XXXIII 



ON A HERMAPHRODITE AND FISSIPAROUS SPECIES 

 OF TUBICOLAR ANNELID 



Edinb. New Phil. Journ., vol. i., 1855,//. 1 13-129 



In the course of a series of dredging operations, in which I have 

 lately been engaged, upon the shores of Caermarthen Bay, in the 

 neighbourhood of Tenby, I took, upon one occasion and in one locahty 

 (in about six fathoms water, near Proud Giltar), the Annehd which 

 is the subject of the present communication. It is questionable^ 

 however, whether the animal is so rare as I might have been led to^ 

 suppose from this solitary instance of its occurrence within my own 

 knowledge — for I had afterwards the opportunity of seeing masses of 

 its calcareous habitation considerably larger than that which I took 

 myself, in the celebrated collection of the late Mr. Lyons of Tenby. 



The Verinidom (as one might conveniently term the habitations 

 of tubicolar annelids in general) of this annelid is composed of very 

 fine, more or less undulated, white, calcareous tubes, attached by one 

 end to some solid body. Rising from this fixed base, they unite 

 together side by side into irregular bundles, and these bundles 

 anastomose like bundles of nerves in their plexuses — leaving irregular 

 spaces here and there, and thus forming a kind of coarse solid network 

 (fig. i). Each tube has a circular section, but can hardly be called 

 cylindrical, because it is thickened at intervals, so as to be obscurely 

 annulated. 



When placed in a vessel of clear sea-water, the annelids issue from 

 the tubules of their vermidom, and each spreading out its eight 

 branchial filaments and displaying its bright red cephalic extremity — 

 the mass assumes a very beautiful and striking appearance — singularly 

 resembling a tubuliparous polyzoarium (fig. 2). 



Z 



