BULLA. 383 



Bulla striata Brugiere, Encycl. Meth. i, p. 572. — Phil. INIoll. 

 Sicil. i, p. 121. — Weinkauff, Conchyl. Mittelm. ii, p. 191. — B.om- 

 jD^a^odes Mke., Zeitschr. f. Mai. 1853, p. 137; Malak. Bl. i, p. 

 44r. — B. colmnme Della Chiage, Test. iitr. Sicil. iii, 2, p. 24, t. 46, 

 f. 17, 18.— i?. dactylis Mke, Zeitscbr. f. Mai. 1853, p. 137.— 5. stri- 

 ata var. attenuata Dall, Trans. Wagner Free Instituteof Science of 

 Philadelphia iii, pt. 2, p. 219, pi. 13, f. 10a. 



The prominent features of this Mediterranean species are its nar- 

 row vertex, widely open apical umbilicus, and the striation of both 

 ends of the shell. There is a variety (from Algeria, etc.) in which 

 the umbilicus is much narrower, not striated within, and without 

 spiral grooves at the upper end ; but my material is not sufficient to 

 show what status this form has. It may be a variety or a mere 

 random variation. Smith has reported striata from St. Helena, but 

 his synonymy is incorrect. 



Specimens from the western Mediterranean are large, dilated 

 below, with compressed outer lip and rounded basal lip ; the super- 

 ior stride few or even obsolete, color as in the type, or boldly clouded 

 with black longitudinally. Figures 42, 43 represent shells of this 

 sort. Alt. as much as 30 mill. 



I have satisfied myself by a comparison of specimens that Ball's 

 var. attenuata from the Pliocene of Shell Creek, Florida, is absolutely 

 identical with typical Mediterranean shells, such as the Grecian 

 specimen drawn in fig. 46 of pi. 37. It is likely that in Pliocene 

 times the species striata had a wide range embracing the Mediter- 

 ranean, West African and Antillean regions. It has persisted 

 almost unchanged in the former of these, and in West Africa and 

 America has diverged to form several ill-defined species, adansoni, 

 occidentalis, amytjdala, etc. However, a recent specimen collected 

 by C. W. Johnson at Clearwater Harbor, W. Florida, is indistin- 

 guishable from the Mediterranean types, having the same com- 

 pressed and widely umbilicated vertex, and subtruncate columella. 



B. ADANSONii Philippi. PI. 38, fig. 61. 



Shell ovate-oblong, solid ; whitish variegated with gray and 

 black, striated below. Vertex perforated. Aperture dilated below, 

 narrow above, the lip depressed and rectilinear in the middle. 

 Alt. 11, diara. 6J lines. Shell smaller and more ventricose than B. 

 striata of the Mediterranean, and ditiering in the very narrow apical 



