme below and the 
enumeration of all Naiades 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).— Sub-Family (I). 
a. — Genus I. • 

(a.) — Generic Group and Sub-Genus (I). 
I. — Species. 

(i). — Sub-Species. 
A. — Gills with no water-tubes, septa incomplete, obliquely arranged; gill- 


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. Margaritanidae Ortmann. 
a. — Gill septa oblique from base of gills, more vertically arranged and 

shorter ventrad Genus I. Cumberlandia, Ortmann 

I. — C. monodonta (Say) — (1. 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, (jeltiform, spined or spine- 
less FAMILY II. Unionidae, 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 undifTerentiated, not distended when gravid; glochidia 

suboval, spineless, tachytictic for the most part 

Sub-Family (I), UnioninaE, 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. Fusconaia Simpson 

2. F. undata (Barnes) — (i. b) 

(i). F. undata trigona (Lea) — (i. c) 

(2). F. undata trigonoides Frierson — (i. a) 

3. F. flava (Raf.) — (j.c) 

4. F. hebetata (Conrad) — (i. c) 

5. F. ebena (Lea) — (i. b) 

(b) — Conglutinates leaf-like, compressed, subsolid white; beak 
sculpture concentric, extending zigzag out on disk which is greatly 
sculptured Genus III Amblema (Raf.) 

6. A. peruviana (Lamarck) — (i. c) 

7. A. rariplicata (Deshayes) — (i. a) 

8. A. perplicata (Conrad) — (3. c) 

'(3). A. perplicata Quintardi (Cragin) — (i. c) 

9. A. (plicata) costata (Raf.) — (i. a) 
Genus IV. Magnonaias Utterback. 

10. M. heros (Say) — (i. a) 
Genus V. Quadrula (Raf.) 

11. Q. pustulosa (Lea) — (i. b) 

(4). Q. pustulosa Schoolcraftensis (Lea) — (i. a) 
(5). Q. pustulosa asperata (Lea) — (i. c) 

12. Q. quadrula (Raf.) — (i. b) 

(6). Q. quadrula contraryensis Utterback — (i. a) 


Q. nodulata (Raf.) — (i. b) 

Q. fragosa (Contrad) — (i. b) 
Q. aspera (Lea) — (i. c) 
Q. nobilis (Conrad) — (2. a) 
Q. verrucosa (Raf.) — (i. c) 
Q. metanevra (Raf.) — (i. c) 
(7). Q. metanevra Wardii (Lea) — (i. b) 

19. Q. cylindrica (Say) — (3. c) 
b. — Only outer gills marsupial. 

(a) — Supra-anal opening absent; beak sculpture zigzag; disk greatly 
sculptured Genus VL RoTundaria (Raf.) 

20. R. tuberculala (Raf.)^(i. c) 

21. R. graniferaihca.) — (i. b) 

(b) — Supra-anal presjent but short; beak sculpture concentric but 
disappearing toward disk which is mostly unsculptured. 

Genus VIL PlEThobasus (Simpson; 

22. P. Cooperianus (Lea)— (2. c) 

23. P. aesopus (Green) — (i. b) 
Genus VIII. Pleurobema (Raf.) 

24. P. obliquum (Lamarck) — (i. b) 

(8). P. obliquum plenum (Lea) — ^(3. c) 
(9). P. obliquum pyramidatum (Lea) — (i. c) 
(10). P. obliquum catillus (Conrad) — (i. c) 
(11). P. obliquum coccineum (Conrad) — (i. c) 

25. P. catillus (Conrad) — (3. c) 

26. P. coccineum (Conrad) — (3. c) 

27. P. missourense (Marsh) — (3. c) 

28. P. Utterbackii Frierson — (3. c) 
Genus IX. Euliptio (Raf.) 

29. E. nigra (Raf.) — (2. c) 

30. E. dilalala (Raf.) — (2. a) 

(12). E. dilatala subgibbosa (Lea) — (3.0) 
(13). E. dilatata delicata (Simpson) — (3. c) 
Genus X. Uniomerus (Conrad) 

31. U. tetralasma (Say) — (i. a) / 
(14). U. tetralasma comptodon (Say) — (i. 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 Sub-Family II. Anodontinae Ortmann 

a. — Inner la'minae 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 Genus XI. Symphynota (Lea) 


32. 5. complanata (Barnes) — (i.a) 

33. 5. coslata (Raf.) — (3. c) 
Genus XII. Arcidens 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) — (i. b) 

36. L. ohiensis (Raf.) — (i. b) 
Genus XIV. Anodonta (Lamarck) 

37. A grandis (Say) — (i. b) • ■ 

38. A. dakolana Frierson — (i. b) 

39. A. corpulenta Cooper — (i. b) 

40. A. Danielsii Lea — (i. a) 

41. A. Bealii Lea — (i. 2c) 

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

42. A. Ferussacianus (Lea) — -(i. 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. marginala Say — (2. c) 

(b) — Marsupium with transverse ovisacs; hinge rudimentary with 
cardinals rounded and suppressed . . Genus VXII. Strophitus (Raf) 

45. 5. 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. Lampsilinae 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. Ellipsaria (Raf.) 

46. E. clintonensis (Simpson) — (3. c) 

(b) — Marsupium occupying outer gill in a few, large, long ovisacs. 

Genus XIX. Obliquaria (Raf.) 

47. 0. reflexa (Raf.) — (i. c) 


Genus XX. Cyprogenia (Agassiz) 

48. C. Aberli (Conrad) — (3. c) 

(15). C. Aherti 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) — Pseudoon (Simpson) 

49. 0. {Pseudoon) ellipsis (Lea) — (i. b) 
Genus XXII. Nephronaias (Cross and Fisher) 

50. N. ligamentina (Lamarck) — (i. b) 

(16). A'^. ligamentina gibba (Simpson) — (i. c) 

51. N. ellipsiformis (Conrad) — (i. c) 

(17). N. ellipsiformis vennsla (Lea)— (i. c) 

52. N. Pleasii (Marsh) — (3. c) 

53. N. ozarkensis (Call) — (3. c) 

Genus XXIII. Amygdalonaias (Cross and Fisher) 

54. A. donaciformis (Lea) — (i. a) 

55. A. truncata (Raf.) — (i. c) 
Genus XXIV. Plagiola (Raf.) 

56. P. securis (Lea) — (1. b) 
Genus XXV. Lasmonos (Raf.) 

57. L.fragilis (Raf.) — (i. a) 

58. L. Simpsoni (Ferriss) — (3. c) 

59. L. leptodon (Raf.) 
Genus XXVI. Proptera (Raf.) 

60. P. alala (Say) — (i. a) 

61. P. purpurata (Lamarack) — (3. c) 

62. P. laevissima (Lea) — (i. a) 

63. P. capax (Green) — -(i. b) 

(b) — Inner post-ventral edge of mantle differentiated with papillae 
and flaps; glochidia normal in shape, medium in size. 

Genus XXVII. Carunculina (Simpson) 

64. C. parva (Sarnes) — (i.b) 

65. C. texensis (Lea) — (i. a) 

66. C. glans (Lea) — (i. a) 
Genus XXVIII. Eurynia (Raf.) 

Sub-Genus (II). Micromya (Agassiz) 

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

68. E. {Micromya) iris (Lea)— (3. c) 

69. E. {Micromya) hrevicula (Call) — {t,. c) 

(18). E. {Micromya) brevicula Britlsi (Simpson) — (i. c) 
Sub-Genus (III).) Eurynia {sens, strict.) 

70. E. {Eurynia) suhrostrata (Say) — (i. a) 
7 J. E. {Eurynia) recta (Lamarck) — (i, c) 


Genus XXIX. Lampsilis (Raf.) 

72. L. anodontoides (Lea) — (i. a) 

73. L. fallaciosa (Smith) — (i. a) 

74. L. Higginsii (Lea) — (i. b) 

75. L. Powellii (Lea) — (3. c) 

76. L. luteola (Lamarck) — (3. c) 

(19). L. luteola rosacea (DeKay) — (3. c) 

77. L. Reeviana (Lea) — (3. c) 

78. L. venlricosa (Barnes) — (3. c) / 
(20). L. ventricosa satura (Lea) — (3. c) 

Genus XXX. Truncilla (Raf.) 

79. T. Curlisi Frierson and Utterback — (3. c) 

80. T. Lefevrei Utterback — (3. c) 



Sub-Families 3 

Genera 30 

Sub-Genera 3 

Species 80 

Sub-SPEciEs 20 

Total of Species and Sub-Species 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; P0 = 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, BIBLIOGRAPHY AND CHECK LIST. — A few technical terms intro- 


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 " celtijorm" (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 - 
dentmn," 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. 
Jl. Phila. A. Sci. — Journal of the Philosophical Academy of Science. 
Mai. Soc. Lon. — Malacological Society of London. 
Moll. Chicago, Pt. I. — Mollusks of Chicago, Part I. 
Monog. Biv, Ohio, — Monograph of the Bivalves of Ohio. 


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 

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



Family I. Margaritanidae Ortmann. 

191 1 — Margaritanidae 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 {191 2 b, p. 22 j). 

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, Unto monodonta Say.) 

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


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. 

SheIvIv 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. 28 A and B. 

1829 — Unio monodonta Say, N. Harm. Diss., Up. 293; 1830, Am. 

Conch I. PI. VI. 
1853 — Margaritana monodonta Conrad, Pr. Ac. N. Sci., Phila. VI, p 262. 
1912a — Cumberlandia monodonta Ortmann, Nautilus XXVI, pp 13 

and 14. 

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


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 


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.' 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. 


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 Naiad shells; beak cavities shallow; nacre bluish 
with a slight tint of salmon in umbonal cavity; no vein marking 
as in most Unioninae. 

9 115 X 44.5 X 25mm (Osage R., Bagnell, Mo.) 

cf 127 X 45 X 27.5mm ( " " Sagrada, Mo.) 

9 122 X 47 X 26mm (Miss. R., Louisiana, Mo.) 

cf 96 X 40 X 20.5mm (Miss. R., Louisiana, 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 is now carried farther south and west of the Miss- 
issippi 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 a season (Nautilus, XXIX, p. 6, May, 1915.), 


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

Family II. Unionidae vSwainson (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 

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- 


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: 

I Anodonta, bearing non-conglutinated glochidia, spadi- 
form, spined. 

2. Proptkra, bearing conglutinated glocliidia, celtiform. 

spined or spineless. 

3. Unio-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 Unionifiae, 
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. 

I — ^Sub-Family 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 

vShell 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 subfamilv are rather constant. However, its shell characters 


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 Unionae 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 dilTerences 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 that the 
author is trying to solve. The unusual variations within the 
sub-family especially is another problem that would also be 


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. 

(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: — vShell 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 Unionidac 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 
epidermis Big Rivers 

2. F. trigona: swollen, lower beaks, mostly reddish epider- 
mis 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 vState seems to be the home mostly 


for intermediate forms not only for Fusconaia, but for other Genera 
of this vSub-family, Unioninae, 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). 

PL XV. F-igs. 2g A and B. 

1823 — Unio undatus Barnes, Am. Jour. Sci., VI, p. 121, pi., iV, fig. 4. 

.1831 — Unio trigonus Lea, Tr. Am. Phil. Soc, IV, p. no, pi XVI, fig. 40. 

1900b — Quadrula trigona, Simpson, Proc. U. S. Nat. Mus., XXII, p. ,787. 

1900 — Quadrula undata Walker, Nautilus, XXIV, pp. 5-1 1 and 16-24, 

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


Nutritive vStructures — 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 

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 


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. 

75 X 63 X 48mm 0.16 (Miss. R., LaGrange, Mo.) 

70 X 64 X 49mm 0.78 ( " " " " 

55 X 43 X 39mm 0.17 (Meramec, R., Fern Glen. Mo.) 

60 X 55 X 46mni 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 mav be 
found in the Meramec and Osage Rivers where it is to be distin- 
guished from F. fiava by its swollen high beaks and darker epi- 
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 fiava. 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 F. 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. 


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

Fusconaia undata trigona (Lea). 
("Little Pigtoe.") 
PL XV. Figs. 31 A and B. 
1913a — Fuscofiaia undata trigona (Lea) Ortmann, Pr. Am. Phil. Soc, 
LII, No. 210. 


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


Shell more quadrate than that of F. fiava, 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, trigonoides, it differs chiefly in being more upright, 
not so elongated, nor as large. 

Length Height Diameter Locality 

65 X 53.5 X 41mm (Osage, R., Sagrada, Mo.) 

( " " Monegaw Springs, Mo.) 

( " " Warsaw, Mo.) 

( " " Linn Creek, Mo.) 

Miscellaneous Remarks: — This sub-species is one of the 
decided intergrades for F. undata and fiava 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 

60 X 




60 X 




48.5 X 





and more typical shell of the main species. This subspecies, 
however, is more like the type than the trigonoid?s of Frierson, 
the latter being more nearly the flava type and hence might be 
well named "F. undata flava (Raf.)" 

Fusconaia undata trigonoides Frierson, MS. 

("Big Pigtoe.") 

PI. XV— Figs. 30 A—D; PL IV, Figs, ga, and gh. 

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. 


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 X 66 X 42 (Platte R., Dixon Falls, Mo.) 

70 X 50 X 38 (Osage R., Schell City, Mo.) 

50 X 40 X 24 (Osage R., Warsaw, Mo.) 

28 X 20 X 14 (Platte R., Gari'etsburg, 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 


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-irigona, 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 Fnsconaia — some reaching 
a length of loomm while the average length of the species (F. 
undata) for the Mississippi only average 6omm. This variety 
seems to be more of a creek form of F. 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 vShell," "Red Nose," "Wabash Pigtoe.") 

PI. XV. Figs. 32 A—D. 

1820 — Unio flavtis Rafinesque, Monog. Bio. Shells of R. Ohio. 

1829 — Unio rubiginosa Lea, Tr. Am. Phil. Soc, III, p. 427. PI. VIII, 

fig. 10. 
J898 — Quadrula rubiginosa Baker, Moll. Chicago. Pt. I. p. 77, PI. 
XIX, fig. i; XX, fig. I. 

1912 — Fusconaia rubiginosa Ortmann, An. Car. Mus., VIII, pp. 241 

242, Text Fig. 4. 



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 0.15.5mm). 


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, rayed 
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. 

65 X 45 X 30mm (St. Francis River, Greensville, Mo.) 

43 X 35 X 25mm ( 

50 X 40 X 24mm (White River, HoUister, Mo.) 

34 X 27 X i6mra ( " " " " ) 

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. 


Miscellaneous Remarks: — This species is distinguished 
mostly from F. iindata and the intergradcs by its more quadrate 
and compressed form of shell, by lower beaks, and less upright 
position. F. undata trigonoid-cs 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 Jwbetata and the vSt. Francis flava are too 
inflated to be very typical. Since this vState 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 y?a?)a. Dr. Sterki 
(1898, p. 30) considers this species as occasionally hermaphroditic 
by examination of its gonads. vSurely this finding can be confirmed 
by the forms of Missouri, for it is rarely that it is even locally a gouo- 
chorist. Flava is typically tachytictic being only found gravid 
from May until August. 

Fusconaia hebetata (Conrad). 
PL XV,— Figs. 33 A and B. 
1854 — Unio hehelatus Conrad., Jl. Ac. N. Sci. Phila. II, p. 296, PI. 

XXVI, Fig. 5; 1888— B. H. Wright, Check List. 
1900b — Quadrula hebetata Simpson, Proc. U. S. Nat. Mus., XXII, 

p. 787. 
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. 


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 


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. 

58 X 50 X 26mm (Osage River, Linn Creek, Mo.) 

MiscELivANEOus REMARKS: — The above measurement is 
that of a moderately compressed shell resembling that of some 
typical liebetata 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 cerina or with Lea's ruhida 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 ehena Lea, Trans. Am. PhiL Soc, V. p. 84, pL IX, fig. 14. 
1900b — Quadrula ehenus, Simpson, Proc. U. S. Nat. Mus., XXII, p. 793. 
1912b — Fusconaia ehena (Lea) Ortmann, An. Car. Mus., VIII, p. 245. 


Nutritive Structures: — Branchial opening large with 
branched papillae; anal smooth or crenulated; supra-anal large 
briefly connected to anal b}^ 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 

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 o. 15 mm), conglutinates subcylindrical, bright pink. 

SHELL characters. 

External Structures: — Shell thick, solid, subrotund, some- 


times shows a tendency to bianguation posteriorly; beaks incurved, 
projecting forward, sculptured with concentric lines but no sculp- 
turing carried out ort 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, 

cf 105 X 75 X 60mm 0.090 (Miss. R., La Grange, Mo.) 

9 95 X 65 X 57mm o.ioo ( " " " " " ) 

cf 56 X 46 X 32mm 0.120 ( " " Hannibal, Mo.) 

cf 20 X 18 X 8mm 0.115 ( " " " " ) 

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 Sphaermm. 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 

Miscellaneous Remarks :^ — The writer, after some years of 
extensive collecting from the largest streams of the state, has 
failed to find ehena 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-Arkansa'^ 
line. Sometimes a black shelled Pleurobema pyramidatum or 
Fusconaia undata trigonoides may be taken for the "Nigger Head" 
(F. ehena), 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 ehena as a rare shell in Louisiana and Isely (19 14, 
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 found by Wilson and Clark 
(1914, p. 42) to extend from May to the middle of July. Surber 


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

Genus Amblema Rafinesque. 

1820 — Amblema Rafinesque, Monograph Biv. Shells of R. Ohio. 
1912b — Crenodonta (Schluter) Ortmann, An. Car. Mas., VIII, pp. 

