. Fresh-water biology. Freshwater biology. THE MOLLUSCA 997 III (112) Surface pustulose; no radial furrow above the posterior ridge; unicolored or rayed, never painted as in Quadnda Section Theliderma Swainson. This section comprises three weU-marked groups: first, that of the typical species, Quadrula lachrymosa Lea (Fig. 14S3), having a quadrate or rhomboid shell with a wide, shallow radial furrow in front of the posterior ridge; second, that of Q. ptistulosa Lea, with a rounded, quad- rate shell with no radial furrow; third, two small species from Georgia and Florida, rounded- rhomboid
. Fresh-water biology. Freshwater biology. THE MOLLUSCA 997 III (112) Surface pustulose; no radial furrow above the posterior ridge; unicolored or rayed, never painted as in Quadnda Section Theliderma Swainson. This section comprises three weU-marked groups: first, that of the typical species, Quadrula lachrymosa Lea (Fig. 14S3), having a quadrate or rhomboid shell with a wide, shallow radial furrow in front of the posterior ridge; second, that of Q. ptistulosa Lea, with a rounded, quad- rate shell with no radial furrow; third, two small species from Georgia and Florida, rounded- rhomboid in shape, without the furrow and with the surface covered with zigzag corrugations. Most of the species are found only in the Southern States, but the first two groups have repre- sentatives ranging north to Michigan and Fig. 1483. 112 (log) Surface smooth Section Fwreowaw Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Ward, Henry Baldwin, 1865-1945; Whipple, George Chandler, 1866-1924. joint author. New York, John Wiley & sons, inc. ; [etc. ,etc. ]
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectfreshwa, bookyear1918
