138 PLIOCENE MOLLUSCA. 



Dimensions. — L. 30 — 40 mm. B. 15 — 20 mm. 



JJistrilmtion. — 'Recent: Puget Sound, Sitka (?). 



Fossil : Waltonian Crag : not very rare at Little Oakley. 

 Newbonrnian. Butleyan. 



Remarks. — This form, originally described by Sowerby, may be regarded as a 

 variety of L. cosfi/cr. Although differing considerably from the typical shell, I 

 have specimens from Oakley which more or less nearly connect them. 



Wood figured two varieties of S. costifer, one of them having finer and more 

 numerous ribs than the other, Avhich, however, extend in both to the body- whorl. 

 In my Oakley specimens of the present variety, on the contrary, the longitudinal 

 sculpture tends to die out on the penultimate whorl, and disappears on the last. 

 It does not seem to have been known to Wood, and is but rarely represented in 

 our public collections. Although fairly common at Oakley, I believe it is less so at 

 other horizons of the Red Crag. It is a somewhat more delicate shell than the 

 type, in which the sculpture is often very coarse, and it seems to pass into the 

 variety pulchra, next to be described. 



I have lately received from Mr. Alfred Bell some specimens procured at the 

 sale of the Damon Collection, labelled Fusus {Neptiinea) incisus, Gould (Puget 

 Sound) = Chrysodomns Sitl-eiisis, Middendorff, one of them being here represented 

 (PL XIII, fig. 2). Although not known living nearer to us than the west coast 

 of North America, it seems allied to the Crag shell. 



Var. pulchra, nov. Plate XIII, fig. 12. 



Dimensions. — L. 30 mm. B. 16 mm. 



Distribution. — Not known living. 



Fossil : Waltonian Crag : Little Oakley. 

 Remarhs. — This is a smaller and more delicate shell with finer sculpture than 

 the one last described. I have a dozen specimens or more from Oakley. 



Var. elongata, nov. Plate XIII, fig. 5. 



Dimensions. — L. 42 mm. B. 17 mm. 

 Distribution. — Not known living. 



Fossil : Waltonian Crag : Little Oakley. 

 Remarhs. — Specimens from Oakley having an elongate spire, like that here 

 figured, belong as a rule to the /3. variety; they are not common. 



Var. cancellata, nov. Plate XIII, fig. 4. 



Dimensions. — L. 40 mm. B. 21 mm. 

 Distribution. — Not known livino:. 