(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 
of Naiades 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 


Jor 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 
Missouri 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 (vSay) and costata (Raf) [ = undidatus (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 


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

(i) — Amblema plicata (Say) 1817 = L^ plicatus Say. = L' . hip- 
popea hea = Quadrula plicata hippopaea Simpson. 

(2) — Amblema plicata costata (Raf) i82o=L^. tmdulatus 
Barnes 1S2 ;^=Quadrula undulata Simpson. 

(3) — Amblema peruviana (Lamarck) iSig = Ouadrtila plicata 

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

Amblema peruviana (Lamarck) 

("Three Ridge," "Big Blue Point"). 

PL XVI,— Figs 35A and B. 

1 8 19 — Unio peruviana Lamarck, An. Sans. Vert., VI, p. 71., Deshayes, 
An. Sans. Vert., 2d ed., VI, 1835, p. 533; 3d. ed., II, 1839, p. 667. 

1900b — Quadrula plicata (Say) Simpson, Pr. U. S. Nat. Mus., XII, 
p. 767. 

Animal Characters: — wSince 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.) 


External vStructures: — 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 


of post-dorsal ridge few, broad, shallow and 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. 

cf loi X 64 X 54mm (Mississippi R., La Grange, Mo.) 

9 112 X 74 X 46 " (Osage R., Monegaw Springs, Mo.) 

9 48 X 40 X 29 " (Mississippi R., Hannibal, Mo.) 

cf 33 X 28 X 20 " (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 jtiveniles. 

Miscellaneous Remarks: — Amhlema peruviana (Lam) is 
the Qviadrula 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 
type 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 railed plicata but which is really the rariplicata 
Deshayes. This species should perhaps be reduced to the sub- 
species, " Amb. rariplicata peruviana (hsiTn); however, because 
of its difference from rariplicata 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 Blue Point.") 
PL IX,— Fig. 20; PI. XV I, —Figs. 36A-D. 
1830 — Unio rariplicata Deshayes, Enc. Meth; II, p. 578; An. Sans. 
Vert., 2d. ed., VI, 1835, p. 533; 3d. ed., II, 1839, p. 667. 

animal characters. 
Nutritive vStructures: — Branchial opening very long with 
short yellowish papillae; anal slightly crenulate; supra-anal very 


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 vStructures: — vShell 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 co.tated; 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. 

d^ 120 X 72 X 52mm — 0.169 (Platte R., Dixon Falls,) 

9 130 X 80 X 62 " — 0.230 ( " " Garretsburg,) 

9 1 1.5 X 80 X 51 " — 0.215 (Tarkio R., Craig,) 

cf 22 X 20 X 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 



no tendency toward posterior biangulation. Perplicata, being 
more of a southern form, is not found in this state north of the 
Missouri, while rariplicata, 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 raripliplicaia from the 
synonomy of Simpson's Ouadrula 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.") 

PL XVI. Figs. 37 A and B. 

184 1 — Unio perplicatiis Conrad, Pr. Ac. N. Sci. Phila., I, p. 19. 

1900 — Quadrida perplicata Simpson, Proc. U. S. Nat. Mus., XXII, 

p. 767. 
1912b — Credononta perplicata Ortmann, An. Car. Mus,. VIII, p. 247-248. 


External Structures: — vShell 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 

d^ 115 X 80 X 48mm (Osage R., Osceola, Mo.,) 

9 90 , X 66 X 46 " (,St. Francis R., Greenville, Mo.,) 

9 83 X 67 X 48 " (Osage R., Linn Creek, Mo.,) 

cf 16 X 14 X 10" ( " " Warsaw, Mo.) 

Many juveniles taken in the Osage average as the above 


\Var?av. 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 Ajnb. pcrplicata 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 vSt. 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, quiniardi of Cragin is the pre- 
dominant form of Amhlemae, and from which it is distinguished 
by the smaller, more compressed, and much plicated shell of 
the latter. Under the description of Amh. 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 
iquintardi) 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 securis or Ohovarid retusa. 

Amblema perplicata quintardi (Cragin) 

("Little Blue-Point," " Multiplicate.") 

PL XVI . Figs. 38 A—D. 

1887 — Unio quintardii Cragin, Bull. Wahb. Coll., II, p. 6; Pilsbry, 
Pr. Ac. N. Sci. Phila., 1892, p. 131, pi. VII, figs, 1-3. 

iSgi — Unio pilsbryi Marsh, Nautilus, V. pp. i and 2; Nautilus, VII, 
1893, pi. I, figs. 7 and 8. 


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 


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 semi- 
circular, medium in size, hinge line nearly straight, measuring 
0.205 ^ 0.2TJ mm. Dr. vSurber kindly indentifies: — "Like plicata, 
but slighlty larger. Easily within the range of variation shown by 
this species from different localities." 


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 

9 115 X 80 X 48mm (Osage R., Proctor, Mo.) 

(White R., Hollister Mo.) 
(Osage R., Monegaw Springs, Mo.) 
( " " Taberville, Mo.) 

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 jtivenile are of the plicata 
group of the Osage the exact relationships of which seems to be 

Miscellaneous Remarks: — Surely this subspecies is a 
decided intergrade of the perplicatus Conrad and costata Rafinesque 
{—U. undulatus Barnes). Mr. Walker has referred this abundant 
shell for vSouth and Central Missouri to perplicata variety quintardi 




















Cragin while Mr. Frierson would assign it to undulata variety Pilshry 
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 Amh. plicata costata (Raf.) and is far from 
either Amb. rariplicata (Des.) or peruviana (Lam). vSince 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.") 

PL XVI, Figs. 39 A—D. 

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

1823 — Unio iindulatus Barnes, Am. Jour. Sci. and Arts, ist. ser., VI, 

p. 120, fig. 2. 
1900b — Quadrula undulata vSimpson, Proc. U. S. Nat. Mus., XXII, 

p. 769. 
1912b — Crendonta undulata Ortmann, An. Car. Mus., VIII, pp. 246-247. 


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


are similar, 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 


External vStructurEs: — vShell 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 vStructure: — 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 

cf 112 X 73 X 36mm (Osage R., Schell City, Mo.) 

? 76 X 55 X 32 " (Gasconade R., Gascondy, Mo.) 

d^ 32 X 25 X 15 " (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: — Amhlema costata Rafinesque is 
without question the Unto undulatus Barnes, but the trinomial 
name, Amh. 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 ''Amhlema.''' 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 Naiad species in this 
vState south of the Missouri River. Most of the students of Naiades 
have returned the results of their studies of the Missouri Amhlemac 
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 


Central Missouri, where ecological conditions are the most diverse 
for the State, the authcf 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 Q. 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 Missouri River. 

Genus Megalonaias Utterback. 

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


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 


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


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, triuynphans Wright, etc., 
yet, from shell characters, these allied forms would naturally 
fall under this new genus, Mcgalonaias. In all probability crassi- 
dens (Lamarck) [ = trapezoides (Lea)], which has been grouped 
ver}^ 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 Naiad shell 
in the possession of a " ventral scar" as pointed out by Mr. Frierson) 
this species of Lamarck 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 Rafinesque 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 



o( Amblema (Raf.) because of Simpson's and Ortmann's treatment, 
(preceded by that of Mnrch in 1853) Schiilter's name cannot be 
used. Thus it may be seen why an original name, " Megalonaias," 
(etymologically embodying a chief character) is herein submitted. 

Megalonaias heros (Say) 
("Giant Heros," "Washboard.") 
PL VII, Fig. 16; PL VXII, Figs. 48 A~F. 

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

1831 — Unio multiplicattis Lea, Tr. Am. Phil. Soc, IV, p. 70, PI. IV, 

fig. 2. 
1900b — Quadrula heros Simpson, Proc. U. S. Nat. Mus., XXII, p. 770. 
1912b — Crenodonta heros (Say) Ortmann, An. Car. Mus., VIII., p. 248. 

Fig. 2. Megalonaias heros (Say). 9 Diagram of a gravid individual 

from Platte River, Garretsburg, showing animal characters 

in left valve. Coll. Jan. 25, 1913. (K "at. size.) 


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 



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 o.34omra,' 

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

Fig. 3B Ventral view of open glochidium of M. heros. (X87 — a 
camera lucida sketch. Right hand figure.) 


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 

^ According to Dr. T. Surber, (U.S. B.F. Doc, No. 813, 191 5) this glochi- 
dium has the greatest variation in size and moreover, he has also found 
it parasitic upon the gills of the "water dog" (Nec/wrMS ntaculosus). 






















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 

9 150 X 116 X 56mm (Platte. R, Dixon Falls.) 
c? 153 X 117 X 56 " ( " " Garretsburg.) > 

39 " (Osage R., Warsaw) 

25 " ( " " Monegaw Springs) 

i2.5mni ( " " Warsaw) 
9.5 " ( " " Proctor) 

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 Naiades 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 


author sees fit to create a new genus for heros of Say:— 

I. — An unusuatty 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 — 
especiallv 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 Naiades 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 Naiades so far 
known, vet 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, 


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 19th. 
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, except 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; 


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. Pustnlosa Group. 

This group is mostly represented in this State by the northern 
and western form, 0. pustulosa schoocraftensis (Lea), 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 Lea), nodvilata (Raf.), fragosa (Conrad), aspera (Lea), 
verrucosa (Raf.), nohilis (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 

III. Metanevra Group. 

This third group is only represented in this state by Q. 
metanevra (Raf.) and cylindrica (vSay) and is characterized especi- 
ally b}' 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 Amhlema 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. 


includes more under this group, that is, the genera, Fusconaia, 
Amblema, Megalonaias, Rotundaria, Plethobasus and even some 
species of Pleurobema. 

Quadrula pustulosa (Lea)' 
(" Wart3^-Back," "Warty Pigtoe," "Pimple Back.") 
PI. XVII. Figs. 41 A and B. 
1 83 1 — Unio pustulosus Lea, Tr. Am. Phil. Soc, IV, p. 76, pi. VII, 

fig- 7- 
1834 — -Unio nodulosus Say., Am. Conch., VI. 
1898 — Quadrula pustulosa Baker, Moll. Chicago, Pt. I., p. 86, pi 



Nutritive vStructures :— 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 vStructures: — All 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. 


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 

9 52 X 46 X 32mm (Miss. R., La. Grange, Mo.) 

cf 60 X 60 X 38 " ( " " " " " ) 

9 54 X ^ X 34 " ( " " Hannibal, " ) 

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). 



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, schooler a ftensis, 
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, mortoni, etc., — all of which are not found in Missouri; 
on the other hand its northern relative (schoolcraftensis) is more 
of a lover 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.") 
PL XVII. Figs. 42 A—D. 

1834 — Ufiio schoolcraftensis Lea, Tr. Am. Phil. Soc, V., p. ,37, pi. Ill, 
fig- 9- 


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 vStructures: — 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 ^ 0.320). 


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


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 Length Height Diameter Um. ra. Locality 

9 70 x 58 X 41mm 0.310 (Platte R., Agency, Mo.) 

c?' 60 X 50 X 30 " 0.300 (Grand R., Darlington, Mo.) 

Q 42 X 36 X 26 " 0.295 (Platte R., Claire, Mo.) 

<f 17 X 14 X 8 " 0.300 (Grand R., Utica, Mo.) 

Since schoolcraftensis 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 Naiades 
in Missouri. The above latter measurement is that of the smallest 
one but it was without hyssi. 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 
piistiilosa." The varieties of typical ptistulosa, 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 pustMlosa-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, 


where it has developed a heavier, less pustulous shell as we 
note in the ecologic results for some shells of Amhlemae. 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). 

PI. XVII. Fig. 42 A and B. 

1861 — Unio asperatus Lea, Pr. ac. Nat. Sci. Phila. V, p. 41; Jl. Ac. 
N. Sci. Phila., v., p. 68. PI. VII. Fig. 218. 

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 


External Structures: — Subtrigonal, very upright, higher 
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 

Sex Length Height Diameter Locality 

<f 44 X 46 X 28mm (Osage R., Warsaw, Mo.) 

9 50 X 48 X 32 " ( " " Osceola, Mo.) 

d' 46 X 46 X 31 " ( " " 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, schooler ajtensis, 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)." 
Comparisons to the actual shell from Alabama (Coosa R., Cedar 
Lluff) shows it to be almost identical both as to external and 
internal features. 


Quadrula quadrula Rafinesque. 
("Maple Leaf," "Monkey Face," "Tear vShell.") 
PL IX., Fig. ig; PI. XV 11 1., Fig.s 45 A—F. 

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

P- 305- 
1828 — Unio lacrymosus Lea, Tr. Phil. Soc., Ill, p. 1272, pi. VI, fig. 8. 
1 83 1 — Unto asperrimus Lea, Tr. Am. Phil. Soc, IV, p. 71, pi. V., fig. 3. 
^834 — Unio quadrulus Say, Am. Conch, VI. 

iSgS— Quadrula lachrymosa Baker, Moll. Chicago, Pt. I, p. 83, pi. 
XXV., fig. I, XII, fig. 2. 


Nutritive Structures: — 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 Oiiadrulae; 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 vStructures: — Shell medium in size, subquadrate 
to subtrigonal, dorsal ridge more or less alated with costae on 
!^ lopes 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. 














48 " 








38 " 








29 " 








4 " 




Internal vStrucTurEs: — 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 

(Lake Contrary, St. Joseph, Mo.) 
(Platte R., Agency Ford) 
(Flat Creek, Sedalia, Mo.) 
(Auxvasse R., Fulton, Mo.) 
(Grand R., Utica) 

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 quadrnla 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. quadnda 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. l£ 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 A^orth Missouri may be 
referred to Pratt's Udio lunulatus (Proc. Dav. Ac. Nat. Sci., I. 
1876, p. 167, PI. XXXI, fig. i). However, this may simply be 
the lacustrine form of the type since the fluviatile forms of North 


Missouri approach more the t3'pical 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 diflficulty 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 0. 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 

Special attention is given here to a deeply sulcated Jorni oj 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 

cf 85 X 70 X 57mm 0.485 (Lake Contrary, St. Joseph, Mo.) 

9 80 X 55 X 54 " 0.450 ( " " " ■" " ) 

o" 48 X 38 X 40 " 0.435 ( " " " " " ) 

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 
fiurow 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.) 


Quadrula quadrula contraryensis Utterback. 

(Round Maple Leaf.) 

PL XVIII, Fig's 47 A and B. 


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 

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, incHned 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 

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 

O^ 73-5 X 64.5 X 44.0mm 0.495 (Lake Contrary, St. Joseph, Mo.) 
9 76.0 X 66.0 X 45.0 " 0.500 ( " " " " " ) 

cf 84.0 X 70.0 X 59.0 " 0.483 ( " " " " " ) 

9 41.0 X 36.0 X 38.0 " 0.520 ( " ' " " " " ) 

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, 


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 Naiades 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 contraryensis. 

Quadrula nodulata Rafinesque. 

(•'Pimple Back," "Warty Back.") 

PI. XVII, Figs. 44 A and B. 

1820 — Obliquaria nodulata Rafinesque, Bivalves of River Ohio, Ann. 

Gen. Sci. Phys. Brux. 
1834 — Unio pustiilatus Lea, Tr. Am. Phil. Soc, p. 79, PI. VII, fig. 9. 
1834 — Unio nodulatus Say, Am. Conch., VI. 

Animal Characters: — Nutritive structures absolutely iden- 
tical with those of Qtiad. pusfulosa (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 Jornt that is to be taken into greater account. 


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 pnstulosa. 

cf 48 X 40 X 30 mm 0.200 (Miss. R., Hannibal, Mo.) 
9 45 X 38 X 28.5 " 0.250 ( " " " " ) 

cf 32 X 28 X 23 " 0.210 ( " " " " ) 

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 


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.") 

PL XVIII, Figs. 48 A and B. 

1836 — Unio fragosus Conrad, Monog. of Fresh-water Shells, II, p. 12, 
PI. VI., fig. 2. 


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 (191 4, pp. 59 and 60) report it with all 
four gills marsupial, thick, pad-like. Glochidium unknown. 

shell characters. 
^;?cternal Structures: — Shell most quadrate of the Quad- 


rtdae, 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 0. quadrula. 

Sex Length Height Diameter Locality 

cf 63 X 59 X 35mm (Miss., R. Hannibal, Mo.) 

9 44 X 39 X 18 " ( " " " " ) 

cf 23 X 16 X 9 " (102 R., St. Joseph, Mo.) 

cf 15.5 X 6.5 X 7 " (Osage R., Schell City, Mo.) 

It may be that the juvenile shell measurement of the last 
two above is only that of 0. 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 0. 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. vSimpson 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.") 

PL XVIII, Figs. 49 A and B. 

1831 — Unio asper Lea, Tr. Am. Phil. Soc, IV, p. 85, pi. IX, fig. 15. 


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), 


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 Q. quadrula. No gravid forms found. 


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 

9 52 X 46 X 29mm (Osage R., Warsaw, Mo.) 

cf' 44 X 39 X 27 " ( " " " " ) 

9 40 X 38 X 24 " ( " " " " ) 

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 Leaf.") 

PL XIX. Figs. 51 A and B. 

1854 — Unio nobilis Conrad. Jl. Acad. Nat. Sci. Phila., II, p. 297, 
PI. XXVII, figs. 2 and 3. 


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- 


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 

9 1 20 X 88 X 57mm (Marais des Cygnes R., Rich HiU,) 

cf 80 X 56 X 30 " (Osage R., Greenwell Ford) 

9 56 X 46 X 27.5mm ( " " " " ) 

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 
0. 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. Nobilis is 
reported by Isely (19 14, 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 



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," "Buck Horn.") 

