34 JNEPHTHYS JOHNSTONI. 



dorsal process or cirrus, besides the lanceolate ventral one ; whereas in N. longisetosa 

 only a small papilla exists dorsally, and the ventral cirrus is much longer. 



In the typical foot (Plate LXVII, fig. 1) the dorsal lamella is narrowed at its 

 attachment, broader and somewhat truncated distally, the reverse being the case in 

 N. longisetosa. Instead of a distinct flap externally, only a trace in the shape of a fillet 

 occurs : the dorsal cirrus is evidently less, while the branchia is larger, though it is 

 likewise curved inward. The spinigerous lobe is produced much further outward as a 

 pointed process, and has a different angle. Moreover, the fillet guarding the barred 

 bristles has a convexity directed upward. 



In the inferior division the posterior lamella is considerably smaller, the spinigerous 

 lobe longer and more acute, whilst anteriorly the upper fillet is somewhat smaller. The 

 ventral cirrus is lanceolate, and shorter and less tapered than in N. longisetosa. 



Both capillary and barred bristles (Plate LXXVI, figs. 9 and 9 a) are more slender 

 than in JSf. longisetosa, and in both the transverse bars of the serrated bristles extend 

 downward till the full diameter of the shaft is reached. 



7. Nephthys Johnstoni, Elders, 1875. Plate LVII, figs. 15 and 16; Plate LXVII, 

 figs. 2 and 2 a— feet ; Plate LXXVI, figs. 10 and 11— bristles. 



Specific Characters. — Head shield-shaped, with a broad and somewhat convex anterior 

 border ; a slender tapering tentacle at each angle, and an oblique translucent patch at its 

 inner base. The second pair of tentacles arises latero-ventrally after a considerable 

 interval. Proboscis with rather long rows (twenty-two) of papillae distally, and a median 

 cirrus dorsally and ventrally. Between the rows of the distal bifid papillae of the 

 aperture is a simple papilla dorsally and ventrally. The anterior folds or lips in front 

 of the mouth are large. The dorsal lamella of the foot has a similar curvature to that 

 of N~. ciliata, but it extends further outward, and only a trace of the rounded terminal 

 lobe appears. The setigerous region stands prominently upward and is smoothly 

 rounded externally. No free flap to the anterior fillet guards the barred bristles. 

 The dorsal cirrus is a variable filiform process. The branchia is not large and is curved 

 externally. The ventral lamella is large and ovato-lanceolate, and the ventral cirrus 

 lanceolate, larger than in N. ciliata, though less than in N. longisetosa. The capillary 

 bristles are longer and less rigid than in N. longisetosa, and the serrations very fine, 

 the long distal region being smooth. The barred region in the anterior bristles is 

 long, and slightly fusiform. 



Synonyms. 



1843. Nephthys longisetosa, CErsted. Gronl. Annul. Dorsibr., p. 195, figs. 75 and 76. 

 1865. „ „ Johnston. Cat. Brit. Mus., p. 172. (?) 



1874. „ Johnstoni, Mcintosh. Ann. Nat. Hist., ser. 4, vol. xiv, p. 196. 



1875. „ „ idem. Invert, and Fishes, St. Andrews, p. 119. 



Ehlers. Zeitsch. f . w. Zool., Bd. xxv, p. 38, Taf. hi, f. 3 and 4. 

 1900. „ „ Mcintosh. Ann. Nat. Hist., ser 7, vol. v, p. 261. 



