98 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 10 



(1) those with tentacular cirri, including the branchiate Eunice and its 

 abranchiate subgenus Nicidion, and (2) those without tentacular cirri. 

 The latter are separable into those with 5, 3, or a single prostomial an- 

 tenna. Nematonereis and Lysidice, with one and 3 prostomial antennae, 

 respectively, are abranchiate; Marphysa and Faramarphysa, each with 5 

 prostomial antennae, are branchiate and abranchiate forms, respectively. 

 These relations are diagrammatically shown on the chart above, sug- 

 gesting possible affinities. 



Other genera that have been referred to the Eunicidae are ( 1 ) Coelo- 

 branchus Izuka, an aberrant member of the superfamily Eunicea, char- 

 acterized by its greatly reduced jaws, modified setae, and peculiar intesti- 

 nal diverticula that extend out into elaborate, branched, branchial-like, 

 dorsal appendages (Izuka, 1912); (2) Amphiro Kinberg, erroneously 

 erected for a species of Marphysa; (3) Aphelothrix Chamberlin referred 

 to Marphysa by Crossland (1924, p. 56) ; and (4) Lithognatha Stewart 

 (1881, p. 717) for a species from Singapore. 



Genus EUNICE Cuvier 



Considerable discussion has centered on the appropriate designation 

 for this genus. European authors have consistently used Eunice; some 

 American authors, including Verrill (1900, p. 638), Chamberlin (1919, 

 p. 229), and Treadwell (1921, p. 4), have favored the use of Leodice 

 Savigny. Since the laws of priority are obscured by other considerations 

 in this case, I am using Eunice, the name which has received the widest 

 acceptance. 



The American species of Eunice are extremely numerous (see p. 

 99), especially those from tropical and subtropical parts of the western 

 Atlantic, but many are too incompletely known through their descrip- 

 tions to permit even a comparison with others. From the West Indian 

 region alone (including Bermuda, south to Brazil), there are over 29 

 described species, with an additional 24 that have been, or are considered 

 to be, reduced to synonymy, and many of these are only partially known. 

 The difficulties are enhanced by the high degree of variability occurring 

 in such characters as body size, presence and number of branchial fila- 

 ments, number of dentations on the maxillary plates, and the degree of 

 annulation of antennae and cirri — all of which have been greatly stressed 

 in specific treatises. These characters vary not only with age and size but 

 with methods of fixation. More stable characters, such as form and dis- 

 tribution of acicular structures and setae, and maxillary parts, have some- 

 times not been disclosed in sufficient detail to permit identity, or have 

 been entirely neglected. 



