88 THE ANNELIDA POLYCHAETA. 



tip are sparse and widely separated. (Plate 1 1, fig. 7, 8) . The setae of the ventral 

 series are, as usual, much more slender than those of the middle series and are 

 mostly also decidedly longer. Each toward the distal end has a fusiform 

 enlargement at which there is an abrupt bend or crook. Above the enlarge- 

 ment is a long, slender, acutely- pointed tip. On each side of the head is a series 

 of coarse scales which are well separated; above the enlargement these scales 

 are succeeded by fine hairs which are very densely crowded. (Plate 12, fig. 2). 

 The setae of the first setigerous somite are conspicuously different from the forms 

 above described. The dorsal setae are exceedingly fine, long, and finely pointed; 

 the surface of these appears in part minutely obscurely roughened. The setae 

 of the median series are slender and elongate; each is expanded into a narrow 

 blade near the middle of its length and is distally drawn out into a long, slender, 

 acuminate and curved tip, the seta as a whole also curving; on the convex side 

 from the base of the expanded blade distad is a close series of processes giving 

 the edge a finely serrate or pectinate appearance. (Plate 12, fig. 1). The setae 

 of the ventral series are of the same general form as those of the other parapodia; 

 but scales occur only along one side and are uniform to the distal end excepting 

 for reduction in size. They are smaller in size. The dorsal and ventral setae 

 of the second setigerous somite are hke those of the first; but those of the median 

 series are conspicuously different, being of the general form described as typical 

 above but lacking the subapical process or spur. (Plate 11, fig. 5, 6). 



The extended proboscis is strictly cylindrical. It is 6 mm. long and about 

 3.2 mm. in thickness. In the dorsal series of papillae at its distal end five on 

 each side of the longer conically acuminate median one. The papillae of the 

 ventral side are the same in number and arrangement. (Plate 11, fig. 4). The 

 maxillae are slender and long with the two upper ones not differing, or differing 

 but httle, in size from the inferior ones. In the type the superior maxillae each 

 closes to the left of the corresponding ventral one. 



The paratype is badly preserved. It is incomplete posteriorly. Exclusive 

 of the proboscis it is 75 nom. long and consists of about ninety-two somites. The 

 posterior half of the body is more strongly narrowed in comparison with the 

 anterior. 



Locality. Panama. Shore. 20 March, 1900. Two specimens. 



This species belongs with those having two pairs of eyes, a sessile one in 

 addition to the stalked pair, the latter alone being present in P. oerstedi, the 

 typical species. It has resemblances to the Japanese P. jagasimae Izuka. 

 From that species it differs, e.g., in the form of the proboscis and in the smaller 



