. Fresh-water biology. Freshwater biology. ioi6 FRESH-WATER BIOLOGY 162 (163) Male and female shells much alike, but the latter is usually some- what inflated in the post-basal region. Shell large, ovate, usually rather thin, but in some species quite solid, gaping at the anterior edge and on the dorsal slope; normally winged on the dorsal slope, but the wing is often lost in the adult; hinge complete. Marsupium occupying the posterior portion of the outer gills. Glochidia celt-shaped, with two spines on each valve and with gaping margins . Proplera Rafinesque. This group is well characterized
. Fresh-water biology. Freshwater biology. ioi6 FRESH-WATER BIOLOGY 162 (163) Male and female shells much alike, but the latter is usually some- what inflated in the post-basal region. Shell large, ovate, usually rather thin, but in some species quite solid, gaping at the anterior edge and on the dorsal slope; normally winged on the dorsal slope, but the wing is often lost in the adult; hinge complete. Marsupium occupying the posterior portion of the outer gills. Glochidia celt-shaped, with two spines on each valve and with gaping margins . Proplera Rafinesque. This group is well characterized by the large, usually thin shell, which is more or less alate in the dorsal region. It occurs throughout the St. Lawrence and Mississippi systems and extends south to Texas and Alabama. Type, P. alata Say (Fig. 1524; X i)-. Fig. 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
