GASTEROrODOUa MOLLUSCA OF BERWICKSHIRE. 273 



8. jR. costata, shell conical, white with a brown tinge, thick, with 

 six rounded whorls strongl}^ striate in a spiral direction and ribbed 

 across, the ribs strong, many, somewhat waved ; aperture roimd- 

 ish, with a thick reflected crenulate rim, and a groove behind the 

 pillar. Length ^th. Turbo costatus, Mont. Test. Brit. 311. tab. 

 10. fig. 6. Cingula costata, Flem. Br. Anim. 305. 



Hah. Berwick Bay, rare. 



14. Odostomia. Fleming. 



" Shell conical ; aperture ovate ; peristome incomplete retrally, and 

 furnished with a tooth on the pillar." — Fleming. 



1. 0. spiralis, " whorls five, the lower part of the largest striated 

 spirally; the remainder of the shell ribbed transversely." Flem. 

 Brit. Anim. 310. 



Hah. In shell sand from Eyemonth. 



Shell conical, white, pellacid, the whorls five, flat, divided by a deep and 

 rather broad suture, transversely ribbed ; the body-whorl angulated 

 towards the base and marked with spiral ridges, the upper half crossed 

 with numerous plain flattish ribs. Length one line ; breadth half its 

 length. 



15. Skenea. Fleming. 



Shell discoid, smooth, the whorls rounded ; aperture circular, the 

 margin united all round ; operculum circular, horny. Littoral. 



1. S. depressa, shell depressed, corneous, flat above, widely umbili- 

 cate beneath ; whorls four, wrinkled across : aperture circular, 

 the margins free. Diam. one line. Flon. 'Brit. Aniva.. 313. Helix 

 depressa, Mont. Test. Brit. 439. tab. 13. fig. 15. 



Hah. On flat rocks between tide marks in Berwick Bay, in great profusion. 



The shell is blackish when alive : operculum horny. Tentacula two, filiform, 

 white, rather short, the eyes at their external base, sessile ; mouth pro- 

 boscidiform ; foot abort, tapered posteriorly, with plain margins. The 

 animal swims with great facility in a reversed position ; and in structure 

 appears to be almost identical with Rissoa. 



^ 16. VaLVATA, MiiLLEfi, 



'' Shell spiral, homy, the spire discoidal or only slightly elevated, with 

 rounded volutions ; aperture circular, with a continuous sharp-edged 

 rim ; operculum horny, spiral, its volutions numerous and close-set. 

 Fluviatile. 

 I. 



I 1. V. piscinalis, shell globular with an elevated obtuse spire, cor- 

 neous ; the whorls four, rounded, finely wrinkled across ; aperture 

 circular, the margins free ; umbilicus deep. Diam. nearly fths. 

 Flem. Brit. Auim. 28U. Turbo thermalis, Di/Iir. Eec. Sli. 852. 



