NO. 3 HARTMAN : POLYCHAETOUS ANNELIDS 319 



flattened, grooved in the middorsal line, the anterior tip expanded. The 

 setae of the ninth segment were not clearly described. The statement 

 concerning setae is ambiguous; it reads: "The anterior [region of the 

 body] in front of the ninth somite, with capillary, double-bordered setae 

 in both fascicles; the posterior, back of and including the ninth somite 

 [italics by me] with uncini both above and below. Ninth somite shorter 

 than the others, and marked by a deeper constriction, with a pair of 

 comb-like fascicles of short, stiff, capillaiy setae." If "including" above 

 actually means "excluding," the statement has meaning, but the nature of 

 setae in the ninth remains obscure. The proboscis was described as smooth 

 and uncini bidentate. This is herein regarded as a species incertae sedis. 



M. obockensis Gravier (1906, pp. 163-166) from the Red Sea has 

 been regarded as a variety of M. papillicornis (Monro, 1933, p. 1048). 



Key to Species of Magelona Muller 



1. Prostomium with frontal horns at anterior end 2 



1. Prostomium without frontal horns (pi. 28, fig. 10) .... 3 



2. Hooded hooks tridentate ; anterior parapodia with cirriform lobes 

 M. japonica Okuda 



2. Hooded hooks bidentate; anterior parapodia with large, foliace- 

 ous lobes M. pacifica 



3. Setae in ninth segment with broad tip 4 



3. Setae in ninth segment distally tapering 5 



4. Special setae in ninth segment mucronate 



M. papillicornis Muller 



4. Special setae in ninth segment not mucronate . . M. pitelkai 



5. Prostomium smooth, lacks longitudinal ridges 



M. cincta Ehlers 



5. Prostomium marked dorsally with longitudinal ridges or also 

 transverse grooves 6 



6. Parapodial lobes conspicuous, foliaceous in anterior and posterior 

 regions; prostomium with longitudinal ridges and transverse 

 grooves M. rosea Moore 



6. Parapodial lobes inconspicuous, small in anterior and posterior 

 regions (pi. 28, fig. 13) ; prostomium with broad, low, longi- 

 tudinal ridges (pi. 28, fig. 10) but without transverse grooves. 

 M. calif ornica 



