1884.] Zoblogy.. 301 
border the canal on each side. These folds are continued around 
the oval tentacles at their distal ends, extending for about half 
the length of the tentacle on the upper side, and enclosing on this 
side a canal similar to that found below. On the edge of each of 
these folds there is placed a row of suckers, or “ mouths,” which 
resemble the well-known mouths in Aurelia, Cassiopea, and other 
similar Discophores. Each oral tentacle is thus bordered above 
and below by a double row of these sucking mouths. The signi- 
fication of my emphasis of this fact will be seen when we come to 
consider their homologues in the strange genus Stomolophus. 
A system of vessels for the transportation of the food from the 
sucking mouths to the central stomach cavity pervades the oral 
tentacles. Through the middle of each tentacle there passes a 
tube, which takes up alternately from upper and lower sides 
smaller vessels, passing to it from the superficial canal on the 
lower and likewise from that already described on the upper 
edges of the oral tentacles. As it nears the common fusion of 
all the oral tentacles, the median vessel of each tentacle becomes 
Superficial, and opens into the groove with which it is continued 
on the lower surface of the oral apparatus, until ultimately it 
passes through a common central orifice into the stomach cavity. 
The two regions of suckers found on the oral tentacles we may 
designate as the upper and lower regions; the former being simply 
a continuation of the latter around the distal end of each oral 
endage. The upper region of suckers is therefore morpho- 
logically the same as the lower, with which it stands in direct 
communication. In Aurelia the lower region of suckers ends on 
the lower side of the oral tentacle near its distal extremity. 
its continuation on the upper side in Stomatonema mean 
anything when we study the distribution of these bodies in some 
other genera? 
The genus Stomolophus, found in Floridan waters, is a Dis- 
cophorous medusa of which little is yet known, either as regards 
i anatomy or embryology. As far as our limited knowledge of 
€ structure of their umbrella goes, there are many points of re- 
oe in the two genera. Both have the same bell-shaped 
St es, and both are destitute of tentacles on the bell margin. 
L polophus is represented in the well-known figure in Professor 
Agassiz’ “Contributions to the Natural History of the United 
man with a reticulated zone surrounding the bell margin, 
ey May correspond with the reticulated zone of tubes in our 
genus, 
. In the Structure of the oral region the two genera seem widely 
eee for while in Stomatonema we find this organ composed 
: thee ora! tentacles, each of which is wholly distinct from the 
een, M Stomolophus there is a consolidated oral cylinder 
eight by longitudinal lines of “crests,” of which there are 
Pairs. Of these crests there are two kinds, an upper, arising 
