MAZATLAN UNIVALVES ADY 
Fasciolaria aurantiaca, Sow. Gen. no. 30: non Lam. loc. cit. 
p. 434, no. 4. 
Mr. Sowerby, having discarded his own original name, ’ 
adopted another which had been preoccupied by Lamarck. 
The dealer unfortunately cleaned the whole stock of this mag- 
nificent species, disregarding both epidermis and opercula. 
Shell of a rich orange, under arather thick reddish brown 
epidermis, striated in lines of growth ; with numerous rounded 
spiral ridges, having broad interstices, most developed near 
the centre of the whirls. In the middle is generally seen a 
row of stout tubercles, sometimes almost wholly evanescent. 
Labrum inside with finely raised reddish spiral strie. Columel- 
lar plaits two, not conspicuous. Operculum pyriform, apex 
terminal: outside with about 5 longitudinal furrows on the 
middle and interior ; exterior with irregular diagonal ribs ; 
inside with very large attachment, not corrugated.* Zong. 11°5, 
long. spir. 5'7, lat. 5°4, div. 40°. 
Hab.— Peru, Cuming.—Mazatlan ; not uncommon ; L’pool Col. 
Tablet 2088 contains a solitary specimen with epidermis that 
escaped the acid bowl.—2089, a strongly tuberculated speci- 
men.—2090, the largest, scarcely tuberculated specimen; and 
an operculum. 
4 Sus-Faminy MITRIN A. 
These creatures, so numerous in form and varied in painting 
in the EK. Indian Islands, are said not to be partial to a con- 
tinental life. Very few species are found on the W. coast of 
America, and only two, of very sombre aspect, occur in the 
Mazatlan collection. 
Genus MITRA, Zam. 
Mitra, Lam. Journ. Hist. Nat. 1799, (pars. —H. & A. Ad. 
Gen. vol. 1. p. 168. 
Thiarella, Swains. 
585. Mirra tens, Mawe. 
Voluta lens, Wood Ind. Test. Suppl. 1828, pl. 3, f. 25. (f. 28, 
sec. Mke.) 
* A few of these opercula having dropped into the Pyrula box, while all the 
shells were taken away to the acid, £ unfortunately distributed them as the 
opercula of the latter. Authentic specimens of each species in Capt. Kellatt’s 
collections, verified the correction of the mistalre. 