PI. XIX, Figs. 30 A—D. 

1820 — Unio {Obliquaria) verrusoca Rafinesque, Ann. Gen. Phys. Brux. 
1823 — Unio tuberculata Barnes, Am. Jl. Sci., VI, p. 125, PI. VII, figs., 

8a, 8b. 
1899 — Tritogonia tuberculata Simpson, Pr. U. S. Nat. Mus., p. 608. 
1912a — Quadrula tuberculata Ortmann, Ann. Car., Mus., p. 254. 


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. 


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. 


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, 
irri descent posteriorly 

Sex Length Width Diameter Locality 

9 169 X 88 X 48 (Grand R., Darlington) 

cT 150 X 78 X 44 (Platte R., Agency Ford) 

cf no X 50 X 30 (Osage R., Warsaw) 

54 X 30 X 15 (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: — Q. verrucosa is the most peculiar 
species of its genus on account of the sexual dimorphism of its 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. quadnda, 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 loth. 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 vState; e. g., the pink-nacred ones are exclusively confined to 
the vSouthern Missouri streams. 


Quadrula metanevra (Rafinesque). 

("Maple Leaf," "Monkey-face" "Stranger.") 

PL XIX, Figs. 53 A and B. 

1820 — Obliquaria (Quadrula) metanevra Rafinesque, Ann. Gen. Sei. 

Brux., V, p. 305- PI- LXXXI, fig. 15 and 16. 
1834 — Unio metanevrus Say, Am. Conch., VI. 
1900b — Quadrula metanevra (Raf.) Simpson, Proc. U. S. Nat. Mus., 

XXII, p. 774- 


Nutritive vStructures: — 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 difterent 
color being a straw-yellow of the mantle margin at branchial 

Reproductive vStructures:- -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 
0.190mm., 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. 




















1 1 


Sex Length Height Diameter Locality 

39nim (Miss. R., Hannibal ) 

36 " (Meramec R., Fern Glen ) 

25 " (Osage R., Proctor) 

30 " ( " " Greenwell Ford) 

6.5mm ( " " 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 — Unio wardii Lea. Pr. Ac. N. Sci. Phila., V, p. 372; Jl. A. C. N. 
Sci. Phila., V., p. 187, PI. XXIV, fig. 257. 

Animal Characters: — Identical, with those of its parent 


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 


its external and internal shell structures are identical with those of 
0. metanevra. 

Sex Length Height Diameter Locality 

^ 9 86 X 70 X 54mm (Des Moines R., Dumas) 

Miscellaneous Remarks: — Shells ii^om the type lot, sent to 
the National Museum and now under the label of variety wardii 
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 (vSay). 

("Razor Handle,"" Cob Shell," "Rabbit's Foot," 

"Spectacle Case.") 

PI. XIX, Figs. 52 A and B. 

1816 — Unio cylindricus Say. Nich. Ency., II, PI. IV, fig. 3. 
1819 — Unio naviformis Lamarck, An. Sans., Vert. VI, p. 75. 
1900b — Quadrula cylindrica (Say) Simpson, Proc. U. S. Nat. Mus., 
XXII, p. 773. 


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 

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


External Structures: — vShell 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 



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. 

c? 105 X 40 X 34 0.190 (White R., HoUister — ) 
9 108 X 40 X 39 0.190 (Center Cr., Webb City) 

? 75 X 30 X 28 0.200 (St. Francis, Greenville) 

cf 70 X 28 X 26 0.210 (Black R., Williamsville) 

Miscellaneous Remarks; — ^It is regretted that the descrip- 
tion of this interesting species still remains incomplece, 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 imique shell and yet it may well be described as an 
extremely elongated 0. metanevra. The breeding record kept by 
the writer is early embryos August 14 and sterile maruspia August 
29; Wilson and Clark (191 1, p. 42) record its gravidity for June 
17 and July 27 but do not indicate the embryonic stages. 

Genus Rotundaria Rafinesque. 

(Type Ohliquaria [Rotundaria] tuber culata 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., XXIL 

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, acutni- 
nate postero-ventrad; only outer gills marsupial water tubes 
more crowded than in non-marsupial 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. 


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 

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 PletJtobasus cooperianus as far as shell 
structure is concerned. 

Rotundaria tuberculata (Rafinesque). 

("Purple Warty Back," "Red Nigger Head.")) 

PI. XIX, Figs. 54 A and B; PI. I, Figs. 1—4. 

1820 — Obliquaria {Rotundaria) tuberculata Rafinesque, Ann. Gen. Sc. 
Brux., v., p. 103. 

1898- — Quadrula verrucosa Baker, Moll, Chicago, Pt. I, p. 85, pi. XXIII. 
1900b — Quadrula tuberculata Simpson, Proc. U. S. Nat. Mus., XXII. 

P- 795- 
1912b — Rotundaria tuberculata (Raf.) Ortmann, An. Car. Mus., VIII, 
pp. 258-259. 

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 black posteriorly, 
foot dark tan. 

Reproductive Structures: — Only outer gills marsupial, 


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 0.26"/ x o.j2jmni., collected by author, 
Aug. II, 1913, Osage River, Bagnell, Missouri. 


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 

Sex Length Height Diameter U. ra. Locality. 

9 80 X 60 X 37mm 0.120 (Meramec R., Fern Glen) 
cf 64 X 54 X 27 " 0.135 (Gasconade R., Gascondy) 
9 63 X 62 X 33 " 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 doating 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 


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. The 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 R. 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 Jor 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. 

Z""'^-^" Rotundaria granifera (Lea). 

("Purple Warty Back," "Purple Pit.") 
PL XIX, Figs. 55 A and B. 
1838 — Unio graniferus Lea, Tr. Am. Phil. Soc, Vi, p. 69, PI. XIX, fig. 60. 
1900b — Quadrula granifera (Lea) Simpson, Proc. U. S. Nat. Mus., 
XXn, p. 795- 


Nutritive Structures: — Identical with those of R. tuber- 
culata 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 


except perhaps shorter laterals arranged at right angles to the 


Sex Length Height Diameter Locality 

c?" 57 X 57 X 40 mm (Miss. R., LaGrange) 

9 56 X 56 X 34 " ( " " " ) 

cf 46 X 46 X 30 " ( " " " ) 

9 23 X 21 X 10.5 " (White " Hollister) 

The latter measurement is of a juveniles from a lot identified 
by Mr. Frierson as approaching granijera although would perhaps 
fall more under tuber culata. 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 granijera. 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 
granijera type. Because of its full, projecting beaks, uprightness 
of shell and disk sculpture this species has sometimes been 
confused with Q. pustulosa and P. cooperianus. However, dis- 
tinction can be easily made by comparing to the rich purple nacre 
of granijera — 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 granijera 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 — Plethoba^s (Simpson) Ortmann, An. Car. Mus., VIII, pp. 


(Type, Unio aesopus Greene). 

Animal Characters: — Anarl separated from supra-anal 


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 sidphur 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. Ortm^nn points out this genus as a con- 
necting link between the more primitive Unioninae and those of 
the type of the genus Pleurohema 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, Figs. 57 A. and B. 

1834 — Unio cooperianus Lea, Tr. Am. Phil. Soc, V., p. 61, pi. VIII, 
fig. 21. 


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 vStructures: — 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. 



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 

cf 60 X 55 X 32 (Gasconade R., Gascondy) 

9 77 X 62 X 41 (Osage R., Monegaw Springs) 

d^ 70 X 64 X 40 ( " " Warsaw) 

Miscellaneous Remarks : — As this state is out of geographic 
range of t5^pical cooperianus it is natural that no real type may be 
found in Missouri. However, the writer upon finding a few shells 
of the tuber citlata (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 granijera" but that the nacre "suggests cooperiana." 
Other Missouri collectors have commented upon this strange 
departure of R. tuberculata and granijera 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 


Plethobasus aesopus (Green).' 

("Bull Head," "Sheep's Nose," "Clear Profit.") 

PL XX, Figs. 56 A and B. 

1827 — Unio aesopus Green, Cont. Mac. Lyceum, I, p. 46, fig. 3. 
1834 — Unio cypJiia 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. 


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). 


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. 


double in right; umbonal cavity moderately deep; nacre pearly 

white, irridescent. 

Sex Length Height Diameter Um. ra. Locality 

9 87 X 70 X 47 — 0.170 (Miss. R., Hannibal) 

cf 63 X 45 X 34 — 0.230 (Des Moines R., Dumas) 

9 55 X 40 X 32 — 00.180 (Little Blue, Courtney) 

cT 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 — Pleurobema (Raf.) Simpson, Proc. U. S. Nat. Mus., XXII, 

p. 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 



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 
PlethobasMS ; 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 Fusconaia 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. Utterbackii 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 ohliqua 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., 
VIII, p. 264. 

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 (19 14, 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- 


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. ohliquwm 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. vSurely 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 ohliquum 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, ohliquum 
occurs in this state, but with its 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. 

Soc, VIII, 1843, p. 211, pi. XIV, fig. 26. • 
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 ohliquum as does also a variety of coccineum found in the same 

Pleurobema obliquum pyramidatum (Lea). 
("Pig-toe," "Pyramid Pig-toe.") 
PI. XX, Figs. 58 A and B. 
1834 — Unio pryramidatus Lea, Tr. Am. Phil. Soc, lY, p. 109, pi. XVI, 

fig- 39- 
1900b — Quadrula pyramidata Simpson, Proc. U. S. Nat. Mus., XXII, 
p. 790. 




1912b — Pleurobema pyramidatum (Lea) Ortmann, An. Car. Mus., 
VIII, p. 264. 


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 vStructures: — 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: — Shell 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 

cf 6,5 X 55 X 40mm (Osage R., Sagrada) 

'9 73-5 X 52.5 X 42 " ( " " Warsaw) 

9 63.5 X 54 X 39 " (Meramec R., Fern Glen) 

cf 27.5 X 26.5 X i9.5mni (Osage R., 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 


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.") 
PL XX, Figs. 62 A and B. 

1836 — Unio catillus Conrad, Monog. Ill, p. 30, pi. XIII, fig. 2. 
1838 — Unio solidus Lea, Tr.,Am. Phil. Soc, VI, PI. V, fig. 13. 


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 0.180mm. 

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 

d^ 57.5 X 41 X 33.0mm (Marais des Cygncs R., Rich Hill) 
9 59 X 42 X 34.5 " ( " " " " " " ) 

cf 45 X 44 X 30.0 " (Osage R., Bagnell) 
9 27 X 26 X 21.5 " ( " " Baker) 

This last measurement shows this juvenile to be sub-globular. 
Its shell is unusually thick with very shallow beak and branchial 


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 catillus. The radial furrow of the type species 
(obliquum) 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 ohliquiini and caiillns seem to be the general rule rather 
than exception, but here m 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 jiilgidus 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, obliqmim 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 

c? 87 X 64 X 41 (White R., Hollister)— S. Mo. 

cf 54 X 44 X 30 (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, Figs. 61 A, B,C and D. 

1836 — Unio coccineus Conrad, Monog. Ill, p. 29, PI. XIII, fig. I. 
1839 — Pleurobema obliqmim coccineum (Conrad) Ortmann, Pr. Am. 
Am. Phil. Soc., LII, pp. 287 — 390. 




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. 


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 

c? 74 X 62 X 34 (Osage R., Warsaw) 

9 64 X 54 X 31 ( " " " ) 

cf 40 X 37 X 22 ( " " 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 0. ellipsis. It can be separated from 
Pleii. ohliquuni 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 b}^ the author in Lastena ohiensis. 
A breeding record of this form shows it to be a summer breeder 


Pleurobema catillus (Conrad). 

("White Pigtoe,-" "Pink Pig-toe," "Solid Pig-toe.") 
PL XX, Figs. 59 A and B. 

1836 — Unio catillus Conrad, Monog. Ill, p. 30, pi. XIII, fig. 2. 

1838 — Unio solidus Lea, Pr. Am. Phil. Soc, VI', pi. V, fig. 13. 

1845 — Unio fulgidus Lea, Pr. Am. Phil. Soc, p. 164; Tr. Am. Phil. 

Soc, X, 1848, p. 73, pi. IV, fig. 10. 
1900b — Quadrida solida Simpson, Pr. U. S. Nat. Mus., XXII, p. 789. 


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.i6omm.). 

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 

-f 82 X 65 X 41 (White R., Hollister) 

9 83 X 64 X 40 (Black R., Williamsville) 

d" 80 X 63 X 40 (White R., Hollister) 

Miscellaneous Remarks :^ — Conrad's catillus (described as 
separate from coccineus by the author, but united by Simpson) is 


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. coccinemn 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 show^s it to be tachytictic. 

Pleurobema coccineum (Conrad). 

("Flat Nigger-Head," "Pink Pig-toe," "Round Pig-toe.") 
PL III, Fig. 60b; PL XX, Fig. 60 A and B. 

1836 — Unio coccineus Conrad, Monog., Ill, p. 29, pi. XIII, fig. I. 
1900b — Quadrula coccinea Simpson, Proc. U. S. Nat. Mu^., XXII, 

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

VIII, p. 263. 


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 


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 

Sex Length Height Diameter Locality 

9 60 X 40 X 24 (White R., HoUister) 

cf 75 X 56 X 31 (St. Francis, Greenville) 

9 47 X 40 X 22 (White R., HoUister) 

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 (Plen. coccineuni) 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- 
souri. 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. 

\()Oi^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 Pleurobema must have been inferred from these char- 



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 X 54 X 36mm (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 tl^e rounded and compressed 
posterior half of the latter. The shell of missourense compares 
well with that of Fusconaia suhrotunda 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, PI. V., figs, i and 2). 


Pleurobema Utterbackii Frierson.' New Species. 
PL v., Figs. 12 a and b; PL XX., Figs. 63 A ~D. 


"Nutritive Structures: — Branchial opening with many 
short antennae; anal very finely cr'enulated; 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. 

SHEiviy 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 

9 68 X 42 X 26 mm (White River, HoUister) 

c? 65 X 41 X 25.5 " (Jack's Fork of Current R.) 

c? 18.5 X 12.5 X 7.5 " ( " " " " " ) 

9 18.0 X 12.5 X 7.0 " (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. 


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., 1900, p. 82). It is 
to be differentiated from the Eastern Tennessee Pleurobema argen- 
teuni (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 Lanipsilis 
very close to hiangulatus (Lea), is an interesting and remarkable 
fact illustrating the power of environmental factors in the family."' 

Genus Elliptic Rafinesque. 

1 8 19 — Elliptio Rafinesque, Jour, de Phys. Chim. et His. Nat. 

1900b — Elliptio Simpson, Proc. U. S. Nat. Mus., XXII, p. 700. (as 

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

(Type, Unio [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. Ulterbackii 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 i 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 C. T. Simpson." 


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. 

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 t3^pe of 
shell but with obscure beak sculpture; the second group is repre- 
sented by E. dilataia (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, 
headleianus 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 

Elliptio nigra Rafinesque.' 
("Elephant's Ear," "Pink.") 
PL XXI, Figs. 64 and 6§ A and B. 
1820 — Unio (Elliptio) nigra Rafinesque, Ann. Gen. Sci. Brux., V, 

p. 291, pi. IvXXX, figs. I — 4. 
1823 — Unio cuneatus Barnes, Am. Jl. Sci., VI, p. 263. 


Nutritive Structures: — Branchial opening large, well set 

' Simpson (1900 b, p. 706) applied the name " U7tio 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 (18 19) as 
the so-called U. trapezoides of Lea (1831). 



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 

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 

Sex Length Height Diameter Locality 

cf 126 X 80 X 51mm (Miss. R., Hannibal) 

c?' 91 X 61 X 37 " ( " " " ) 

9 115 X 66 X 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. 


EUiptio dilatata (Rafinesque). 
("Lady Finger," "Spike," "Pistol Grip.") 
PL XXI, Figs. 66 A and B. 
1820 — Unto (EUiptio) dilatata Rafinesque Monog. of Bivalves of Ohio, 

Ann. Gen. Sci. Phys. Brux. 
1823 — Unio gibbosus Barnes, Am. JI. Sci., VI, p. 262, pi. XI, fig. 12. 
1838 — Unio arclior Lea, Tr. Am. Phil. Soc, VI, p. 10, pi. IV, fig. 10. 
1912b — EUiptio g^ibbosiis (Barnes) Ortmann, An. Car. Mus., VIII, 
p. 271. 


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 o. 220mm. 


External Structures: — Shell elonga-te-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 

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 

? 135 X 65 X 43.0 0.260 (Miss. R., Hannibal) 

cf 120 X 50 X 38.0 0.255 (Osage R., Osceola) 

9 42 X 20 X 9.5 0.255 ( " " " ) 

cf 39 X 18 X 9.5 0.250 (Niangua R., Hahatonka) 


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 Ellip- 
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 dilatata with white nacre {E. 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). 
("lyittle Lady Finger," "Little Spike.") 
PL XXL, Figs. 68 A—D 

1857 — Unio subgihbostis Lea, Pr. Ac. N. Sci. Phila., IX, p. 169; 1858, 

JL Ac. N. Sci. Phila., IV, p. 53, pi. VI, fig. 36. 
1868 — Unio lazarus Sowerby, Conch, Icon., XVI, pi. LXVIII, 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, 


• not so pointed posteriorly, older shells tending toward post-dorsal 
trunction, dorsal line arched, v^entral rather straight, epidermis 
brownish; nacre white with pinkish umbonal cavity or solid color. 
Sex Length Height Diameter Locality 

9 70 X 30 X 20mm (Black R., Williamsville) 

cf 56 X 26 X 13 " ( " " " ) 

9 46 X 23 X 12 " ( " " " ) 

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 suhgihhosus. 
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. 

