352 MOLLUSCA. 
lated with about equal proportions of green and whitish ; interior mar- 
ginal limb broad and tessellated, the dark predominating. 
The length, width, and height of two specimens were as follows, in 
tenths of inches: 16, 134, 4, and 14, 11, 5. 
Collected at Straits of De Fuca, and mouth of Columbia River. 
s. SHELL similar in form, but the colours cinereous and arranged 
rather in radiating stripes, occasionally bifurcating ; internal marginal 
limb narrower, the light predominating over the dark. 
Dimensions, 18, 15, 5, and 10, 9, 5. 
Found at Columbia River; Puget Sound; Straits of De Fuca. 
y. SHELL more solid, more elevated, the vertex more anterior, the 
colour very dusky, some specimens scarcely exhibiting light spots, 
though a few are generally found anteriorly. Internal marginal limb 
black or broken with occasional lines of whitish. 
Dimensions, 11, 9, 3, and 15, 13, 9. 
Found at Straits of De Fuca; Kallimook ; San Francisco. 
Two shells in the Cabinet of the Boston Soc. Nat. History, are 
much thinner and depressed, strongly striated, and have a chestnut 
ground-colour, when held up to the light, and the whitish spots are 
arranged in fine, broken, radiating lines. 
It would seem strange that a shell so conspicuous and so abundant 
should have escaped description, but I can find none answering to it, 
unless it be Acmea patina, Eschscholtz, the same as his A. scutwm, in 
his Zoological Atlas, which agrees well with our second group. 
Figures 455, 455 a, outer and inner views of the shell; 455 6, 455c, 
profile views of two varieties. 
Lortia ZEBRINA (Lesson), in Voy. Amer. Merid., pl. 65, f. 1-3. 
L. variabilis, Gray ; Append. to Beechey’s Voyage. 
AnimaL. Foot clear ochre, very large and thick; head lighter 
coloured ; mouth very large, and surrounded by a sort of veil-like pro- 
longation, which is occasionally spread out, like a broad, circular disk. 
Tentacles short and stout, under side same colour as head, upper side 
darker; plumule very long and large compared with other species 
