MAZATLAN UNIVALVES 471 



congeners from the W. Indies, the differences appear extremely 

 slight. The spire is rather narrower in the upper whirls, pure 

 white ; parietal callosity rather smaller ; lower columellar 

 plaits rather more projecting, especially in the young shell. 

 Spire with 7 whirls, and a faint line of opaque white just below 

 the suture. Long. '25, long. spir. "1, lat. '09, div. 45. 

 Hob. Panama ; 4 sp. among drift ; C. B. Adams. Mazatlan ; 



traces of 20 sp. off Chama and Spondylus ; L'pool Col. 



Tablet 2187 contains 2 perfect specimens, young and old. 



rf 600. OLIVELLA DAMA, Matve. 



Voluta Dama, Mawe, in Wood, Suppl. pi. 5, f. 37. (1828.) 

 Oliva lineolata, Gray in Zool. Beech. Voy. p. 131. (1839.) 



five. Conch. Ic. pi. 23, f. 63. 

 Oliva purpurata, Swains. Zool. III. pi. 2, f. 1 : teste Hani, in 



Wood, ed. 2, p. 212. 



Oliva gracilis, Duel. Monogr. Oliv. pi. 1, f. 17, 18. 

 Olivella lineolata, H. # A. Ad. Gen. i. 146. 



This shell is remarkable for its rich gloss, elevated spire and 

 yet stumpy growth, rich violet within the mouth, and great 

 twist of the columella inside, not visible in the front view. 

 The long spire is nearly covered with a thick enamel ; and the 

 body whirl is painted with olive brown, orange or faint gray, 

 leaving a white pattern more or less triangulated, with long 

 infrasutural lines. The labrum is not often found quite per- 

 fect, and is much advanced in the middle. The largest speci- 

 men measures long. '95, long. spir. '44, lat. '38, div. 50. 



A broad sp. '75, '32, '36, 50. 



A slender sp. '8, '38, '32, 40. 



Hab. Mazatlan ; abundant ; L'pool Col. 



Tablet 2188 contains 10 sp. dark olive brown tint. 2189, 9 do. 

 lighter shade. 2190, 5 sp. flesh colour. 2191, . 3 sp. orange 

 tint. 2192, 5 sp. grey tint. 2193, 2 sp. almost white ; one 

 scarcely displaying either pattern or violet mouth. 2194, 3 sp. 

 shewing interior. 2195, 3 sp. slender form. 2196, 3 stumpy 

 form. 2197, 2 sp. mended after fracture. 



601. OLIVELLA ZONALIS, Lam. 



Oliva zonalis, Lam. An. s. Vert. vol. x. p. 631, no. 61 -.Ann. 

 p. 327, no. 58. Gray, in Zool. Beech. Voy. p. 131, pi. 36, 



