APPENDIX. 367 
mis, which is striated transversely. The ventral margin 
is gaping and flexuous. This species resembles consi- 
derably the L. navicula of Adams and Reeve (‘ Zoology 
of the Voyage of the Samarang’), from the Sooloo Sea, 
and might be taken for a very large specimen of it, 
and, indeed, is considered to be so by Mr. Adams him- 
self, who informed me he had taken identically the same 
species, as to size, &c., from the seas of Japan. Besides 
the size, habitat, and place of abode, this species differs 
from L. navicula in the form of the anterior extremity 
of the shell and the more gaping ventral margin. 
Owing to the peculiar place of abode (holes in the 
rocks), it varies considerably in size and form; but in 
all the specimens which I have seen, ten in number, it 
does not vary in the produced anterior extremity. The 
striz seen on the surface of the epidermis do not appear 
to extend from it to the shell underneath. It lodges 
always in holes in the rocks, from which it is very dif- 
ficult to extract it, without breaking it; for it would 
appear to take up its abode in a small hole, enlarging 
it as it increases in size itself. The substance of the 
shell, without being very thin, is exceedingly brittle ; 
and few specimens were brought over without being 
cracked across in various places, apparently in the act 
of drying. The ossicle covering the front of the inter- 
nal cartilage is strong and well developed. The length 
of a moderate-sized specimen is about 3 inches, of a 
large specimen 44 inches; the breadth from the beaks 
to the ventral margin is about 2 inches and 24 inches. 
—Hab. Holes in rocks in Esquimalt Harbour, Van- 
couver Island. (Brit. Mus.) 
