NO. 2 NEW TURRITID MOLLUSKS BARTSCH 9 



Lamarck in 1816, in his " Tableau Encyclopedique et Methodique ", 

 figured on plate 439, as figure 2, the West Indian shell without 

 naming it. Wood, in 1818, in his " Index Testaceologicus ", on page 

 125, names this species Murex virgo, referring to Lamarck's figure 

 cited above. This appears to be the oldest available name for the 

 type species. 



The type of Polystira Woodring must therefore be Murex virgo 

 Wood = Polystira albida Woodring, not Perry. 



POLYSTIRA FLORENCAE, n. sp. 



Plate 3, figs. 4-7 



Shell rather large, fusiform, pale brown, excepting the large median 

 keel between summit and suture and a broad area that extends over 

 a little more than half of the posterior part of the columella, which 

 are white. The tops of the other spiral keels are also a trifle paler 

 than the spaces between them. The first 1.5 nuclear whorls are large, 

 well rounded, and smooth. These are followed by about one half of 

 a turn that is crossed by about 10 slightly retractively curved, axial 

 ribs, which are about one fourth as wide as the spaces that separate 

 them. The postnuclear whorls are marked by very strong spiral keels, 

 of which the most conspicuous one is the second one below the sum- 

 mit, which bears the deeply narrow posterior sinus. The first keel 

 occupies the space almost midway between the summit and this keel. 

 Anterior to the strong keel, there are on each whorl two additional 

 keels, one, the stronger, occupying the periphery of the whorls, 

 another a little nearer to the strong second keel than the peripheral 

 and slightly weaker than the peripheral. A slender spiral thread is 

 present midway between the summit and the first, and between the 

 second and third ; and two are present between the third and fourth. 

 The spaces between the keels are decidedly concave, and they are 

 crossed by slender, axial riblets, which are retractively curved pos- 

 terior to the strong keel and protractively curved anterior to it. In 

 addition to this the whorls are marked by microscopic lines of growth 

 and spiral striations. The base is short and marked by four keels, 

 which grow consecutively weaker anteriorly. In the middle of the 

 broad spaces between these keels is a slender spiral thread. A con- 

 tinuation of the axial sculpture of the spire is present here. The 

 columella is rather long, slender, and marked by oblique spiral cords, 

 which grow consecutively weaker anteriorly, becoming obsolete to- 

 ward the anterior tip. This also holds good for the continuation of 

 the axial sculpture, which likewise becomes enfeebled and obsolete. 



