NO. 2124. THE WEST AMERICAN SPECIES OF NVCELLA—DALL. 



565 



THAIS LAMELLOSA, new variety FRANCISCANA. 



San Francisco Bay. 



Shell subfusiform, heavy, with a subconio spire shorter than the 

 aperture, laminae reduced to obsolete low imbrications or usually 

 none; whorls flattened behind the shoulder; major spirals low, feeble, 

 two on the penultimate whorl, seven or more on the last whorl, 

 minor spirals obsolete or none; aperture large, the outer lip flaring, 

 umbilical chink usually distinct but closed (63909). 



Measurements. 



Whorls. 



Height 

 of shell. 



Height 

 of last 

 whorl. 



Breadth. 



4i 

 4i 

 5. 



THAIS LAMELLOSA, new variety HORMICA. 



Inner part of Sitka Harbor, Alaska. 



Shell of smaller size than either of the preceding, thin, with spire 

 subacute, produced, longer than the aperture; whorls angular with 

 more or less prominent axial laminae, 10 or more to the last whorl, 

 often produced at the angles into guttered spines; major spirals two 

 on the penultimate, five or six on the last whorl; aperture small, 

 the outer lip hardly expanded, only moderately callous; the umbilical 

 chink usually obsolete (88862). 



Measurements. 



THAIS LAMELLOSA, new variety NEPTUNEA. 



Cook Inlet. 



Shell large, heavy, smooth, with rounded whorls and deep though 

 appressed sutures, resembhng a very thick and heavy Chrysodomus. 

 The measurements are about the same as in the typical form. 



THAIS LAMELLOSA, new variety CYMICA. 



Typical locahty: Rocks exposed to the surf, coast of Washington. 



Shell short, robust, heavy, very thick, spire short-conic, shorter 

 than the aperture, one mutation being sparsely laminate, the other 

 with a smooth surface; whorls flattened behind the shoulder; major 

 spirals obsolete or none; when present, there is one on the penultimate 

 whorl and five or six on the last whorl; aperture large, outer lip 

 flaring, umbilical chink usually concealed by the callus. 



