418 CRETACEOUS GASTROPODA 
anteriorly rounded; the outer lip sharp at the edge, internally smooth, anteriorly 
broadly effuse; the inner lip of moderate thickness, smooth, anteriorly with a 
slight, twisted fold. 
This species is principally characterized by its elongated and thin form; it 
closely resembles in this point the Neocomien Acteon Dupiniana, VOrb. (Pal. frang. 
terr. cret., II, pl. 167, figs. 1-3) which is said to have no columellar folds, and was 
therefore transferred to the genus Acteonina (or Orthostoma). 
Locality—N. of Odium, in yellowish and dark brown earthy limestone; 
very rare. 
Formation.—Ootatoor group. 
CI. TROCHACTAON, eek, 1863. 
On Plate XIV the species of this genus are noted under the name Actaonella. 
1. TrocHact£on TRUNCATUS, Stoliczka, Pl. XIV, Fig. 8. 
Trochact. testa cylindracea multi-spirata, involuta, levigata, supra truncata 
et lente excavata, partem superiorem omnium anfractuum exhibente; anfractibus 
numerosis, angustissimis, labio antice plicis tribus, acutis, subequalibus, sub-obliquis 
instructo. 
Approximate width of shell : its height (considered as 1:00) ... poo Nash, 
A sub-cylindrical shell composed of numerous, very narrow volutions, being 
anteriorly somewhat thinner, and at the apex truncate or rather excavated, so as 
to expose all the upper flat top-portions of the whorls; the three columellar folds 
are very sharp and not very oblique. 
The only known form which is allied to our fossil is Zroch. (Acteonella ) 
fusiformis, Coqg., being, however, much narrower at the truncate apex and forming 
in this way a passage to Acteonella (Monog. Etage Aptien de l’Espagne, 1865, 
p- 69, pl. 3, fig. 7). 
Locality —Shillagoody, in a light brown, rather siliceous sandstone ; apparently 
very rare. 
Formation.—Arrialoor group. 
2, TROCHACTHON MINUTUS, Stoliczka, Pl. XIV, Fig. 9; Pl. XXVIII, Fig. 17. 
Trochact. testa cylindraceo-elongata, levigata, spira brevi, obtuse acuminata, antice 
paulo attenuata ; anfractibus angustissimis, numerosissimis, postice anguste applanatis 
et prope suturam linea impressa notatis; labio tenui, antice imcrassato, oblique 
triplicato. 
Spiral angle 95°. - 
Height of spire : total of shell ee» (considered as 1:00) 300 eee 0°20. 
Width of last whorl : height of shell ( : i cor) ary oo. 0°40. 
This species has usually a broadly pointed, more or less short spire, consisting 
of numerous volutions, which are posteriorly obliquely flattened and closely marked 
