258 THE ANNELIDA POLYCHAETA. 



which is most distinct anteriorly. The venter is weakly convex. From the 

 fourth somite caudad there is a distinct neural furrow of moderate width and 

 depth. 



The parapodia are very small, subcylindrical and distally rounded processes. 

 The notocirri are not jointed, though some of them may give the impression of a 

 very vague, irregular annulation; they are stout at base, from which they taper 

 strongly to a point. They increase in length from the first to about the twelfth, 

 where they extend near halfway to the middorsal line when laid back against 

 the body. They become shorter and more slender caudad, the base or cerato- 

 phore appearing there especially abruptly thicker. The neurocirri are short. 

 The first four to six appear subcorneal with the base constricted and the terminal 

 article continuing the outline of the proximal without abrupt change. The 

 cirri then become stouter and cylindrical, with the small terminal article abruptly 

 very much narrower. They continue of this form to the end of the fragment. 

 The branchiae begin on somite VII and occur on all subsequent somites 

 to the end of the fragment. Excepting the first, they are of the unilaterally 

 pectinate type. The filaments arise at an angle of about forty-five degrees to 

 the stem, and the terminal filament is parallel with the others. The individual 

 filaments are shorter than the notocirrus. Each of the first branchiae is a simple, 

 unbranched, slender filament shorter than the notocirrus. (Plate 59, fig. 4). 

 The second branchia on the left side has four filaments, the right apparently 

 but three. Of these four filaments the one next the* last is longest, the first and 

 last the shortest. (Plate 59, fig. 5). The third branchia is likewise composed 

 of four filaments similarly related, but they are distinctly larger than in the 

 second. The fourth has six filaments, the fifth seven, the sixth has six primary 

 filaments, but of these the second gives off two lateral branches of which the 

 proximal one is much the longer, making the total number of filaments eight, 

 the maximum number noted. (Plate 59, fig. 6). In the thirty eighth and for- 

 tieth branchiae the number of filaments has again fallen to five. The forty 

 second branchia has four filaments, the number that prevails on succeeding 

 branchiae to the seventy third somite, the last present in the type, though only 

 three filaments occur in some. (Plate 59, fig. 8). The filaments are nearly 

 always entirely simple, the branched condition being exceptional. The bran- 

 chiae are erect, usually curling away from the body rather than lying against it. 

 When stretched back against the body the longer branchiae fail much of reaching 

 the middorsal line. 

 The acicula proper are pale in color. They are comparatively slender and 



