194 PROCEEDINGS: BOSTON SOCIETY NATURAL HISTORY. 
twice the length of the shell. The tubes are enclosed in a light 
brown periosteum strongly wrinkled and extending below and 
between the shells. The opening of the branchial syphon is 
fringed with eight very short papillae and, at its junction with the 
opening of the anal syphon, two small papillae are seen incurved. 
Between the papillae, inside, a brown area runs down the syphon. 
Fig. 46. — Pholas truncata Say. 
Similar color markings are seen inside the anal syphon but no 
papillae and no trace of a valve were discovered. In older 
specimens the branchial papillae seem worn away. The foot is 
short with broad, oval face, in color light purple. I found the 
animal when boiled very good to eat having, however, a pecuhar 
smoky taste. 
ZIRFAEA CRISPATA (Lmn6). 
Fig. 47. Length, 60 mm. 
This species was found abundantly in company with Pholas 
truncata. The syphons are united and extend about twice the 
Fig. 47. — Zirfaea ariapata (Lmn6). 
length of the shell, maroon in color. The opening of the branchial 
syphon supports seven large fimbriated papillae with short inter- 
