MELINNA PALMATA. 89 



plate of the Terebellids — which leads to the mouth. In his account of the species Maren- 

 zeller mentions only four tentacles, but they are easily removed in preparations. The 

 shape of the anterior region of the body agrees with that of the typical forms, three 

 bristle-tufts being borne by the oblique anterior part. The ventral collar behind the 

 snout is prominent and smooth, the angle in front of the first bristle-bundle being 

 conspicuous in a ventral view. Posteriorly the body terminates in an anus with a 

 somewhat dilated rim. 



The branchiae resemble in general aspect those of M. cristata, though distinguished 

 by their transverse bars and arrangement, for the four branchiae on each side arise from a 

 curved base and are all visible from the rear. The branchial hooks are minute and 

 readily escape detection, and thus are in contrast with the two forms most abundant in the 

 north. The shaft is broad and short (Plate CXXV, fig. 3 a), striated, and the sharp hook 

 at the tip leaves the neck at more than a right angle, the whole being similar to that of 

 Melinna metadata, Webster, which approaches Grrube's form. Behind the foregoing region 

 at the fourth bristled segment is the dorsal collar (Plate OXIX, fig. 1), which is somewhat 

 narrower and less distinctly denticulated than in the two forms previously mentioned, the 

 papillae having a tendency to fuse with each other and thus lose the feature so 

 characteristic of M. cristata. There are usually four to eight rounded fimbriae. 



The tip of the foot (Plate OXXV, fig. 3 c) is more distinctly differentiated than in 

 M. cristata as a bluntly conical process marked off from the rest of the foot by a 

 shoulder. Moreover, the bristles are proportionally larger and more deeply tinted yellow 

 by transmitted light. The longer forms (Plate CXXV, fig. 3) have nearly straight shafts 

 and finely-tapered tips with just a trace of a bend and with distinct but narrow wings, 

 whereas the shorter bristles have boldly-curved tips which in some are much worn. The 

 wings of these commenced a little beyond the cuticle. The number of the setigerous 

 processes is the same as in the other forms, viz., eighteen, the first three being immersed 

 in the tissues and the tips appearing beyond the surface. 



The anterior hooks, which are in a single row (Plate CXXV, fig. 3 b), follow a similar 

 arrangement to those of the other species but have five teeth besides a process above 

 the prow, and thus a greater number as a rule than in the two previous forms. The 

 posterior outline is inflected, whilst the inferior border of the base, after a slight inflection 

 posteriorly, becomes convex as it approaches the anterior prow. The posterior hooks 

 do not differ materially from the foregoing except in size. They are distinguished from 

 those of Melinna maculata, Webster, by having a process between the prow and the 

 first tooth. 



The tube is composed of secretion covered with a layer of mud. It is friable. 



Grube describes Melinna palmata from St. Malo, where he obtained a single specimen, 

 as having a smooth (entire) margin to the dorsal collar on the fourth bristled segment 

 instead of the fimbriated margin of M. cristata and M. elisabethse. There are eight 

 branchiae which differ at their base from those of M. cristata, and in the spirit-preparation 

 the anterior and the inner filaments of the posterior branchia are longer and more pointed 

 than the rest. The frontal border is three-lobed as in M. elisabethse. The hooks have four 

 teeth. No mention is made of the two dorsal post-branchial hooks, and though Fauvel 

 subsequently alludes to them as the homologues of the paleae and transformed dorsal 



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