336 BULLA. 



not unquestionable, but is likely. Some specimens before me agree 

 very well with Knorr's figure. Ou pi. 43 , figs. 1, 2, I have illus- 

 trated what I take to be a typical specimen from the Gulf of Mar- 

 aeaibo. Fig. 54 of pi. 38 is also typical, but worn, from Vera Cruz. 

 Figs. 36-38 of pi. 37 represent a large individual with the outer 

 Avhitish coat worn off, showing the brown under-color; for the 

 purple tint of unrubbed specimens seems to be the effect of a milky 

 film laid over brown markings, just as we find it in many bird's 

 eggs. 



B. ROPERiANA Pilsbry, n. sp. PI. 48, figs. 19, 20. 



Shell oval, similar in contour and general appearance to B. solida 

 Gmel., but smaller, thinner, with the internal columellar ledge of 

 callus more developed. 



Color purplish, irregularly and copiously sprinkled with whitish 

 dots, sometimes coalesing into short zigzags, each shaded on the left 

 side with slaty- or purplish-black. Surface polished, with no spiral 

 grooves at base or vertex, but showing under a strong lens an ex- 

 cessively fine (in places vanishing) spiral striation — far more 

 minute and indistinct than in B. solida. Apical umbilicus moderate, 

 about as in B. solida, with 7-9 spiral grooves on the last whorl 

 within. (In B. solida they are fewer and more spaced, sometimes 

 obsolete). Outer lip evenly arcuate; columella arcuate, with a 

 reflexed crescentic callus the outer edge of which is lead-brown ; 

 inner edge thickened below by a ledge of callus somewhat as in the 

 typical B. striata. Parietal callus thin, extending far out of aper- 

 ture, and downward to the middle of the columellar crescent, the 

 outer edge of which is elevated below the junction of the appressed 

 parietal film; no umbilical chink. Alt. 22, diam. 15 mill.; a 

 smaller specimen measures, Alt. 20, diam. 14 mill. 



Balearic Is. 



Several specimens occurred among B. striata of the form shown 

 in figs. 42, 43 of pi. 37, communicated to me by Mr. E. W. Roper 

 of Revere, Mass. Its only ally in the Atlantic seems to be the 

 West Indian B. solida. B. perdicina Mke., which I have not seen, 

 is a much narrower species; Menke's measurements being (in 

 jnillimeters) about 20 by 11 mill. 



{Deep sea species, white or without mottled color-pattern.^ 

 B. GUERNEi Dautzenberg. PI. 39, figs. 68, 69 70. 



Shell 3 mill, high, 2 mill, wide ; convolute, solid, ovate-globose. 

 J'irst whorl almost wholly concealed ; last whorl very narrowly per- 



