l6 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. I25 



Genus PERISTICHIA Ball 

 1889. Peristichia Dall, Bull. Mus. Comp. Zool., vol. 18, p. 339. 



Shell turrited, whorls with strong axial ribs between summit and 

 periphery which extend feebly over the base. The spiral sculpture 

 consists of three strong cords that render the axial ribs strongly 

 nodulose. Base with two strong spiral cords, one immediately below 

 the periphery, which is weakly nodulose, and a second less strong on 

 the middle of the base, which is almost smooth. 



Type: Peristichia toreta Dall. 



PERISTICHIA MARTSCHI, new species 

 Plate 2, figure 6 



Shell small, elongate-ovate, cream-yellow. The nucleus is deeply 

 obliquely immersed in the first postnuclear turn. The postnuclear 

 whorls are very strongly rounded and marked by strong retractively 

 slanting axial ribs, of which 12 are present from the second to the 

 last whorl, the latter having 15. The intercostal spaces are a little 

 wider than the ribs. The spiral sculpture consists of three cords, of 

 which the first, which is at the summit, is a little less strong than the 

 other two and a little nearer to the second than that is to the 

 third. The junction of the axial ribs and spiral cords form strong 

 tubercles, those on the first cord at the summit being a little less 

 strong than the rest. The spaces enclosed by the axial ribs and spiral 

 cords are deep, squarish pits. The periphery is marked by a sulcus, 

 which is crossed by the strong axial ribs extending to the strong 

 nodulose basal cord immediately below the periphery enclosing pit- 

 tings like those on the spire. The base is slightly concave and bears 

 a strong median spiral cord, which is rendered feebly nodulose by 

 the threadlike extensions of the axial ribs. The aperture is sub- 

 quadrate; the columella is stout, oblique; the parietal wall bears a 

 weak callus; the outer lip is strongly angled at its junction with the 

 basal lip and rendered sinuous by the spiral cords. 



The type, U.S.N.M. No. 561671, comes from the Pliocene of 

 North St. Petersburg, Fla. It has 5.2 whorls and measures : Length 

 2.4 mm., diameter i.i mm. 



The species is named for William P. Martsch, who has done much 

 collecting in the region. 



