20 NEPHTHYS HOMBERGIL 



longer and more slender than the others, so that it is a conspicuous process. The number 

 of papilla in each row is two or three, and thus the species, as De St. Joseph observes, 

 is distinguished from N. caeca. Moreover, each often rises from the distal edge of a 

 thickened base like the stump of an injured papilla. In some only the truncated stump 

 remains. In a large Neapolitan example the two median dorsal rows converge distally, 

 and beyond the point of junction the long cirrus arises. On the ventral surface the 

 median row agrees with its fellows. 



The typical foot (Plate LXVI, fig. 4) is distinguished from that of N. cseca by the 

 less prominent superior lamella, which has a shorter vertical diameter though its 

 elongation transversely carries its outer edge beyond the tip of the foot. The bristles 

 are also darker (brownish). In front a tongue-shaped flap, guarding the base of the 

 bristles, occurs superiorly, while another small flap of similar shape is situated 

 inferiorly, a view from the front thus presenting a bifid surface. Below the point 

 of the spine is a prominent papilla. No part of the foot is more diagnostic when 

 contrasting it with the homologous region in N. cseca. Its free margin is often sinuous 

 or incurved. Beneath the short dorsal cirrus, which is separated by a deep notch, is the 

 richly ciliated (two rows of cilia, St. Joseph) branchia often curved inwards in the prepara- 

 tions, and a little less massive than in N. cseca though not shorter. The outer part of its 

 base is enlarged into a projecting papilla, which in the variety kersivalensis 1 (Plate LXVI, 

 figs. 5 and 6) forms a short cirrus. The serrate bristles are much shorter than in N. cseca, 

 have long cylindrical shafts, and an expanded blade — bent downwards at an angle — 

 tapering somewhat quickly to a delicate point (Plate LXXVII, fig. 2), the edge being 

 finely serrated, and thus in all respects contrasting with the corresponding bristle in 

 N. cseca. St. Joseph speaks of minutely spinose bristles in the superior division of 

 the posterior segments — modifications of the elongated forms. The barred bristles 

 (Plate LXXVII, fig. 3) do not offer much for comment except perhaps that the bars are 

 somewhat closer, and the region is shorter. They form a vertical curved palisade in front 

 of the spine-papilla, while the long serrated forms present in the line of insertion a 

 considerably smaller arc, and the tips are incurved superiorly and inferiorly, so that the 

 form of the bristle is diagnostic— a flattened and pointed hair-pencil. The longer dorsal 

 bristles are near the inferior margin, the longer ventral near the superior margin. 

 Moreover, the ellipse formed by the insertions of the two groups of bristles differ in so 

 far as the dorsal have a gap superiorly, while the ventral have it inferiorly. In the 

 ventral division the lamella is largely developed, directed upward and outward, and with 

 a characteristically broad and somewhat truncated tip. In front are two small lamellae — 

 flap-like in character and spatulate in outline — which guard the bristle-bundles, and 

 make a duplication of the bifid arrangement in the superior division. Instead of the 

 elongated spinigerous region of N. cseca, the part, as in the superior division, is ovoid, but 

 the papilla is superior instead of inferior. The bristles agree with those of the dorsal 

 division, except that the tips of the serrated forms are longer. The ventral cirrus is 

 short and broadly lanceolate in outline. 



1 From the old name of Lochmaddy, North-TJist, where it is plentiful. 



