48 ANIMALS OF THE SEASHORE 



chitinous receptacle (hydrotheca) into which the 

 hydranth retracts; stalk of hydranth annulated and 

 arises from the stem in a verticillate manner. 



Reproductive polyps on main stem and branches, 

 oblong flask-shaped with necks often produced into 

 tubular extensions with terminal openings. No free 

 swimming medusae are found in this genus. 



Found attached to stones, shells, etc., in Block 

 Island Sound, Fishers Island Sound and Delaware 

 Bay; not common. Numerous other species of 

 Campamilaria have been reported along the New 

 England and Carolina coasts and may be looked 

 for in New Jersey waters. 



Obelia commissuralis McCrady 



PLATE II. Fig. 5 



A delicate form, up to 8 inches high; stem not 

 fascicled, branched in a flabellate manner with 4 

 or 5 annulations above the origin of each branch; 

 hydranths on annulated stalks; hydrothecae sub- 

 triangular, not toothed. 



Reproductive polyps (gonosomes) are ovoid 

 and larger than the hydranths and are borne at the 

 angles of the branches. Medusae are liberated 

 from these gonosomes (seepage 55). 



Abundant along the New England coast growing 

 on docks, etc. Present but not so abundant in 

 similar situations along the New Jersey coast: 

 occasionally found stranded on the beach; southern 

 limit of species, South Carolina. 