Elliptic dilatata delicata (vSimpson). 
("Little Lady Finger.") 
PI. XXL, Figs. 68 A—D. 
1900b — 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 

d" 55 X 26 X 13 " (White R., Holltster) 
9 48 X 24 X 1 1 " ( " " " ) 

cf 43 X 21 X 10 " ( ) 

Miscellaneous Remarks: — The writer has in his collection 
a shell of this subspecies bearing the original label of Mr. Simpson, 
the author. The dilatata 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. 


Genus Uniomerus Conrad. 

1853 — Uniomerus Conrad, Proc. Ac. Nat. Sci. Phila, VI, p. 268. (as 

1900b — Uniomerus (Conrad) Simpson, Proc. U. S. Nat. Mus., XXII, 

P- 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-sheW (See Plate xxi, fig. 6g). 
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. 

TJniomerus tetralasmus (Say). 

(^Pond Horn Shell.") 
PL XXI, Figs. 69 A and B. 
1830 — Unio tetralasmus Say, Am. Conch., Ill, pi. XXIII. . ''^\ 

1836 — Unio declivis Conrad, Monog., V, p. 45, pi. XXIII, fig. i. 
1839 — Unio sayi Ward, (in Tappan). Am. Jl. Sd., XXXV, p. 26S, 
pi. Ill, fig. I. 




igi2h—Uniomerus tetralasmus (Say) Ortmann, An. Car. Mus.. VIII, 
pp. 272 and 273. 

/AV _J 

Fig. 4. Uniomeriis tetralasma (Say) 9- Diagram of a gravid individual 

from Lost Cr., Amity, showing animal characters in left valve. 

Coll. May 3, 1913. (%" nat. size.) 


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 
in outline, hinge line short and straight, medium in size measuring 
0.160 X 0.210 mm. 



l"'iG. 5. Mature closed glochidium of JJ. tetralasma. (xSy) 

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 

cf 95 X 45 X 31 mm 0.260 (Batterton Pond, Columbia) 

9 88 X 44 X 32 " 0.265 (Lost Creek, Amity) 

9 76 X 42 X 24.5 " 0.260 (Mill Creek, Courtney) 

9 23 X 12 X 8 " 0.270 (Lost Creek, Amity) 

nbia) ^ ' 

Miscellaneous Remarks:— L". tetralasma is peculiar ecolo-^' , W ' 

gically, as well as morphologically, in that it can become more nCto Jj-* .. 
quickly established in artificial ponds and lakes than any species. U^*V''^il \ 
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 Danielsii, or Eurynia 
suhrostrata. From the fact that the writer has not found any 
individuals of this species in North Mis.souri without marsupial 
characters he is led to believe that it is locally hermaphroditic at 


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 vState, 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, pi. XIII. 
1832 — Unio geometriciis Lea, Tr. Am. Phil. Soc, V, p. 28, pi. 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 

Sex Length Height Diameter Locality 

9 80 X 40 X 25mm (Grindstone Creek, Maysville) 

9 75 X 40 X 24 " (Lost Creek, Amity) 

? 63 X 33 X 20 " ( " " " ) 

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 m the 
Division of Mollusks of the U. vS. National Museum under the 
number, 150402. According to Henderson (1907, p. 87, pi. 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 


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

II — Sub -Family 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 — occupying 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 a rule ; sexual dimorphism rarely seen. 

Miscellaneous Remarks : — The 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 whik 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 


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 diflfer from those 
of the Lampsilinae; however, the Anodontine species are like the 
Unionine in the possession of large palpi, whereas those of the 
Lawt;f'577zw£' 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 
Naiades 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 


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, 5. complanaia (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, 

p. 278, pi. XIII, fig. 21. 
1900b — Symphynota complanata (Batnes) Simpson, Proc. U. S. Nat. 

Mus., XXII, pp. 665-666. 


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. 


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 



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 

9 170 X 105 X 72mm 0.26 (Big Mud Lake) 

c?' 175 X 105 X 55 " 0.26 (Platte R.) 

9 100 X 65 X 29 " 0.20 ( " " ) 

9 88 X 55 X 25 " 0.20 (102 River) 

The juvenile shell is very fiat, 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 (5. 
compressa) that it may well deserve its subgeneric name, Pierosygna 
Raf. (18 13), that Simpson applied. 

Symphynota costata (Rafinesque). 
("Fluted Shell," "Squaw Foot," "Sand Mussel.") 
PL XXII, Figs. 71 A—F. 
1820 — Alasmidonta costata Rafinesque, Ann. Gen Sci, Brux., p. 318, 

PI. LXXXII, fig. 15, 16 
1823 — Alasmidonta rugosa Barnes, Am. Jour. Sci. and Arts, p. 27S, 

pi. XIII, fig. 21. 
1900b — Symphynota costata (Raf), Simpson, Proc. Nat. Mus., XXII, 
p. 665. 


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


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; glocliidium 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. 


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.) 
cf 125 X 56 X 35 " 0.280 (Black R., Williamsville, Mo.) 
9 100 X 52 X 32 " 0.275 (Miss. R., LaGrange, Mo.) 
75 X 42 X 24 " 0.280 (St. Francis R., Greenville) 

Miscellaneous Remarks: — 5. costaia 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 Naiad 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 PI. xxii, Figs, fi A — F .) This compression and plica- 
tion are due, doubtless, to swifter current and more rocky bottom. 


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. Frier son 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 Alasmidonia confragosa Say). 


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 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 lacustrine 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. 


Arcidens confragosus (Say). 

("Black Pocket-Book," "Black Pocket," "Rock Shell," 
"Rock Pocket-Book.") 

PI. 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. 
XXII, p. 662. 


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 

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, (0.355 ^ 0.350mm.) but possessing same shape, 
i. e., subtriangular, with undulate hinge line. 


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 

9' 103 X 67 X 48 mm 0.30 (Platte R., Mo.) 

102 X 65 X 48 " 0.34 (L. Contrary, Mo.) 

c?" 115 X 74.5 X 51.5 " 0.31 (Osage R., Mo.) 

45 X 33 X 22.5 " 0.30 ( " " " ) 


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. conjragosus 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. Conjragosus 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. vSci. 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 


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: — -vShell 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 suborbiciilaia (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 
Anodonia 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 

Lastena suborbiculata (Say). 

("Suborb," " Heel-splitter.") 

PL IV, Fig. 19a; PI. IX, Fig. 19; PL XXIII, Figs. 73 A~D. 

1 83 1 — Anodonia 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. 1 1, 


Nutritive Structures: — Branchial opening comparatively 
small, upward curved with many fine orange colored papillae; 
anal also directed upward, smooth with Y-shaped yellow markings; 
suora-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 




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. 

Fio. 6. Lastena suhurbicidata (Say) 9. Diagram of a gravid individual 

from Lake Contrary, St. Joseph, showing animal characters 

in left valve. {% 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 spadijorm, 
hinge line straight, longer than high, {0.325 x 0.320mm.) glochidial 
shell russet color, bluish spots jor the adductors; no conglutinates 



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

Fig. 7. 


Mature closed glochidium of L. suborhicidata. 

External Structures: — Shell subround, or suborbicular, 
thin, compressed, rounded before, bowed ventrad, pointed behind, 
sulcated 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 Unes; 
epidermis polished, straw colored in young, light brown-horn 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. 
? 185 X 130 X 67mm 0.290 
cf 150 X 117 X 49 " 0.270 
9 47 X 35 X 14 " 0.260 
cf 34 X 23 X 9 " 0.250 

(Lower L. Contrary, St. Joseph) 
(Upper L. Contrary, " " ) 

(Sugar Lake, Armour, Mo.) 
(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 

io8 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 

Miscellaneous Remarks: — This species is especially charac- 
teristic for the shape of its shell being not variable, but somewhat 
like an ordinary dinner plate 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 Naiades, 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 it is 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 indivi- 
duals have the crowded septa of the outer gills disproves that all have 
marsupial characters of these gills. Thus hermaphroditism can not 
he applied to this genus Lastena, as a general character, li 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 its 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, 



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.") 

PI. XXIII, Figs. 74 A and B. 
1820 — Lastena ohiensis Rafinesque, Ann. Gen. Sci. Brux., V, p. 316. 
1829 — Anodonta imbecillis Say, N. Narm. Diss. II, p. 355. 


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 0.290mm.); no conglutinates; 
glochidia enmeshed in a tangle of larval threads. 

SHELL characters. 

External Structures :—vShell 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 



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

Sex Length Height Diameter Um.ra. Locality 

9 98 X 40 X 39mm X 0.320 (Mud Lake, Kenmoor, Mo.) 

c? 63 X 34 X 31 " X 0.340 (Lower Lake, St. Joseph, Mo.) 

9 61 X 28 X 35 " X 0.360 (Spring Lake, Monegaw Spgs. Mo.) 

cf 25 X 10 X 2 " X 0.330 (Mud Lake, Halls, Mo.) 

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 Naiades. 
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 Jiermaphoroditic gives it a character possessed 
by few Naiades. 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 distinctlv 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 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 ohiensis 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. Coq., p. 87. 
1 81 7 — 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, 

Shell CHARAG;rERS: — 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, 3^et it is 


really only represented in this state by A. grandis and Danielsii. 
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 
will only receive passing notice. The members of this group being 
lacustrine, they are limited more to the lake distinct in Northwest 
Missouri, to that portion of Central Missouri where lakes, ponds 
and sloughs abound, and to the Mississippi Lowlands of South- 
east Missouri. Very few Anodontac are reported for vSouth Missouri 
where lacustrine conditions are rare. 

Anodonta grandis Say. 


PI. VII, Fig. 75; PL XXIII, Figs. 7S ^4 and B. 

i&2g— Anodonta grandis Say, N. Harm. Diss., II., p. 341. 
1852 — Anodonta opaca Lea, Rr. Am. Phil. Soc, X, p. 285, pi. XXV, 
fig. 46. 


Nutritive vStructurES: — 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 longe'r, 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, 


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 — 0.360 — (Mud Lake, Kenmoor, Mo.) 
cf 155 X 80 X 66 " — 0.285 — (L. Contrary, St. Joseph, Mo.) 
9 105 X 63 X 50 " — 0.380 — (" " " " ") 

9 16 X II X 5 " — 0.300 — (" " " " ") 

Several of these juvenile shells oi 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 jre-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 Naiades 
is so polymorphic as A. grandis. Probably these mutations are 
only zoogeographical 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 


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, leonensis, 
etc., 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 
sulcated at the post-ventral point and another with its shell 
extremely truncated post-dorsad. To the latter A. jootiana and 
perhaps A. dakotana, maybe referred. A.salmonia may also be 
assigned to a grandis-jorm 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 vState 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 conformit}^ 
to other writers. 

Anodonta dakotana Frierson. 
("Dakota Shell," "Short Nose.") 
PI. XXIV, Figs. 77 A and B. 
191 4 — 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 


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 

9 114 X 78 X 48 (L- Contrary, St. Joseph, Mo.) 

cf 108 X 73 X 49 " (L. " " " " ) 

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. henediciis (a form of grandis-Jootiana) 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 St. L., 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 Naiades 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. vSimpson 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, PI. XXIX, 
fig. i) has found this species to be an occasional fin-parasite upon 


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.") 

PL XXIV, Figs. 76 A and B. 

1858 — Anodonta danielsii Lea, Proc. Ac. N. Sci. Phila., Ill, p. 113; 

Jl. Ac. N. Sci. Phila., i860, IV, p. 365, PI. LXIII, fig. 190. 
1859 — Anodonta texasensis Lea, Proc. Ac. N. Sci. Phila; p. 113; Jl. 

Ac. N. Sci. Phila. i860, p. 366, PI. LXIII, fig. 191. 

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: — vShell 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 

Sex Length Width Diameter Um.ra. Locality 

9 115 X 55 X 40mm — 0.304 — (Lost Creek, Amity, Mo.) 
cf 180 X 65 X 42 " — 0.290 — (Tarkio R., Craig, Mo.) 
9 82 X 42 X 30 " — 0.268 — (Flat Cr., Sedalia, Mo.) 
9 ,so X 30 X 17 " — 0.280 — ( " " " " ) 

The last measurement is that of the smallest and youngest 
Danielsii 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 Jorm 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 


with alternate brownish bands. It is striking to note such a close 
likeness of its shell to that of Uniomerus tetralasnia 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 Danielsii, 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 Danielsii 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 grandis after all. 

Anodonta Bealei Lea. 
("Beale's Shell.") 

Not figured. 

1863 — Anodonta bealei Lea, Pr. Ac. N. Sci. Phila., VII, p. 194; Jl. 
Ac. N. Sci. Phila., VI, 1866, p. 26, PI. IX, fig. 25. 

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. Bealei 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 

Genus, Anodontoides Simpson. 
1898a — Anodontopsis Simpson (in Baker), Tr. St. Louis Ac. Sci., 

VIII, p. 76. 
1898b — Anodontoides Simpson (in Baker), Moll. Chicago, p. 72. 


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

' o 

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. 


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, Jerussaci- 
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 

Anodontoides ferussacianus (Lea). 
("Ferussac's vShell.") 
PL III, Figs, ya—Sa. 

1834 — Anodonta ferussaciana Lea, Tr. Am. PhiL Soc. V, p. 45, pL 

VI, fig. 15. 
1898 — Anodontoides ferussacianus (Lea) Baker, MolL Chicago, 

Pt. I, p. 72, pL III, fig. 6; V, fig. 2. 


According to Dr. Ortmann (1912b, 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 
i8iib, pi. 89, fig. 12) are described as rather small (0.320 x 0.320 
mm.) for the subfamily, subtriangular and spined. 


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- 


times rayed; hinge teeth rudimentray, usually lacking; muscle 
scars faint, confluent; nacre whitish or pearl blue. 

Length Width Diameter Um. ra. Locality 

48 X 29 X 18 — 0.280 — (Miss. R., Hannibal, Mo.) 
47 X 28 X 20 — o.285o-(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. ferussacianits 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 Mai., p. 382. 


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. 

t2o The naiades of Missouri 


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.") 

PI. XXIV, Figs. 79 A—D. 

1830 — Unio calceola Lea, Tr. Am. PhiL Soc, III, p. 265, pL IIL Fig. i 
1898 — Alasmodonta deltoidea Baker, MolL Chicago, Pb. I., p. 63, 

PL VI, fig. 2; VII, fig. 4- 
1900b — Alasmidonta calceola (Lea) Simpson, LT. S. Proc. Nat. Mus . 

XXII, p. 668. 


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 121 

Sex Length Width Diameter Locality 

35 X 24 X 18 " — (White R., Hollister, Mo.) 
cf 26 X 18 X 10 " — (Jack's Fork, Shannon Co.) 
9 18 X II 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 

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. 78 A and B. 

1819 — Alasmidonta marginata Say, Nich. Inc., No. i. 
1843 — Alasmidonta corrugata DeKay, Zool. of N. Y., Pt. 5, p. iQi< 
PI. XXIV; fig. 259. 


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 


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.). 


1 , ^ 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 full, 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 
kV^' 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 X 34 mm — (Gasconade, R., Gascondy, Mo.) 
cf 60 X 31 X 24 " — ( " " " " ) 

9 66 X 35 X 24 " — (Jack's Fork, Shannon, Co. Mo.) 
9 37-5 X 21.5 X 11.5 " — ( " " " " " ) 

The juvenile of this last measurement presents the same 
sculpturing as in the juvenile calceolus except that the bars are 
somewhat more elongated in niarginata 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 vSimpson. 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 niarginata is found in the Miss- 
issippi north of the Missouri River. The author has records of 

the; naiades of MISSOURI 


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 long 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 placeniulae by Ortmann.) 

Shell Characters: — Shell, subrhomboid to subelliptical, 
subsolid, inflated, with low post-umbonai 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 5. edentulus. 

Strophitus edentulus (Say.) 
("Squaw-Foot," "Creeper.") 
PL XXIV, Figs. 8u 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. 


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


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 vStructurES: — 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). 


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 
9 95 X 55 X 38 — mm — 0.360 — (Marais des Cygnes R., 

Rich Hill, Mo.,) 
27 — mm — 0.430 (Osage R., Linn Cr.,) 
14 — mm — 0.330 (102 R., Wyeth, Mo.,) 
13.5 — mm — 0.335 (Grand R., Darlington.) 

The last two measurements are those oj the only shells oj eden- 
tuhis jound in the interior north oj 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: — 5. edentulus is rather easily 
recognized even through casual observation by its somewhat 


77-5 X 

45-5 X 


34 X 

20 X 


41 X 

24 X 


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 itg 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 jragilis; 
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 


ol 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 Propterc 
("ax-head") and Lmnpsilis ("apron-form") types, varying much 
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, etc. 

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 aeration due to the action of papillae, car- 
uncles, flaps, etc. 

1. EUipsaria-Groiip. Marsupium most primitive in that 
the whole outer gill is occupied; yet advantage is secured for the 
aeration 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 E. 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 Cy progenia Aherii (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. 


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 difi'erentiation 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 
Unioninae, 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 — Ptychohranchus Simpson, Proc. Ac. N. Sci. Phila., p. 79. 

'^Type, Ellipsaria fasciolaris Rafinesque 1 820 = phaseolus 
Hildreth, 1828). 


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 
Lampsilinae, like those of Anodontinae and some genera of Union- 
inae, 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 /rom 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.") 

PI. XXV, Figs. 81 A and B. 

