Page:American Seashells (1954).djvu/392

310 Eubranchus pallidus Alder and Hancock Painted Balloon Eolis Plate i5h Arctic Seas to Boston, Massachusetts. Europe. % inch in length, characters as shown in our figure and the generic description. Uncommon (?), Genus Coryphella Gray 1850 Branchiae numerous, clustered, elongate or fusiform. Foot narrow, with the anterior angles much produced. Radula with a single longitudinal series of central teeth which bear a large central denticle and several marginal denticles. There is a denticulated lateral tooth on each side of the central. Coryphella rufibranchialis Johnston Red-fingered Eolis Plate 15a Arctic Seas to New York. Europe. I inch in length, characters as shown in figure and in the generic de- scription. Common (?) in New England. Subclass PULMONATA Order BASO MM ATOP MORA Family SIPHON ARllDAE Genus Siphonaria Sowerby 1824 Shells closely resembling the true limpets, Acmaea, but at once distin- guished by the nature of the muscle scars on the inside. In both, the long, narrow scar is horseshoe-shaped, but in Siphonaria the gap between the ends is located on one side of the shell, while in Acmaea it is located at the front end. In some Siphonaria, the area near the gap is trough-shaped. These are air-breathers and are more closely related to the land garden snails than to the gill-bearing, water-breathing limpets. Siphonaria pectinata Linne Striped False Limpet Figure 65b Eastern Florida, Texas, Mexico and St. Thomas. I inch in length, rather high, with an elHptical base. Exterior with numerous, fine, radial threads or rather smoothish. Color whitish with nu- merous, brown, bifurcating, radial lines. Interior glossy, similarly striped. Center cream to brown. Muscle scar with 3 swellings, the gap occurring be- tween the two at the side. Do not confuse with Acmaea leiicopleura which commonly has a blackish owl-shaped figure inside. Common along the shores on rocks. This is S. ?iaufragum Stearns and S. lineolata Orbigny.