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, lai. 1'04/aft. *33. 



Sab. 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 slightly. 1005, 

 3 do. uniform red. 1006, 1 do. with light ring. In all 146 

 specimens, of which no two are exactly alike. 



565. ACM^A PATINA, Esch. 



Eschscholtz Zool. Atl. ed. RathJce, 1831, p. 19, pi. 24, f. 7, 8. 



Mid. Bui. Ac. St. Pet. vol. vi. no. 20 -.Sib. Reise, p. 187, 



pi. 16, f. 1 a-d, 2 a-c, 3. 

 + A. scutum, Esch. loc. cit. p. 19, pi. 23, f. 13; teste Mid. 



loc. cit. et Phil, in Zeit.f. Mai. 18^6, p. 107. ? D'Orb. Voy. 



Am. Mer. p. 479 (excl. fig.) 

 = Patella mammillata, Nutt. in Jay's Cat. no. 2839 : JRve. 



Conch. Ic. pi. 42, f. 140, a, b. 

 + Patella tessellata, Nult. in Jays Cat. no. 2885. 

 + Jun. Patella fenestrata, Nutt. in Jays Cat. no. 2815. : JKve. 



Conch. Ic. pi. 38, f. 121, a, b. 



+ Patella verriculata, Rve. Conch. Ic. pi. 31, f. 87, a, b. 

 + Patella cinis, Eve. Conch. Ic. pi. 24, f. 60, a, b, c. 



