VARICELLA. 55 



Bulimus (Melaniella) pickardi ARANGO, Journ. de Conch. 

 1862, p. 409. PFR., Monogr. vi, 103; Novit. Conch, p. 427, 

 pi. 96, f. 21-23. Melaniella pichardi Ar., CROSSE, Journ. de 

 Conchyl. 1869, p. 21, pi. 1, f . 5 ; J. de C. 1890, p. 249. 



''Similar fto the nearly unarmed variety of acuticostata 

 [var. filipensis], but it differs by the entirely unarmed ribs, 

 and by having the whorls flattened [like -a narrow shelf] be- 

 low the suture, not sloping up to it as an acuticostata. The 

 color also is darker. It differs from tuberculata Gundl. by 

 the unarmed ribs and more numerous, longitudinal [spiral] 

 lines. It is larger than gracillima and manzanillensis, and 

 has longitudinal [spiral] lines." (Arango). 



A typical specimen is figured, length 12, diam. 3, aperture 

 3.2 mm., with 9 Whorls, the first 3 embryonic, delicately 

 6'triate as in V. acuticostata. The later whorls are quite con- 

 vex and peculiarly turned in just below the suture, else- 

 where flattened. There are about 13 to 15 vertical ribs on 

 the last whorl, besides two or sometimes three sigmoid varices. 

 In each interval there are about 18 to 20 very fine striae paral- 

 lel to the ribs, but 'Crinkled where they pass over the low 

 spiral 'cords. The aperture is like that of acuticostata or a 

 little more narrowly pirif orm. 



In the very closely related V. a. filipensis, there are weak 

 traces of nodes or spines on the ribs ; the shell is larger with 

 dark streaks behind the varices, and there are not so many 

 intercostal striae. 



V. pickardi, V. a. filipensis, V. acuticostata an'd V. a. kor- 

 rida form a series of progressively more strongly sculptured 

 forms, which will probably prove to belong to one species. 



3. Y. GRACILLIMA (Pfeiffer). PL 14, figs. 26, 29, 30. 



Shell imperforate, subulate, thin, sculptured with nearly 

 straight longitudinal ribs and very close parallel lines in the 

 intervals off the ribs ; pale corneous- whitish ; suture impressed. 

 Whorls 7 to 8, flattened, the last slightly more than one- 

 fourth the total length, obtusely angular below 'the middle. 

 Columella subsimple, forming an angle at the base of the 

 aperture. Aperture oval-subtriangular ; peristome simple, 



