492 Howard Edwin Enders. 



of the same segment. The free distal margins bear a row of uncinal 

 plates. They have already been pointed out in the homologous 

 structures : the posterior margins of the adhesive discs, the similar 

 but larger spatulate neuropodia of the mid-region, and the epaulet- 

 like appendages of the eleventh segment (last of the anterior region). 

 The external lobes of the neuropodia are situated just lateral to the 

 internal lobes, so that a narrow cleft exists between their bases. 

 These lobes are larger than the internal lobes. In form they resem- 

 ble a greatly thickened broad-ax whose head forms the thick pedicel 

 (Figs. 6 and 8). Its free edge lies on the same plane with the seg- 

 ment but it is directed obliquely outward from a mid-ventral line. 

 The edge bears a row of uncinal plates and has been homologized 

 by Laffuie with the same patches of uncinal plates on the fourteenth, 

 fifteenth and sixteenth segments, and to the anterior margins of the 

 adhesive discs of the twelfth and thirteenth segments. The outer edge 

 of the external lobe bears a slender conical cirrus in whose cavity 

 the sexual products of ripe individuals may be seen by transparency. 

 The form and the tint of the branches of the parapodia vary greatly 

 with the turgor. 



The nephridia have been mentioned only incidentally. As pointed 

 out by Laffuie, the first pair of nephrostomes occurs in the twelfth 

 segment (first of the mid-region) and the nephridiopores open to 

 the exterior in the succeeding segment. Each segment back of this, 

 except a few terminal ones, bears the nephridiopores of one pair of 

 nephridia and the nephrostomes of the succeeding pair. The 

 nephridia of the segments back of the sixteenth serve both as organs 

 of excretion and for the discharge of the sexual products. 



The sexually mature males and females may be distinguished with 

 ease by the color of the sexual products which in the posterior 

 region fill the body cavity and its diverticulse. The males appear 

 milky white and the females are more yellow or roseate yellow. The 

 eggs can be seen surging about with the general movements of the 

 body. Adults that have discharged their sexual products can still 

 be distinguished by the same characteristic colors of the more slender 

 convoluted testes or ovaries, but the segments are more transparent. 

 The sex of immature or young specimens can not be distinguished 

 by any difference in color. 



