PHILIPPINE POLYCHAETOUS ANNELIDS 321 



viduals. They have been considered as representing the holotype 

 of the species. 



The prostomial disk is oval in outline and has a prominent median 

 keel extending from the anterior to the posterior border. (Fig. 4, a.) 

 The margin is elevated to form a distinct rim, which is cut by two 

 pairs of incisions. Those of the anterior pair extend one on either 

 side from near the anterior end of the central keel to the margin, 

 cutting off an upper lip the margin of which extends about one- 

 quarter of a circle. The other pair of incisions cut only the marginal 

 rim and lie on either side about one-third of the distance forward 

 from the posterior border. The mouth lies immediately under the 

 rounded anterior lip. The pygidium is broadly oval and has a thin, 

 elevated margin all the way around, this margin incised on either side 

 just dorsal to the lateral median line. (Fig. 4, b.) The anus is 

 dorsal. 



The dorsal setae are long, slender, and very sharp-pointed. Eight 

 or ten of these occur in each tuft, and they vary in size. (Fig. 4, c.) 

 The hooks lie in a single row. Each (fig. 4, d) is heavy and has a 

 large terminal hook and a series of poorly defined apical denticula- 

 tions. At the point where the hook pierces the cuticle the shaft is 

 swollen, and from this point it tapers to the inner end, the embedded 

 portion of the hook being about eight times the length of the exposed. 



Holotype.— TJ.S.Ts.M. No. 19546. 



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