158 DTTBLIN NATURAI HISTORY SOClETy. 



ANNELLIDA. 



JANUARY, 1855. 



ON THB OCCURRENCE OF NEREIS TUBICOLA. BY WILLIAM ANDREWS, M.R.I.A. 



In one of the experimental trials in which I was engaged, in connexion with 

 the fisheries, we had run out soundings nearly ten miles to the north-west of the 

 Tiraght Rock, one of the Blasket group, where we found bottoms of fine gravel 

 and shells, from fifty to eighty fathoms, and which we found, on trial, to be va- 

 luable fishing-grounds. The soundings were taken up in a small dredge, to 

 which a heavy iron box had been attached. I shall pass, for the present, the 

 several objects of interest captured, and submit to you the subject of the present 

 paper. It belongs to that class of articulated animals, the Annelides. The An- 

 nelides and Nereids constitute a tribe of exceedingly interesting animals, appa- 

 rently insignificant from their habits, yet beautiful in structure, and rich in 

 brilliant tints. These invertebrate creatures form a peculiar class in the eyes 

 of naturalists, verging on the confines of the sub-kingdom, yet exhibiting modi- 

 fications of their higher groups. Their annulose character and nervous system 

 range them in an intermediate link between the Articulata and Radiata. They 

 possess a vascular apparatus for circulation, with generally a long, slender 

 body, soft, and divided by circular folds into a great number of rings. On each 

 side of the body is a long series of fasciculi of bristles, supported in fleshy tu- 

 bercles, which act as feet. The characters, however, vary in many species. In 

 some the head is distinct, in others it is wanting ; and the head is frequently or- 

 namented with fascicles or plumose cirrhi. These animals are distributed (the 

 greater number marine) from the shoalest to the deepest water. Some, for pro- 

 tection, form a calcareous tube, almost like the shells of molluscs; others form 

 a coating by agglutinating grains of sand or shells, and, likewise, some are in 

 tubes, which are entirely membraneous or horny. Of this last number is the 

 species that I shall bring to your notice, as being an addition to the Fauna of 

 Ireland. It belongs to the genus Eunice Cuv. — characterized by having plumose 

 branchiae, proboscis armed with horny jaws, each foot armed with two cirrhi and 

 a bundle of setaa, five tentacula surrounding the mouth and nape. The animal, 

 in the living state, was almost colourless, inhabiting a horny tube, beautifully 

 transparent, and from 2| to 3 inches in length — the head of the animal plumose, 

 the plumes of a delicate pink or violet tinge. I obtained three specimens from a 

 depth of eighty-one fathoms, in soundings of fine gravel. It appears to be iden- 

 tical with the Nereis tubicola of Muller, which inhabits a horny tube, and is 

 figured and described in the Zoologica Danica. I may mention that I have also 

 obtained on the same coast, in shoal soundings of soft sand, Pectinaria Belgica, 

 the animal enclosed in a fragile tube of agglutinated grains of sand, the head of 

 the animal ornamented with golden plumes. It is beautifully figured in Dono- 

 van, as the Sabclla tubiformis. 



POLYPIFERA. 



FEBRUARY 11, 1852. 



Dr. Allman communicated an abstract of his views of the Medusae and Hy- 

 droid Polypes. He believed that the essential part of the disk of a Medusae was 

 the system of gastro-vascular canals which at their origin communicate with the 

 stomach, and thence radiate to the margin of the disk. These canals are repre- 



