IH CLAVID^E. 



The genus occurs in North America, Prof. Leidy having 

 discovered another species, according to Agassiz, in New- 

 port Harbour, R. I. 



Van Beneden has recently studied C. lacustris, and sup- 

 plies some curious illustrations of the voracity of the poly- 

 pites and their power of dealing with their prey. 



Having put some water-fleas (Daphne) into the vessels 

 containing the Cordylophora, he was surprised in a short 

 time to see these active Crustaceans struggling amongst 

 the arms of the polypites, and soon losing their power of 

 motion, and lying, as it were, paralysed in their solid 

 carapaces. He has also seen worms (Nais) and Planariee 

 seized and devoured. The former, though very tenacious 

 of life, yielded rapidly to their assailants, and passed into 

 the digestive cavity of the polypites. 



C. LACUSTRIS, Allman. 



CoRDYLornouA LACUSTRIS, Allman, Ann. N. H. xiii. (1844) 330; Phil. Trans. 



for 1853, 367, pi. xxv. and xxvi. ; Johnst. B. Z. 44, woodc. 



fig. 5 : Hincks, Ann. N. H. (2nd scr.) ii. 180 (March 1853), 



pi. vi. figs. 1, 2. 

 SVNCORYNA LACUSTRIS, Agassis, N. H. U. S. IT. 33 ( .i. 



Plate III. fig. 2. 



STEM slightly flexuous, more or less branched; branches 

 alternate, cylindrical, suberect, annulated above the 

 point of origin ; POLYPITES white, ovoid, prolonged above 

 into a conical proboscis, and supported on a fleshy neck, 

 to the base of which the chitinous polypary extends ; 

 tentacles 12-14; GONOPHORES oval, subsessile, invested 

 by a delicate chitinous covering, generally from one to 

 three on each branch. 



Height between 2 and 3 inches. 



THIS is the only composite and plant-like Hydroid which 



