NEPTHYS ECTOPA. 95 



by the prostomium, the apex of which extends into it. It bears both notopodia 

 and neuropodia. The succeeding somites are all complete and simple. They 

 are separated above and laterally by deep intersegmental furrows; ventrally 

 between the base of the neuropodia on each side and the prominent neural 

 furrow, the intersegmental furrows are rather faint, becoming again more pro- 

 nounced in this furrow. The ventral furrow widens out clavately toward the 

 anterior end in the wider region of the body, the elevated part of the venter 

 on each side curving ectad and dorsad. The furrow between the peristomium 

 and the succeeding part of the venter is very deep, in strong contrast with the 

 following intersegmental furrows which are weak. 



With the exception of the first two pairs, the parapodia are biramous. 

 In each of the first two pairs the parapodium is represented by the notopodium 

 alone, this having the essential form of those in the typical parapodia succeed- 

 ing. Each is low, subcorneal, but with a broad top and bears a pointed, conical, 

 somewhat flattened appendage on its ventral side at base. The parapodia 

 (notopodia) of these first two pairs are situated much farther dorsad than the 

 others, lying up close to the prostomium. The notopodium of each one of the 

 third pair of parapodia is abruptly farther ventrad and about halfway from 

 the second to the lev^el of the fourth; from the fourth, the notopodia become 

 gradually located farther and farther ventrad to about the tenth somite, after 

 which the same level is maintained. In a typical parapodium the two branches 

 are widely separated. (Plate 15, fig. 3). The notopodium is short and thick, 

 with the distal end convex, oblique to the main axis, and bearing along its cir- 

 cumferential line the numerous setae excepting for a short open space or break 

 on the dorsal side, while the top of the aciculum touches the surface near the 

 centre of this area and shows conspicuously in a small dark elevation; from 

 the ventral side of the notopodium a conspicuous branchial lobe projects ventrad 

 reaching the neuropodium; this lobe is thick at base but conspicuously flat- 

 tened distally in the anteriocaudal direction and is also expanded distally, the 

 distal end subtruncate with a tendency to be weakly bilobate from a small 

 notch at middle, while slight crenulations may also show along the ventral edge. 

 In the anterior region in going cephalad this lobe becomes smaller and smaller, 

 at the same time becoming more pointed distad until of the conical form above 

 mentioned on the most anterior ones. No notocirri are present in the type. 

 The neuropodium of a typical parapodium of the middle region of the body is 

 also short and thick with the upper side straight, the ventral more slanting; 

 the distal surface is broad and convex and slopes obliquely ventromesad; 



