650 



RETORT 18G3. 



236. Leptochiton nexus, n. s. Like asellus : scarcely sculptured : mantle-margin with 



striated chaffy scales, like Magdalensis. interspersed with transparent needles. 

 20-80 fin. Cp. 



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



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



Family Patellidez. 



238. Nacella imtabilis, Old. E.E. Large : shape of compressa. 



239. Nacella incessa, Hds. Sulphur. Small : Ancyloid. 



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



lina. 10-20 fm. Cp. 



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



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



2426. Nacella ?var. triangularis. Shorter: apex raised: scarcely striated : whitish ^ 

 with brown spots. 



Family Acmaidee. (For synonyms, v. Reports in loci?*) 



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



striae. Between tides, Lord. 



244. Acmeea pelta, Esch. More conical; border narrow; smooth, with blunt ribs 



often obsolete. Between tides, Lord. 



244 b. Acmeea ?var. Asrrn, Midd. Stout, small, black, conical. Probably an ab- 

 normal growth of pelta, jun. (1 sp. beginning on pelta) Cp. 



-15. Acmesa persona, Esch. Smaller: apex posterior: colour blotched or freckled : 

 sculpture in irregular ribs. Maz. Cat. no. 266. Var. umbonata, arched, with 

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

 from margin, approaching pelta. 



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



red tint, glossy. Var. limatula, sculpture stronger, border black : perhaps = 

 Maz. Cat. no. 265. 



247. Acmaa spectrum, Nutt. Rve. Flattened, with verv strong ribs, irregular. 



248. Acmeea (?pileolus, Midd. var.) rosace?. Pink, small : like Herm specimens of 



virginea. 



249. Lottia gigantea, Gray. Genus reconstituted : mantle with papillae interrupted 



in front. Shell large, flat, dark, lustrous (= Tecturclla (jrandis, Smiths. Inst. 

 Check List). 



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



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

 250 b. Scurria ? var. funiculata. With rounded riblets ; somewhat aoduloua. 



136 



