138 CRETACEOUS GASTROPODA 
2. LAGENA SECANS, Sfoliczka. Pl. XI, Fig. 19. 
Lag. testa ovate elongata, turrvita, tenui; anfractibus ad medium acutissime 
carinatis, ultimo bicarinato; superficie spiraliter striata; apertura ?—labio levi; 
postice plicose dentato. 
Spiral angle 55°; sutural angle 6°—7°., 
This species, although not very rare, has not yet been procured in a desirable 
state of preservation, but its similarity to the preceding cannot leave a single doubt 
that it belongs to the same genus; in both, the structure of the shell is exactly 
alike. 
It differs from LZ. nodulosa in having the keel of the upper whorls sharper, 
devoid of any distinct tuberculations, and only one additional keel on the last whorl. 
The outer joins the inner lip on the upper keel, while in ZL. nodulosa the aperture 
does not reach higher than to the median keel. The shell surface exhibits no farther 
ornamentation than a fine spiral striation and equally fine strize of growth. Frag- 
ments of the upper whorls of specimens with not well preserved shell surface are 
much like Trichotropis (Turbo) Konincki, Mill. sp. 
Localities—Olapaudy, W. of Arrialoor, and 8. W. of Mulloor, in the Trichino- 
poly district. 
Formation.—Arrialoor group. 
XII. Fanily,—COLUMBELLIDZ. 
This family embraces a small number of genera, which agree in the ovate or 
elongated form of a rather solid shell, a very short anterior canal, often replaced by 
an emergination of the anterior extremity only, and crenulated or plaited margins 
of the aperture, which is very often much narrowed by the thickening of the lips, 
specially of the outer one. 
Dr. F. Rolle published in 1861 some very able notes (Sitzungsb. Akad. 
Wien., Vol. XLII, p. 261, &c.) on the different types of Colwmbella (sensu 
Lamarcki) which occur living and neogene, being represented in the cretaceous 
period by Columbellina, D’Orb. and in the upper jurassic strata by the genus Colwn- 
bellaria, Rolle (the typical species being Col. corallina, Quenst. sp., Cassis idem, 
Quenst.) ; it will be sufficient to refer here to these valuable observations. The 
living Colwnbelle have been divided by Bellardi and others into different sections, 
according to the varying form of the shells. Gray, Adams and others accept a cer- 
tain number of genera and sub-genera, and there can be no question that this 
system ought to be carried out; but great difference of opinion still exists as to the 
limits of these divisions, and they ought to be brought probably more into accordance 
with the apparently artificial classification of Bellardi. It does not seem likely 
that any other separation will practically sueceed, than one based chiefly on the 
principal variations in the form of the shell, otherwise we must still imcrease the 
number of the sub-genera, which are quoted by Chenu and others. No less difference 
