ACTEONIDAE 275 



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. 



