48 
CHLAMY DOCONCHA ORCUTTI. 
Dall, Science. 4: 50 (18 Jl 1884). U S na mu pr 1885, 510. 
Or U Snamn pr 1885, 59:—False bay, near San Diego, Cali- 
fornia, under stones. 
Animal somewhat of the shape of a small globose Cypraea, 
of inflated, ovoid form, trans!ucent, jelly-like, dotted above with 
small, rounded papillae, which appear of an opaque white on the 
general translucent ground. Over an inch in length when liv- 
ing, contracting in a'cchol to less than half. Mantie coverivig the 
dome of the body tough and thick;.sides smooth, nearly free of 
the papillae, superior median line a little depressed; basal part of 
the anterior line in life pro'onged beyond the general mass in a 
trough with the convexity upward, and somewhat expanded at 
its anterior: estremity; ebcut one-third from anterior end 
the mantle is perforated by an orifice, which pierces it in the 
vicinity of the mouth. The edges of this orifice project from the 
general surface, lined with close-set small papillae. At about the 
same distance from the posterior end is another tubular perfcra- 
tion, holding a similar relation to the anus; which has, nowever, 
plain edges, and is not internally papi!'ose. Beneath the anter-or 
surface, lined with close-set small papil’ae. At about the same 
distance from the nosterior end is another tubular perforation, 
holding a similar relation te the anus; which has, however, plain 
edges, and is not internally papillose. Beneath the anterior 
trough of the mantle proionged backward, like a slit with p!ain 
edges, to about the posterier third; from this projects a narrow. 
hatchet-shaped foot, with a strongly marked byssus-gland at its 
posterior angle; from this a bunch of white byssus extends to the 
stone or object to which this mollusk attaches itself. The cavity 
of the mautle extends some distance behind the commissure of 
the pedal opening. The anterior point of the foot is roofed by 
the troughtike expansion above mentioned. The mouth is pro- 
vided with 2 pairs of smail palpi. Two gills very finely micros- 
