MORSE: OBSERVATIONS ON LAMELLIBRANCHS. 163 
Syphons very short but broad at their bases, occupying the 
entire posterior margin of the shell. The branchial syphon is 
twice the width of the anal syphon, and is crowded with short 
papillae of varying lengths, many bifurcated, also a few larger 
papillae, with a shorter one budding at their bases (Fig. 19, a). 
Anal syphon with very short valve with large aperture irregular 
in shape, marked inside with a row of dots. Both syphons extend 
only a few millimeters beyond the edge of the shell and the exposed 
region is clothed with short papillae. The entire surface is 
reddish brown in color, the tips of the papillae somewhat lighter. 
The j^oung form, four millimeters in diameter, has the same short 
syphonal tubes, with a very long tubular valve (Fig. 19, b). 
The foot is long and pointed and very active in turning the shell 
over. The young shell was marked by radiating lines which do 
not appear in the adult shell. The epidermis of the adult shell 
is difficult to preserve as it peels very rapidly on drying. 
ASTARTE CASTANEA (Say). 
Fig. 20. Length, 24 mm. 
Fig. 20. — Astarte coitanea (Say). 
The three species of Astarte studied required days of patient 
watching; indeed, it was a matter of days before the creatures 
showed the slightest signs of life. At intervals they were exam- 
