Morse.] 304 [March 19, 
ment in a bowl or dish, it covers the bottom of the vessel with an © 
irregular sand tube. When I first found Lingula pyramidata buried 
in the sand shoals of Beaufort Harbor, North Carolina, I was sur- 
prised to find them living free in the sand, and not attached by their 
peduncle as I had supposed. My astonishment was greater to find 
that the peduncle was sheathed in a sand tube. When this tube was 
broken or removed from the peduncle, they promptly formed ancther 
one. The shell, nearly tothe anterior margin, would often be enclosed 
in this sand case. When the peduncle was broken off, a bulb of sand 
would soon be agglutinated to protect the broken end, and not only 
sand was used, but bits of seaweed ; and in one case a little stick was 
incorporated in this structure. 
I brought home with me to Salem, Mass., a number of living speci- 
mens, and these were kept alive in large bowls, from June till Octo- 
ber, by imitating as far as possible their natural surroundings. They 
would often protrude above the surface of the sand, and instantlr 
jerk back when alarmed. | | 
On emptying the sand from the bowl one day, great was my sur- 
prise to find that all of the Lingulas had covered the bottom of the 
‘bowl with large irregular sand tubes, cemented to the sides and bot- 
tom of the dish, the tubes running over each other, and presenting 
precisely the appearance as that produced by Terebella and allied 
forms when kept in dishes in this way. (See Plate I., Fig. 7.) 
In this place it is proper to state that the peduncle of Lingula is 
highly mobile. When removed from the sand it twists and turns in 
all sorts of worm-like contortions, and in Plate I., accompanying this 
paper, some actual sketches are given of different individuals, show- 
ing the various contortions of the peduncle, as well as the character 
of thesand tubes. Fig. 6 shows a portion of the peduncle of Lingula 
pyramidata, drawn from life, showing its annulated character. The 
direction of the corpusculated fluid circulating through the central 
cavity is indicated by the arrows. . 
Muscular System. 
In respect to the muscles of the integument, the Brachiopods bear 
the closest resemblance to the worms. 
In worms, the muscles of the integument are arranged in two 
layers, transverse and longitudinal, producing a reticulated appear- 
ance. The same arrangement is distinctly seen in the perivisceral 
walls of Discina and Lingula, as well as in the peduncle of the 
