MURICIDAE 



217 



often fimbriated axially between the cords, Siphonal canal moderately long, 

 usually sealed over. Littoral to several fathoms. Common. There are 2 

 named varieties of doubtful biological significance: atropurpurea Cpr. and 

 clathrata Dall. 



Figure 49. Dwarf Tritons of the Pacific coast, a, Ocenebra inter jossa Cpr.; b, 

 O. circmntexta Stearns; c and d, O. hirida Alidd. All natural size. 



Ocenebra lurida Middendorff 



Alaska to Catahna Island, California. 



Lurid Dwarf Triton 



Figure 49c, d 



I to I % inches in length; 5 to 6 whorls; moderately elongate spire whose 

 whorls show the axial ribs more prominently than the numerous fine spiral 

 threads. Suture well-impressed. Body whorl with 8 to 10 rounded ribs which 

 are strongest and shouldered just below the suture but which fade out below 

 the periphery of the whorl. The smaller, smooth, spiral cords are elevated 

 and prominent, often with numerous tiny axial lamellae between them. 6 to 

 8 small teeth on the inside of the outer lip. Color variable, whitish to rusty- 

 brown, sometimes banded. Periostracum dark-brown and fuzzy. Siphonal 

 canal usually sealed over. Very common from northern California north. 

 Littoral to 30 fathoms. 



Ocenebra gracilli?7ta Stearns 



Graceful Dwarf Triton 



Plate 24m 



Monterey, California, to the Gulf of California. 



Ys inch in length, similar to lurida in shape; with 5 whorls, those in the 

 spire weakly cancellate with the axial ribs the strongest. Last whorl without 



