364 PROCEEDINGS : BOSTON SOCIETY NATURAL HISTORY. 
Nematophores tubular, the lateral ones of medium size projecting 
ear-like from the sides of the cups, the anterior one long, adnate 
except at the extremity which is free, and extending beyond the 
toothed rim. Aperture small, terminal. The nematophores on 
the corbulae are a trifle larger, and arranged in rows which pass 
upwards to the dorsal side, make a short turn there, and come down 
again parallel. The corbulae are large and cylindrical, with 
numerous ridges (10-16) composed of oblique rows of nemato¬ 
phores, and with 4 liydrothecae at the base. 
. Clarke figures this corbula with rings of nematophores around the 
ventral ridge; but in the present specimens there are no such 
rings and no nematophores on the ridge except at the extreme tip 
where there is one. 
Habitat. On rocks dredged from 15 fathoms at Marrowstone, 
Townsend Bay. Common. 
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