134 THE AMERICAN MIDLAND NATURALIST 
where it has developed a heavier, less pustulous shell as we 
note in the ecologic results for some shells of Amblemae. This 
form is reported also for the St. Lawrence basin as well as through 
all the northern part of the Mississippi Valley, even down into the 
South-west as far as Kansas and Oklahoma. The writer has been 
able to keep a good breeding record for this very acessible form 
for Missouri to find it only gravid through June and July. 
Quadrula pustulosa asperata (lea). 
Ph. POV hs tae. ZeacANand Bs 
1861— Unto asperatus Lea, Pr. ac. Nat: Sci. Phila. V, p. 41; Jl. Ac. 
Ne Sel Phila) Ve p68. Pl Vilky Bigs one: 
ANIMAL CHARACTERS:—-Soft parts have been examined 
afield and found to be identical with those of the parent species. 
None were found gravid. All four gills of sterile females were 
marsupial in character through the test of finding more crowded 
septa. 
SHELL CHARACTERS. 
EXTERNAL STRUCTURES:—Subtrigonal, very upright, 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:—lIdentical with those of type, pus- 
tulosa except perhaps a broader, thinner and more upright 
interdentum. 
Sex Length Height Diameter Locality 
O44 x 46" x, (2 Sn (Osage R., Warsaw, Mo.) 
OES OWEN A DY OX ers en Qitots ” Osceola, Mo.) 
or) OAOy XA Or exene Tr any (Gh tee ”  Bagnell, Mo.) 
MISCELLANEOUS REMARKS:—The form of the above des- 
cription is of rare occurrence in the Osage River, but still the 
other form for this state, schoolcraftensis, does not occur much 
oftener in this river. According to Mr. Bryant Walker this is 
“a western form of Q. pustulosa and if it came from the Coosa 
River, Alabama, it would surely be referred to Q. asperata (Lea).”’ 
Comparisons to the actual shell from Alabama (Coosa R., Cedar 
Bluff) shows it to be almost identical both as to external and 
internal features. 
