Fig. 1. — The entire Medusa iu profile, five times the natural size. Both the sixteen 

 complete radial ribs of the exumbrella and the sixteen alternating incomplete ribs in the 

 middle of the exumbral intercostal depressions are both distinctly visible, also the 

 numerous sucking-cups and the longer sucking tentacles at the umbrella margin. 



Fig. 2. — Subumbral view of the entire Medusa seen from below, five times the 

 natural size. One of the two perradial diameters stands vertically, the other horizontally. 

 We look through the quadrate oral opening into the gastral cavity, in which four 

 adradial ridges of the gastral wall project. Strong folds of the circular muscle pass from 

 the margin of the mouth on the inner gastral wall, interrupted by four perradial labial 

 furrows of the corners of the mouth and four interradial bands of the longitudinal 

 muscle. The larger part, the eight folded genital sacs, is visible in the bottom of the 

 umbrella cavity. Their distal part is covered by the broad velum, which was extremely 

 ddated. Outside the velum we see sixteen lobes of the umbrella margin, on its lower 

 side the forty-eight triangular sucking plates (composed of many small sucking-cups) and 

 the alternating forty-eight larger sucking-cups (sixteen of the first size, and thirty-two of 

 the second) : inside, projecting from the insertion of the velum, forty-eight longer, 

 thinner tentacles with terminal sucking-cups. 



