4 JOHNS HOPKINS UNIVERSITY MORPHOLOGICAL MONOGRAPHS. 



occupy the sides of the bell and extend to the margin. Immediately 

 below the gastric ostia, and in the bell cavity, are the suspensoria, one 

 in each perradius. These support the floor of the stomach much as the 

 frenula support the velarium, except that the suspensoria are placed 

 under the shelf (to continue Conant's figure) and not above it as are 

 the frenula. 



A nerve ring, underneath the epithelium of the subumbrella, 

 passes from near the origin of each pedalium at the margin to the 

 origin of the peduncles of the sensory clubs, a little above the margin, 

 giving off a branch to each club. Eight ganglia are found in the 

 course of this nerve. The four pedal ganglia lie near the bases of 

 the pedalia, and are hence interradial ; the four radial ganglia lie 

 near the bases of the peduncles of the clubs, and are perradial. A 

 small nerve, radial nerve, can be traced a short distance upwards 

 from each radial ganglion. Underlying the epithelium of the frenula 

 and the suspensoria are ganglion cells and nerve fibers in larger 

 numbers than elsewhere (excepting the ganglia mentioned) in the 

 subumbrella. Otherwise, ganglion cells and nerve fibers underlie the 

 epithelium of the subumbrella, including the inner surface of the 

 velarium, as also do muscle fibers, except in the perradii and in the 

 region of the nerve, where the latter become interrupted. 



