SEMELIDAE 435 



Semele pwpiirascens Gmelin Purplish Semele 



Plate 40b 



North Carolina to south half of Florida and the West Indies. 



I to i^ inches in length, oblong, thin-shelled, smooth except for very 

 fine concentric growth threads over which run another set of fine, micro- 

 scopic concentric lines at an oblique angle. External color variable: com- 

 monly gray or cream with purple or orangish mottlings. Interior glossy and 

 suffused with purple, brownish or orange. A fairly common, shallow-water 

 species. 



Semele bellastriata Conrad Cancellate Semele 



Plate 30) 



North Carolina to south half of Florida and the West Indies. 



/4 to % inch in length, similar in shape to piirpurascens, but a much 

 smaller species with numerous radial and concentric riblets which cross to 

 give a cancellate appearance. Some specimens well-beaded, others have the 

 radial ribs more prominent. External color yellowish white with reddish 

 flecks or a solid, purplish gray. Interior white, cream or suffused with mauve 

 or violet, 5. cancellata Orbigny is this species. Fairly common just offshore. 



Semele nibropicta Dall Rose Petal Semele 



Plate 29\v 



Alaska to Mexico. 



I to 1% inches in length; beaks % toward the posterior end; rather 

 thick-shelled, especially in the south. Concentric sculpture of small, irreg- 

 ular growth lines. Radial incised lines numerous. Periostracum thin, smooth 

 and yellowish brown. Exterior of shell dull grayish or tannish white with 

 faint, radial rays of light-mauve. Imterior glossy-white, with a small splotch 

 of mauve at both ends of the hinge line. Uncommon from 20 to 50 fathoms. 



Se77iele rupicola Dall Rock-dwelling Semele 



Plate 29t 



Santa Cruz, California, to the Gulf of California. 



I to 1% inches in length. Irregular in shape: ovalish, oval-elongate or 

 obliquely oval. Exterior yellowish cream with numerous, concentric crinkles 

 and a few ^eak radial threads. Interior glossy, white at the center, bright 

 purplish red at the margins and hinge. John Q. Burch finds this species com- 

 mon in Chama and Mytilus beds and in rocks and crevices. 



Semele decisa Conrad Bark Semele 



Plate 29Z 

 San Pedro, California, to Lower California. 



