318 EDWARD S. MORSE ON 



tips. In no instance did I observe the fabrication of the setal tubes to be described in 

 L. lepidula. The anterior margins of the pallium were thrown into folds and the anterior 

 bundles of setae converged in a way to form rude channels for the water, which steadily 

 flowed in and out in definite currents. The creature, though not very timid, would on 

 certain alarms quickly jerk its body beneath the sand and out of sight. The extent of 

 the oscillation of the dorsal shell is shown in 40: ;i. It will be seen that the right 

 anterior corner of the dorsal shell is moved to the left so far as to cover the left anterior 

 corner of the ventral shell. This movement is vigorous and quite rapid but not jerky. 

 In this oscillation, the peduncular end of the shell also swings to the right and left, and 

 the posterior adductor muscle is greatly stretched by this action. The dorsal sliell oscil- 

 lates from a centre near the middle of the coelomic cavity at a point about two-fifths the 

 length of the shell, measured from the posterior end. When adhering to a plain surface, 

 as at the bottom of a shallow dish, a wide, irregular sand tube is made, which in some 

 cases covers the hinder part of the body (41: 13) . 



In studpng Glottidia for the purpose of ascertaining its duration of life, it was 

 observed that there was but little variation in the size of the specimens. The shells were 

 equally fresh-looking, and there was in no instance any parasitic growth upon the shell. 

 In an examination of a hundred indi\iduals, no young were found. With the Llncjula 

 lepidula of Japan, I had precisely the same experience; the individuals appeared to be all 

 full o-rown. A number of Glottidia were kept in confinement, and while showing the 

 most remarkable vitality, as already alluded to, they all died in the fall and within a few 

 days of one another, evidently of old age. Lhujula lepidtda, also, apparently lived its 

 allotted span and perished in the same way. On dying, the body protrudes from its 

 burrow and rests full length upon the sand ; it gradually turns black as a result of decom- 

 position and the slightest jar of the vessel holding it causes the body to separate from 

 the buried peduncle and float away. An examination of the peduncle after a lapse of 

 forty-eight hours shows the circulation of fluid mtliin the peduncle as active as ever. 



Lingula lejndida. A species of Lingula collected at Yenoshima, Japan, averaging 

 half an inch in length, rarely exceeding' this dimension, is rather doubtfully referred 

 to L. lepidula of Adams. Davidson ('86-88) supposed this form might be the young 

 of some larger species. Adams's statement that the shell is yeUowish, tinged with red 

 (which is really the effect of the red coelomic fluid within) , with the outhne and dimen- 

 sions given by him agrees more or less with the Yenoshima species, so for convenience of 

 designation it will be considered as the L. lepidula of Adams. 



The species was dredged in a few fathoms of water from a sandy bottom in a little 

 cove on the western side of Yenoshima. The peduncle is from 2^ to 3 inches in length, 

 the posterior third of which is encased in a sand tube of not so compact a nature as that 



