GASTEROPODA. 47 



Shell elongato-fusiform ; turreted, \Adth an obtuse apex ; whorls 7 — 8, convex, striated 

 along the volutions ; outer lip sharp, slightly sinuous ; aperture ovate, terminating in 

 an elongated and curved canal. 



Axis, 2 5 inches. 



Localifi/. Cor. Crag, Gedgrave. 

 Red Crag, passim. 

 Mam. Crag, Bridlington. Recent, British Seas. 



Abundant in the Red Crag ; and I have recently obtained two specimens from the 

 Coralline beds. The latter present a slight difference in sculpture from the recent 

 specimens, having the strias, or ridges, which cover the exterior of the shell, flatter and 

 broader, with narrow sulci between them. In the recent shell the striae are narrow, 

 sharp, and elevated, with broad spaces intervening. Among a large series fi-om the 

 Red Crag these markings may be obsen-ed to vary ; they are generally flat and broad, 

 but in some they are sharp and narrow. In many specimens the shell is left nearly 

 smooth, with a deep depression at the suture, which is the principal difference between 

 the fossil and the recent shell, and is probably produced by alteration or loss of a por- 

 tion of the shell, as, in some instances, the volutions appear nearly separated. The 

 apex is obtuse and smooth, but can scarcely be said to be mammillated, and the canal 

 is generally a good deal twisted. Some specimens are short and tumid, with a 

 diameter three sevenths of the axis, while others are elongated, with a diameter only 

 one third. The same proportionate variations may be observed in the recent shell. 



A specimen, sent from Mr. Bean, with a label " F. Listen, Crag, Bridlington," 

 appears to me only a variety of this species. 



4. Trophon altum. S. Wood. Tab. VI, fig. 13, a — h. 

 FusDS ALTDS. S. Wood. Catalogue 1842. 

 MuREX PULLUS (?). Woodward. Geol. of Norf. t. 3, fig. 2", 1833. 



Tr. Testa turritd, altct, subidatd, tenui ; anfractibus 1 — 8, convexis, longitudinaliter 

 obsolete costatis, et transversim striatis ; aperturd ovatd; labro tenui, intus Icevigato; canali 

 brevi vix recurvd. 



Shell fusiform and turreted ; very thin, with an obtuse apex ; volutions 7 — 8, convex, 

 with obsolete longitudinal costse, and the remains of transverse striae ; aperture ovate, 

 terminating in an open and short canal, slightly inflected; outer lip faintly sinuated. 



Axis, nearly 2 inches. 



Locality, Red Crag, Butley, near Orford. 



About a dozen specimens were found by myself many years since at a locality where 

 a section of the Crag is not at present visible. The specimens are evidently in an 

 altered condition, like the attenuated specimens of Bm. undatum, var. tenerum, many of 

 which were found with them at the same time. The cause which reduced the sub- 

 stance of the one no doubt acted in the same way upon the other. The canal is 

 shorter and more open than in T. (/racile, and it is a little imbricated behind the left 



