592 J. E. DUERDEN. 
has been assisted by an appropriation from the Carnegie 
Institution. 
EXPERIMENTS witH FUNGIA. 
On account of its size and simple (not colonial) character 
the coral Fungia was found to be especially suitable for ex- 
perimental studies on the feeding and other processes of 
madreporarian polyps. The disc is large and flat, Hawatan 
specimens sometimes measuring as much as 15 em. along the 
larger axis, thus readily admitting of observations on the 
transference of food and other substances across it. In their 
Fic. 1.—Diagram to show the distribution of particles dropped 
over the mouth of Fungia when an exhalent current is in progress. 
The particles are wafted away from the mouth, fall on the dise, 
become embedded in mucus, and are carried towards the edge of the 
polyp over which they fall. 
living condition, resting on the sea-floor, the polyps are 
usually fully expanded, and the column is unable to close 
over the disc on retraction. The mouth is elongated and sht- 
like or oval according as it is closed or open. The tentacles 
are comparatively short (about 5 mm.), arranged at some dis- 
tance from one another, and distributed over nearly the entire 
discal area; when fully extended they are sickle-shaped, 
broad below, and narrow above. 
When very light non-nutritive particles, such as accumulate 
on the bottom of vessels containing cloudy sea-water, are 
gently dropped upon the disc of an expanded Fungia they 
produce no decided response on the part of the polyp. If 
the mouth be open many of the particles are wafted away 
