MADE1HAX SPECIES OF LAUBIA. 95 



compact, short, broadly short-oblong, obtuse at botli ends, 

 the width subequal in the last 2-2 Vl> whorls, forming %-% 

 of the length, then the rest of the whorls suddenly contract- 

 ing in a slightly projecting umbonate apex, all obsoletely 

 striatulate, smooth, shining; dark browu (the spire decor- 

 ticated and white towards the apex), very narrowly 1 to 2 

 banded with paler color. Whorls 6, flattened or a little 

 convex, (the last 2 or 3 abruptly swollen and projecting be- 

 low the somewhat channeled suture, the last whorl anteriorly 

 more distinctly concave in the middle, or lightly spirally 

 subeanaliculate preceding the labrum, traversed by somewhat 

 Huxuously oblique obsolete striohe, the impressed suture 

 deeply cut. Aperture siubtrilobate-auriform or triangular, 

 the angles rounded, ringent, 5-plicate ; 2 ventral folds, the 

 exterior larger, 2 columellar, the lower one larger, 1 palatal; 

 two centrals and the lower columellar subequal, large, the 

 upper columellar and palatal smaller, less conspicuous, im- 

 mersed; outer lip somewhat thickened, a little reflected, in- 

 flected above, a distinct tooth projecting inward at the sinus; 

 respiratory sinus nearly entire. Length 3, diam. 2'-, 

 aperture 1 mm. long, 1 wide; 6 whorls. {Lowe). 



" At once distinguished from P. concinna Lowe by its 

 much greater proportionate breadth and short, thick squarish 

 figure; and from P. gibba and P. abbreviata, besides other 

 differences, by its being so much larger. There is also much 

 about it which reminds one of P. cassida and P. cassiduht, 

 but it is most distinct from all, especially by the abrupt con- 

 traction of the spire about the last two or three volutions, 

 and by the scalariform character of these, each rising up 

 into a blunt keel or ridge below the deeply impressed or sub- 

 canaliculated suture. The colour also is peculiar, being 

 more of a dark umber than chestnut brown, with two re- 

 mote, narrow pale bands, one at the base, the other on the 

 infrasutural ridge or shoulder at the top of the last volution, 

 but these will probably prove variable and even in the pres- 

 ent example the upper band is obscure and inconspicuous. 

 The spire is abruptly contracted above the second or third 

 volution into a short obtuse decorticated umbo; the lowest 

 two or three volutions are of nearly equal breadth, or broadly 

 and shortly barrel-shaped, and the last is spirally concave 

 or slightly grooved or channeled a little way backward from 

 the outer lip below the middle. The aperture, both in shape 

 and in the form, size and proportion of its plaits, differs from 

 that of all the species, above mentioned. The umbilicus is 

 moderately Large and infundibuliform. 