1900a — Ptychobranchus clintonensis Simpson, Pr. Acad. Nat. Sci. 

Phila., Ft. r, p. 79, pi. v., fig. 3; 1900b, Proc. U. S. Nat. IVIus., 

XXII, p. 613. 
1906 — Ptychobranchus cluitonense (Simpson) vScammon, vSci. Bull, 

Univ. Kans., Ill, p. 319. 

Animal Characters: — Identical with those of the type for 
this genus as to its nutritive structures and also as to the repro- 


ductive as far as able to determine from sterile material that is 
only at hand. Glochidia not known. 


External Structures: — vShell 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 

9 95 X 50 X 28 (Spring R., Webb City) 

9 86 X 44 X 25 (White R.. Hollister) 

c? 85 X 45 X 24 (Jack's Rork, Shannon Co.) 

9 60 X 30 X 17.5 (White R., Hollister) 

This last specimen being yotmg 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 E. 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 Naiades 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, 


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 { = phaseohis) of the Tennessee 
drainage for the Southwest. 

Genus Obliquaria Rafinesque. 

1830 — Obliquaria Rafinesque, Ann. Gen. Sci. Phys. Bru.x., 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 

Shell Characters: — Shell 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 

Miscellaneous Remarks: — 0. 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, pi. XXXVI, fig. 23) is the Pty. clintonense Simpson (1900-a and b) 
and hence this species, whose type locality is the Current River, Missouri, 
should be: — Ellipsaria occidentalis (Conrad), 


described above and is not often seen among the Naiades. In 
that there are not such advantages for the aeration 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.") 

PI. XXV, Figs. 82 A—F. 

1820 — Obliquaria (Quadrula) reflexa Rafinesque, Ann. Gen. Sci. Phys., 
p. 306; Chenu. Bib. Conch., ist ser., Ill, 1845, p. 19. 

1823 — Unto cornutus Barnes, Am. Jl. Sci., VI, p. 122, pi. 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. 


Nutritive Structures:— Branchial opening large with light 
colored papillae on a black back-ground; anal crenulated; supra- 
anal 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 vStructures: — 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- 







55 X 




45 X 




26 X 




15 X 




14-5 X 


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. 

Diameter Locality 

35mni (Platte R., Platte R. Station) 

30mm (Marais des Cygnes, Athol) 

17mm (Platte R., Dixon Falls) 

12mm (Miss. R., Hannibal) 

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 0. reflexa is rather primitive, but as to marsupial 
characters it naturally falls under the lower groups of the Lampsi- 
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 (19 12, 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 late 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 



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. 60Q. 

(Type, Unio irroratus 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. 
Aberii (Conrad). The variety of irroraia pusilla of vSimpson, is so 
doubtfully reported for the St. Francis River that it is not listed 
here. Simpson is of the opinion that all C. irrurata, reported for 
the localities west of the Mississippi, are really C. Aherti. As to 
soft parts there is a similarity to those of Ohliquaria; however, 
the slight difi"erentiation 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, pi. LXXXII, figs. 4, 5) we should make C. irrorata 
(Lea) a synonym for C. stegaria (Raf.) 


Cyprogenia Aberti (Conrad.) 

("Young Fan-Tail.") 
PL XXV, Figs. 83 A and B. 

1850 — Unio aberti Conrad, Pr. Ac. Nat. vSci. Phila., V, p. 10; 1854, 

Jl. Ac. Nat. vSci. Phila., p. 295, pi. XXV, fig. I. 
1885— ;7nzo popenoi Call, Bull, Washb. Col., I, p. 49, pi. II. 
1900b — -Cyprogenia aberti (Conrad) Simpson, Proc. U. vS. Nat. Mus., 

XXII, p. 610. 


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 arotmd 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 vStructurEs: — 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 ra3^s 
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 

cf 42 X 32 X 16.5 (St. Franci.s R., Greenville 

9 40 X 32 X 16.0 (White R.. HoUister) 

cf 37 X 30 X 14.5 ( " 

V 30 X 22 X II. o ( '■ ■ ' ; 


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. Aherti is a rather common 
little shell in the White, Black and Neosho basins of this State. 
It is distinguished from C. irrorata 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 irrorata, 
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. 


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: — Although 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 defined enough to be retained. 

Thus we have the following grouping: — 
I. — Sub-Genus Obovaria {seyis. strict.) 

Shell upright, oval, rather solid; beaks drawn up more 
toward the middle of the dorsal line; cardinals mostly tiormal. 
Type, 0. retusa (Lamarck.) 
2. — Sub-Genus Pseudoon Simpson (1900b, p. 601). 

Shell oblique, elliptical, solid, thick; beaks protruding 
anteriorly; cardinals subparallel to laterals. 
Type, 0. 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 i;- 


only represented in this State by ellipsis and that in a limited 
distribution both in the geographical and individualistic sense. 

Obovaria (Pseudoon) ellipsis (Lea). 

("Missouri Nigger-Head," "Egg Shell," "Hickory Nut.") 

PL XXV, Figs. 84 A and B. 

1S28— Unto ellipsis Lea, Tr. Am. Phil. Soc, III, p. 268, pi. IV, fig. 4. 
1900b — Obovaria ellipsis (Lea) Simpson, Proc. U. S. Nat. Mus.; 1912b, 
Ortmann, Car. Mus., VIII, pp. 323-324. 


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-elHptic, 
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 StrucTur-ES: — 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 



Sex Length Height Diameter Locality 

9 80 X 61 X 47 (Grand River, Sumner) 

cf^ 70 X 55 X 39 (Mississippi River, Hannibal) 

9 65 X 52 X 41 (Osage River, Warsaw) 

cf 30 X 24 X 18 (Mississippi River, Hannibal) 

9 2': X 20 X 14 ( " " " ) 

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 giv^e 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 
oj this opening into the anal. The bare connection between the two 
openings wou'd 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, IL P- 556; 
1900b, Simpson, Proc. U. S. Nat. Mus., XXH, 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 




to yellowish, generally with very distinct green rays; sex dimor- I 

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 Ohovaria and Nephronaias. Chiefly 
because of the lack of much specialization of the mantle border 
antero-ventrad to the branchial opening Unio ligam'entina (Lam.) 
is taken out of Simpson's grouping of it as a Lampsilis. In this 
State this genus is best represented by N. liganientina and ellipsi- 
jormis (Lea). 

Nephronaias ligamentina (Lamarck). /' 

PI. XXV, Figs. 85 A and B. 
1 8 19 — Unio ligamentina Lamarck, An. San. Vert., VI, p. 72. 
1900 — Lampsilis ligamentina Simpson, Proc. U. S. Nat. Mus., XXII, 
P- 539- 

1912b — Nephronaias ligamentina (Lam.) Ortmann, An. Car. Mus., 
VIII, p. 325. 


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. 




































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 

(Marais des Cygnes, Rich Hill) 
(Meramec R., Meramec Highlands) 
(Osage R., Osceola) 
(Gasconade R., Gascondy) 
(St. Francis R., Greenville) 
(St. Francis R., Greenvile). 

These last two measurements are those of two hyssijerous 
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 A^^. ligamentina may have 
the widest general distribution of the North American Naiades, 
yet it is not found anywhere in the interior oj 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 


except A^. ellipsi formis when the former is young. However, the 
more elliptic shell with broader, straighter rays would serve as 
the main distinguishing features. vSurber (1913, p. 109) has found 
that its glochidium is a gill parasite upon the white bass {R. 
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 (vSimpson). 

1900b — Lampsilis ligamenliuus gibbus Simpson, Proc. U. S. Nat. Mus 
XXII.p. 540. 

("Southern Mucket," "Yello\Y 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 

Sex Length Height Diameter Locality 

cf 85 X 60 X 40mm (Osage R., Monegaw Springs) 

9 80 X 64 X 40mm ( " " Linn Creek) 

9 89 X 70 X 38mm ( " " Bagnell) 

Miscellaneous Remarks: — Gihha 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, gihha, 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 

Nephronaias ellipsiformis (Conrad). 


PI. XXV, Figs. 86 A—D. 

1836 — Unto ellipsiformis Conrad, Monog. VIH, p. 60, pi. XXXI\', fig. I. 
1845 — Unio spatulatus Lea, Proc. Am. Phil. Soc, IV, p. 164. 
1898 — Lampsilis spatulatus Baker, Moll. Chicago, Pt. I, p. 106, pi 
X, fig. 5; pi. Xin, fig. 2. 


1900b — LampsHis ellipsijormis Simpson, Proc. U. S. Nat. Mus., XXTl, 
P- 557- 


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-s'haped; 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 

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 

cf 56 X 33 X 22.5mm (Gasconade R., Gascondy) 

cf 43 X 28 X 21.5mm (Osage R., Warsaw) 

9 41 X 25 X 17.5mm ( " "., Proctor) 

9 35 X 22 X 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 


daily throughout July and the first two weeks of August to find 
them sterile in every case. Since Wilson and Clark (191 2, 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 — Unio venustus Lea, Tr. Am. Phil. Soc, VI, pi. 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- 
/orm w-shell except for a small guttered furrow just antero-parallel 
to post umbonal-ridge of shell. The male shell of this sub-species 
is also more pointed posteriorly than the male type species. 
Sex Length Height Diameter Locality 

cf 60 X 37 X 22mm (Niangua R., Hahatonka) 

9 55 X 31 X 22mm ( " " " ) 

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 
ellipsiformis. The type locality for U. venustus of Lea is Potosi, 
Washington County, Missouri, and belongs to the Meramec River 
basin. Simpson (1900b, 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 A", ellipsiformis there should 
be no hesitancy in naming venusta as a variety. From N. pleas ii 
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 — Unto pleasii Marsh, "The Observer" (a newspaper), II, May; 
Nautilus, V. p. 2. 

iQOob — Lampsilis pleasii Simpson Pr. U. S. Nat. Mus., XXII, p. 557. 

Animal Characters: — No females have been secured bv the 


writer; however, the nutritive structures of the males are identical 
with those of N. ligamcntina and cllipsiforniis. 


External Structures: — Shell sub-elliptical, rather thin, 
smooth, somewhat compressed, rounded before, obtusely angular 
behind; beaks rather low, sculptured by three or four fine shaped 
undulations; epidermis brown polished horn, with numerous green 
capillary rays, disposed mostly posteriorly and showing through 
the thin shell 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, copper}^ or salmon in umbonal cavity. 

Sex Length Height Diameter LocaHty 

cf 55 X 21 X 13 mm (White R., Hollisterj 

cf 35-5 X 21.5 X 13.5mm ( " " " ) 

c? 30 X 18 X 12 mm (James R., Galena) 

Miscellaneous Remarks: — According to Mr. Marsh this 
shell bears some resemblance to Unio spatidatus Lea (i. e., U 
ellipsiformis 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 pkasii as a rather common shell in the White 
River, this State. 

Nephronaias ozarkensis (Call). 
("The Ozark vShell.") 

{Not figured.) 

1887 — Unio ozarkensis Call, Pr. U. S. Nat. Mus., X, p. 498, pi. XXVII; 
1895, Tr. Ac. Sci. St. Louis, VII, pp. 33-34, PI- XVIII. 

1900b — Lampsilis ozarkensis Simpson, Pr. U. S. Nat. Mus., XXII, 
P- .557- 

Animal Characters: — Reference to rough field notes show 


that the soft parts are those of Nephronaias. The shell was 
identified later as ozarkensis of Call. 


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 usuaPy white, 
sometimes salmon or pink, irridescent; muscle scars confluent. 

Sex Length Height Diameter Locality 

9 550 X 35.0 X 21.0 (Jack's Fork, Current R.) 

<^ 54-5 X 32.7 X 15.2 (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 th*^ 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. pleasit 
as to general outline, but is a little thicker and has a diflferent 
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- 
silis" are doubtless only Pleurohemae utterbackii 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. utterbackii 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 


(Type, Unto 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 smallest of all Naiades. 

Shell Characters: — Shell among the smallest, roundly 
triangular, inflated, flattened on post-dorsal slopes; post-umbonal 
ridge sharply angular; 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 Ohovaria 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. donacijormis (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.") 
PL XXV, Figs. 89 A—D. 

1828 — Unto donaciformis Lea, Tr. Am. PhiL Soc, iii, p. 267, pi. 
IV. Fig. 3. 

1820 — Unio zigzag Lea, Tr. Am. PhiL Soc, III, p. 440, p. XII, fig. 19. 

1898 — Plagiola donaciformis Baker, MoU. 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 


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 o.o6j min., semicircular, spineless, 
hinge line short, very slightly undulated; conglutinates white, loosely 
connected when glochidia mature. 


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 



The last two are among the smallest juveniles in the writer's 
collection. The smallest 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 donacijormis 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. 
Donacijormis is more supplanted in Central Missouri by truncata 




30 X 




22 X 




20 X 




8.5 X 


1 1 


7.0 X 



R., Gallatin) 


R., Dixon Falls) 

( " 

" Agency Ford) 


R., Darlington) 

( " 

" Chillicothc) 


(Raf.). but, as stated before, it takes the place of the latter wholly 
in North Missouri. The North Missouri Grand River bears dona- 
cijormis 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 live times the size 
of the glochidial one. Surber (1913, p. 109) finds that its specific 
distributor is "Sheep's Head" (^4. grunniens). 

Amygdalonaias truncata (Rafinesque). 

("Deer-Foot," or "Deer-Toe.") 

XXV, Fig. 88 A and B. 

1820 — Unio truncata Rafinesque, Ann. Gen. Sci. Phys. Brux. 

1831 — Unio elegans Lea, Am. Phil. Soc, IV, p. 83., pi. fig. 13. 

1898 — Plagiola elegans Baker, Moll. Chicago, Pr. I, p. 91, pi. XXI, 
fig. i; 1900b, Simpson, Pr. U. S. Nat. Mus., XXII, p. 604. 

1912b — Amygdalonaias elegans (Lea) Ortmann, An. Car. Mus., XXII, 
p. 328. 


Nutritive Structures: — Identical with those of donaciformis. 

Reproductive Structures: — Branchial mantle margin a 
little more thickened with slight crenulations than in donacijormis; 
glochidia a little larger, measuring 0.060 x 0.070 mm — otherwise 
these structures are identical with those of donacijormis. 

SHELL structures. 

External vStructures: — Shell short, roundly triangular, 
inflated; post-umbonal ridge sharply angulated from beaks to 
posterior point of shell; disk smooth; beaks rather prominent, 
sciUptured 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- 

Internal Structures: — With the exception of a deeper and 


more rounded out branchial cavity and somewhat coarser cardinals 
these structures are identical with those of donacijormis. 
Sex Length Height Diameter Locality 

c?' 50 X 36 X 25 mm (Osage R., Linn Creek) 

9 43 X 34 X 23 mm (Gasconade R., Gascondy) 

9 38 X 30 X 17 mm (Osage R., Schell City) 

cf 37 X 27 X 16.5mm ( " " Proctor) 

Miscellaneous Remarks: — As pointed out under the des- 
cription of donacijormis, 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 donacijormis. 
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 donacijormis as far as records 

Genus Plagiola Rafinesque. 

1819 — Plagiola Rafinesque, J. de Phys. Chim. Hist. Nat., p. 426; 
1852, Agassiz, Arch, Fur Nat., p. 48, (redefined); 1900b, Simpson, Pr. 
U. S. Nat. Mus., XXII, p. 603. 

(Type, Unio securis Lea.) 

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 


genus is in its peculiar shell and glochidial characters. As to its 
animal characters it is essentially that of Obovaria and Amyg- 
dalonaias. 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). 

(Butterfly.") . 
PL II, Figs. 3a— 6b. 

1829 — Unio securis Lea, Tr. Am. Phil. Soc, III, p. 437, pi. XI, fig. 17. 
1834 — Unio lineolata Say,' Am. Conch., VI. 

1900b — Plagiola securis (Lea) Simpson, Proc. U. vS. Nat. Mus., XXII, 
p. 603. 


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. 


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 

cf 96 X 79 X 33mm (Merame R., Meramec Highlands) 

9 70 X 56 X 37mm (Marais des Cygnes, Athol) 

9 67 X 53 X 30mm (Miss. R., Hannibal) 

cf 48 X 36 X i6mm ( " " 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 — Paraptera Ortmann, Mem. Car, Mus., IV pp. 331, 334, 338. 

(Type, Lasmonos Jragilis 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 


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 vState 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, 
Jor should it be found to he really congeneric with Jragilis, 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 IX, Fig. 19; PI. XXVI, Figs. 90 A—D. 

1820 — Lasmonos fragilis Rafinesque, Mono. Biv. of Ohio. 

1823 — Unio gracilis Barnes, Am. JL Sci., VI, p. 274. 

1861 — Unio dolosus Lea, 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. 


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 


and thickened on edges of siphonal openings, white patch at base 
oi 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, bookless, 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 

(Perche Cr., Columbia) 
(Grande R., Utica) 
(Platte R., Agency Ford) 
(102 R., St. Joseph) 
(Osage R., Colley's Ford) 

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 i6omm. long and was attached 














0.2 10 

















1 1 





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 

Miscellaneous Remarks: — L. jragilis is distinctly a river 
form for this State, although we would naturally think that this 
f^p- ' 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 Amygdalona]as donacijormis (L,ea) and A. elegans (Lea) 
with yvhich. jragilis 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; 



St. Lawrence system; Red River of the North; Eastern Texas 
and Cumberland River. 

Lasmonos simpsoni (Ferriss). 

(Simpson's vShell.) 
PL XXVI, Figs. 91 A and B. 
1900 — Lampsilis simpsoni Ferriss, Nautilus, xiv, p. 38. 

