1918. J N. Annandale : MoIIusck of tic InJe Lale. 133 



We found four shells of this species on the He-Ho plain in super- 

 ficial deposits. They are all filled with peaty substance. I class the 

 form as subfossil, but it may have considerable antiquity. As it 

 occurred in much smaller numbers than the other forms associated 

 with it, it may not have lived in precisely the same habitat as T. 

 intermedia, 



Taia conica, sp. nov. 



Plate XV, fig. 8; plate' xvii, fig. 8. 



The shell is thick, of moderate size, conical in outline, sharply 

 pointed apically. There are seven complete whorls and a rudiment 

 of an eighth. The protoconch (apart from the rudimentary apical whorl) 

 consists of four whorls, of which the first three have together a pyra- 

 midical outline. They are all very small. The fourth whorl is con- 

 siderably broader, but not very much deeper than the third, and the 

 four together are only a little longer than the fifth, while the five are 

 not much longer than the sixth, and the six a little shorter than the 

 seventh or body-whorl. The suture is not deeply depressed ; on the 

 spire it runs almost transversely across the shell, but above the body- 

 whorl assumes a marked outward and downward obliquity. None 

 of the whorls are swollen. The spire as a whole is conical, the body- 

 whorl, as seen from below, truncate-ovoid, the broader and rounded 

 end being situated anteriorly. The aperture is oblique, broad and 

 patent, subtriangular but with all the angles rounded. The lip is a 

 little expanded outwards and forwards and joins the columellar callus 

 at the posterior end of the aperture. The callus is very broad and 

 almost smooth. 



The whorls of the protochonch are somewhat worn, though not at 

 all eroded, in my specimens. Traces can still be seen under the micro- 

 scope of a pair of spiral ridges. These ridges grow stronger on the fourth 

 whorl and gradually assume a coarsely granular structure. On the 

 fifth whorl they are still stronger, and a third ridge begins to arise below 

 them round the base of the whorl. On the sixth whorl they remain 

 much as on the fifth, but the new ridge becomes stronger and more 

 tubercular, while a fourth, which has from its commencement an irre- 

 gularly tubercular structure, appears at the base of the whorl and soon 

 grows stronger than any of the others ; on the ventral surface of the 

 shell its projections assume a distinctly squamous appearance. It is 

 this ridge that becomes the chief ridge of the body- whorl, on which 

 the upper of the two primitive ridges grows obsolete and disappears. 

 On the chief ridge of the body-whorl a series of strong but not exactly 

 spinous scale-like projections appear. They are truncate apically 

 and strongly concave outwardly. Below the chief ridge two others 

 and finally traces of a third make their appearance. These three ridges 

 are undulate or irregularly serrate on the surface. 



As the shell is only known as a fossil, nothing can be said about 

 its natural colouration. It is actually yellowish white, stained with 

 red. It retains a certain degree of translucency. 



