TEREDO. 237 



its systematic position must still be regarded as uncertain, tor altliougli the tubes 

 ai'e common the valves Lave not been found in association Avitli them. Fritscli 

 (1893) and MiiUer (1898) liave Found the valves of 'I'lrnnis 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 (lastrorlin'i/u, l)ut 

 Stoliczka points out that the}^ resemljle more nearly the tubes of Teredo. 



Tijpea. — From the Senonian of Maestricht and Bochum. The specimens 

 figured by Sowerby (except fig. 2, which is in the British Museum), by Mantel), and 

 by Dixon cannot l^e found. 



Disfriliittioii. — C'hloritic Marl of Eastbourne. (Aunbridge Greensaud. Chalk 

 IMarl of Chard and Ventnor. Zone of Holaster suhglobosus of Holborongh near 

 Eochester, Totternhoe, Cherry Hinton, and Burwell. Zone of Bliijnclionella Cuvieri 

 of the Devon coast, Winchester, the Isle of AVight, and Lewes. Zone of Terehra- 

 tidiiKi of Winchester, the Isle of AVight, Croydon, and Devon. Zone of Holaster 

 phinus of the Dorset coast, the Isle of Wight, Dover, and Lnton. Zone of Micraster 

 cor-teshuVuutr'uim of Mitcheldevei-, Dover, the Sussex coast, and Coulsdon (Surrey). 

 Zone of M. cor-nnguinuin of the Sussex coast, St. Margaret's, Thanet, and Graves- 

 end. Zone of Marsiijntes tcstiidinarius of Highfield, near Salisburj-, the Sussex 

 coast, and Thanet. Zone of Actiuncnmax qitiidriifns of the Sussex coast. 



i^tr/H////— TEREDINID.E, Scacchi 



Genus — Tkreuo, Liiuia'its, 1758. 

 (' Syst. Nat.,' ed. 10, p. 651 ; ed. 12, 1767, p. 1267.) 



Tehedo GAUi/nxA, sp. nov. Plate XXXVIII, fig. 21. 



Prscri/ilioii — Shell convex, inequilateral. Anterior gape large, angular. 

 Postero-veutral gape small. Postero-dorsal margin produced upwards and out- 

 wards. L'mbones 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 furi-ows, which soon bend iloi'sally, and disappear or become indistinct on 

 the postero-doi-sal part; in front of the furrow tiie ribs are much smaller, and 

 are pai'alld to the margin of tlie anterioi' ga[ie; at first they are directed dorsally, 

 but soon bentl forwards. Length, 9 mm. ; l)readth, 8"-j mm. 



Affinities. — In 1\ rarennensis, Buvignier,^ 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. i,'('ol. mill, ot paKVmt. de hi Meiise," Atlas (1852), p. 6, pi. vi, figs. 40—48. 



