1923] POLYCHMTOUS ANNELIDS 9 



Lumbrinereis bifilaris Ehlers 



Lumbriconereis bifilaris Ehlers, 1901, pp. 139-144, PI. xviii, figs. 1-10. 

 Lumbrinereis bifilaris Moore, 1911, pp. 291-294, PI. xx, figs. 135-142. 



Station D.5694; 640 fathoms. 



Cirratulidae 

 A fragment of a cirratulid of indeterminable species was collected 

 at Station D.5694; 640 fathoms. 



Maldanidae 

 Maldane similis Moore 

 Maldane similis Moore, 1906, pp. 233-236, PI. xi, figs. 26-30. 

 The only deviation from Moore's description which these show is 

 that on the lateral margins of the cephalic plate the lobes are more 

 definitely toothed. 



Station D.5683; 630 fathoms; bottom temp., F. 39.1°. 



Maldane cristata, new species 



Figures 5 to 8 



Distinguished by the prominence of the cephalic crest and the smooth margins 

 of the cephalic and anal plates. The type is 130 mm. long and has a cephalic width 

 of 2.5 mm. It is entire, though the median region is very poorly preserved. 



The prostomium makes an angle of about 45° with the body axis (Figs. 5 and 6). 

 The cephalic plate is roughly triangular in outline, and is surrounded by a definite 

 raised margin, which, possibly as a result of the preservation, is thrown into folds 

 but shows no trace of lobings or denticulations. On either side at the postero-lateral 

 angle is a notch separating the margin into a basal and two lateral lobes. The basal 

 lobe is the more prominent and is bent caudad near its middle. The lateral lobes 

 decrease in height anteriorly and are separated by a constriction from the hemi- 

 spherical palpode. The crest is narrow, elevated and prominent, extending from the 

 posterior margin of the cephalic plate into the base of the palpode (Fig. 6) . Numerous 

 fine grooves extend outward from the side of the ridge at an angle of 45 degrees, but 

 these may be due to shrinkage after preservation. The mouth is a narrow elongated 

 slit with no prominent lips. 



The first two setigerous somites have thick body- walls; on succeeding somites 

 the dorsal wall becomes thinner while the ventral wall remains thick; on the seventh 

 setigerous somite only a small portion of the -ventral wall is thick, while in the follow- 

 ing somites the thickening is restricted to the line of insertion of the setae. In the type 

 there is not much difference l)ct ween the preanal somites and those in the middle 

 of the body, but in another specimen the five somites in front of the pygidium are 

 short and thick-walled, while those through the middle of the body are long and thin- 

 walled. These variations are doubtless due to differences in the degree of contraction. 

 The anal plate is circular in outline (Fig. 7). On either side is a rounded notch, 

 whose ventral margin lies at the equator of the circle, thus dividing the circle into a 

 dorsal and ventral portion, the ventral being the larger. The margin of the dorsal 

 part is smooth, that of the ventral part is six- to eight-lobed. The anus is situated 



