137 
BUCCINUM POLARE, var. PERCRASSUM. 
Near Victoria, V. I., J. Richardson, 1875, two dead specimens. 
Off False Head, Queen Charlotte Sound, in thirty fathoms, Dr. G. M. 
Dawson, 1885 ; one specimen. These three shells were named 
Buccinuin polare, var. compartum by the writer, on the authority of Dr. 
Dall. The writer, however, has recently been informed by Dr. C. F. 
Newcombe, of Victoria, that, in a letter received by him on the second 
of November last, Dr. Dall writes that the word compaction is probably 
a lapsus for percrassum, and that his B. polare, var. percrassum was 
" figured and described in the new edition of Martini and Chemnitz's 
Conch. Cabinet, Suppl., p. 189, pi. 91, fig. 5." In the official report 
on the expedition to Point Barrow, Alaska, published at Washington in 
1885, Dr. Dall contributes a chapter (vi) on the mollusca obtained. 
On page 180 of that volume, under the head Buccinum polare, Gray, 
Dr. Dall makes the following remarks. " I have seen two specimens of 
a singularly thick and short variety percrassum from the Arctic north of 
Bering Strait. It must be exceedingly rare ; the upper whorls are 
smaller, less inflated and less turreted than in the normal form. The 
operculum is also proportionally larger and more oval. It may prove 
distinct from polare." But in the explanation of the plate of Point 
Barrow Mollusca, in that volume, fig. 9 is said to represent " Buccinum 
p/ecfrum, Stm., forma pet crassa, minor, 
Onchidella borealis, Dall. 
North side of Qiieen Charlotte Sound, between tides, Dr. G. M. 
Dawson, 1885 ; several specimens. 
EXPLANATION OF THE PLATE. 
Plate I. 
Pecten (Pseudamusium) Vancouverensis. 
Fig. 1. Side view of the type specimen, four times the natural size, 
and showing the left valve. 
" 1 a. Another view of the same specimen, to show the right valve. 
TURRICULA CIDARIS. 
Fig. 2. Dorsal view of an adult shell of this specie. 1 --. Natural size. 
" 2. a. Ventral view of the same, showing the aperture and operculum. 
