PSEUDOTROCHUS. 237 



than in saulcydi, the last not perceptibly constricted below 

 the suture. Suture margined below by a narrow crenate or 

 beaded band. The surface is unequally, obliquely subobso- 

 letely plicatulate, sometimes with subobsolete spirals on the 

 penultimate whorl, the last whorl with faint, obliquely de- 

 scending, scar-like impressions or color-markings at right 

 angles to the growth-lines. Aperture oblique, dark purplish- 

 brown inside; parietal wall more or less distinctly orange- 

 brown from the retention of the cuticle under the parietal 

 glaze. Columella narrow, wholly appressed, somewhat con- 

 cave, passing gradually into the thin basal lip. 



Length 77.5, diam. 41, oblique length of apert. 40 mm. 



Length 76.5, diam. 40, oblique length of apert. 38.5 mm. 



" Taboo Africa" (Robert Swift coll. in A. N. S. Phila,). 



Perideris saulcydi var. normalis PILS., Proc. Acad. Nat. 

 Sci. Phila., 1897, p. 503 (1898). ? Bulimus torridus REEVE, 

 Conch. Icon., v, pi. 89, f. 6620. 



This form differs from P. saulcydi (Joannis) in being 

 more elongated and slender throughout, the last whorl not 

 concave above, aperture consequently not acuminate poster- 

 iorly as in that species; the spire is more elongated and 

 tapering, and the terminal " mamelon " more pronounced. 

 It is also dextral; but as the apparent sinistrality of Joannis' 

 species may be due to an artist's failure to reverse, I do not 

 place great stress upon this feature. 



20. P. KOBELTI (Pilsbry). PL 11, figs. 23, 24. 



Shell ovate, ventricose, whitish under an olivaceous yellow 

 or on the penult, whorl brown cuticle. Surface obliquely finely 

 plicatulate in the direction of growth-lines, and above the 

 periphery decussated by numerous rather inconspicuous 

 spiral impressed lines. Spire abruptly contracted above, 

 mucronate. Whorls about 6%, the earlier 2y 2 forming a 

 mamillar projection, the rest rapidly widening, last whorl 

 swollen. Suture narrowly white bordered from loss of 

 cuticle, and minutely beaded. Aperture oblique, reddish; 

 lip obtuse, brown-edged; columella whitish, vertical, rather 

 straight, subtruncate below. Alt. 68, diam. 41, longest axis 

 of aperture incl. peristome 38 mm. 



