OCINEBRA TORTUOSA. 125 



Street Museum. 0. crinacca must be very rare in tlie Crag, as with the exception 

 of the fragment found by Mr. A. Bell at Butley and some doubtful specimens from 

 Harwich and Bramerton alluded to l^y Wood, it has not been recorded from those 

 deposits. 



Ocinebra tortuosa (J. Sowerby). 



1825. Miirex tortuosus, J. Sowerby, Min. Conch., vol. v, p. 48, tab. ccccxxxiv, fig. 2. 

 1848. Mttrex tortuosus, S. V. Wood, Mon. Crag Moll., pt. i, p. 40, tab. iv, fig. 9. 

 1881. Murex tortuosus, Nyst, Couch. Terr. Tert. Belg., p. 3, pi. i, fig. 1. 



Var, boytonensis, nov. Plate XII, fig. 8. 



Dimensions. — L. 36 mm. B. 18 mm. 



Distribution. — Not known living. 



Fossil : Coralline Crag : Boyton, Kamsholt. 



BemarJis. — Specimens of 0. tortnosa from the Coralline Crag of Boyton and 

 Ramsholt which, as before stated, is possibly an intermediate horizon between that 

 of Gedgrave and the Red Crag of Walton, are to be found in the Museums at South 

 Kensington, Cambridge, York, and elsewhere, and may be generally recognised by 

 their special character and appearance ; they differ from those usually found in the 

 Red Crag in form and sculpture {cf. Wood's figure). The Miocene shell from the 

 Vienna basin described by Homes as M. tortuosus seems to be a different species.^ 



Var. minor, nov. Plate XII, figs. 9 — 11. 



1903. Murex tortuosus, Lamplugh, Mem. Geol. Surv., Isle of Mau, p. 475. 



Distribution. — Not known living. 



Fossil : Coralline Crag : Boyton. Waltouiau : Little Oakley. 

 Probably elsewhere in the Red Crag. Isle of Man. 



Dimensions. — L. 25 mm. B. 12 mm. 



BemarluS. — Of this shell I have about fifty specimens from Oakley which seem 

 to be full-grown. They appear to represent a dwarf form of the typical Crag 

 species ; there are similar fossils from the Manx drift in the Jermyn Street Museum. 

 They are thinner in texture and more delicately sculptured than the bulk of the 

 Crag shells or than that figured by Wood, 



1 Foss. Moll. Tert. Wien, vol. i, p. 249, pi. xxv, fig. 12, 1856. 



