196 PROCEEDINGS: BOSTON SOCIETY NATURAL HISTORY. 
mediate ones of a similar character. Two papillae at the junc- 
tion of the tubes are slightly larger, maroon color; the others 
white. The opening of the anal tube is rimmed with many 
minute papillae. A light brown periosteum covers the nearer 
half of the syphons continuing between the shells but leaving an 
open narrow space below. The parts not covered by the peri- 
osteum are white in color and marked by broken lines of maroon 
color. Viewed from below a palpus is seen projecting forward 
on each side of the disk-hke foot which is white in color. A 
young shell (Fig. 47, a), slightly over a millimeter in its longest 
diameter, shows the protoconch at the beak with an outhne re- 
sembling the shell of Teredo. On Lynn and other beaches 
huge single valves of Zirfaea crispata are often found after an 
easterly storm ; they are invariably colored blue and are evidently 
semi-fossil, washed away from some submerged clay bank off 
the shore. Dr. Harold S. Colton has described the occurence of 
these large, blue, single valves of Z. crispata on the New Jersey 
beaches. 
TEREDO sp. 
Fig. 48. 
At North Haven, Maine, I made a few drawings of a species 
of Teredo, the shells of which have been misplaced so that the 
species cannot be determined. The syphons were evidently 
much contracted. The palates were not secured. The animal 
was white. The curious divergent attitude of the sy phonal 
openings, fringed with minute papillae, the short valve, and the 
strong and efl&cient foot to rotate the rasping shell are clearly 
shown in the figures. 
