dd CRETACEOUS GASTROPODA 
IV. ROSTELLARIA, Lamarck, 1799. 
1, Rosreriarta PALLIATA, Forbes. Pl. IT, Figs. 18—20. 
1846. Rostellaria palliata, Forbes, Trans. Geol. Soc, Lond. VII, p. 129, Pl. 13, Fig. 15. 
4847. Fusus Fontanieri, D’Orbigny, Voy. Astrolabe et Zélée, Paléont. Pl. 5, Figs. 6 and 7. 
1850. Rostellaria palliata, Forb. D’Orb. in Prod. II. p. 228. 
1861. Calyptraphorus palliatus, Gabb. Proc, Am. Phil. Soc. VIII. p. 98. 
1864. Aporrhais palliata, Pictet and Camp. Mat. Pal. Suisse. me Ser. Foss. Ste.Croix, 2 pt. p. 629. 
Rost. testa cuspidiformi, depressa, levigata atque polita; juniore spira Susiformi, 
anfractibus planis, contiguis ; adulta anfractu ultimo subventricoso, ad basim spiraliter 
striato ; apertura elongate ovata, obliqua, antice (?) atque postice canaliculata; labro 
parum extenso, extus reflexo, postice callose pronato, spiram fere ad apicem dorso- 
lateraliter incrustante ; labro callosissimo, postice ad marginem intus subdentato, infra 
atque lateraliter totam spiram cum apice tegente atque canali augustissimo a callositate 
labri separato. 
The young shell of this species, or rather the first whorls of an imperfect shell, 
consists of about 5 or 6 flat volutions with scarcely impressed suture; the surface 
is smooth, exhibiting only fine strive of growth and on the basis of the ultimate 
whorl a fine spiral striation; the angle of the spira varies from 30 to 35 degrees; on 
the whole the species in this state resembles very much an Luwlima, or, when the 
anterior extremity of the columella is somewhat better preserved, a Fusus, for which 
it was mistaken by D’Orbigny (vide Fig. 19). 
Well preserved specimens and usually those of larger size and in advanced age, 
have the last volution by much the largest and somewhat inflated, but at the same 
time a little depressed and occupying about one-half or little more of the total height 
of the shell. This last whorl is equally smooth and polished, or finely striated, like 
the others. 
The aperture is elongated-ovate obliquely placed to the spire with a thickened 
inner and somewhat expanded outer lip. None of the specimens at our disposal have 
the anterior portion of the aperture perfectly preserved, but there are no certain 
indications of a long canal, as has been previously noticed. Most probably the 
aperture had only an anterior notch the outer margin being somewhat produced, 
as in the figure of Rost. levigata, Melleville, previously referred to (p. 24). 
The posterior canal is very distinct and separates both margins. The outer lip 
extends posteriorly as a callose band and covers the dorso-lateral portion of the 
preceding whorl up to near the spire; on the peristome it appears to be single, 
although not yet observed in complete preservation. ‘The inner lip bears, near the 
posterior canal, a thick tubercle-like tooth and envelopes in a similar way as the 
outer lip with its callosity the whole frontal (Fig. 20a) or ventral portion of the 
previous whorls up to the apex, extending over this also on the sides of the shell. 
There it is considerably thickened and on the dorsal side in its entire extension, 
beginning at the posterior termination of the aperture, separated by a very narrow 
canal from the callosity of the outer lip. The lateral thickening of the outer lip 
