ARICIIDAE 159 



rather numerous— 10 to 12— teeth ; M. Ill have a large tooth, beneath which are one or 

 two minute denticles ; M. IV and M. V are unidentate. The labrum consists of a pair of 

 more or less triangular plates. 



Remarks. This specimen shows certain differences from a typical D. filiim. The 

 capillary bristles are more elongate and narrowly bordered than is usual in this species. 

 Only the anterior end of the animal is preserved, and I assume that the capillary bristles 

 from the middle region would have shown the more typical rather wide wings. More- 

 over, although I cannot count the teeth of M. II exactly, they seem to be more 

 numerous than in the European examples of this species. These differences do not in 

 my opinion justify a separation. Ehlers has described a species from the Magellan 

 region, Aracoda tenuis, which appears to be a Drilonereis. If Ehlers 's figure of the upper 

 jaws (Ehlers, 1901, pi. xix, fig. 9) is accurate, it would seem to be a distinct species, for 

 it has four heavy teeth at the base of the pincers, M. II have about five large teeth and 

 M. Ill have three large teeth instead of one main tooth and two or three minute 

 denticles. 



Family ARICIIDAE 



With hooks in the thoracic region Scoloplos 



No hooks in the thoracic region Haploscoloplos 



Genus Scoloplos, Blainville 

 Prostomium conical. Buccal segment achaetous. A pair of erect strap-Hke branchiae 

 on all but a few anterior segments. A somewhat flattened thoracic region passing 

 gradually into a rounded abdominal region. Thoracic feet with an erect dorsal cirrus 

 and a bundle of crenate capillary bristles; in the ventral ramus there are hooks and 

 usually a number of capillary bristles. There may be one to three podial papillae or they 

 may be absent. No subpodial papillae. In the abdominal region an erect dorsal cirrus, 

 capillary bristles and sometimes forked bristles. A ciliated lateral organ takes the place 

 of an intermediate cirrus. Ventral ramus bilobed with capillary bristles. Ventral cirrus 

 often absent. 



Scoloplos marginatus (Ehlers). 



Aricia marginata, Ehlers, 1897, p. 95, pi. vi, figs. 150-156. 

 Benham, 1921, p. 77. 

 Monro, 1930, p. 144. 



Nainereis marginata, Fauvel, 1916, p. 445, pi. viii, figs. 26-33. 

 Occurrence. St. WS 25 (2). 



Specific characters. Prostomium bluntly conical. Between 11 and 14 thoracic 

 chaetigers. The strap-like gills begin at the 6th chaetiger. Dorsal cirri lanceolate. 

 Dorsal bristles delicately crenate and capillary. The ventral thoracic rami carry three 

 rows of hooks and no capillary bristles. There are no podial papillae. In the abdominal 

 region the dorsal bristles are long capillaries and forked bristles are sometimes present. 

 The ventral ramus carries a large aciculum with a hooked tip and a few capillary bristles, 

 the latter often disappearing towards the hinder end of the body. 



