POLYCTLF-TA. 315 



scalprate process which von Marenzeller calls the " Meisselzahn." In the last 

 thoracic torus the teeth of the uncini were not 80 numerous as in the preceding 

 segments, not exceeding nine. 



The collar is approximately as long as the rest of the thorax, entire below and at 

 the sides, open above and continuous with the thoracic membrane on each side. 

 The operculiferous style carries a broad wing-like membrane on each side which 

 terminates above in a short free simple lobe. This membrane can embrace and 

 protect the gills when retracted within the tube. 



The disc of the operculum is covered with a chitinous cuticle and carries a long 

 narrow columella arising excentrically near the dorsal side and furnished with circlets 

 of spines at intervals (Plate VIII., fig. 4). The circlets of spines may be webbed or 

 free. In the former case the chitinous membrane which they support projects beyond 

 the spines and forms a stage or disc equal in diameter to the actual basal disc of the 

 operculum. In the specimen before me the columella carries four stages above the 

 opercular disc and two circlets of spines above the topmost stage. Another from the 

 same locality shows two stages above the disc and three free circlets of spines above. 

 A third has one stage above the disc and six circlets of free spines beyond. A fourth 

 has three stages above the disc and two circlets beyond. A fifth has one stage above 

 the disc, then two free circlets, then two more, narrower, stages followed by a terminal 

 circlet. The abdominal seta?, as mentioned by Grube, have the apical portion slightly 

 marked off. They closely resemble the abdominal setae of Omphalopoma langerhansii 

 figured by Marenzeller (' Siidjap. Ann.'). 



In another example taken from the Muttuvaratu Paar the opercular style retains a 

 roseate flush in the preserved state. The tube has a low dorsal keel. The columella 

 of the operculum carries two corneous stages over the disc, surmounted by five circlets 

 of spines. The radioles of the gills are disposed in a simple spiral, about 27 in each 

 gill ; they are slender and the surface is smooth. Thoracic uncini from the sixth (last 

 thoracic) torus show 7 to 9 teeth in addition to the scalprate process. A specimen 

 from the South-west Cheval Paar shows three stages above the opercular disc 

 followed by three circlets. Others were obtained from the East Cheval Paar in 

 8 fathoms. 



The buccal setae of this species are delicate, forming a small, frequently incon- 

 spicuous bundle of about a dozen setae, among which may be found some slightly 

 distinguished as bayonet setae. On each side of the buccal segment, on its ventral 

 aspect, there is a large orifice bounded by prominent lips (Plate VIII., fig. 3). 

 The collar-margin projects forwards as a tongue between the gills ventrally as in 

 Spirobranchus cervicornis. 



An individual was taken off Panadure, Station XLV., 25 fathoms, measuring 

 20 millims. in side view from the free edge of the collar to the posterior extremity of 

 the body; the collar and thorax 7 millims. ; the operculum projects 7 '5 millims. 

 beyond the collar; width of thorax 4 5 millims. The brachysomatic condition of the 



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