114 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxxi. 



abruptly anteriorly and more gradually posteriorl3\ The insertion of 

 this lamella is near the floor of the whorl; from that point it curves 

 upward and outward, then aoain downward at the free edge. The 

 latter in the penultimate whorl is at about one-third of the distance 

 between the floor and the roof above the floor, and extends about one- 

 third the wa}' across from the columella to the wall. In the penulti- 

 mate whorl the lamella is thickened at regular intervals on its upper 

 surface, lending to this a somewhat beaded effect. These thickenings 

 are not very prominent but rather low and broad. In the antipenul- 

 timate whorl the lamella is cut by a series of regularly spaced, obliquely 

 forward curved slits, which extend about one-third of the way from 

 the peripher}^ of the lamella toward its insertion. The type. Cat. No. 

 186161, U.S.N. M., was obtained by Dr. R. E. 0. Stearns from Bland 



Fig. 1.— Interior view of Fig. 2.— Detail of pillar of 



Anisospiea stearnsi. Anisospira steaensi. 



and is said to come from near Mazatlan. It has T whorls and measures: 

 Length, 30 mm. ; diameter of penultimate whorl, 11.6 mm. ; diameter of 

 fourth to last whorl, 12.5 mm.; diameter of first whorl, 7 mm. 



ANISOSPIRA (DISSOTROPIS) BLANDI, new species. 

 Plate III, fig. 3. 



Shell subcylindric from the last to the seventh to last whorl, the next 

 two evenly and suddenly contracted, the first is less sloping, and lends 

 the spire a capped appearance. Decollated apex very minutel}^ punc- 

 tured. Plug evenly, finely granulose. Whorls moderately rounded, 

 marked by numerous, equally developed and evenly spaced, low 

 rounded, obliquely backward curved thread-like riblets, of which about 

 120 occur upon the fourth to last whorl. The spaces between these 

 riblets are a little less than twice as wide as the riblets. Sutures well 

 impressed. Periphery of the last whorl angular. Base somewhat 



