SABELLARIIDAE. 483 



The thoracic notopodial fascicles arc of similar appearance throughout, 

 and the setae are alike. The fascicles contain a minor number of more slender, 

 narrowly Umbate capillary setae and more numerous coarse setae which are 

 obviously curved toward the distal end, at which they are drawn out into slender 

 acute tips; each is broadly winged at the curve from where the wing gradually 

 narrows and finally disappears both distad and proximad. (Plate 78, fig, 2). 

 The uncini have mostly twelve small teeth along the edge in addition to the 

 larger tooth at the anterior end. Cephalad of the large tooth the edge is smooth 

 for a short distance before it rounds about the anterior end. The number of 

 teeth is progressively reduced towards the ends of each series, the end-plates 

 reduced essentially to a smgle large hook. (Plate 78, fig. 3). The abdominal 

 setae of the anterior and median regions are stout, distally acute, curved spines 

 which are somewhat compressed. There are three or four in a transverse series 

 in each group. The setae of the caudal somites are very long and fine and 

 straight, excepting at the distal ends, where curved, the curved region flattened, 

 limbate, a furrow or depression along its middle region; apex acutely pointed. 

 (Plate 78, fig. 1, 4). 



Locality. Paumotu Archipelago: Makemo. Depth, 13 fms. From coral 

 at bottom of lagoon. 19 October, 1899. One specimen. 



Sabellariidae. 



In this family the body presents a very characteristic appearance due to 

 the development from the first setigerous somite of two usually large lobes 

 nearly always fused dorsally and extending forwards so as completely to obliter- 

 ate the prostomium as a separate organ, though it is partially distinguishable 

 between the lobes — the so-called opercular lobes — in one Madagascar form 

 {Cryptopomatus geayi Gravier). These lobes seems to represent the greatly 

 developed notopodial branches of the first somite, or peristomium, with which 

 the prostomium is fused (Comp. rend. Acad, sci., 1908, 146, p. 250). Dorsally 

 each lobe bears an inner and an outer, with sometimes an intermediate, series 

 of stout paleae of varied form, which together form an operculum. These 

 paleae rarely almost obliterated (Cryptopomatus). On the ventral side of the 

 lobes are series of ridges, or lamellae, bearing numerous branchial filaments 

 presumably outgrowths of the palpi, which are fused with the lobes. From the 

 prostomial area proper arise two tentacles. At the base of the principal opercular 

 lobe on each side a small setigerous tubercle, the neuropodium of the correspond- 



