MAZATLAN UNIVALVES 205 



slightest doubt, having carefully examined about 11,000 speci- 

 mens, from which those here enumerated were selected by a 

 carefully repeated process of reduction and comparison. No 

 very young shells were found ; the youngest measuring ' 5 in. 

 in length ; the largest, long. 1*56, lot. 1*33, alt. '39. 

 Hob. Mazatlan ; in extreme profusion ; L'pool fy Havre 

 Coll. Central America, Cuminq, Hinds, Kellatt. ? Panama ; 

 on and under stones at neap tide low water mark, rare ; 

 G. JB. Adams. (A. seruginosa, Mid. non Rve. Conch. Ic. pi. 16, 

 sp. 38) Bodejas, WosnessensJci. (A. striata, Hve.) Gallapagos, 

 Cuming. (A. personoides) Kenai Bay, Wosnessenslci. 

 Tablet 945 contains 28 specimens in the normal state, outside 

 striped, with a prevailing greenish tinge, and regularly tessel- 

 lated margin. 946, 26 sp. do. outside tessellated. 947, 27 sp. 

 do. prevailing brownish tinge ; more often worn outside. 

 948, 5 sp. the same, tessellated. 949, 12 sp. yellowish ground ; 

 broad streaks of brown. 950, 6 sp. do. narrow streaks. 951, 



6 sp. do. scarcely rayed. 952, 12 sp. do. tessellated. 953, 4 do. 

 greenish tinge. 954, 6 sp. border with broad patches of dark, 

 narrow .of light, green inside ; yellow ground. 955, 6 sp. do. 

 light ground. 956, 6 sp. do. tessellated. 957, 6 sp. brownish. 

 958, 8 sp. broad dark margin, interrupted by narrow light 

 rays ; brownish cast. 959, 10 sp. green cast. 960, 4 sp. light 

 border ; brown, finely rayed with white. 961, 9 sp. do. faintly 

 mottled. 962, 2 sp. do. with purplish tinge. 963, 8 sp. do. 

 with narrow brown dotted edge. 964, 9 sp. do. green tinge, 

 mottled with brown. 965, 4 sp. do. green margin, scarcely 

 tipped with brown. 966, 4 sp. do. very light. 967, 1 sp. do. 

 nearly white. 968, 4 sp. do. with dark brown edge. 969, 8 sp, 

 margin nearly uniform ; dark, with a few white rays. 970, 

 8 sp. do. scarcely mottled with white. 971, 12 sp. do. lighter 

 tint. 972, 9 sp. margin uniform, ( = P. striata, jun. Rve. not 

 Quo?/,) dark green. 973, 11 sp. do. intermediate. 974, 9 sp. 

 brown. 975, 8 sp. of distorted growth ; of which one has made 

 a series of raised laminse, another a fresh margin greatly con- 

 tracted. 976, 5 sp. shewing the exterior ; tessellated. 677, 



7 sp. do. abounding in white. 978, 3 sp. do. striped 979, 4 sp. 

 do. pattern changing. 980, 4 do. dark green var. In all 301 

 specimens, of which no two are exactly alike. 



J- 264. ACM^EA FASCICULAKIS, MJce. 

 Zeit.f. Mai. 1851, p. 38, no. 134. 

 f Acmsea mutabilis (pars quidem jun.), Zeit. /. Mai. 1851,. 



p. 37, no. 133. 

 May 1856. t 



