Tubicolom Marine Worms, 25 



Genus Spirorhis. 



A stroller by tlie sea side, searching for shells or algae, is sure 

 to meet with Sea weeds more or less thickly covered with little 

 white shells, coiled up and attached firmly by one side to the 

 weed. Sometimes they are so abundant that large fronds may 

 have as many as a hundred on a square inch. If taken out of 

 the sea while alive, and examined under a microscope, there may 

 be seen to extend from the mouths of their tubes little conical 

 buttons mounted on stalks, which are the stoppers or lids that 

 close the orifices of their dwellings. These are followed by 

 a group of little filaments, the gills of the animal, and amidst 

 them is the simple suctorial mouth. These organs are slowly ex- 

 tended, but very rapidly withdrawn when the animal is alarmed by 

 any agitation of the water or the vessel in which it is contained. If 

 the animal is extracted from its tube it will be found to be a little 

 jointed worm terminating in a point, and having at its sides 

 minute hooks and bristles for enabling it to hold fast by the sides 

 of its habitation and to ascend and descend at pleasure. 



The species most commonly found on the shores of the gulf of 

 St. Lawrence is the Sinrorhis spirillum — Serpula spirillum 

 of Linnaeus. It is regularly spiral, with smooth rounded whorls, 

 not enlarging rapidly nor much flattened at the lower side, but 

 sometimes rising nearly into an erect position toward the mouth. 

 Its favourite residence is on the fuci in shallow water. It is 

 found on both sides of the Atlantic and as far north as Greenland. 



On sea weeds and zoophytes from somewhat deeper water, we 

 may often observe another species, smaller and more delicate in 

 texture than >S^. spirillum, coiled less closely, and in the opposite 

 way, or from right to left when the aperture of the shell is held 

 from the observer. This is the Spirorhis sinistrorsa. It is not 

 noted by Fabricius as a Greenland shell, but is found on zoophytes 

 at Gaspe, and abounds on sea weed in deep water off" the coast of 

 Maine. This and the previous species are the only ones that an 

 observer'who confines his attention to the sea weeds of the shore 



tj (At 



may chance to meet with; but dredging in deep water will 

 procure the following species. 



Sp)irorhis nautiloides, the Serjnila spirorhis of Linnaeus, is of 

 the same size with S. Spirillum, but is thicker, less smooth, trans- 

 versely wrinkled, and more flattened at the base, so that when 

 removed from its attachment it appears like a shell split into two 

 equal halves. Its whorls also are more closely united and increase 



