PERIDERIOPSIS. 



columella is not so distinctly truncate. The area inhabited 

 by Perideriopsis lies south of that of Pseudotrochus, and is 

 inland, while the other genus has not yet been found far 

 from the coast. 



1. P. UMBILICATA Putzeys. PI. 17, fig. 85. 



Shell perforate, conic-turrite, rather solid, a little shining, 

 striatulate, frequently decussate irregularly and very deli- 

 cately with spiral lines. Spire long, conic, the apex obtuse; 

 suture impressed, delicately wrinkled. Whorls 7-8, a little 

 convex, the upper white or roseate, following ones slightly 

 yellowish, irregularly ornamented with streaks or flames of 

 tawny or chestnut; last whorl subangular, the base marked 

 with buff or chestnut, with a white band below the angle. 

 Aperture trapezoidal, somewhat channelled; lip acute, the 

 base visibly reflexed, thickened within; columella callous, 

 straight, vertical, white or violaceous; margins joined by a 

 very thin parietal callous, the columellar margin reflexed 

 above the perforation. Length 40-45, diam. 15-18, length 

 aperture 15-18 mm. (Putz.). 



Congo Free State: Bena Bendi (Putzeys). 



Perideriopsis umbilicata PUTZ., Proces-verbaux des seances 

 de la Soc. Roy. Malac. Belg., 8 Jan., 1898, p. vi, fig. 5. 

 P. umbilicata, var. nsendweensis (p. xxxix), and var. albida, 

 lowaensis (p. xl) DUPUIS et PUTZEYS, Ann. Soc. Roy. Malac. 

 Belg., Bull, des seances, 1901 (March, 1902). 



la. Var. NSENDWEENSIS Dupuis et Putzeys. PI. 8, figs. 43, 44. 

 Resembles the type, but the upper part of the last whorl 

 and the upper whorls are irregularly marbled with spots 

 and flames of brownish and purple of various shades on a 

 whitish ground. These patches or flames become roseate or 

 deep brown towards the summit, which is generally roseate. 

 'The lower half of the last whorl is black-brown from the 

 "basal angle to the umbilicus, a belt of irregular yellowish 

 spots lying below the angle. These spots may be reduced to 

 a series of dots, or may form flames converging to the per- 

 foration. Length 45, diam. 18, length apert. 16, width 14 mm. 



