PLEUROTOMARIA. 403 
1873. Prevroromarta Agatua, d’Orbigny. Tawney, Dundry Gasteropoda, p. 
40 (32). 
Svn, — MUTABILIS, var. c@LAta, Deslongchamps. Vol. cit., 
p- 109, pl. x, fig. 17. 
Bibliography, Sc.—It is through the figure rather than the description that 
English specimens are connected with the var. cwlata of Deslongchamps. On the 
other hand, as pointed out by Tawney, d’Orbigny’s figure more nearly resembles 
the var. corrugata than the var. celata of Deslongchamps. The principal 
characters by which I recognise Pl. Agatha are (1) the nodular character of the 
caring, and (2) the coarse ornamentation of the intercarinal spaces. 
Description : 
Height (full size) : : s . 50 mm. 
Basal diameter : ; F 5 0) seanan,, 
Spiral angle é : 5 Or, 
Shell conical, thick, not umbilicated. The spire is shghtly concave. The 
whorls are flat, but owing to the prominence of the caring in some cases appear 
to be concave. The suture is extremely close. In the more typical forms the 
carine are coarsely nodular, and the intercarinal groovings (spiral) are deep and 
coarsely decussated. 
The sinus-band is narrow, flat, and inconspicuous, and situate very close to 
the basal rim or carina. The body-whorl is more or less angular at the periphery, 
the base varying from rather flat to subconvex with spiral strie. The aperture 
is subdepressed, with an oblique inner lip and but slight trace of the columellar 
notch. 
Var. Sandersii, Tawney. 
1873. Pxrevroromarta SanpeErstt, Tawney. Dundry Gasteropoda, p. 39 (81), 
pl. in, fig. 1. 
The indications, as noted by Tawney, are very much those of Deslongchamps’ 
var. celata. But the whorls and also the base are more convex. The sinus-band 
alsois very sunken and flat. 
The unique specimen on which this variety is founded comes from Dundry. It 
is in a highly crystalline condition, a circumstance which may partly account for the 
peculiarities of the sinus-band. 
