. Fresh-water biology. Freshwater biology. 1000 FRESH-WATER BIOLOGY ii6 Shell large, irregularly oval, inflated; surface with a number of large, scattered tubercles. Section Pkthobasus Simpson. This section contains only two spe ies, inhabiting the Ohio and Tennessee drainage areas, The type, Pleurobemaaesophus Green (Fig. 1488; X j),extends west into Missouri and Fig. 1488. 117 (loS) Outer gills only serving as marsupia. Shell alike in both sexes; ovate to elongate, rounded in front, pointed or biangulate behind; beaks nearer to the middle than to the anterior end; hinge complete;
. Fresh-water biology. Freshwater biology. 1000 FRESH-WATER BIOLOGY ii6 Shell large, irregularly oval, inflated; surface with a number of large, scattered tubercles. Section Pkthobasus Simpson. This section contains only two spe ies, inhabiting the Ohio and Tennessee drainage areas, The type, Pleurobemaaesophus Green (Fig. 1488; X j),extends west into Missouri and Fig. 1488. 117 (loS) Outer gills only serving as marsupia. Shell alike in both sexes; ovate to elongate, rounded in front, pointed or biangulate behind; beaks nearer to the middle than to the anterior end; hinge complete; surface usually smooth, dark brown to black, often indistinctly rayed. Ujiio Retzius 118 118 (119, 120) Shell elongated, rhomboid or oval, more or less biangulated behind; surface smooth or feebly corrugated; beak sculpture consisting of a few rather strong ridges, which are nearly parallel to the growth lines or slightly double-looped. Section Elliptio Rafinesque. The typical section of this genus is restricted to the Old World. The section Elliptio is the largest group of Unionidae represented in our fauna. More than ninety species are recognized. The metropolis of the genus is in the Southeastern States, but representatives are found in all ni the Eastern, Southern, and Central States. Type, Unio crassidens Lam. (Fig. 1489; X !)â. 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