Animal Characters unknown to writer. 


External Structures: — Shell subovate, elongated, sub- 
solid, narrowly rounded in front, broadly rounded behind, some- 
what alated; disk smooth; beaks low, sculptured b}^ 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 

cf 78 X 46 X 28mm. (White R., Hollister) 
9 95 X 50 X 22 " ( " " " ) 

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 weU determined conchcologically. 
Future studies of its marsupial and glochidial characters of this 
species, as well as that of leptodon (=5. ieniussimus Lea), may 
classify it far differently, since shell characters are too liable for- 
parallelism and convergence as true bases of classification. 



Lasmonos leptodon? (Rafinesque). 
Not Figured. 

1820 — Unio (Leptodea) leptodon Rafinesque, Ann. Gen. Sci. Phys. 
Brux., p. 295, PI- LXXX. 

1829 — Symphynota tenuissima Lea, Tr. Am. Phil. Soc, III, p. 435, 
PI. XI, Fig. 21. 

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. Surety 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. Mus., VIII, p. 332. 

(Type, Unio alaius 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. leptodon 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 ) 


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., purptirata which 
only occurs in South Mo., laevissinia 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, would 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," 

"Pan Cake.") 

PL IV, Fig. iia. 

1816 — Unto alatus Say, Nich, Encyc, II, pi. IV, fig. 2. 

1898 — Lampsilis alatus Baker, MoU. Chicago, Pt. I, p. 97, pi. XVIII. 

1912b — Proptera alata (Say) Ortmann, An. Car. Mus., VIII, p. 2i33- 


Nutritive Structures: — Branchial and 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 



Fig. 8. Proptera alala (Say) 9. Diagram of a gravid individual from 

Platte River, Agency Ford, showing animal characters in left 

valve. Coll. June 7, 1913. (^ Nat. size.) 

crenulations; conglutinates large, broken with ova or glochidia 
all through the mass; glochidia large, ax-head shape, with spine 
at each ventral corner of shell (0.220 x 0.380 mm.). 

Fig. 9a. Lateral view of mature Fig. 9b. Anterior view of open 
glochidium of P. alata. (xSy.) glochidium of P. alata. (X87.) 



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 shells 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 

9 156 X 117 X 56.5 (Platte, R., Dixon Falls) 

cf 150 X 114 X 53.0 ( " ' Platte City) 

9 115 X 55 X 33.0 (Osage R., Warsaw) 

9 82 X 54 X 26.0 (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 — Unto purpurata Lamack, An. Sans, Vert., VI, p. 71. 

1900b — Lampsilis purpuratus Smpson, Pr. U. S. Nat. Mus., XXII, 
p. 568. 4 

1912b — Proptera purpurata (Lam.) Ortmann, An. Car. Mus., VIII, 
p. 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; — vShell large, rather elongate — ellip- 

( " " Forsyth) 

( " " Hollister) 

( " " " ) 


tical, inflated; disk smooth; beaks high and full; post dorsal 
ridge somewhat alated; post umbonal ridge biangulated; epidermis 
i^lossy 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 

o^ 120 X 75 X 53mm (White R., Hollister) 

9 125 X 70 X 44mm 

d' 83 X 56 X 40mm 

9 70 X 47 X 34mm 

Miscellaneous Remarks: — The young shells of P. purpurata 
are thin and fragile but later become thick and solid; resembling 
alaia 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 IX, Figs. 19 and 20; PI. XXVI, Figs. 94 A—D. 

1830 — Symphynota laevissima Lea, Tr. Am Phil See, III, p. 444, 
pi. XIII, fig. 23. 

1900b — Lampsilis laevissima Simpson, Pr. U. S. Nat. Mus., XXII, 

P- 5 74- 

1912b — Proptera laevissima (Lea) Ortmann, An. Car. Mus., VIII, 

P- 334- 


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 


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 
o.ioox 0.155mm; branchial mantle edge thickened, lamellar, but 
without palpilae. 


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; 

(102 R., St. Joseph) 
(Mud Lake, Kenmoor) 
(Platte, R., Agency Ford) 
(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/orm w wo^ 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 

solid purple. 

Sex Length 



cf 150 X 

105 X 


cf 145 X 

90 X 


9 137 X 

89 X 


9 41 X 

23 X 



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 shoivs the highest modern development of the siphonal 
openings, i. e., into the actual tubular J or m. (See Plate IX). This 
Species is distinctly bradytictic. 

Proptera capax (Green). 

("Pocket Book," "Swell Shell.") 

PI. XXVI, Figs. 93 A and B. 

1832 — Utiio capax Green, Cab. Nat. Hist., II, p. 290. 

1899 — Lampsilis capax Smith, Bull U. S. Fish Com., p. 291, pi. LXXIV. 


Nutritive Structures: — Branchial opening with rusty red 
papillae arranged in two ranks; anal finely crenulated; supra-anal 
large with two large tentacular structures 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- 

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 o.iSsmm. 


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, 


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 


Sex Length Height Diameter Locality 

d^ 10 X 82 X 65mm (Mississippi R.,Hanibal) 

9 95 X 75 X 66mm ( " " " ) 

9 66 X 50 X 42mm ( " " La Grange) 

Miscellaneous Remarks: — Capax has the most inflated 
shell of the Naiades, 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 laevissinia shell in the last 
stage of its parasitic life. Most of all, anatomical material kept 
by the writer, shows no mantle flap {PL XXVI, fig. gj B) as seen 
in L. ventricosa, nor as to be noted in any Lampsilis, and the mantle 
edge antero-ventrad to the branchial opening is not even as much 
specialized as in laevissinia, or alata; hence its place perhaps 
should precede laevissinia, 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, Unio 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. Mas., VIII, p. 337 (as subgenus). 

Animal Characters: — Branchial opening small with rather 


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. 

Sheel Characters: — -Shell very small, elliptic, rounded 
before, rather thick, disk smooth; beaks low, coarsely sculptured 
by regular concentric bars upcurved behind; epidermis dark 

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 Eitrynia, but even then he was inclined to consider 
it as merely conventional whether we use it generically or sub- 
generically. Carunculifia is remarkable for its smallest 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 typ^, 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 

Carunculina parva (Barnes). 

("Liliput Shell.") 

PL III, Fig. 8c; PL XXVII, Figs. 95 A—D. 

1823 — -Unio parvus Barnes, Am. Jl. Sci., VI, pi. 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. 


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- 


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 (xSy) lens, is cellular — each cell being hexagonal in 
shape; conglutinates white, discharged whole, club-shaped, 
glochidia medmm in size, sub-elliptical, hinge line straight, spineless, 
measures o.iyj x o.ioo. 


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 

* 38 X 23 X 19mm (Lake Contrary, St. Joseph — ) 
cf 27 X 13 X iimm (Pond, Columbia) 

* 25 X 13.5 X 11.5mm (Lower L. Contrary, St. Joseph) 

* 14.5 X 8.5 X 5.5mm (Singleton Lake, Halls) 

* 1 1.5 X 6.5 X 4.0mm ( " " " ) 

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 ivriter is able to bear out the 
statements of Drs. Sterki and Ortmann 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. 



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 Naiades. 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 
glochidiuyn and make more of a definite study than has been recorded 
since Lea left his sttidies. (Obs. XIII, 1874, pi. XXI, fig. 2.) 

Carunculina texasensis (Lea). 

("Texas Shell.") 

Not figured. 

1857 — Unio texasensis Lea, Pr. Ac. Nat. Sci. Phila., p. 84; Jl. Ac. 
N. Sci., IV, i860, p. 359, pl. XLI, fig. 184. 

1862 — Unio bealei Lea, Jl. Ac. N. Sci., V., p. 204, pl. XXX, fig. 273. 

1912b — Eurynia (Carunculina) texasensis Ortmann, An. Car. Mus., 
VIII, p. 339- 

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- 

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- 

Sex Length Height Diameter Locality 

cf 45 X 24 X 1 7. 5, mm (Lost Creek, Amity) 
9 37 X 20 X 1 2.0mm (Lost Creek, Amity) 

Miscellaneous Remarks: — Comparison to some types of 
texasensis from Wimberly Lake, Texas, assures the writer that 


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 a- 
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.) 

1S34 — Unio glans Lea, Tr. Am. Phil. Soc, p. 82, PI. VIII, fig. 12, 
Obs. X, 1863 p. 402. 

1900b — Lampsilis glans Simpson, Pr. U. S. Nat. Mus. XXII, p. 565. 

1912b — Eurynia {Carunculina) glans Ortmann, An. Car. Mus., VIII, 
P- 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 405) and also from Wilson and Clark's (191 2, 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). 


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 aeration 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 jahalis Lea.) 

1852 — Micromya Agassiz, Arch, fiir Nat., p. 57; 1912b, Ortmann, 
An. Car. Mus., VIII, p. 337. 

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 Jahalis of Lea of Micromya is not found anywhere in 
Missouri. The essentia) distinction between the two sub-genera, 
Micromya and Eiirynia (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. 


Eurynia (Micromya) lienosa (Conrad.) 

("I^ittle Spectacle Case.") 

PI. XXVII, Figs. 96 A—D. 

1834 — Unto lienosus Conrad, An. Jl. Sci., XXV, p. 339, pi. i, 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. 


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 subf alcate connected 
antero-dorsad about one-half of their length; color of soft parts 
soiled white except mantle edge of siphonal area blackish, gills 

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 o. 270 mm. 


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 

9 53 -^ 30 X 21.5mm (Black R., Williamsville) 

cf 50 X 30 X 2o.omm ( " " " ) 

o^ 42 X 26 X 17.0mm ( " " " ) 

9 29 X 18 X 1 1 .omm ( " " " ) 

ijo 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 stihrostrata. This species is only found 
in the Black River for this State. Rev. Wheeler considers lienosa 
as intergrading with nigerrinia and while the two are usually found 
in the same locality yet nigerrima 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 suhrostrata 
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 XXVII, Figs. 97 A and B. 

1830 — Unia iris Lea, Tr. Am. Phil. Soc, III, p. 439, pi. IX, fig. 18. 

1898 — Lampsilis iris Baker, Moll. Chicago, Pt. I., p. 105, pi. XIII, 
fig. I; pi. XIV, fig. 2. 

1912b — Eurynia {Micromya) iris (Lea) Ortmann, An. Car. Mus., 
VIII, p. p. 341 and 342. 

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 

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 — all 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-looped ridges; epidermis 


smooth reddish-brown with bright green rays arranged all over 
its shell. 

Interna:^ vStructurES: — Cardinals double in both valves, 
laterals double in left, single in right; beak cavities rather shallow; 
nacre white or light bluish. 

Sex Length Height Diameter Locality 

cT 45 X 22 X 15mm (Jack's Fork of Current R.) 

9 35 X 18 X lomm (White R., HoUister) 

9 34 X 16 X iimm (Black R., Williamsville) 

c? 22 X 12 X 7mm (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. 98 A~D. 

1887 — Unio breviculus Call, Pr. U. S. Nat. Mus., X, p. 499, pi. XXVIII; 

Tr. Ac. Sci. St. Louis, VII, (1895) p. 6, pi. XVI. 
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 


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, Brittsi. 


External Structures: — Shell 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 

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 

27 mm — (White R., Hollisterj 

22.5mm — ( " " " ) 

23 mm — ( " " " ) 

18 mm — ( " " " ) 

Miscellaneous Remarks: — This species is strictly a S. 
Mo. shell and its sub-species is only found in Central Missouri. 
vSome of the South Missouri streams bear hrevicula that almost 
approach Brittsi; however, brevicula is a rather common shell in 
the streams of the south 3lope 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. Brevicula is the largest, 
most emphatic member of the Micromya group. 

Eurynia (Micromya) brevicula Brittsi (Simpson). 

("Britts' Shell.") 

PI. XXVII; F.igs. 99 A and B. 

1900a — Lampsilis brittsi Simpson, Pr. Ac. Nat. Sci. Phila., p. 76, pL 
v., fig. I and 2; lyoo b, U. S. Nat. Mus. Pr., XXII, p. 533- 



















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, semi-elliptical, 
hinge line slightly oblique and undnlate measuring o.2joxo.jOj 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. 


External Structures: — Shell medium in size, thick to thin, 
subelliptical ; post-umbonal ridge lacking; beaks large but low- 
sculptured b)" 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-shaped 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 R., Hahatonka ) 

9 55 X 36 X 25mm — ( " " , " ) 

cf" 40 X 24 X 14mm — ( " " " ) 



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: — vSurely 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 w4de, 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. Brittsi 
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 Naiad shells now living in this State. 
This sub-species is bradytictic as inferred from the waiter's brief 
breeding record. He has had the good fortune to collect the glo- 
chidia oj 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 difl"erent 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 


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 Micromya 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) 
suhrostrata and rccia, both having rather wide distribution. 

Eurynia (Eurynia) subrostrata (Say). 

("Common Pond- Mussel," "Lilliputian.") 

PI. XXVII; Figs. 101 A—D. 

1 83 1 — Unio subrostratiis »Say, New Harm. Dips. 

1850 — Unio mississippiensis Conrad, Jl. Ac. N. Sci. Phila., i, p. 277, 

pi. XXXVIII, fig. u. 
1868 — Unio topekensis Lea, Pr. Acad. Nat. Sci. Phila., XII, p. 144. 
1900b — Lavipsilis sitbrostratiis Simpson, Pr. U. S. Nat. Mus., XXII, 

P- 546. 
1912b — Eurytiia (Eurynia) subrostrata (Say), Ortinann, An. Car. Mus., 

VIII, p. 344- 


Nutritive Structures: — Branchial opening narrowly papil- 
lose; anal finely 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; 


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 


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 

cf 62 X 27 X 21.5mm — (Flat Creek, Sedalia). 

9 65 X 36 X 25.5mm — (Hinkston Creek, Columbia) 

cf 50 X 28 X 15.5mm — (Lost Creek, Amity) 

9 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 3^oung 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: — Subrostrata 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. tetralasnia 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 


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.") 

PI. XXVII; Figs.joo A—D. 

1 819 — Unio recta Lamarck, An. Sans. Vert., VI, p. 74. 

1823 — Unio praelongus Barnes, Am. Jl. Sci., istser., VII, p. 261, fig. 11. 

1900b — Lampsilis rectus Simpson, Pr. U. S. Nat. Mus., XXII, pp. 

1912b — Eurynia {Eurynia) recta (Lam.) Ortmann, An. Car. Mus., 

VIII, p. 344. 


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. 


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 

' This Species is the most generally distributed of the Lampsilinae. 
(See accompanying Map (Plate XXIX) for three other generally distributed 
Species; viz., Cumberlandia monodonta {Say) as representative of Margari- 
tanidae, Quadrula verrucosa {Raf.) of Unioninae and Strophitus edentulus 
{Say) of Anodontinae. 



subrostrata; epidermis black, glossy, rayed with broad reddish 

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 

Sex Length Height Diameter Locality 

<f 125 X 53 X 31mm — (Black R., Williamsville) 

9 109 X 48 X 30mm — (Osage R., Osceola) 
cf 96 X 40 X 25mm — (Gasconade, Gascondy) 
9 78 X 30 X 1 8mm — (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 fiuviatile. 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 brad3rtictic. 

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- 


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 brillian^tly 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 difl^rentiation 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 
aeration 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.") 
PI. VIII, Figs. 17 A and B; PI. XXVIII, Figs. 102 A—D. 

1834 — Unto anodontoides Lea, Tr. Am. PhiL Soc, IV, p. 81, pi. VIII, 

fig. II- 
1834 — Unio teres Say, Am. Conch,. VI; 1820, Rafinesque, Monog. 
1898 — Lampsilis anodontoides Baker, Moll Chicago, Pt. I, p. 100, 

pi. X, fig. I. 

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 Umo teres {Elliptio teres) Lea's name, 
as given here by Simpson, (1900b, p. 543,) should stand as a synonym for 
Lampsilis teres (Raf.). 


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 ^ 0.210 mm. 


External Structures: — Shell 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 

cT^ 120 X 60 X 45mm — (Chariton R., Kern) 
9 100 X 50 X 38mm — (Miss. R., Hannibal) 
50 X 23 X i6mm — (Grand R., Darlington) 
12.5 X 6 X 5nim — (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. 

Mi'CELLANEous 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 jallaciosa 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 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 hy J allaciosa. 
From the writer's breeding record for this species it is bradytictic. 

Lampsilis f allaciosa Smith. 

("Slough Sand Shell," "Creeper.)" 

PI. VII, Figs. i8 A and B. 

1899 — Lampsilis fallaciosa Smith, Bull. U. S. Fish., p. 291, pi. LXXIX; 
1900a, Simpson, Pr. Ac. N. Sci. Phila., p. 74, pi. II, fig. 5. 

Animal Characters: — Identical 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 

mm — (Lower L. Contrary, St. Joseph) 
mm — (Chariton R., Kern) 
mm — (Miss. R., Hannibal) 
mm — (Osage R., Warsaw) 
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 




45 X 





30 X 





31 X 




245 X 




7-5 X 



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 difTerence in size of glochidia, those of Jallaciosa being 
larger (0.200 x 0.240 mm.) than those of anodontoides (0.185 x 

Surber (1913 p. 107) also reports that this species {jallaciosa) 
has for its fish host the erappie (P. platorhynchus) its glochidium 
being a gill parasite. 

Lampsilis Higginsii (Lea). 
("Higgin's Shell.") 
PL XXVIII, Figs. 105 A and B. 

1857 — Unio higginsii Lea, Pr. Ac. N. Sci. Phila., IX, p. 84. 

