PHYLLODOCE LAMELLIGERA. 81 



It is interesting to note how an animal of such extreme length moves so gracefully 

 in the water, emerging from its folds and coils with ease and dexterity, and making 

 progress over the bottom with considerable rapidity. 



The specimens of this species from Naples are but pigmy representatives of the 

 gorgeous Scotch examples, a condition, perhaps, not unexpected in view of the small size 

 of those from the Channel Islands. The head is more elongated, but this may arise from 

 the mode of preparation, and it is noteworthy that whilst these small southern examples 

 were diagnosed as P. lamelligera, the large, brightly coloured forms, were termed 

 P. Paretti. The lateral papillae posteriorly, and the median in the sinus of the same 

 region, are not distinguishable. The dorsal lamellae (Plate LXVIII, fig. 3), moreover, are 

 more rounded, and the posterior ciliated band is very distinct. The tip of the ventral 

 lamella is also more pointed. Judging from the spirit-preparations the pigment would 

 seem to be much less developed than in the large northern examples. 



The specimens collected in Shetland were also of comparatively small size, but this 

 may have been accidental. 



A variety apparently of this species was sent by Dr. Allen from Rum Bay, 

 Plymouth, where it occurred in sand. The general hue was yellowish brown with white 

 touches on the head, body, and tentacular cirri, the latter indeed being almost white. A 

 white patch — bifid in front — ran forward to the inner side of each eye, and both were 

 separated from the pale area bearing the tentacles by a brown belt — the bifid part being 

 thus prominent. On the dorsum of the body the pale madder-brown pigment was cut 

 into three rows by a touch of white on each side of the median stripe (Plate XLIX, fig. 1). 

 On the ventral surface (Ibid. fig. 2) the median sulcus had a stripe of madder-brown, and 

 a yellowish brown touch, fading externally on each side of it. The dorsal cirri had a 

 central brown touch and a pale margin, and their shape seemed to be more distinctly 

 triangular (or heart-shaped) than in the ordinary form (Plate L, fig. 7). The shape of 

 the head, which agreed with those from the Channel Islands in being more elongate, and 

 its processes, correspond with P. lamelligera, and so far as observed the proportions and 

 minute structure of the bristles do not differ in any respect, and the same with regard to 

 the setigerous region and the other parts of the foot. The specimen was much softened 

 and injured before it was minutely examined by other than the artist. 



In transverse section of the body-wall of P. lamelligera the great depth of the 

 hypoderm and its glandular nature are marked, as also is the strength of the circular 

 muscular coat, and the great extent of the dorsal longitudinal sheets which come down on 

 each side of the oblique muscles. The ventral longitudinal muscles are considerably less. 



In this species the nephridial region of the segmental organ is stated by Louis 

 Fage 1 to be four-lobed, but the genital funnel resembles that in allied forms, e.g. that of 

 P. Paretti. 



Col. Montagu (1808), in the MS. volume of drawings by Miss Dorville, represents a 

 comparatively small and pale specimen of this species, and a foot. It is such southern 

 variations which subsequently have given rise to confusion in species. Montagu himself 

 probably referred to one of these variations, as Nereis argentea, in Plate XXXII, fig. 2, 

 but whether of this or another species is uncertain. 



1 ' Ann. Sc. Nat./ 9 e ser. ; in, p. 263, fig. 10. 



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