THE NAUTILUS. ail 
The ten mile descent of the mountain on its western side was com- 
paratively easy as the road was in excellent condition. The weather 
has been delightful since we have been here and trust that it will 
continue so throughout our stay. 
Although the ground on the mountain’s side was quite dry, care- 
ful searching with the aid of a short limb of a tree, raking deeply 
among the fallen leaves, revealed to us, quantities of the following 
Helicies, all with the living animal within. 
Helix arrosa, nickliniana, Polygyra armigera and Selenites van- 
couverensis. No fresh-water shells were found in the streams and 
pools on the way over. In fact, I do not believe there are any in the 
vicinity of this place, for I have been unable to secure a single speci- 
men during the past six years. 
The tides so far, have been very good and several species have 
been added to my collection, which are entirely new to me. 
The beach from the bluffs near the channel (entrance to the Bay 
of Bolinas) out to the dangerous reef—Duxbury reef—is at inter- 
vals composed of billions of particles of shells, ground so fine that 
the casual observer would naturally suppose they were grains of 
sand. Certain spots I have seen on the beach are almost wholly 
composed of these diminutive bits to a depth of about five or six 
inches, 
The reef upon which I had formerly seen attached thousands of 
immense Chlorostoma funebrale and fairly good sized Chrysodomus 
dirus are now almost destitute of the above named species. The 
reason of their disappearance is unknown to me. The species ob- 
served attached to the rocks and the blue clay at the present date 
are Monoceros engonatum and Litorina scutulata. M. engonatum 
predominating. Of Chlorostoma brunneum, I have gathered hundreds 
at previous visits, from a point just a short distance from the reef in 
a north-westerly direction. Not one in a living state have I found 
since arriving. 
Strolling up the sandy beach in the early morning, (4.30) until 
we reached the stretch of mossy rocks which had been left bare by 
the retreating tide, we secured dozens of the common edible clam, 
Tapes staminea, which is sold by the sackful in the markets of San 
Francisco. These were brought back to our camp and served at 
breakfast. 
The Bay of Bolinas, which at one time was quite commodious, is 
now almost completely filled with sand and mud. The channel, no 