1900b — Lampsilis higginsii 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 (19 12 p. 9) reports its glochidium as sub- 
elliptic, spineless, with hinge line short and measures 0.210 x 
0.260 mm. 


External Structures: — Shell very thick; male sub-elliptic; 
female subrhomboid with posterior end vertically truncate; beaks 
very large, rovmded, 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 

cf 86 X 63 X 45mm — (Mississippi R., Hannibal) 

9 68 X 50 X 38mm — ( " " " ) 

cf 85 X 48 X 48mra — { " " Louisiana) 

The naiades of MISSOURI 183 

Miscellaneous Remarks: — According to Simpson this is a 
puzzling species that closely resembles 0. 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 
"Sanger" (S. canadense) as its fish host. 

Lampsilis Powellii (Lea). 

("Powell's Shell.") 

Not figured. 

1852 — Unio powellii Lea, Pr. Am. Phil. Soc, V., p. 252; Tr. Am. Phil. 
Soc, X, p. 270, pi. XIX, fig. 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 


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 vSprings, 
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 Powellii 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.") 

PL XXVIII, Figs. 103 A—F. 

1819 — U7iio luteola Lamarck, His. Sans. Vert., VI, p. 79. 
1898 — Lampsilis luteola Baker, Mol. Chicago, Pt. I, p. 103, pi. XI, 
fig. 12; pi. XXXVII, fig. 12. 


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 posteriorl3\ 

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 luteola), subelliptic, spineless, 
measuring 0.250 x 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. 


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 
right; laterals doubled the same; nacre white. 

Sex Length Height Diameter Locality 

9 1 10 X 65 X 48mm — (Flat Creek, Sedalia) 

cf 130 X 68 X 48mm — ( " " " ) 

9 82 X 46 X 30mm — (Black R., Williamsville) 

cf 54 X 30 X 17mm — (White R., HoUister) 

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 (191 2, p. 4) and 
thinks that the larger size of the river form may be correlated with 
the larva. Luteola is bradytictic. 

Lampsilis luteola rosacea (DeKay). 

("Rosy Mucket.") 
PL XXVIII, Figs. 104 A and B. 

1843 — Unio rosaceus DeKay, Zool. of New York, V., p. 192, pi. XXXIV, 

figs. 355 and 356. 
1900b — Lampsilis luteolus rosaceus (DeKay) Simpson, Pr. U. S. Nat. 

Mus., XXII, p. 535. 

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 

cf 125 X 72 x 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 


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 
hiteola from the southwest. The Great Lakes form, rosacea DeKay, 
is typically red or rather pink." 

Lampsilis reeviana (Lea). 

("Reeve's Shell.") 
No/ figured nor described. 

1852 — Unio reevianiis Lea, Tr. Am. Phil. Soc, X, p. 272, pi. 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.") 
PI. XXVIII, Figs. 106 A—-D. 

1823 — Unio ventricosus Barnes, Am. Jl. Sci., VI, p. 267, pi, XIII, 

fig. 14. (in outline). 
1900b — Lampsilis ventricosus Simpson, Pr. U. S. Nat. Mus., XXII, p. 



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, 1. c, (fgis, 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, PI. 80, Figs. 
16, 17, 18 and 19, as now identified from Types in the A. N. S. P. Coll., 
No. 20, 210. 



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. 


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 

9 100 X 65 X 45 mm — (Gasconade R., Gascondy) 

cf 90 X 65 X 42mni — (Black R., Williamsville) 

cf iio X 39 X 26mm — (Osage R., Osceola) 

9 55 X 39 X 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 
vmltiradiata 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. Muliira- 
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 



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. Veniricosa 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. vSouth of the Missouri it is one of the com- 
monest of shells. 

' Lampsilis ventricosa satura (Lea). 
("Plain Pocket Book.") 
PL XXVIII, Figs. loy A—B. 

1852 — Unto satur Lea, Pr. Am. Phil. Soc, V., p. 252; Tr. Am. Phil. 

Soc, X. 1852, p. 205, pi. XXVII, fig. 19. 
1900b — Lampsilis ventricosits satur (Lea) Simpson, Pr. U. S. Nat. Mus. 

XXII, p. 527. 

Animal Characters: — Identical in every way to the parent 

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 

9 88 X 55 X 45mm — (Black R., Williamsville) 
cf 75 X 54 X 42mm — (White R., HoUister) 

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 Blufl". The writer collected 
some of these forms of ventricosa from the same stream a few miles 
north. The Black is a metropolis for veniricosa where it is found 
in all forms, since this species is liable to intergrading — satura 
being one of these intergradations. Yet its rayless character (like 
that of capax) would make it worthy of a name. 


Genus Truncilla Rafinesque. 

(Type, Truncilla triqueter Rafinesque). 
1819 — Truncilla i^afinesque, 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 tnost recent classification of the Unionidae is based 
primarily upon the modification of the marsupium and that Ihc 
genus Truncilla has carried out this sexual difi"ercntion to the 



greatest extent, Walker (1910c pp. 75-81) gives us the following 
systematic arrangement of Triincillae on the basis of reproduction: 

I. — 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. i4a-d; PL XXVIII, Figs, ioq A—D. 


Nutritive StructuTES: — Branchial opening densely bordered 
with papillae; anal crenulated; supra-anal high, rather small, 
separated from anal by moderately short mantle connection, 
rnantle 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 gra3dsh 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 


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 15 mm — (White R., HoUister, Mo.) 

cf 22.5 X 19.5 X 13.5mm — (White R., Holilster, Mo.) 

9 26.5 X 18.5 X 14 mm — (White R., Hollister, Mo.) 

Miscellaneous Remarks:- — The position of this interesting 
species is exactl}^ between capsaejormis Lea and hiemargiatus 
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 capsaejormis and our shell is not so regularly 
rounded behind. From hiemarginata our species may be differen- 
tiated by its lack of pronounced angles and ridges of the former 
and b}' 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 
capsaejormis. 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, 19 13, and is named in 
honor of Dr. W. C. Curtis of the Department of Zoology, Univer- 


sit}^ of Missouri. The type shells, Avhich are line-drawn and also 
photographed herewith, are now in the /possession of Mr. 

Truncilla Lefevrei' Utterback. New Species. 

("Lefevre's Shell.") 
PI. VI., Figs. 13 a—d; PL XXVIII., Figs. 108 A—D. 


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 
entirel}^ 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 evidentl}^ as a water reservoir; no conglutinates nor 
glochidia observed. 


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 

'As 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 eflforts 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). 


out sculpture. Female shell broader posteriorly, marsupial expan- 
sion formed post-ventrad, above basal line ]ust anterior to post- 
umbonal rtdge 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 

9 32 X 21 X ismrn — (Black River, Williamsville) 
cf 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 T. triquetra, 
but comparisons to actual shells of typical triquetra show that it 
is placed in the third group of Truncilla 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. Lefevrei diflfers 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, Curtisii 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 Naiades in their monumental work, "Studies on 
the Reproduction and Artificial Propagation of Fresh-Water Mussels." 

(The End) 



1898b — Baker, F. C. — The Mollusca of Chicago Area. The Pelecypodc. 

(Nat. Hist. Survey of the Chicago Acad, of Sci., BuU. No. 3, Pt. i . 
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 Unionidae of Arkansas with Incidental 

Reference to their Distribution in the Mississippi Valley. (Tr. 

St. Louis Acad. Sci., VII, No. i, pp. 1-65, 21 plates). 
191 2 — 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.— The Unionidae of DeSoto Parish, Louisiana. 

(Reprint from Gulf Fauna and Flora., Bull., I, No. i.) 
1901 — Frierson, L. S. — A New Unio from Texas. (Naut., 15, pp. 75-76). 
1904 — Frierson, L. S. — Observations on the Genus Quadrula (Naut. 17, 

pp. 1 1 1 and 1 12). 
191 1 — Frierson, L. S. — A Comparison of the Unionidae of the Sabine 

Rivers (Naut., XXIV, pp. 134-136). 
1 914 — Frierson, L. S. — Remarks on Classification of Unionidae. (Naut., 

XXVIII, pp. 6-8.) 
1900 — Ferriss, J. H. — A New Arkansas Species {Lampsilis Simpsoni) (Naiit. 

XIV, p. 38). 
1 91 2 — Hannibal, Harold — A Synopsis of the Recent and Tertiary Fresh- 
water Mollusca of the California Province. (Proc. Mala. Soc. 

Lon., X, pp. 112-166, Pt. II; pp. 167-211, Pt. III). 
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.) 
191 2 — 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). 
191 4 — Isely, F. B. — Mussel Streams of Eastern Oklahoma. (U. S. B. F., 

Ec. Cir., No. 9). 
1913 — Israel, Von W. — Biologic 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, 



183 1 — Lea, Isaac — Observations on the Naiades. (Tr. Am. Phil. See, 

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. 

(Tr. Am. Phil. Soc, pp. 252-294). 
1862 — Lea, Isaac — Description of Ten Unionidae of United States. (Pr. 

Acad. Nat. Sci. Phila., pp. 168 and 169). 
191 2 — Lefevre, Geo. and Curtis, W. C. — Studies on the Reproduction and 

Artificial Propagation of Fresh-water Mussels. (U. S. B. F., 

XXX, Doc, No. 756). 
1906 — Lindahl, Josua — Orthography of the Names of the Naiades. (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 Pleasii) (Naut., V, pp. 1-2; 1892, VI, pp. 1-2: 

1893, VII, p. I. pi. I. 
1 901 — Marsh, W. A. — Description of a New Unio from Missouri. {P. mis- 

sourensis, n. sp.) (Naut., XV, pp. 74-75). 
191 2 — Meek, S. E., and H. Walton Clark— The Mussels of the Big Buflfalo 

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). 
1911a — Ortmann, A. E. — The Anatomical Structure of Certain Exotic 

Naiades 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 Naiades 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., 

V, pp. 74-77)- 
1901 — Pilsbry and Fox. On Alasmidonta marginata. (Naut. 15, pp. 16 and 

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. — Monographic 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; el 

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. ,111, pp. 279-373.). 

c ' 


1 913 — Shira, A. F. — The Mussel Fisheries of Caddo Lake and the Cypress 

and Sulphur Rivers of Texas and Louisiana. (U. S. B. F. Econ. 

Cir., No. 6). 
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 Unionidae. (Pr. Acad. N. 

N. Sci. Phil., Vol. 52, pp. 74-86). 
1900b — Simpson, C. T. — Synopsis of the Naiades 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 Unio. (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 

Mollusca 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. — MoUusks of Thompson Lake, Illinois. (Naut., IV, 

PP- 133-134)- 
1891b — Strode, W. S. — Mollusks of Spoon River, Illinois. (Naut., V., pp. 

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. 

(U. S. B. F., Doc. No. 771). 
1913 — Surber, T. — Notes on the Natural Hosts of Fresh-water Mussels. 

(U. S. B. F. Bull., XXXII, No. 778). 
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., 

XXX, No. 2, pp. 13-21.) 
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). 


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). 
i9i2b~Wilson, C. B. and H. Walton Clark — The Mussel Fauna of the 

Maumee River. (U. S. B. F. Bull., No. 757). 
191 2 — Wilson, C. B. and E. Danglade — The Mussels of Central and Northern 

Minnesota. (U. S. B. F. Econ. 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 MoUusks 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. 

1902 — Wright, B. H. and Bryant Walker — Check List of the North American 

Naiades. (Detroit Pub. Co.). ?^ 



(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 Naiades," — 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 Lefevrei, 
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 19, for "marsupial" read "marsupia"; line 40, for 
" Magnonaias" read " Megalonaias" ; line 44, for " Schoolcraftensis" read 
" schoolcraftensis." 

Page 8, line 16, for " Cooperianus" read " coo peri anus." 

Page 9, line 7, for "Genus XII" read "Genus XIII"; line 19, for 
" Ferussacianus" read "ferussacianus"; line 29, for "Genus VXII" 
read "Genus XVII". 

Page ID, line 39, for " texensis" read " texasensis." 


Page II, line 12, for " Curtisi" read " Curtisii" (This latter inflection 
really should occur for all Latinized substantives derived from names ot 
persons terminated by a consonant). 

Page 19, line 25, insert "inner" before "usually." 

Page 20, line 11, for " Unionae" read " Unionidac" ; 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 
"Plates I and I" read "Plates I and IT". 

Page 29, line 21, insert next line below this reference: — "PI. XV., 
Figs. 34A and B". 

Page ;i:i, 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 
" quintardi" read " Quintardii (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 as in Amblemae". 

Page 48, line 10, for "charasterized" read "characterized". 

Page 49, line 4, for all statements of " Quadrula pustulosa {Lea)" 
read " Quardrula hullata (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 " wardii" read " Wardii" (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" (All 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, betw^een " 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 10, 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". 


Page lOo, line 2, for "climed" read "claimed"; line 27, for " Ptero- 
sygna" read " Pterosyna" . 

Page loi, line 19, 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 
Raf.);" line 36, separate "outer " and "and". 

Page 105, line 26, for "p." read "PI."; line 36, for " pericardinal " 
read "pericardial". 

Page 106, line 10, omit comma after "distinct" and supply after 
" veining". 

Page 107, in Text- Fig. 7, transpose "An" and "PO". 

Page III, line 33, for "brownsih" read "brownish-yellow". 

Page 112, line 22, for "moss" read "mass"; line 33, for "mosses" 
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". 

Page 119, line 30, insert next line below: — " {Alasmidonta undulata 
Say) ". 

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 

Page 129, line 34, for "facsiolaris" read "fasciolaris" ; as indicated 
in Foot-note for this page, for all statements of " EUipsaria clintonensis 
{Simpson)" read "EUipsaria 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 

Page 143, line 30, for " pleasii" read " Peasii" ; (do. page 144, line 
29; do. page 145, line 20); line 32, for "clolored" read "colored". 

Page 145, line 26, for " utterbackii" read " UUerbackii" ; (do. line 31). 

Page 148, line 18, insert "IX" after "pi". 

Page 152, line 15, for " simpsoni" read " Simpsoni" ; (do. page 155, 
line 3). 

Page 153, line 38, for "bysuss" read "byssus". 

Page 155, .line 34, for " leniussimus" read " tcnuissimiis" . 

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 " Propt:ra" . 

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:— 


Shell Characters: — Shell elliptical, small or medium, beak sculp- 
ture rather double-looped or distinctly sinuate with posterior sinuation 
somewhat open. 


(Plates I— XXVIII.) 

PI. I, Fig. 2, for "vavel" read "valve". 

PI. II, Fig. 5a, Supply label 4, i. e., "Extreme dorsal point." 

PI. V, Fig. 12b, for " Utterbacki" read " Utterbackii" ; do. PI. XX, 
Figs. 63 A — D. 

PI. VI, Figs. 14 a— d, for " Curtisi" read " Ciirtisii" \ do. PI. XXVIII, 
Figs. 109 A — D. 

PI. IX, Fig. 19, After "feeding" supply comma and "respiring". 

PI. XIII, Fig, 26, Supply "-Hundred" after "One;" do. PI. XXVI, 
Fig. 90. 

PI. XVI, Figs. 38 A — D, for " Quintardi" read " Quintardii" . 

PI. XIX, Fig 52, for " cylindirca" read " cylindrica" . 

PI. XXV, Fig. 81, for " clintonesnsis" read " clintonensis" . 

PI. XXVIII, Fig. 107, for " ventricoas" read "ventricosa" 




Marsupium differentiated with 
special ovisacs mostly arranged post- 
eriorily near the post-ventral mantle 
margin specialized with crenulations, 
papillae, etc. ; only outer gills marsu- 
pial; glochidium Lamp'u'lis Type; 

Proptera Type 
(Intermediate to 
modern form) of 
glochidium: Axe- 
head shape, spin- 


MarsujMum differentiated with lat- 
eral water tubes when gravid; j^ost- 
ventral mantle margin undifferenti- 
ated; alMour gills marsupial; gloch- 
idium A)wdon!a Type: hradytictic. 

The Spineless 
glochidia are fol- 
lowed in the adult 
life by perfect 
and complete 
hinge teeth. 

Lamps His 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. 

Anodonta Type 
Form) of glochid- 
ium: Subtriangu- 
lar. spined, fol- 
lowed in adult by 
incomplete hinge 


Sub = Family I 

marsupium and 
mantle margin; 
all four (or outer) 
gills marsupial; 
ta chyt i ct ic spe- 
cies; glochidia 
Lamp si lis Type. 


Marsupium more i)rimitive than 
that of Family II; post-ventral 
mantle margin undifferentiated; all 
four gills marsupial; glochidium 
Lampsilis Type; tachytictic 



Bachelor of Science, (B. S.), Wabash College, Crawfords- 
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 Univer.sity as a 
Master's Thesis 


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. 


Fig. I. — External structure of left valve of Rotundaria tnherculata 
Rafinesque, 9 (Nat. size). 

Anterior end. 
— Posterior end. 
— Ventral side. 
— Dorsal side. 
— Antero-ventral side. 
— Antero-dorsal side. 
— Post-dorsal section. 
— Post-ventral section. 
— Nodule. 

ID. — Tubercle. — Umbonal region. 

1 1 . — Center of disk. 

I 2. — 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. tuberciilata (Raf.) 9 
(Nat. size.) 
I. — Epidermis. 9. — Branchial cavity. 

— Outer nacreous zone. 

— Middle nacreous zone. 

— Inner nacreous zone. 

— Vein marks. 

— Retractor muscle scar. 

— Post, add. mus. scar. 

— Anterior adductor muscle scar. 

