LITTORINA. 585 
Hab. Lower Catirornta, especially at La Paz (Forrer, in Mus. Berol.); Cape San 
Lucas (Xantus). : 
N.W. Mexico: Mazatlan, one specimen (Ringe). 
In general appearance this form, except for the two bands, comes very near the 
var. alba of L. philippii, obtained by the same collector, Forrer, at Mazatlan. ‘The 
upper band is placed on the last whorl in the position where the white and grey colours 
join in L. lineata and in many Mazatlan examples of L. philippii. In one of the latter, 
among many collected by Ringe in that locality, two spiral bands are visible, but the 
spiral strie are somewhat deeper than in the Californian specimens; this example, 
therefore, forms a connecting-link between the variety penicillata and the typical 
L. philippii. It is somewhat remarkable that Carpenter}, who examined many 
Specimens, does not mention any with spiral bands among the colour-varieties 
enumerated by him. 
Var. alba, n. (Tab. XLIII. fig. 13.) 
Of small size and shining pure white, with very pale, thin, brownish streaks, which are sometimes interrupted. 
Impressed spiral lines very faint. Interior of the aperture pale brown; pillar-lip also pale, but outwardly 
marked with a dark brown streak. 
Long. 64, diam. 5, apert. 44 millim. 
Hab. N.W. Mexico: Mazatlan (Forrer, in Mus. Berol.). 
Var. subsuturalis, n. (Tab. XLIII. fig. 17.) 
A deeper spiral furrow below the suture, and some 3-6 other furrows above the angle of the last whorl ; colour 
white below the suture, and bluish-grey on the lower half between the suture and the angle of the last 
whorl, the two portions thus coloured with oblique, or more rarely zigzag, brownish streaks; interior of 
the aperture dark brown, with the usual two white bands; edge of the aperture with dark dots. The 
general form more conical, not so blunt as in the typical form, the aperture occupying rather more than 
half the length of the shell. 
Long. 114, diam. 74, apert. 63 millim. 
Hab. W. Guaremata: San José, on the iron piles of the pier (Stoll). 
In the general form of the shell this variety is more like the Atlantic L. lineata than 
the typical L. philippii; it has, however, a very distinct furrow below the suture, as 
in some Californian specimens of L. philippii, a character not found in L. lineata, so 
far as I know. 
Var. latistrigata, n. (Tab, XLIII. fig. 18.) 
White, with rather broad dark brown or black streaks, which run parallel in an oblique direction, or are a 
little waved in the upper half of the space between the suture and the basal angle, intermingling in an 
irregular network, leaving only small white intervals in the lower half; in the upper whorls this zone is 
even often uniformly black. About nine equal, faint, impressed spiral lines between the suture and the 
angle. Interior of the aperture with the usual two white bands; pillar-lip brown in the middle, darker 
outwards. General form of the shell very like that of the var. subsuturalis. 
Long. 11, diam. 7, apert. 63 millim. 
Hab. W. Costa Rica: Punta Arenas (Biolley). 
BIOL. CENTR.-AMER., Terr. and Fluviat. Mollusca, November 1900. 74 
