On a supposed new Boring Annelid. By Charles Stewart. 719 



the point of origin of the shell, and which is bounded in front by a 

 line extending from it to the anterior internal angle, and behind 

 extends for a short distance on the inner margin of the process. 



The process is about half as long again as the broad piece. It 

 is of a prismatic form with an edge directed downvrards ; its upper 

 surface is slightly concave. 



Contour hnes run parallel to the margins. Its upper surface 

 is of a fawn-colour, deepening in front where it is well-defined 

 from the dark mark on the larger portion of the jaw. Interiorly 

 the brown colour is continued throughout the whole length of the 

 process, but is darkest along the crest. 



There are three pans of horny jaws. The inferior pair are 

 broad, their opposed margins are coarsely dentate, so that they 

 interlock with one another. 



The jaws immediately above these are sickle-shaped, broad 

 behind ; the latter part is lodged in a corresponding depression 

 on the upper surface of the inferior pair. 



These three pairs of jaws are those only which are directly 

 concerned in boring or biting, but above them is a pair having a 

 flattened surface imperfectly divided into four pieces. 



Above the protruded jaws are two pairs of rounded fleshy 

 masses, and behind the larger and uppermost of these a row of five 

 tentacles, the longest being the central azygos one. The region 

 which bears these is broad, and it is followed by a short somite, 

 having a small pair of tentacles on its upper surface. 



This latter is followed by ordinary body somites, but with para- 

 podia lying concealed first of all below the margin, but gradually 

 passing to their normal lateral position. 



The branchiae borne on each somite are small, and have only 

 one secondary process at their base. The seta is sHghtly bent at 

 its tip in most cases. The aciculi above the seta are very slender 

 and are not jointed ; there are usually about five in each bundle. 

 Beneath the seta is a much larger bundle of jointed acicuH. The 

 neuropodial cirrus is short; immediately internal to it is an oval 

 elevation of the somite, apparently formed by a great elongation 

 of the epidermic cells, which are here firnily adherent to the 

 cuticle ; this organ is perhaps of a sensory natiu'e. A large opaque 

 mass lies between it and the bundles of acicuh ; it perhaps repre- 

 sents a nephridium. 



There can be no doubt that this woite belongs to the family 

 Eunicidffi, but I have not been able to find a description of any 

 possessing calcareous jaws. 



This featm-e seems to me so important as to justify a distinct 

 genus being made for it. 



B 2 



