466 MAZATLAN UNIVALVES 
Hab.—Mazailan ; extremely rare; L’pool Col. 
Tablet 2121 contains 3 sp. shewing the extremes of variation. 
593 Ottva PvenuLaTa, Lam. 
An. s. Vert. vol. x. p. 611, no. 13.—Mke. in Zeit. f. Mal. 1851, 
p. 23, no. 103.—C. B. Ad. Pan. Shells, p. 56, no. 40. 
P =Oliva venulata, Ducl. Mon. Oliv. pl. 16, f. 5, 6. 
+ Oliva araneosa, C. B. Ad. Pan. Shells, p. 49, no. 33; (Pnon 
Lam.) 
©P?+O. Julieta, Whe. in Zeit. f. Mal. 1851, p. 23, no. 102.— 
Pee C.. Cat:-Prov.: (non Diet.) » = 
= Oliva reticularis, var., Rve. Conch. Ic. pl. 10, f. 16 8, d, g. 
‘The true O. Julieta was not found in this collection. Whether 
Menke’s shell was the true one imported, or whether he made 
the same mistake that I had copied, cannot be certainly told. 
His description suits best with the dark variety of this species. 
The O. venulata and Ovaraneosa of Prof. Adams, are separated, 
from single specimens of each, “principally by the short, dark 
brown, bent lines of the former.” This character is variable. 
Whether the O. venulata of Duel. is that of Lam. and whether 
either or both of them represent this, the Pacific analogue of 
O. reticularis, is also a matter of doubt. 
Shell going through the same changes of pattern as O. Mel- 
chersi, but ordinarily much smaller; 1°2 in. being the usual size 
of large specimens. The prevailing tint is a yellowish olive, with 
purple brown markings; rarely of a general greenish yellow, 
very rarely dark brown. The triangulation is less common 
and distinct in this species; and the dark lines often run into 
spots resembling O. Julieta. The shape is intermediate be- 
tween O. reticularis proper and O. Melchersi. It has a less 
elevated spire than the latter, with the angulation very slight 
and nearer the shoulder. The infrasutural pencilings are 
generally, but not always, present. Very fine parietal denticu- 
lations sometimes appear in the adult, but are generally absent. 
There is usually a purple or chesnut tinge on the lower colu- 
mellar plaits, the upper one being always left white, or at least 
of a lighter shade. A remarkably large specimen measures 
long. 1°5, long. spir. °27, lat. ‘68, div. 90°. 
Hab.—Panama, extremely rare, C. B. Adams. — Mazatlan ; 
not uncommon ; L’pool Col. 
