Page:American Seashells (1954).djvu/357

Rh 5 mm. in length; body oblong, with its ends circularly rounded; upper surface regularly arched; uniform smoke-gray in color. Fresh specimens are needed to make a better description. Littoral to shallow water. Habits not known. Onchidella borealis Dall Northwest Onchidella Alaska to Coos Bay, Oregon. 8 to 12 mm. (% inch) in length; back regularly arched but a little pointed in the middle, smooth or very finely granulose, tough and coriaceous. Color black or gray, with dots and streaks of yellowish white; foot light- colored, also the head and tentacles. On rocks near high-tide mark. Gre- garious. Common. Order TECTIBRANCHIA (Bubble-shells, Sea-hares) Faimly ACTEONIDAE Genus Acteo7i Montfort i8io External shell with a prominent spire; cephalic disk divided; operculum thin, corneous. Erroneously spelled Actaeon. Acteon piinctostrianis C. B. Adams Adams' Baby-bubble Plate 26t Cape Cod to the Gulf of Mexico and the West Indies. 3 to 6 mm. in length, solid, moderately globose, w^ith a rather high spire. Columella with a single, twisted fold. Lower half of body whorl with nu- merous spiral rows of fine, punctate dots. Color white. Commonly found from low tide to 6o fathoms. Acteon punctocaelatiis Carpenter Carpenter's Baby-bubble British Columbia to Lower California. lo to 2o mm. (% inch) in length, solid, oblong, 4 to 5 whorls, with two broad, ashy or brown spiral zones and about 16 spiral grooves on the body whorl. Columella obliquely truncated at base, and with one spiral fold. Base stained orange. Commonly found in shallow water in sand. A. vancouverensis Oldroyd is the same species. Acteon candens Rehder Rehder's Baby-bubble North Carolina to southeast Florida and Cuba.