72 



of these casts, so that they do not give a very good idea of the original 

 contour of the spire, and the only surface markings that they show, are 

 numerous flexuous growth lines upon the outer volution. 



The umbilical side of a shell of this species is well seen in the gutta- 

 percha impression of a natural mould of the exterior of a specimen col- 

 lected by Mr. Townsend and the writer at Belwood in 1893, and repre- 

 sented by fig. 3 on Plate 11. In this specimen the peripheral alation of 

 the outer volution is remarkably perfect, the outer lip is clearly deiined 

 and the incremental strise are beautifully preserved. These latter are 

 curved concavely backward on the tubular part of the outer volution, and 

 obliquely as well as convexly outward and forward on the peripheral alation. 



From the additional information afforded by these specimens it would 

 seem that P. Valeria is most probably synonymous with P. alata. Still, as 

 the few specimens of P. Valeria that have been collected so far, are 

 neither sufficiently perfect nor well preserved to admit of a satisfactory 

 comparison with thg published descriptions and figures of P. alata, it is 

 thought better to provisionally retain the name already given to the 

 former. 



Pledeotomabia velaris. (N. Sp.) 



Plate 11, figs. 4 and 4 a. 



Shell conical, more than twice as broad as high : its base widely and 

 deeply umbilicated. Volutions perhaps as many as six or seven when 

 perfect, though only the last four are preserved in the single specimen 

 collected, those of the spire obliquely compressed, the alation of each of 

 its three later volutions partially overlapping and appressed to the volu- 

 tion that immediately succeeds it. Outer volution expanded laterally and 

 rather strongly convex next to the alate periphery above : the alation 

 broad and curving concavely outward and downward, as viewed from the 

 apical side : base of the tubular portion gently convex around the umbilicus : 

 aperture transversely subelliptical, a little broader than high. 



Surface of the apical side marked by low, rounded, flexuous, transverse 

 plications and strise of growth, also by numerous small revolving raised 

 lines or minute spiral ridges, that are more distinct upon the peripheral 

 alation of the last volution than upon its tubular portion. Crescents of 

 the slit band unknown. Base marked only by flexuous incremental strise, 

 that curve concavely and obliquely forward upon the tubular portion of 

 the outer volution, and convexly outward and forward on its alate expan 

 sion. 



The specimen described is not sufficiently perfect to admit of an accurate 

 statement of its proportionate dimensions, but both the figures are of the 

 natural size. 



