[501 



MR. JAMES RITCUIE ON' HYDROIDS 



[May 28, 



proboscis and short (0'3 mm.) stumpy tentacle.<!. These, between 

 40 and 50 in number, are scattered over the body of the polyp, 

 only the distal 4 or 5 being placed in a whorl, although an 

 approximation to whorling is sometimes simulated by others of 

 the tentacles. At the proximal end of the hydranth there is a 

 short neck, and just within the margin of the tube a sharp bulge 

 connecting the polyp with the caniosarc of the ramulus and almost 



Text-fig. 142. 



ram. 3 



t.-t- 



Soleniopsis deiidriformis. To show mode of bi*anching, x8. 



c««., cojiiosarc ; peri., perisarc; 6r., branch bending off and becoming free fi'om 

 main stem; sf., main stem ; ram. 1, 2, 3, short ramuli from which hydranths 

 project ; n.t. 1, 2, 3, 4, new tubes, enveloping a branch from a coenosarcal 

 strand and wedged in between older tubes. 



plugging up the entrance to the tube. Contracted, the liydranths 

 form almost spherical bulbs about 0'7 mm. in diameter. Although 

 the tube from which the hydranth springs generally ends abruptly 

 with an even circular margin, in not a few cases the terminal 

 496 



