MAZATLAN UNIVALVES 207 
shells are known by their finely cancellated texture and deli- 
cate reddish penciling ; and generally, by a white spot proceed- 
ing from the apex posteriorly bounded by red lines. In all 
stages it is thin, and very glossy within. The largest specimen 
measures long. 1°34, lat. 1°04, alt. °33. 
Hab.—Mazatlan, Menke.—Do. ; not uncommon ; L’pool Col.— 
San Diego; Lieut. Green. 
Tablet 981 contains 12 specimens, extremely young, whitish.— 
982, 8 sp. do. reddish.—983, 4. sp. do. much compressed at the 
sides; but, as they agree in colour and markings, they are 
probably only a variety.—984, 5 sp. light margin; scarcely 
touched with penciling.—985, 5 sp. do. very slight posterior 
pencilings.—986, 5 sp. do. margin fawn coloured.—987, 5 sp. do. 
greenish tinge.—988, 4 do. purplish brown.—989, ‘5 sp. pencil- 
ings more distinct. —990, 6 sp. with faint dots all round.— 
991, 8 sp. do. darker margin.—992, 8 sp. do. still darker.— 
993, 4 sp. do. very narrow margin.—994, 3 sp. penciling regular ; 
slight and shaded.—995, 4. sp. do. white border, penciling in 
single rays.—996, 8 sp. do. penciling fretted, rays distinct.— 
997, 7 sp. do. margin coloured.—998, 7 sp. penciling interlaced, 
reddish margin.—999, 7 sp. do. margin dark with penciling.— 
1000, 9 sp. do.margin very dark, interior white.—1001, 5 sp. do. 
penciling visible within.—1002, 3 sp. distorted growth.—1003, 
6 sp. shewing exterior, rayed.—1004, 4 do. very shghtly.—1005, 
3 do. uniform red.—1006, 1 do. with light rmg.—In all 146 
specimens, of which no two are exactly alike. 
265. ACMHEA PATINA, Esch. 
Eschscholtz Zool. Atl. ed. Rathke, 1831, p. 19, pl. 24, f. 7, 8.— 
Mid. Bul. Ac. St. Pet. vol. vi. no. 20:—Sib. Reise, p. 187, 
pLdGy frlia-d,2 a-c, 3, 
+A.scutum, Esch. loc. cit. p. 19, pl. 23, f.1—38; teste Mid. 
loc. cit. et Phil. in Zeit. f. Mal. 1846, p. 107.—? D’ Orb. Voy. 
Am. Mer. p. 479 (excl. fig.) 
= Patella mammillata, Nutt. in Jay’s Cat. no. 2839 :— Rve. 
Conch. Ic. pl. 42, f. 140, a, 6. 
+ Patella tessellata, Nutt. in Jay’s Cat. no. 2885. 
+ Jun. Patella fenestrata, Nutt. in Jay’s Cat. no. 2815. :—Rve. 
Conch. Ic. pl. 38, f. 121, a, 6. 
+ Patella verriculata, Rve. Conch. Ic. pl. 31, f. 87, a, b. 
+ Patella cinis, Rve. Conch. Ic. pl. 24, f. 60, a, b, ¢. 
