306 PROCLYMENE. 



third occur on the crown — those in front being considerably altered. The strise in these 

 occupy the greater part of the neck. Moreover, there are no gular bristles, so that there 

 can be no confusion. 



It seems doubtful if Arwidsson's species — Nicomache minor, Nicomache trispinat a var., 

 Nicomache quadrispinata—^re other than varieties, for in the common form four spines 

 sometimes occur, and so with eyes. The only approach to Arwidsson's Nicomache quadri- 

 spinata is the occasional presence of four segments with spines in the common Nicomache 

 maculata, the pigment of which on the head occasionally simulates eyes. In certain of 

 these the spine is transversely and somewhat regularly striated. 



Reproduction. — Arwidsson found a large male from Howth near sexual maturity in 

 October. 



A young form, 3 or 4 mm. in length (posterior end being absent), occurred in 

 Ardmaddy Bay, Lochmaddy, on the 13th August, 1872. 



Habits. — It is a brittle species, comparatively few being collected in a perfect 

 condition. Thus regenerated anterior and posterior ends are common in this as in other 

 Maldanids. The intestine is filled with the . greyish mud of its habitat in which sand- 

 grains, sponge-spicules, diatoms, radiolarians, and other debris abound. 



Tube composed of mud or sandy mud, lined by secretion, in the fissures of rocks. 

 Arwidsson found the tubes from Blacksod Bay, Ireland, composed of small, light-coloured 

 grains of sand, occasionally with shells of small mussels. 



It is difficult to say what the Olymene amphistoma of Delle Chiaje 1 is, for he represents 

 only the posterior end projecting from its tube of sand. It is probably a littoral form 

 and may be this species. 



Dalyell (1853) apparently refers to this species under the name Olymene borealis, and 

 he says it is not rare in rocky clefts near low water, and has twenty-four segments. He 

 thought the teeth of the anal funnel might be instrumental in fashioning its hard sandy 

 tube during the night, but this is conjectural. 



A funnel dredged in 30 fathoms, Gaspe Bay, in 1873, resembles nothing hitherto 

 seen, and may be that of a Nicomache. It forms a short vase with three unarmed rings 

 in front of it — all equally prominent, and marked by elevations indicating the mid-ventral 

 streak, which is continued on the funnel rather to the left of a short cirrus. The cirri are 

 short broad cones, and, for the size of the funnel, few in number, viz. fourteen. One on 

 the left has its apex produced as a short filiform process. The anus opens in the centre 

 without an anal cone, but with nine short furrows radiating from it, 



De St. Joseph (1894) mentions the occurrence of Donusia clymenicola, a parasitic 

 copepod, on a form which is probably Nicomache maculata. 



Genus CXIX. — Pboclymene, Arwidsson. 



Nuchal organ hook-like ; straight limb, short and deep. Margin of cephalic plate 

 feebly developed. Naked segments large posteriorly ; between the last and the anal 

 funnel is a wider part. Anal cirri short and triangular, with two larger ventral cirri and 

 1 ( Memorie' and ' Descrizione } (e.g. Descriz., pi. lxxx, fig. 3). 



