Galty Marine Laboratory^ St. Anilreios. 12'S 



some, narrower in others. Tlie median keel whieh runs 

 backward from the central process h, perhaps, scarcely so 

 long as in P. prfetcnnisnu, but the nuchal grooves are deeper 

 and they run forward to the edge on each side of the median 

 process. No trace of eyes is present. The proboscis forms 

 a smooth ovoid mass in extrusion, and, so far as could be 

 observed, is devoid of papillie. 



The body, which in the examples seemed to reach about 

 40 mm., somewhat resembles that of P. praierinissa, yet it is 

 easily distinguished by the presence of a distinct collar at 

 the fourth bristled segment, whieh ensheaths the posterior 

 part of the third segment. It has a shallow notch on the 

 median line dorsally, or occasionally a similar notch appears 

 in the mid-ventral line. The number of segments is nineteen, 

 and tlie last five bristle-bearing se.i;ments are somewhat urn- 

 shaped, the dilated posterior end of each — Irorn the elevations 

 for the rows of hooks — corresponding to the lip of the urn. 

 Tlie median ventral streak is elevated as a ridge, which pro- 

 jects as a low cone at the border of the cicatrix formed after 

 rupture. The two terminal segments are devoid of bristles, 

 the anal funnel projecting like a vase fi'om the promment 

 ]im of the adjoining segment at its base. The number of 

 the cirri on the edge varies a little, twenty to twenty-one or 

 thereabout ; in the former case one being double. The 

 cirri or processes of the rim are of moderate length and have 

 the shape of elongated blunt cones, one occasionally being 

 shorter than the others, or a broad one is bitid at the tip. 

 Keproduction of the tail readily occurs, the terminal funnel 

 being well formed, though small, at an early stage. its 

 cirri increase in number as it develops. 



The bristles are similar to those of P. pratermissa, viz., a 

 group of stronger forms with tapered tips and distinct wings 

 and a group of more delicate bristles with only a trace of 

 wings. No barbs occur on the tips of either. The hooks 

 of the first bristled segment (PI. 111. fig. 7) are distinguished 

 by their great length and comparatively slight curvature. 

 The shoulder is fairly marked and the neck short. Tiie 

 great fang is largely developed and stands straight out, and 

 the teeth on the crown behind form a flattened surface so 

 ditterent from the posterior hooks. Those of the second 

 segment have a similarly Hatteued crown (four or five 

 teeth), but the shafts are somewhat shorter. In both the 

 hooks are few in number. In the fourth bristled segment 

 the crown of the hook is higher, three or four prominent 

 teeth being visible, whilst the great fang is curved down- 

 ward at less than a right angle. The shoulder is better 

 marked, and the shaft shorter and more distiuctly curved. 



