154 NEREIS. ; 
The intestine of a young specimen, shorter than an inch, appeared 
corrugated by the microscope. 
Few specimens, especially those of larger dimensions, are found en- 
tire, for rupture of the body is common ; and even when entire, the due 
proportions are seldom seen, owing to the progress of regeneration, which 
readily ensues. But perfection may be always ascertained by the forked 
extremity, which is more conspicuous in this species than in any of the 
preceding. It is not improbable that the fork is obliterated by the gene- 
ration of new parts in its vicinity, as the natural dimensions of the ani- 
mal are augmented. However, this is a subject of difficult explanation. 
This creature constructs a very thin transparent silky tube, from a 
matter exuding apparently from the whole body. Here it rests, expos- 
ing the head, which commonly waves from side to side. The tube is 
strengthened by the incorporation of sand where accessible. When other- 
wise it remains quite transparent, and it is framed of sufficient width to 
admit of the animal’s reversing itself within. Sometimes the quantity of 
the secreted matter employed in the covering is copious. 
This is a littoral Nereis ; it retreats from the light, lurking under 
stones, or in the clefts of the rocks. A very fine specimen was found on 
raising a large shelving portion of rock, near low-water, where always 
moist. 
I cannot speak definitely of the propagation of the species. Early in 
February a mutilated specimen discharged thousands of minute ova ; and 
early in March, I found a quantity of spawn in a vessel containing a 
specimen, but not solitary. This spawn consisted of thousands of minute 
yellowish ova, amidst a thin, faint brown, albumenous matter, of too 
little tenacity to retain them in connection when the vessel was moved ; 
no development followed. 
It is not rare. 
Pirate XXII. 
Fic. 6. Nereis versicolor | fulgens |. 
7. Head, enlarged. ; 
8. Posterior extremity, enlarged. 
