THEREDO. 237 
its systematic position must still be regarded as uncertain, for although the tubes 
are common the valves have not been found in association with them. Fritsch 
(1893) and Miiller (1898) have found the valves of Turis in the same deposit as 
the tubes, and think it probable that the former belong to the same species as the 
latter. Some authors have referred these tubes to the genus Gastrochena, but 
Stoliczka points out that they resemble more nearly the tubes of T'eredo. 
Types.—From the Senonmian of Maestricht and Bochum. The specimens 
figured by Sowerby (except fig. 2, which is in the British Museum), by Mantell, and 
by Dixon cannot be found. 
Distiibution.—Chloritic Marl of Kastbourne. Cambridge Greensand. Chalk 
Marl of Chard and Ventnor. Zone of Holaster subglobosus of Holborough near 
Rochester, Totternhoe, Cherry Hinton, and Burwell. Zone of Lhynchonella Cuvieri 
of the Devon coast, Winchester, the Isle of Wight, and Lewes. Zone of Terebra- 
tulinaw of Winchester, the Isle of Wight, Croydon, and Devon. Zone of Holaster 
planus of the Dorset coast, the Isle of Wight, Dover, and Luton. Zone of Micraster 
cor-testudinarium of Mitcheldever, Dover, the Sussex coast, and Coulsdon (Surrey). 
Zone of M. cor-anguinum of the Sussex coast, St. Margaret’s, Thanet, and Graves- 
end. Zone of Marsiupites testudinarius of Highfield, near Salisbury, the Sussex 
coast, and Thanet. Zone of Actinocamax quadratus of the Sussex coast. 
Lamily—TEREDINIDAN, Scacchi. 
Genus—TerrEDO, Linneus, 1758. 
(‘Syst. Nat.,’ ed. 10, p. 651; ed. 12, 1767, p. 1267.) 
TEREDO GAULTINA, sp. nov. Plate XXXVIII, fig. 21. 
Description —Shell convex, inequilateral. Anterior gape large, angular. 
Postero-ventral gape small. Postero-dorsal margin produced upwards and out- 
wards. Umbones large, incurved. A shallow furrow extends from the umbo to 
the ventral margin. Posterior to the furrow the shell is ornamented with ribs and 
narrow furrows, which soon bend dorsally, and disappear or become indistinct on 
the postero-dorsal part; in front of the furrow the ribs are much smaller, and 
are parallel to the margin of the anterior gape; at first they are directed dorsally, 
but soon bend forwards. Length, 9 mm.; breadth, 8°5 mm. 
Affinities—In T. varennensis, Buyignier,! the anterior ribs are coarser and the 
posterior end of the shell is more produced than in this species. 
Distribution.— Gault of Folkestone. 
1 «Statist. géol. min. et paléont. de la Meuse,’ Atlas (1852), p. 6, pl. vi, figs. 40—48. 
