NICOMACHE. 301 



and the shaft of the hook is, as a rule, less curved than in R. Loveni. They became 

 smaller and smaller posteriorly. 



The anterior bristles are in two groups as in R. Loveni, the anterior (Plate OVIII, 

 figs. 3 and 3 a) having broader wings, with a long, tapering tip, and the posterior bristles 

 have narrower wings. 



The Hebridean example (1866) was in fragments, softened, and without head or tail, 

 but it evidently belonged to a form of considerable size for the family, and its bristles were 

 exceptionally strong. It is often difficult to determine the distinctions of closely allied 

 forms where the specimens are fragmentary, and where descriptions and figures are 

 capable of various interpretations. 



Tauber (1879) mentions three varieties, the infundibuliform posterior segments being 

 long in the first and stouter variety, shorter in the more slender forms, and in the third 

 considerably shorter. 



Arwidsson (1906) in his comprehensive survey of the northern Maldanidse more 

 clearly defined this species from R. Loveni, yet in regard to the hooks there are certain 

 differences between the British and the more northern examples which need further 

 investigation. 



Nolte : (1913) gives longitudinal sections of the collar and the collar-organ of Rhodine 

 Loveni. The latter is situated at the inner edge of the base, and consists of hypodermic 

 cells, nerves, and muscular fibres covered by cuticle. 



The same author has a figure of a bristle of this species in which he speaks of the 

 capsule which in his figure is separated from the shaft at a fractured part, the interior of 

 the shaft being fibrillar. 



Sub-family. — Nicomachin^, Arwidsson, 1906. 



Nuchal organs more or less bow-like, diverging anteriorly. Cephalic plate absent. 

 First bristled segment short, those following to the eighth longer, those near the tail 

 shorter, segment-junction absent between the seventh and eighth segments. Anal cup 

 with well-marked cirri, a larger one in the mid- ventral line. Anus in the centre of the 

 cup, Nephridia in several segments. Glandular belts anteriorly in bristled segments 

 1 to 7. Spines in single row in segments 3 to 4. Hooks in a single row in the first 

 series, with a bold curve at the neck, a great fang with several spines on the crown, 

 and a tuft of hair on the throat. Anterior bristles with narrow wings and some 

 with long, tapered tips and minute spines. Others with slender axes and opposite spikes. 

 The posterior long bristles have their tapered tips smooth. Tubes of sand, free. 



Genus CXVIII, Nicomache. 2 Holmgren, 1866. 



Cephalic lobe fused with the bare buccal segment, oval, convex, inclined, without a 

 border. Body sub-cylindrical, slightly attenuated posteriorly, segments twenty-six, of 



1 'Wiss. Meeresuntersuch/ n.f., Bd. xv, p. 83, figs. 26 and 27. 



2 Arwidsson again makes Nicomache a, sub-genus, characterised by the anal funnel being slightly 

 oblique, and the border with short cirri ; nephridia in the sixth bristled segment. 



