15 
Davis, on the genus (Ecistes. 
lines form one broad central annulation and two narrow rings 
near the head ; to one, apparently the strongest, are attached 
the long antennae. The trochal disc at its base seems hinged 
in each lateral aspect ; the movements of these curious hinges 
are best seen when the animal is slowly expanding, then the 
ciliary wreath has a waved and oblong outline. In the 
ventral aspect, outside the rotary organ and beneath the 
ciliary frill, is an arcuate process forming the cheek of the 
buccal cavity or “ funnel,” and below this the ciliated pro- 
jection, termed the “ chin ” when applied by Gosse to 
Limnias, or the “ additional 99 and fifth lobe ” to Melicerta 
by Williamson.* 
Atoms of carmine are greedily swallowed by healthy 
specimens ; and the whole course of the red particles is 
easily watched from their entrance into the buccal funnel 
and the mastax, through the curved and undulating oesopha- 
gus into the stomach, to their discharge (apparently unal- 
tered) from the everted anus. 
On treating the animal with solution of potash the foot, 
antennae, and rotary organ, are immediately dissolved, but 
the integument and the mastax remain unaltered. The latter 
is pretty plainly constructed on the plan of Limnias, as 
figured by Mr. Gosse in the c Philosophical Transactions 
but the required number of teeth — three to each ramus — is, 
I think, greatly exceeded ; three teeth are very distinct, and, 
I fancy, a fourth and fifth; but as they gradually grow 
fainter as they recede from the joint of the rami, it becomes 
exceedingly difficult to determine the exact number. Mr. 
Gosse’s figure shows a faint striation on the surface of each 
ramus, parallel with the three teeth, and extending beyond 
them, and it is quite possible that I may have confounded a 
similar striation with the teeth, for the exceedingly minute 
size of the gizzard in GE. longcornis precludes nil hope of 
trustworthy observation on it with the moderately high 
powers at my command. 
Whatever may be the function of the ciliated “ chin ” in 
other species, it appears to me in these to be intimately con- 
nected with the formation of the tube ; for on several occa- 
sions I have noticed minute particles of the extraneous matter 
in suspension drawn across and from the buccal aperture, 
and directed by the cilia over the chin into a slight depression 
beneath it ; the granules were not rotated nor formed into 
* Mr. Slack believes that he has detected an unusually complicated 
ciliation of the trochal disc in (E. longicornU. Certainly his skilful handling 
of a Beck’s a \jth, with this object and a fine condenser, warrants me in 
accepting his opinion with the greatest respect. 
