190 SEMKLE. 



Standella Califoniica, Conr., Stan-deF-la Cal-i- 

 for'-ni-ca. Shell somewhat oval, hollowed in front of 

 the beaks; edges thin, surface smooth, white, covered 

 with a thin epidermis somewhat roughened at the 

 posterior end. Ligament internal, lodged in a small 

 triangular pit; pallial sinus small, U-shaped; beaks 

 narrow and distinct, length about three inches. 



Semele decisa^ Conr., Sem'-e-le de-ci^-sa, has a 

 shell nearly circular in outline, with a short straight 

 portion at one end. The shell is somewhat flattened, 

 the lines of growth are distinct and somewhat rough, 

 and the ligament is internal, with small hinge-teeth 

 on either side. Pallial sinus large and oval, beaks 

 turned forward, posterior end of the shell truncated 

 and somewhat wrinkled. The epidermis is brownish, 

 when present, and beneath it is the white shell. 

 Internally the shell is beautifully polished, looking 

 like fine white porcelain, tinged with rose or violet. 



The rich tinting is particularly seen in large shells, 

 especially around the edges and the hinge. The 

 length of the shell is three inches or less. It is to be 

 found along the southern coast, and like all of the 

 following dozen species it lives buried in the sand or 

 mud, and sends up two tubes to the water for pur- 

 poses of respiration. It is one of our most beautiful 

 shells. 



Semele riipmm^ Sby. , ru'-pi-um. Smaller, less 

 wrinkled; white, with a pink hinge area. Its length 

 is an inch or more. From Santa Catalina Island. 



Semele pulchra^ Sby., puF-kra. About half an 

 inch in length, flat, oval; marked with closely 

 crowded concentric ridges, with radiating lines at one 

 end. Yellowish white; southern. 



