88 CRETACEOUS GASTROPODA 
contracted portion of the whorls next the suture they are always distinct, often 
laminated and bent inwards, according to the thickened margin of. the respective 
portions of the outer lip. On this same portion of the whorls, the spiral strize are 
occasionally more numerous and finer; sometimes there are only three of them, 
equally distinct, or even two only close together near the suture; rarely they are 
wanting entirely. All these variations are not at all connected with the form of the 
shell, but they depend very often upon the state of preservation, or on the age and 
on the strength of the strize of growth. 
On larger grown specimens the posterior portions of the outer lip remain so 
strongly marked, that they cause every other ornamentation to become obliterated 
(see Figs. 4,9a.). The anterior portion of the outer lip is sharpened, and according to 
the elevation of the exterior striz undulating on its margin and internally sulcated. 
The inner lip is thickened, and its callosity often extends over the entire fore-part of 
the last whorl. There are, without exception, so far as has been observed, only three 
oblique folds present, and the interior portion of the columella is very much flattened, 
flanking the side of the aperture nearly perpendicularly and bearing the folds so 
far internally, that there is barely a trace of them perceptible in the apertural space on 
the perfect shell. The embryonal whorls are smooth, but not so markedly enlarged 
and papillose as usually in the rozvrzyv or in the recent Pulguraria. 
We come now to the variations in form, and in this point of view we are able to 
distinguish three principal varieties. 
Var. a.—The spire is short with an angle of from 55—80 degrees, the posterior 
portion of the whorls along the suture is concave, the angle below sharp, tubereulated 
in young specimens in consequence of the elevated terminations of the transverse ribs, 
(see Figs. 8 and 9), the tubercles disappearing perfectly im full grown specimens 
and being replaced by a smooth keel (vide Fig. 5). This is a very common variety 
throughout the upper beds of the South Indian cretaceous deposits. Romer’s first pub- 
lished figure of this species refers to this variety. (Vide Pl. VII, Figs. 4, 5, 7, 8, 9.) 
Var. b.—tThe entire shell is slender, the spire produced, the striz: on the con- 
tracted portion of the whorls usually 5-6, and on the last whorl distant transverse 
ribs sharpened on the keel in young, and indistinctly tuberculated on larger grown, 
specimens. D’Orbigny’s and Zekeli’s figures refer to this variety. (Vide Pl. VII, 
Figs. Land 2). The Mitra Murchisoni of Miller could also belong to this variety. 
Var. c.—Shell very much elongated with numerous fine spiral strize on the 
contracted portion of the whorls, the other strize on the last whorl from the first not 
very thick and usually soon becoming more or less obsolete in more largely grown 
specimens. Keel more distinct in elder specimens than in smaller, the transverse 
ribs less except on the keel itself, where they form pointed tuberculations. ( Vide 
Pl. VII, Figs. 3, 6.) 
Bach of these varieties, although not strictly confined to certain localities, may 
be said to prevail at one or the other. The Var. a. is most common at H. of 
Alundanapuram, W. of Kullgoody and EB. of Anapaudy; the Var. 6. near Koloture 
and Veraghoor; and the Var. c. near Serdamungalum. The species is in general very 
common throughout the Trichinopoly district, and there are several small specimens of 
