G50 



et:poft— 18C3. 



236. Leptochiton nexus, n. s. Like asellus : seai'cely sculptured : mantle-margin with 



striated cbafTy scales^ like 3£uydalensis, interspersed with transparent needles. 

 20-80 fm. Cp. 



237. Acanthochites avicula, n. s. Like arragonites, but valves sculptured in large 



snake-skin pattern. 8-20 fm. r. Cp. 



Family Patellidce, 



238. Nacella instahilis, Gld. E E. Large : shape of compressa, 



239. Nacella incessa, Hds. Sidphur. Small : Ancvloid. 



240. ? Nacella .subspiralis, n. s. Shaped like Emaryimda rosea, and may be a Scutel- 



lina. 10-20 fm. Cp. 



241. Nacella depicta, Hds. Sulphur. Small, long, flat, smooth : colour in rays. 



242. Nacella paleacea, Gld. (Jtia. Narrower, brown, striated at each end. 



242b. Nacella ?var. triangidaris. Shorter: apex raised: scarcely striated : whitisbj 

 with brown spots. 



Family Acmaidce. (For sjTionyms, v. Reports in locis.) 



243. Acmcea patina, Esch. Large, blackish or tessellated : with very fine distant 



strise. Between tides, Lord. 



244. Acm<ea pelta, Esch. Mo/e conical ; border narrow ; smooth, wtb blunt ribs 



often obsolete. Between tides. Lord. 

 244 6. Acmcea ?var. Asmi, Midd. Stout, small, black, conical. Probably an ab- 

 normal gi'owth oi pelta, TfVm. (1 sp. beginning on pelta) Cp. 



245. Acmcea persona, Esch. Smaller : apex posterior : colour blotched or treckled : 



sculpture in irregular ribs. Maz. Cat. no. 200. \ai: u7nbonata, arched, with 

 narrow distant ribs. Var. digitalis, apex near margin. Var. textilis, apex far 

 fi'om margin, approaching pelta. 



246. Acmcea scabra, Nutt. Rve. Outside with close rows of fine granules : orange- 



red tint, glossy. Var. limatula, sculptm'e stronger, border black: perhaps = 

 Maz. CatI no. '265. 



247. Acmcea spectrum, Nutt. Rve. Flattened, with very strong ribs, irregular. 



248. Acmcea {? pileolus, Midd. var.) rosacea. Pink, small : like Herm specimens of 



virginea. 



249. Lottia gigantea, Gray. Genus reconstituted : mantle ■nnth papillfe interrupted 



in front. Shell large, flat, dark, lustrous {—Tecturella grandis. Smiths. Inst. 

 Check List). 



250. Scurria mitra, Esch. Papillas all round the mantle. White, conical : young 



sometimes faintly sculptured. In dead clam, 12 fm. Lord. 

 250 6. Scurria .^var. fjiicidata, "VVIth rounded riblets^ somewhat itoduloua. 



136 



I 



