20 MARINE ANIMALS OP MASSACHUSETTS BAT. 



and fringed around the margin. Our Halcyonium commimities 



(Fig. 22) usually live iii deep water, 

 attached to dead shells, though they 

 may occasionally be found growing at 

 low-water mark, but this is very rare. 

 They have received a rather lugubri- 

 ous name from the fishermen, who call 

 them " dead-men's fingers," and in- 

 deed, when the animals are contract- 

 ed, such a community, with its short 

 branches attached to the main stock, 

 looks not unlike the stump of a hand, 

 with short, fat fingers. In such a con- 

 dition they are very ugly, the whole 

 mass being somewhat gelatinous in tex- 

 ture, and a dull, yellowish pink in color. 

 But when the animals, which are capable of great extension, are 

 fully spread, as in Fig. 22, such a polyp-stock has a mossy, tufted 

 look, and is by no means an unsightly object. When the individ- 

 uals are entirely expanded, as in Fig. 23, they be- 

 come qiiite transparent, and their internal structure 

 can readily be seen through the walls of the body ; 

 we can then easily distinguish the digestive cavity, 

 siipported for its whole length by the eight radiating 

 partitions, as well as the great size of the main diges- 

 tive cavity surrounding it. Notwithstanding the re- 

 markable power of contraction and dilatation in 

 the animals themselves, the tentacles are but slight- 

 ly contractile. This kind of community increases 

 altogether by budding, the individual polyps remaining more or 

 less united, the tissues of the individuals becoming thicker by 

 the deposition of lime nodules, and thus forming a massive 

 semi-cartilaginoiis pulp, uniting the whole community. In the 

 neighborhood of Provincetown they are very plentiful, and are 

 found all along the shores of our Bay in deep water. 



rig. 22. nalcyonium community} natural Bize. 



Fi{?. 2.3. Individual of Halcyonium fully expanded ; magnilied. 



