MAZATLAN UNIVALVES 2p5 
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 1n. 
in length; the largest, Jong. 1°56, lat. 1°33, alt. °39. 
Hab.— Mazatlan ; in extreme profusion; L’pool & Havre 
Coll.—Central America, Cuming, Hinds, Kellatt.—? Panama ; 
on and under stones at neap tide low water mark, rare ; 
C. B. Adams.—(A. eruginosa, Wid. non ve. Conch. Ic. pl. 16, 
sp. 88) Bodejas, Wosnessenski.—(A. striata, Fve.) Gallapagos, 
Cuming.—(A. personoides) Kenai Bay, Wosnessenski. 
Tablet 945 contains 28 specimens in the normal state,utside 
- 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. bordér 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. Ive. not 
~Quoy,) 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 laminz, 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. 
264. AcMEA FASCICULARIS, Whe. 
Zeit. f. Mal. 1851, p. 38, no. 134. 
+Acmeza mutabilis (pars quidem jun.), Zeit. f. Mal. 1851, 
p. 37, no. 133. 
May 1856. t 
