24 Tuhicolous Marine Worms, 



In this and the article above referred to, nearly all the Plien- 

 ogamoiis plants in the neighborhood are enumerated, with the 

 exception of a few Salices and Carices, the characters of which 

 are too variable or obscure for me to determine them with confi- 

 dence. No attempt has been made to give anything like a complete 

 list of our Cryptogamia ; and, little else than the more common 

 forms are noticed. 



ARTICLE III. — On the Tuhicolous Marine Worms of the Gulf 

 of St. Lawrence^ hy J. W. Dawson, LL.D., F.G.S. 



Eead before the Natural History Society of Montreal. 



The legions of marine worms that haunt the borders of the 

 sea are not usually very attractive to amateurs, nor have they 

 received the attention that they merit from naturalists, yet there 

 are few of the humbler animals that are more remarkable or 

 interesting in their structure and habits. They constitute two 

 orders, the errantia or vagrant sea worms, and the tubicol?e or 

 tube dwellers. The former are the sea centipedes, sea mice, lob- 

 worms, mud worms, &c. ; and though some of them are hideous 

 in general aspect, they are all remarkable for the singular struc- 

 ture of their locomotive and respiratory apparatus, as well as for 

 many curious points in their modes of life and reproduction. 

 The report presented by Dr. Williamson to the British Association 

 in 1851, on these creatures, is one of the most interesting 

 zoological monographs that we possess. 



The tube dwellers are simpler in the structure of their external 

 appendages, though these are still very curious, and they are 

 more sedentary in their habits; but their colour is often brilliant, 

 and their shells, though generally inferior in beauty to those of 

 the mollusks, are elegant in form, and have the advantage of 

 being capable of easy preservation as permanent specimens. 



The tuhicolous worms constitute several well marked genera. 

 Some, the Amphitrites and Sabellce, construct fragile tubes of 

 agglutinated grains of sand, others, the Terehelloe^ are more select, 

 and gather around them a tube of minute shells and shelly frag- 

 ments cemented together, so that each of them is in his way 

 a sort of little concholo2:ist. Others secrete hard calcareous 

 tubes, which may, as in the Serjmlce, be straight or irregularly 

 curved, or, as in the Spirorhes, rolled into a regular spiral. 



