180 PROCEEDINGS: BOSTON SOCIETY NATURAL HISTORY. 
valve was seen. The branchial opening is fringed by long and 
short papillae alternating and fimbriated. These papillae turn 
toward the center of the opening. The tubes are yellowish^ 
mottled with hght brown. In some of their attitudes they turn 
abruptly away from each other, one dorsally the other ventrally 
(Fig. 33, a) . The papillae of the two openings curiously resemble 
the same parts in Pholas crispata. Their habits being precisely 
alike, is there any common adaptation? The creature shows no 
timidity. 
In the extremely young stage the shell bears a close resemblance 
to Turtonia minuta in color and form. In a little later stage the 
margin of the shell becomes hghter in color, almost white; the 
beaks are very round and tumid. In a still later stage a few 
faint radiating ribs show on the anterior part of the shell and these 
reveal its true character as the young of P. pholadiformis. The 
opening of the anal syphon is fringed with six long and six short 
papillae, truncate at their tips. The opening of the branchial 
syphon is furnished with six or eight long papillae coarsely 
fimbriated and alternating with short papillae which are simple. 
The syphons are very short compared to those of the adult. The 
foot is large and long. The young shows no timidity. This 
shell in its early stages was defined by Professor Verrill as a new 
genus under the name of Gastranella. 
TELLINA TENERA Say. 
Fig. 34. Length, 13 mm. 
The syphons are separate, bluish white in color. The branchial 
syphon is very mobile; at times both syphons collapse while 
extended and flatten out like an empty hose. The foot is quite 
long and active in movement. The cruciform muscles are 
sharply marked (Fig. 34, a). The protoconch is shown in a 
young shell (Fig. 34, 6). It is somewhat oval in shape. 
TELLINA TENTA Say. 
Fig. 35. Length, 14 mm. 
The foot is long, white, and protrudes slowly in a series of 
tremulous undulations. The syphons are identical with those of 
T. tenera. The foot appears the same. The shell differs from 
that of T. tenera in being somewhat blunter at the posterior end 
