26 XEPHTHYS CILIATA. 



of forming a free lamella guarding the capillary bristles in front, so that they lie in a 

 fissure between it and the posterior lamella. This spinigerous flap has the spine a little 

 beyond its middle, and thereafter it ends in a rounded or disc-like free lamella at the edge 

 of the foot. The anterior base of the foregoing has a slight fillet from which the barred 

 or camerated bristles project. The bristles have a distinct curvature (Plate LXXVII, 

 fig. 6) along the dilation above the shaft, and this is spinose or serrated. The barred 

 forms (Plate LXXVII, fig. 7) are finely tapered, and perhaps less robust than those of 

 N. caeca. 



The inferior division has a short posterior lamella which superiorly in the large 

 examples rises as a free rounded lobe. The spinigerous region forms another lamella 

 anteriorly from the upper border to the lower, an interval, however, occurring between 

 it and the cirrus. The capillary bristles arise between it and the posterior lamella, and 

 thus lie in a deep pit. The barred bristles spring from a line marked by a ridge of skin, 

 which superiorly ends in a distinct flap or lamella at the commencement of the spinigerous 

 region. 



The conical ventral cirrus is comparatively large. The ventral bristles agree with 

 the superior in having a well-marked series of spikes on the curved and dilated portion 

 above the shaft. On the whole N. ciliata has comparatively short and slender 

 bristles. 



The figures of 0. F. Miiller in the ' Zoologia Danica ' (1789) are recognizable not so 

 much in minute detail, as in the firm outline and general contour of figs. 1 and 2. The 

 description of the plate, moreover, bears out this interpretation, though the author adheres 

 to there being two caudal cirri, but as only traces of these were left in the specimens which 

 Mohr had sent him from Faroe, the mistake is explained. He correctly discriminated it 

 from the N. caeca of 0. Fabricius. He distinguished it from the gigantea (Seba Thesaur, I, 

 81, fig. 7) of Linnaeus by the third series of bristles, whilst from Nereis caeca (Fabricius, 

 'Fauna Groenlandica ') it differs by the absence of "scales" between the feet, Midler's 

 form having only fleshy fimbriae. 



H. Eathke (1843) described this as a new species, but in all probability it is the 

 same form. He gives no figures. 



(Ersted (1843) at first confused the species with N. longisetosa, but soon corrected 

 himself, and gave an excellent figure of a foot in his ' Conspectus.' 



The formation of a new genus by De Quatrefages (1865) for this species rested on 

 misapprehensions, somewhat increased by his entering Rathke's Nephthys ciliata and 

 (Ersted's N. borealis as separate forms. 



Dr. Johnston did not separate the species from N. cseca. 



Malmgren's account and figures, with the supplementary note in the 'Annulata 

 Polychgeta,' readily define the species from allied forms. 



Ehlers (1868) corrected the synonymy up to date, and gave a reliable description 

 without figures. 



Smith and Harger's figure (1874) might do for either Nejphthys ciliata or incisa, 

 though it more nearly approaches the latter. These and other Annelids described in their 

 paper were dredged on St. George's Bank. 



