POLYCHAETOUS AXXELIDS FROM PHILIPPINE SEAS. 609 



mites. 167. Color, grayish, with marine blue mid-dorsal stripe. 

 Light refractive spot just median to dorsal lobe of parapodium on 

 each somite; most conspicuous on heteronereid somites. Ventral 

 surface milky white. 



Head (pi. 47, fig. 13) iridescent. Length somewhat less than twice 

 breadth. The figure shows the head in a flattened condition for 

 purposes of comparison. In the specimen the head was bent directly 

 ventrally along a line just in front of the posterior eyes. Palps, 

 two, the same length as the head; provided with terminal articles 

 not seeen in the figure. Tentacles short and bluntly pointed. Ten- 

 tacular cirri, four pairs, the longest pair slightly exceeding the 

 breadth of the peristomium. Eyes, two pairs; posterior pair small, 

 provided with lenses and situated nearer the mid line than the an- 

 terior; anterior pair large, provided with lenses and directed lat- 

 erally. 



As the pharynx was not extruded it is represented diagrammati- 

 cally (pi. 47, figs. 14, 15). Paragnath formula as follows: I, two 

 small groups; II, absent; III, three groups, the central one the larg- 

 est ; IV, crescent-shaped group with heavier teeth anteriorly; V, three 

 groups roughly triangular in shape with teeth in longitudinal rows 

 and heavier teeth anteriorly; VI, single row of heavy black teeth; 

 VII, zigzag group across ventral side; VIII, gradually decreasing 

 continuation of VI. 



First 28 pairs of parapodia in the ordinary nereid condition (pi. 



47. fig. 16). Notopodium subdivided into three lobes, the dorsal cir- 

 rus situated on the most dorsal of these and extending to the limit 

 of the notopodium laterally. Middle and ventral lobes pigmented 

 with brown laterally. Acicula passing to base of ventral lobe. Neu- 

 ropodium subdivided into three lobes, with acicula passing to base of 

 dorsal lobe. Middle lobe shorter and pigmented ; ventral lobe still 

 shorter and bearing ventral cirrus. Setae bundle on dorsal lobe. 

 Twenty-ninth and following parapodia in heteronereid condition (pi. 



48, fig. 1). Notopodium subdivided into three lobes: the dorsal large 

 and flat bearing a short cirrus subterminally and a large finger-like 

 lobe ventrally; middle short and bearing setae: ventral lobe interme- 

 diate in size. Neuropodium subdivided into three lobes: the dorsal 

 pointed and provided with acicula and seta bundle; the middle re- 

 sembling the ventral lobe of the notopodium; the ventral flat and 

 fan shaped, bearing a small ventral cirrus and provided dorso- 

 anteriorlv with a vascularized area. Extra lobe, large and faintly 

 bordered with pink borne posteriorly by neuropodium. Margins of 

 all lobes provided with papillae. 



Setae on heteronereid parapodium of two kinds, the most abundant 

 of the large natatory type (pi. 48, fig. 2) with one edge finely ser- 



