4.24. CRETACEOUS GASTROPODA 
CV. RINGICULA, Deshayes, 1838. 
1. RineicuLta acuta, Forbes, Pl. XXVII, Fig. 3. 
1846. Ringicula ? acuta, Forbes, Trans. Geol. Soc., London, VII, p. 136, Pl. XV, Fig. 3. 
1850. Acteon subacutus, dOrbigny, Prodrome II, p. 220; idem., auctorum. 
Ring. testa ovato-turrita, spira producta, acuminata; anfractibus quinis, sub- 
convexis, sutura simplici, paulo impressa sejunctis, levigatis, ultimo spiraliter obsolete 
striato, striis ad terminationem anteriorem distinctioribus ; labro varicoso, uniforme 
arcuato, extus levi, intus crenulato ; labio valde incrassato, ad medium acute angulato, 
antice biplicato, plica antica in margine sita, obliqua; emarginatione angusta sed 
profunda. 
Spiral angle 60°; sutural angle 6°- 8°. 
Height of spire : total of shell (considered as 1:00) 00 Goo ees 
Width of shell : itsheight ...( ss Panes) a 600 . 0°56. 
This is a typical species of Ringicula extremely resembling some recent ones, 
occurring at Ceylon and at Aden. The spire is rather prominent and pointed, the 
surface of the shell smooth and polished, having only some obsolete spiral strize 
traceable on the last volution. 
The aperture is narrow, pointed and sub-canaliculated posteriorly, truncated 
anteriorly, the outer lip being varicose, externally smooth, internally crenulated, 
and posteriorly extending to nearly three-fourths of the height of the previous 
whorl. The inner lip is rather thick, smooth, about the middle sharply angular, 
near to, and on, the anterior margin provided with strong oblique folds. Imperfect 
specimens very much resemble Odostomia antiqua, n. sp. (see p. 182), having only 
the posterior columellar fold preserved. 
Forbes was perfectly correct in referring this species to Ringicula, while 
d’Orbigny placed it in the genus Act@on under a new specific name. 
Locality —Near Garudamungalum, in bluish calcareous sandstone ; rare. 
Formation.—Trichinopoly group. 
2. RINGICULA LABIOSA, Forbes, sp., Pl. XXVIII, Fig. 28 (original). 
1846. Tornatella labiosa, Forbes, Trans. Geol. Soc., London, VII, p. 135, Pl. XII, Fig. 24. 
1847. Acteon wnidentatus, @Orbigny, Voy. d’Astrolabe, Paléont., Pl. ITI, Figs. 22-25, idem, 1850, Prod. 
p. 219. 
1850. Avellana labiosa, @Orb., Prod. II, p. 220. 
1863. <Aptycha labiosa, Meek, Amer. Journ., Sc. and Arts, XX XV, p. 93. 
Ring. testa ovata, spira subturrita, apice acuminato ; superficie spiraliter lirata, 
apertura ampla, postice obtuse acuta et angulata, labro extus crassissimo, late 
varicoso, labio ad medium valde calloso, crenulato, antice tenwiori biplicato, plica 
antica brevi, in margine sita; emarginatione anterior lata ac profunda. 
Spiral angle 65°; sutural angle 2-10°. 
Height of spire : total of shell (considered as 1:00) 500 000 We O28s 
Width of shell : itsheight.., (  ,, es) O00 oe noo ORES, 
Shell with a produced, acuminate and somewhat irregularly twisted spire, 
surface narrowly spirally sulcated, one or two posterior sulci close to the suture being 
