212 CRETACEOUS GASTROPODA 
At last come the species from the Gosau and a few from Northern Germany. 
They have been enumerated by Pictet et Campiche (Mat. Pal. Suisse, 3me. Ser., 
pp. 324-825, under sect. 2 and 3 of Twrritelia) and in part critically examined by 
myself (Revision der Gosau-Gastropoden, p. 15, ete., in Sitzb. Akad., Wien, 1865, 
Vol. LIT). I may add, that I have since examined the originals of D’Orbigny’s 
Turritella Bauga, and believe it to be a true Zurritella, not a Glauconia as 
stated in my paper. IJ have also examined the specimens of D’Orbigny’s Twrr. 
provincialis (Prod. II, p. 217,) and found them to be identical with the Glauconia 
conoidea, Sow. sp. from the Gosau deposits of the North-eastern Alps. 
In our South Indian cretaceous deposits only fragments have as yet occurred, 
which could doubtfully be referred to Glauconia. 
2.—Arcotia, Stoliczka, 1868. 
Arc. testa turrita, elongata, crassiuscula; anfractibus spiraliter striatis ; striis 
incrementi rectis, non sinuatis; columella excavata; apertura angulate-rotundata, 
antice sub-effusa. 
The species, described under the name of <Arcotia indica, Stol. (p. 215 ) is 
considered as the type of the genus. The difference from Zwrritella (as restricted) 
consists in the want of any insinuations on the strize of growth, and in the presence 
of a hollow columella. 
The only other fossil species, which we were able to trace as belonging to this 
genus, is the Turrit. Roissyi, d’Arch. from the oolitic — (with Zerebratula decorata, 
Schloth.),—beds near Eparcy, in the dept. of Aisne in France, (Mem. Soc. Géol., 
France, 1842, Vol. V, p. 380, pl. 30, fig. 2). The genus recalls, moreover, some 
paleeozoic species, which are often referred to the Trocuzpa, like Trochus Yvanii 
Léveille, (Mem. Soc. Géol., France, 1835, II, p. 39, pl. 2, fig. 24) and oth. 
Dunker describes (Journ. de Conchiliologie, 1862, Vol. X, p. 354, pl. 18, 
fig. 8), a recent Turr. umbilicata [non idem Coquand, 1859]; but the specimen, 
which he figures, is evidently a very young shell, and the strize of growth are not 
marked, for which reason it is difficult to say whether it belongs to Arcotia. 
3.—Desalia, Gray, 1842, a form of Turritella, which is characterised by 
having the last whorl much larger than the others, the aperture more produced 
anteriorly, and the columella somewhat twisted at its termination. It strongly recalls 
the form of Sandbergeria in the Cerrraupmx. There are several very characteristic 
species known from tertiary deposits, and Deshayes (Paris foss., Vol. IT, p. 322, etc.,) 
accepts Mesalia as a division of Turritella, proper. Cretaceous species are as yet 
scarcely known. The Chem. clathrata, Binkh. (Monog. Gast. et Ceph. Limbg., 1861, 
pt. I, p. 22, pl. 5, fig. 4) is probably a Mesalia. 
4.—The name Lithotrochus has been proposed by Conrad for the Turritella 
Humboldtii, Buch., sp. (non idem, J. Miiller, 1851,—7Z. Andii, d’Orb., Mem. Soe. 
Géol., France, 1851, IV, p. 12, pl. 2, figs. 7-8). This is no doubt a remarkable 
form, differing considerably from all true Twrritell@, and approaching somewhat to 
Mesalia, but it has not the produced basis of the last whorl of that genus, unless 
