MAZATLAN UNIVALVES 371 
ate. The colour varies from light buff to pink and dark violet 
purple, the latter prevailing. The posterior beak is broadly keel- 
ed outside. The largest sp. measures long. °63, lat.°23, alt. 16. 
A short sp. 3 ath a, ay EG ge ee 
A young, acuminate sp. 27°38, 5, Li ae 
Hab.—Panama; rare, on Gorgonia (the various colours of 
which are imitated by the shell,) at low water mark of 
spring tides ; C. B. Adams.—Mazatlan ; rare; L’pool. Col.— 
San Juan, L. Cal., Lieut. Green.—Sta Barbara, Col. Jewett. 
Tablet 1733 contains 8 sp. displaying the principal differences, 
kindly presented by J. Hibbert, Esq. of Liverpool. 
Faminy CYPRAIDA. 
Genus CYPRAEA, Linn. 
Cyprea, Zinn. pars. Shell comparatively thin, cylindrical, 
faintly callous at the sides. 
436. CYPREA EXANTHEMA, Linn. 
Syst. Nat. ed. 12, p. 1172.— Wood. Ind. Test. pl. 16, f. 1.—Dillw. 
Descr. Cat. vol. 1. p. 436, no. 1.— Gray, Monogr. Cypr. Zool. 
Journ. vol. 1. p. 1389 :—Descr. Cat. p. 2, no. 7.—Sow. Conch. 
Ill. £.170.—Kien. Icon. Conch. p. 71, no. 62, pl, 4, 5, (f. 1.) 
9,10, (f. 1.) 21, (f. 1.)—Rve. Conch. Ic. pl. 5, sp. 16.—Lam. 
An. s. Vert. vol. x. p. 489, no. 2.—(For other references, 
v. Desh. in loco.) 
Jun.=Cyprea zebra. Linn. p. 3400, no. 8. et auct. antiq. 
+ Cyprea cervinetta, Kien. Icon. Conch. p. 74, pl. 6, f. 1, 2,— 
Desh. in Lam. An. s. Vert. vol. x. p. 547, no. 71.—=C. exan- 
thema, Hinds, Voy. Sulph. Moll. p. 6, (teste C. B. Ad.J— 
=C. exanthema, var. a & b. Gray, Zool. Journ. vol. i. p. 139.— 
=C. cervus, var. Rve. Conch. Ic. (teste C. B. Ad.) 
Comp. Cyprea cervus, Linn. Mant. p. 548.—Rve. Conch. Ie. 
pl. 2, sp. 6.—=Cyprea cervina, Zam. loc. cit. no. 1.— Gray, 
p. 140.— Sow. f.175.— Kien. pl. 2, 3.—Rve. Conch. Syst. vol. ii. 
p. 263, pl. 287, 288, f. 175. 
The form C. cervinetta was distinguished by Kiener, who 
regarded it as from the W. Indies and Senegal; and was 
allowed with hesitation by Deshayes, who says that it is per- 
haps only an intermediate variety between the C. exanthema 
