100 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 10 



co; E. splendida Grube (1856, p. 58) from Valparaiso, CEUe; E. sub- 

 depressa Grube (1866, p. 68) from Puerto Cabello, Venezuela; E. tenuis 

 (Treadwell) (1921, p. 51) from Florida; E. thomasiana Augener 

 (1922, p. 45) from Florida; £. tibiana (Pourtales) (1869, p. 108) from 

 Havana; E. tridentata Ehlers; E. valens (Chamberlin) ; E. vittata (delle 

 Chiaje) ; E. vivida Stimpson (1853, p, 35) from New Brunswick. 



An attempt to ascertain a more accurate, less fallible means of de- 

 termination has involved the detailed examination of large numbers of 

 individuals. The degree of variability of certain characters, especially 

 total length and number of body segments, constitution of branchial parts, 

 and number of teeth on the maxillary plates, is such that they alone can- 

 not be taken as criteria for speciation. Color in life and distribution of 

 pigment, though significant, are too fugitive to be of practical value. On 

 the whole, the hooded composite setae are fairly uniform throughout the 

 genus, hence of little value for specific identity ; however, in some species 

 there is a tendency toward a tridentate appendage in posterior segments, 

 especially when the subacicular hooks are tridentate. 



It seems that the known species may be grouped on a character be- 

 lieved to be constant and specific. It concerns the form and color of the 

 subacicular hooks. Four groups may be recognized : (A) the flavus-bi- 

 dentate group, (B) the fuscus-bidentate group, (C) the flavus-tridentate 

 group, and (D) the fuscus-unidentate group. One other group, E below, 

 is incompletely known in these respects. The species enumerated above 

 may be arranged as follows. Two species, herein newly described, are 

 added. 



(A) Flavus-bidentate group. Subacicular hooks pale, distally bidentate. 



1. E. afuerensisj n.sp. 5. E.longicirrata 



2. E. filamentosa 6. E. pennata 



3. E. harasii 7. E. segregate 



4. E. kobiensis 8. E. tibiana 



(B) Fuscus-bidentate group. Subacicular hooks dark (or black), dis- 



tally bidentate. 



