’ - 
370 APPENDIX. 
ventrali subeostato; dentibus anticis ad numerum un- °* 
decim, posticis novemdecim. 
This very interesting species is the fourth of this 
peculiar divaricately ribbed group which has been dis- 
covered in a recent state. The three others are Nucula 
divaricata and N. castrensis of Hinds, and NV. mirabilis 
of Adams and Reeve. This species approaches very 
nearly to the fossil species from the Crag, NV. cobboldie, 
but differs from it in being less transversely ovate, in 
having the beaks more prominent, the posterior row of 
teeth in the hinge fewer in number (in VV. cobboldia 
they are 22), and in the costations being stronger in 
proportion to the size of the shell, and much fewer in 
number. It was with some hesitation that I decided 
upon describing it as a new species; but these marks, 
the size, and the habitat all induce me to consider it as 
distinct. I have named it after Dr. Lyall, of H.M.S. 
‘Plumper,’ who has sent us only one specimen. Long. 
rather more than 4 inch; lat. rather more than 4 inch. 
— Hab. Esquimalt Harbour, Vancouver Island ; 
dredged by Dr. Lyall, H.M.S. ‘ Plumper,’ in from 
8 to 10 fathoms. (Brit. Mus.) 
PECTENIDE. 
Pecten hericius. (Gould.) Esquimalt Harbour, 8 to 10 fathoms water. 
Hinnites giganteus. (Gray.) Rocks between tide marks. 
OSTRID. 
Ostrea edulis. (Lamk.) Abundant along the island and mainland 
coasts. 
Placunanomia cipio. (Gray.) Rocks between tide marks. 
