16 JOHNS HOPKINS UNIVERSITY MORPHOLOGICAL MONOGRAPHS. 



most point of the depression. The figure gives the wall of the stomach 

 lined with high columnar epithelium (ens), and the wall of the stomach 

 pockets, with the suspensorium (su) connecting them. The section is 

 taken just above the broad angle that lies between the two parts of the 

 suspensorium, that is, in a plane parallel to the arrow a-b in Fig. 32, but 

 a little lower down. At the points to which the reference letter x (Fig. 

 31) refers are seen the first indications of the division into two parts, i. e. 

 of the apex of the angle. The next section or two lower down show the 

 relation seen in Fig. 10 (su). There can be no doubt in this case that the 

 depression or pocket lies in the outer vertical limb of the suspensorium. 

 It is the position that gives it at least the appearance of some mor- 

 phological significance. In two genera of Lucernaridse named and 

 described by Clark (78), Halicyathus and Craterolophus, the mesogonia 

 or suspensoria in all four perradii contain bi-oad pockets. These mesogo- 

 nial pockets in the Lucernarida? have given rise to considerable misun- 

 derstanding owing to the fact that in some forms the reproductive 

 organs bulge out from the stomach pockets in which they structurally 

 lie, and come to take up a secondary position in the walls of the mesogo- 

 nial pockets. The sections of Charybdea above referred to indicate that 

 among the Cubomedusaa we may have the same structure reduced to its 

 lowest terms, and may be a feather's weight in favor of the view that the 

 Cubomedusas are descendants of an attached Lucernaria-like form. 



Two more diagrams, Figs. 33 and 34, are added in order to give a 

 more complete understanding of a gastric ostium and its neighboring 

 structures, the mesogonial pocket and the valve. Fig. 33 is a view of the 

 gastric ostium and valve from the stomach side, and represents the 

 appearance that would be given by a thick section through the arrow x-y in 

 Fig. 32, in a plane at right angles to the paper. The heavy lines outlining 

 the gastric ostium (enr and enft) represent the place where the plane of the 

 section has cut across the epithelium of the roof of the stomach above the 

 ostium and the epithelium of the floor of the pocket-like depression 

 internal to the valve. The continuation of the two heavy lines in either 

 side of the ostium represents the region where the roof and floor of the 

 stomach meet ; i. e., the edge of the lens-shaped stomach. The semilunar 

 outline of the valve (vg) is shown by alight line just above the epithelium 

 of the depression. As is seen by the reference arrow in Fig. 32, the valve 

 lies a little external to the immediate plane of the section, and hence it is 

 that its inner surface is seen in Fig. 33 and not a section of it. The 

 vertical part of the suspensorium (su) is seen in section below the epithe- 



