MORSE: OBSERVATIONS ON LAMELLIBRANCHS. 
147 
only specimen I ever found alive was taken from the fluke of an 
anchor which had just been drawn up. My friend, Major John 
M. Gould, collected a rare lot of them by watching a huge steam 
dredger at work in deepening a channel in Portland Harbor, 
Maine, and these I had the privilege of studying alive at his house. 
It was a marvelous sight to see a huge panful of these extraor- 
dinary black mollusks all lying on their backs, at times thrusting 
out the foot or jumping in the water. The two species are 
markedly distinct though identical in their habits. They, how- 
ever, vary greatly in size. 
NUCULA PROXIMA Say. 
Fig. 3. Length, 6 mm. 
Watching this creature ever so carefully very little of the soft 
parts was seen. The foot is occasionally thrown out but no 
trace of the mantle edge is detected; the palpi, however, as in 
their relatives Yoldia and Leda, are of extraordinary length and 
very mobile. Professor Drew has given the 
most complete life histories of Yoldia limatula 
(Mem. Biol. Lab. Johns Hopkins Univ., 
1899, vol. 4, no. 2) and Nucula delphino- 
donta (Quart. Journ. Micr. Sci., 1901, vol. 44, 
p. 313) in which the size and functions of the 
palpi have been described. Professor Mit- 
sukuri has also described the functions of the 
palpi in Nucula proxima (Quart. Journ. Micr. 
Sci., 1881, vol. 21, p. 595). Without seeing 
the behavior of these appendages it is diffi- 
cult to appreciate the remarkable action of 
these feeding organs. The graceful move- 
ments of these beautiful and translucent 
appendages, exceeding in diameter the length of the shell, sweep- 
ing rapidly the bottom of the dish in which they are confined, 
or even turned back and feeding on the surface of the shell, are a 
most curious and interesting sight. The figure gives only a faint 
idea of the appearance of the palpi. 
Fig. 3. — Nucula proxima 
Say. 
