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On a critical comparison of the California with W. India specimens, 

 the following differences seem to be constant, so far as these speci- 

 mens are concerned. 



W. INDIA. 



Form strictly pyramidal. 



Whorls very slightly convex, suture 

 somewhat constricted. 



Surface, corrugate or undate at right 

 angles with the lines of increment. 



Flammules confused or blotched. 



Base with no tendency to distinct tes- 

 sellation. 



Lip black at edge, submargin dead 

 white. 



Aperture very oblique, its lip regularly 

 sloping from junction to periphery. 



Columellar tooth well marked. 



Columettar lip somewhat sinuous. 



CALIFORNIA. 



A more elevated pyramid. 



Whorls decidedly convex and more 



girt in at the suture. 

 Surface without undulations but girdled 



by a few obsolete ridges on the last 



whorl. 



Figurations well defined. 

 Base more or less tessellated with 



ranges of squarish black spots. 

 Lip nacreous and iridescent to the 



margin. 



Aperture less oblique, lip arched. 

 Columellar tooth obsolete ; inner lip 



forming a regular sweep. 



As I have seen no young specimens from California, it is not 

 unlikely that some of the above diagnostic marks may not prove 

 constant in some stages, the more elevated form, more convex 

 whorls, and destitution of undulations may be regarded as the most 

 important characters. I present this comparison for verification 

 when more numerous specimens shall have been obtained. Should 

 the differences prove constant, it will be one of the most remarkable 

 examples of analogous species from correlative regions. 



TROCHUS (MOXODOXTA) PYRIFORMIS. 



T. ovato-conica, crassa, striis obtusis remotis antice cincta, nigra, flavido 

 oblique et undulatim lineolata ; spira conica, anfr. sex convexiusculis, ad peri- 

 pheriam rotundatis ; basis convexa, fovea umbilicali albo-cincta notata, imper- 

 forata ; apertura circularis ; columella acuta, bidenticulata ; labro acuto nigro ; 

 cavositas alba. 



Shell thick and heavy, elevated ovate pyramidal, eroded at tip, 

 without sculpture, bluish-black, or with a few obtuse revolving lines 

 on the last whorl, with numerous oblique, fine, undulating stripes 

 of yellowish crossing the lines of growth nearly at right angles. 

 Whorls six, slightly convex ; suture linear ; periphery of the last 

 whorl obtusely rounded ; base convex, white at centre, with a small 

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