ri MOLLUSCA. 
The calcareous rudiment is oblong, the angles truncated so as to 
give an hexagonal outline ; apex median and nearly terminal. 
Oregon, at Nisqually, by Mr. Dyes, and at Discovery Harbour, 
Puget Sound, by Lieutenant Case. 
There can be no doubt that the mottled animals are varieties of the 
uniformly coloured ones, because they were not only taken in com- 
pany, but in coitu. A smaller specimen is of a uniform slate-colour. 
In general it resembles A. empiricorum in form, marking, and colour- 
ing, with the exception of the head, which in that species is slate- 
coloured. The position of the respiratory orifice is also much more 
anterior. No land mollusk has yet been found to the west of the 
Rocky Mountains identical with any species on the Atlantic side ; and 
although several European slugs have been carried to distant shores, 
where they have become naturalized in limited districts, it is too much 
to suppose that any of them have thus become numerous at several 
localities about Puget Sound. 
Figure 1, side view; 1a, mottled variety; 10, face; 1c, calcareous 
rudiment. 
Limax ontvaceus (Gould). 
L. elevatus, retrorsum carinatus, plus minusve acuminatus, ex olivaceo 
purpurascens, papillis angustis, elongatis, obliquis reticulatus : clypeo 
curto, rotundato, concentricé rugoso ; foramine antico; fronte reticu- 
lato ; tentaculis cervicalibus elongatis, attenuatis, nigricantibus. 
ANIMAL elevated, more or less carinated, acuminated posteriorly. 
Colour dark olive, inclining to purplish or mahogany colour on the 
back, paler on the corselet and at the edges; tentacles dark slate. 
Surface minutely and obliquely reticulated with very delicate lines. 
Corselet short and rounded, concentrically lineated, evidently con- 
taining a calcareous rudiment; the respiratory orifice situated at the 
posterior fourth. Head small, front reticulated; cervical tentacles 
long and slender, the oral ones small. 
Length two and a half inches. 
