218 THE ANNELIDA POLYCHAETA. 



sents a thick, obliquely placed base shaped like the frustrum of a cone, from 

 the distal surface of which projects a slender, cylindroconical process proper, 

 which exceeds the other lobe in length, and contiguously with it the notocirrus, 

 which is subfiliform, but tapers gradually distad, and is very long, much exceed- 

 ing the parapodial lobes in length and, when laid back caudad, extending entirely 

 across the succeeding two somites. The ventral lobe arises at the base of the 

 neuropodial lobe proper, which it sUghtly exceeds in length and than which it is 

 more slender, being of nearly the same form and size as the infrasetal notopodial 

 lobes. Just proximad of the ventral lobe arises the neurocirrus. This has a 

 small, low, subcorneal cirrophore and a slender style which reaches to near the 

 tip of the ventral lobe. The neurocirrus remains of uniform proportions through- 

 out, but the notocirrus decreases both in relative and in actual length both to- 

 ward the anterior and toward the posterior end of the body. The notopodial 

 lobe is stouter in the widest region of the body, that is, on the somites imme- 

 diately following the fifth, and the ventral and dorsal lobes of the same region 

 are also much stouter. (Plate 30, fig. 1). 



In a typical parapodium of the middle region of the body there are setae 

 of three distinct and well-marked types. In the notopodial fascicle are usu- 

 ally two stout crochets, each of which distaUy curves first strongly dorsad and 

 then bends ventrad and proximad into a thus somewhat recurving, acute tooth 

 or beak, on the distal curve of which is placed a small, colorless, and transparent 

 rounded tooth or nodule, the main process and distal end of the curved portion of 

 the crochet being dark browai and the remainder of the shaft colorless. A thin 

 transparent process, or keel, extends from the shaft to the tip of the principal 

 tooth. In the notopodium there are in addition compound setae. In these the 

 shafts are finely cross-striate, or camerated, and end in symmetrical sockets. The 

 blades are long and finely tipped, and are finely pectinate below the smooth tip 

 on one side. In the netu-opodium, in addition to homogomphs of this type, there 

 are compound setae with unsymmetrical sockets and blades that are short, with 

 small, narrow, and distally rounded tips below which they are finely pectinate 

 on one side in the usual way. 



The maxillae have short, acute, only shghtly incurved, smooth fangs, below 

 which are six short and mostly blunt teeth. The paragnatha are all corneous 

 and are pectinate, being arranged densely in munerous, transverse rows. Their 

 precise distribution was not satisfactorily determined from the partial dissec- 

 tion, the proboscis being wholly retracted. 



Locality. Off E. point Santa Rosa Island, California; Sta. 4571 