Lunular hinge. 
Cardinal tooth. 
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. tubercnlata 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 close4 glochidium (X87) of R. tuberculata 
{nov. glochidium) showing; — 

I. — Anterior end. 5. — Center of disk. 

2. — Posterior end. 6. — Adductor muscle. 

3. — Dorsal, or hinge line. 7. — Posterior adductor. 

4. — Ventral margin. 8. — Pericardial area. 

Fig. 3 a 

Fi;SL 3b 


pig. 4: 




Fig. 5a. — External structures of left valve of Plagiola sectiris (Lea)- 
Male shell reduced one-fourth from natural adult size. 



— Extreme ventral point. 
— Extreme anterior point. 
— Extreme posterior point. 
— Antero-ventral section. 
— Post-ventral section. 
— Antero-dorsal section. 



— Post-dorsal section. 
— Minor lines of growth. 
— Rest lines of growth. 
— Lunule. 
— Beak or umbone. 

Post-dorsal truncation. 
Broken rays. 

Fig. 5b. — Internal view of right valve of P. securis. cf 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. 

Ventral margin. 8. — Beak cavity. 

— Epidermis. 

— Mantle line. 

— Vein marks. 

— Ant. retractor mus. scar. 

— Ant. adductor mus. scar. 

— Cardinal tooth. 

— Interdentum. 


— Hinge ligament. 

— Hinge tooth. 

— Protractor mus. scar. 

— Post add. mus. scar. 


Fig- 6b. -^ 



Fig. 7a. — External structures of Anodontoides ferussacianns (Lea). 9 
(Nat. size). 

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 . 
— Ventral extremity. 6. — Mantle line. 

— Dorsal extremity. 7- — Ant. add. scar. 

— rAnterior extremity. 8. — Post. add. scar. 

— Posterior extremity. 9. — Beak cavity. 

— Rest lines of growth showing 10. — Apex of beak, 

through shell. 

Fig. 8a. — Dorsal view of A. jerussarianns shell showing Anodoiitiiie beak 

Fig. 8b. — Dorsal view of P. coccinciim shell showing Uuioninc beak 

Fig. 8c. — Dorsal view of E. (C.) parva shell showing Lampsilinc beak 

fig-7b, ' ^ 



Fig. 9a. — Right gills of Fusconaia undata Irigonoides Frierson, showing 
both marsupial, — a Unionine character. 

Fig. 9b. — Diagrammatic, vertical section of a Unionine ovisac at 
ventral margin. 

Fig. loa. — Right gills of Lastena suborbiculata (Say) showing entire 
outer one marsupial, — an Anodontine character. 

Fig. lob. — Diagram of Anodontine ovisac showing lateral water tubes 
as provision for aeration of embryos. 

Fig. iia. — Right gills of Proplera alata (Say) showing only posterior 
portion of outer one marsupial, — a Lampsiline character. 

Fig. lib. — Diagram of Lampsiline ovisac, showing rupture of ventral 
edge to allow escape of glochidia. 

Fig. 9a 


FiS'"^ Fi^.» 




{Drawings by G. T. Kline.) 

Fig. 12a. — External view of left valve of a new species, Plcurobema 
Utterbackii Frierson. o"^ (Nat. size.) 

Fig. 12b. — Internal view of right valve of P. Vtlcrbacki. 9 

Fig. 12a. 

Fig. 12b. 

(Draivings by G. T. Kline.) 

Fig. 13a. — External view of left valve of a new species, Truncilla 

Lefevrei Utterback. cT (Nat. size.) 

Fig. 13b. — Internal view of right valve of T. Lefevrei. cf 

Fig. 1 3c. — External view of left valve of T. Lefevrei. 9 

Fig. 13d. — Internal view of right valve of T. Lefevrei. 9 

Fig. 14a. — External view of left valve of a new species, Truncilla 

Curtisi Frierson and Utterback. cT (Nat. size). 

Fig. 14b. — Internal view of right valve of T. Curtisi. cf 
Fig. 14c. — External view of left valve of T. Curtisi. 9 
Fig. i4d. — Internal view of right valve of T. Curtisi. 9 

Fig. 13a. 

Fig. 13c. 

Fig. 13b. 

Fig. 13d. 

Fig. 14a. 

Fig. 14c. 

Fig. 14!). Fig. i4d. 



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. (^ Nat. size). 

Fig. 16. — Megalonaias heros (Say) 9 Photograph of gravid specimen 
showing animal structure in left valve. (^4 Nat. size). 




Fig. 1 7 A. — hampsilis a^iodojitoides (Lea), cf — Extenal view of right 
valve. {% Nat. size). 

Fig. 17B. — L. anodontoides. cf — Internal view of left valve. 

Fig. 18A. — Lampsilis fallaciosa (Smith) Simpson. 9 — External view 
of right valve. (i^4 Nat. size). 

Fig. 18B. — L. fallaciosa. 9 — Dorsal view showing Lampsiline beak 




Fig. 19. — Posterior views of live mussels in aquarium showing "siphons" 
open in act of feeding and discharging wastes. Reading from left to right 
are: — One P. laevissima d^ , L. fragilis 9 (next three) and L. suborbiculata 9 
(two at extreme right). Young of L. Jragilis (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). 




Fig. 21. — Platte River below a small falls showing a quiet, sheltered 
"pocket" where juveniles and small species of mussels congregate in great 
numbers. Note dead shells on the rocky bar. 




Fig. 22. — Limestone cliff.s and mussel bed at the foot above Dixon 
Falls, Platte River. Abundance of lime in the water here contributes to 
the unusual growth of shell. 

Fig. 23. — "Fishing" for mussels in the West Bayou of Lake Contrary 
St. Joseph. A garden rake is used in deep water, but hand, picking, where- 
ever possible, is the most successful. 




Fig. 24. — Beach of a North- West Missouri Lake showing the common 
sight of a pile of cleaned mussel shells made by a musk-rat after feeding on 
the soft parts. These ravages, as well as the receding of the water, tend 
greatly to deplete the mussel beds. 




Fig. 25. — Lake Contrary, (St. Joseph), — the home of the Anodonlinae, 
especially Lastena siiborhiciilata. Although originally the bed of the Missouri 
River, yet the only river species found here are: — Q. qitadrula and P. 

Fig. 26. — One-and-Two River, Corby Mill. — Above the dam the 
mussel fauna is different, due to the limitation of the range of certain fish 
as distributors of mussel life in the parasitic stage. 




Eig. 27. — Shells in situ (above and to right of iiat) embedded in a bank 
along Peck's Slough, St. Joseph. This shows a former mussel life now extinct 




Fig's. 28. — A and B Cumherlandia monodonta (Say) 9, Miss. R. 


Fig's. 29 A and B. — Fusconaia tuidata (Barnes) 9, Miss. R., Hannibal 
Fig's. 30 A and B. — Adult F. undata trigonoides Frierson MS. Z 

Platte R., Agency Ford. 

Fig's. 30 C and D. — Juvenile of trigonoides. 

Fig's 31 A and B. — F. undata trigona (Lea) 9, Osage R., Warsaw. 
Fig's. 32 A and B. — Adult F. flava (Raf.) cf, White R., HnlHster 
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. 







/ % 

3 OB 3 C 




SSltfB 3^c 




PL^ r£ A- r. 



Fig's 35 A and B. — Anihlenia peruviana (Lamarck) 9, Osage R, 

Fig's 36 A and B. — A. rariplicata (Deshayes) 9, Platte R., Dixon Falls. 

Fig's 36 C and D. — A. rariplicata (Des) a', Tarkio R., Craig. 

Fig's 37 A and B. — A. perplicata (Conrad) 9 , vSt. Francis R., Greenville. 

Fig's 38 A and B. — A. perplicata Quintardi (Cragin) 9, White R., 

Fig's 38 C and D. — A. perplicata Quintardi (Cragin) 9, Osage R . 

Fig's 39 A and B. — A. plicata costata (Raf.) cf, Chariton R., Kern 

Fig's 39 C and D. — Juvenile of costata. — Same locality as adult 

38 D. 

PLATE A' 17. 



Fig's 40 A and B. — Adult Megalonaias heros (vSay) 9 , Platte R. 

Fig's 40 C and D. — Juvenile heros, Osage R., Monegaw Springs. 

Fig's 40 E and F. — Young heros, Osage R., Warsaw. 

Fig's 41 A and B. — Quadrida 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 asperala (Lea) cf , Osage R., Bagnell. 

Fig's 44 A and B. — (). nodulata (Raf.) cf. Miss. R., Hannibal. 

43 B 



42 JB 






Fig's 45 A and B. — Q. qitadntla (Raf.) 9, Lake Contrary, St. Joseph. 

Fig's 45 C and D. — Q. quadrula cf . Same locality as female. 

Fig's 45 E and F. — Q. quadrula d', Flat Cr., Sedalia. 

Vig's 4.6 A and B.-Q. quadrula 9, L. Contrary. — A common pathologic 
shell found in the N. W. Mo. Lakes, 

Frig's 47 A and B. — Q. quadrula contraryensis Utterback 9 , 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. 




Fig's. 50 A and B. — Q. verrucosa (Raf.) cf , Grand R., Darlington. 

Fig's 50 C and D. — Young Q. verrucosa (Raf.) 9, White R., Hollister. 

Fig's 51 A and B. — Q. ywhilis (Conrad) 9, Marais des Cygnes R., 
Rich Hill. 

Fig's 52 A and B. — Q. cylindirca (Say) 9, Black R., Williamsville. 

Fig's 53 A and B. — Q. metanevra (Raf.) a', Meramec R., Meramcc 

Fig's 54 A and B. — Rolundaria tnherculala 'Raf.) 9, Osage R., vSchell 

Fig's 55 A and B. — R. grant/era (Lea) 9, Miss. R., LaGrange. 




Fig's 56 A and B. — Plethobasus aesopus (Green) 9, Des Moines R., 

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. — Pleurohema obliquum pyramidatum (Lea) 9, 
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.) 9, 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.) 9, Osage R., Colley's 

Fig's 63 A and B. — P. Utterbacki Frierson (n. sp.) 9 , White R., Hollister. 

Fig's 63 C and D. — P. Utterbacki F. d", Jack's Fork of the Current R. 

£3 a. 






Fig's 64 A and B. — EUiptio nigra (Raf.) cf, Meramec R., ISleramec 

Fig's 65 A and B. — E. nigra (Raf.) 9, 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., HoUistcr. 

Fig's 67 C and D. — E. dilatata delicata (Simp.) c?, Black R., Williams- 

Fig's 68 A and B. — E. dilatata subgibbosa (Lea) 9, Black R., Williams- 

Fig's 68 C and D. — E. dilatata subgibbosa (Lea) d', Black R., Williams- 

Fig's 69 A and B. — Uniomcrus letralasmu (Say) 9, Batterton Pond, 




Fig's 70 A and B. — Symphynota complanata (Barnes) 9, Big Mud 
Lake, Kenmoor. 

Fig's 71 A and B. — Syniphy}iola costata (Raf.) 9, Black R., 

Fig's 71 C and D. — 5. costata (Raf.) cf, Gasconade R., Gascondy. 

Fig's 71 E and F. — S. costata (Raf.) 9, Miss. R., Hannibal. 

Fig's 72 A and B. — Arcidens conjragosa (Say) 9> Marais des Cygnes 
R., Papinsville. 




Fig's 73 A and B. — Lastena suhorhiculata (Say) 9 , Lower Lake Contrary, 
St. Joseph. 

Fig's 73 C — F. — Juveniles of L. si(borbiculata. — Upper L. Contrary — 
Note the coarse Anodontine beak sculpture which reaches well down on the 

Fig's 74 A and B. — Lastena ohiensis Raf.O, Singleton Lake, Halls. 

Fig's 75 A and B. — Anodonta grandis (Say) 9, Mud Lake, Kenmoor. 




Fig's 76 A and B. — Anodonta Danielsii Lea 9, Lost Cr., Amity. 
Fig's 77 A and B. — A. dakotana Frierson 9, L. Contrary, St. Joseph. 
Fig's 78 A and B. — Alasmidonia marginata Say 9, Gasconade R 

Fig's 79 A and B. — A. calceolus (Lea) 9, Jack's Fork, Current R. 
Fig's 79 C and D. — A. calceolus, cf, White R., Branson. 
Fig's 80 A and B. — Strophitus edentulus (vSay) 9 , Osage R., Linn Cr 
Fig's 80 C and-D. — S. edentulus cf. White R., Branson. 




Fig's <Si A and B. — Ellipsaria clintoiiesnsis (vSimpson) 9, White R., 

Fig's 82 A and B.— Ohliqiiaria reflexa Raf. & , Platte R., Platte R. vSta. 

Fig's 82 C and D., — O. reflexa Raf.- 9, Osage R., Mor.egaw Springs. 

.Fig's 82 E and F. — Juvenile reflexa. — Crow's Fork, Fulton. 

Fig's 83 A and B. — Cyprogenia Aberti (Conrad) 9, vSt. Francis R., 

Fig's 84 A and B. — Obovaria {Pseudoon) eltipsis (Lea) 9, Grand R., 
Sumner. • 

Fig's 85 A and B. — Nephronaias ligamentina (Lamarck) 9, Meramec 
R., Fern Glen. 

Fig's 86 A and B. — A'^. ellisijormis (Conrad) (^ , Osage R., Warsaw. 

Fig's 86 C and D. — N. ellipsiformis (Con.) 9 , Niangua R., Hahatonka. 

•Fig's 87 A and B. — N. Pleasii ( 9, White R., Branson. 

Fig's 87" C and D. — N. Pleasii (Marsh) cf , White R., Branson. 

Fig's 88 A and B. — Amygdalonaias truficata (Raf.) cT, Osage R., Schell 
City, Mo. 

Fig's 8g A and B. — A. donacijonnis (Lea) cT, Grand R., Gallatin. 

Fig's 89 C and D. — A. do)iaciformis (Lea) 9, One-and-Two R., St. 

cie Ik 

J \ 

.82F 82 E 








Fig's 90 A and B. — Lasmonos fragilis (Raf.) 9, One— and-Two River, 
vSt. Joseph. Fig. 90 B is the photograph of the animal in the left valve 
showing the gravid marsupium. 

Fig's 90 C and D. — L. fragilis (Raf.) cf, Platte R., Agency Ford. 

Fig. 90 D. — A photograph of soft parts in left valve. 

Fig's. 91 A and B. — Lasmonos Simpsoni (Ferriss) 9, White R., Branson. 

Fig's 92. — A and B. — Proptera purpurata (Lamarck) a', White R., 

Fig's 92 C and D. — Proptera purpurata (Lamarck) 9, White R., 

Fig's 93 A and B. — Prop, capax (Green) 9, Miss. R., Hannibal. Fig. 
93b sljows photograph of animal with gravid marsupinm. Note non-speciali- 
zed post-ventral mantle margin. 

Fig's 94 A and B. — Prop, laeinssima (Lea) 9, Mud Lake, Kenmoor. 

Fig's 94 C and D. — Juveniles of laevissima, L. Contrary, St. Joseph. 




Fig's 95 A and B. — Carnvculiua parva (Barnes) vSingleton Lake, 

Fig's 95 C and D. — C. parva (Barnes) d^, Artificial Pond, Columbia. 

Fig's 96 A and B. — Eitrynia {Micromya) lienosa (Conrad) cf, Black R., 

Fig's 96 C and D.— £ (A/) lienosa (Con) 9, Black R., Williamsville. 

Fig's 97 A and B.— £. (M) iris (Lea) 9, White R., Hollister. 

Fig's 98 A and B.—E (M.) brevicuhi (Call) cf, White R., Branson. 

Fig's 98 C and D.— £ (M.) hrevicula (Call) 9, Jack's Ford, Current R. 

Fig's 99 A and B. — E (M.) hrevicula Brittsi (Simpson) 9, Niangua R., 

Fig's 100 A and B. — £. (Eurynia) recta (Lamarck) cT, Osage R., Oseola. 

Fig's 100 C and D. — E. (E.) recta (Lam.) 9, Meramec R., Meramec 

Fig's loi A and B. — E. (E.) sulnostrala (Say) o^. Lost Cr., Maysville. 

Fig's loi C and Y^. — E. (E.) suhroslrata (Say) 9. Flat Cr., Sedalia. 

97 B 


101 D -^i 




Fig's I02 A and B. — Laiiipsili.s anodontoides (Lea) o"^, Chariton R., Kern. 

Fig's I02 C and D. — L. anodnntoides (Lea) 9, Chariton R., Kern. 

Fig's 103 A and B. — L. luteola (Lamarck) d" , Black R., Williatnsvillc. 

Fig's 103 C and D. — L. luteola (Lam.) 9, Black R., Williamsville. 

Fig's 103 E and F. — Young L. luteola (Lam.) cf ,- Black R., Williamsville. 

Fig's 104 A and B. — L. luteola rosacea (Dekay) c?, White R., Branson. 

Fig's 105 A and B. — L. Higginsii (Lea) 9, Miss. R., Hannibal. 

Fig's 106 A and B. — L. ventricosa (Barnes) cf, 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. 

Fig's 108 A and B. — Truncilla Lefevrci LItterback 9, Black R-, 

Fig's 108 C and D. — T. Lef evrei Vtierhack d" , Black R., Williamsville. 

Fig's 109 A and B. — Truncilla ciirtisi Frierson and Utterback 9, 
White R., Hollister. 

Fig's 109 C and D.— T. Curtisi F. and U. a\ White R., Hollister. 


10a B 

\m p m% E 


10 4 B 

lOBE 103 i> 



id^B 109 Q 



i);:i)i/i )'^ 



3 9088 00675 4972