PH ASIAN ELLA. 171 



angulate at periphery; sutures lightly impressed; aperture oblique, 

 ovate, outer and inner margins equally curved ; columella with a 

 white callus; umbilical region excavated, and usually obviously 

 perforated ; color white, yellow or reddish, longitudinally clouded 

 with white, red or brown, sometimes broken into subsutural and 

 peripheral series of flammules, encircled with close continuous narrow 

 revolving obliquely descending, regularly spaced orange or red lines. 



Alt. 5 2 diam. 85 mill. 



West Indies. 



P. minuta Anton (?), P. zebrina d'Orb. (figs. 99, 100.), and P. 

 tesselata C. B. Ad. are synonyms. 



This species and the P. affinis are very abundant in many West 

 Indian localities. They are usually associated together. Fresh 

 specimens of both exhibit microscopic revolving impressed striae. 

 Reeve, who has subdivided the larger species of this genus so minute- 

 ly, "lumps" these forms, with most of the other small species, under 

 P. pulld L. I have never seen a specimen among hundreds I have 

 examined from the West Indies which could not be most readily 

 separated from the Mediterranean shell. Indeed both affinis and 

 tessellata exhibit a surprising uniformity in color-pattern and form. 

 The dentition of affinis differs from that of pulla. P. perforata Phil. 

 I should be inclined to unite with tessellata were it not from the 

 AVest Coast. 



The P. concolor of Adams I have identified with a rather rare 

 color-variety which generally occurs with P. tessellata. It is extremely 

 dark, almost unicolored ; but Avith a glass one can perceive sfcill 

 darker diagonal lines upon the surface. This form is figured on PI- 

 45, fig. 1. The following description is from the original one of 

 Adams : 



P. concolor C. B. Adams, 1850. 



Shell rather long ovate-conic; uniform glossy brown, rarely with 

 a sutural band of a deeper shade of the same; surface polished, 

 apex rather obtuse; sutures impressed; spire with nearly rectilinear 

 outlines; whorls 5, convex, the last subangular; aperture ovate; 

 columella with a thick deposit, and with an umbilical indentation. 



Alt. 21 mill. Jamaica. 



P. UMBILICATA d'Orb., 1853. PI. 39, figs. 95, 3, 4. 



Shell ovate-conic, composed of 5 very convex whorls, separated 

 by deeply impressed sutures, and encircled by rather coarse revolv- 



