Additional comments or qualifications on distribution and habitat information.

Descriptions of colour and colour patterns are entered as text. Whether this information is based on examination of live or preserved material is also specified here.

One pair of eyes is typical for phyllodocids, although they may be difficult to see. Eyes are normally on the surface of the prostomium, but in Eteone, Hypereteone and Mysta eyes are located beneath a sometimes opaque dermal layer (Pleijel, 1991: 226–229).

Eye colour is used here as a multi-state character, but is probably only useful at the species level.

In the genera Phyllodoce and Zverlinum the posterior margin of the prostomium is indented, with a lateral lobe on each side projecting posteriorly over the dorsum of the first segment (Pleijel, 1991: 226–229).

The proportions of the prostomium may assist in distinguishing some species, especially in the genera Eteone and Hypereteone (see Wilson, 1988).

Additional information on the shape of the prostomium is recorded for each taxon as a text character.

Most authors refer to phyllodocids as having two pairs of frontal antennae, however following the homologies recognised by Fauchald & Rouse (1997 Zoo. Scripta 26: 71–138) the dorsal pair are here recognised as antennae and the ventral pair as palps. In most phyllodocids the antennae taper towards the tip, but the genera Australophyllum, Clavodoce, Nereiphylla and Notophyllum are inflated and widest at the midpoint of the antenna (Pleijel, 1991: 226–229).

Most authors refer to phyllodocids as having two pairs of frontal antennae, however following the homologies recognised by Fauchald & Rouse (1997 Zoo. Scripta 26: 71–138) the dorsal pair are here recognised as antennae and the ventral pair as palps. In most phyllodocids the antennae and palps are almost identical, but occasionally the slightly ventrally located palps are recognisably different in shape and length.

A distinct distal region of the prostomium where the antennae are inserted may be delineated in some genera. Other phyllodocids have an entire prostomium not obviously delineated as separate regions (Pleijel, 1991: 226–229).

Nuchal organs are present in all polychaetes, although they may be difficult to see; even in phyllodocids SEM examination may be required to see this character. In phyllodocids, they may be present as knob-like lateral prostomial protrusions; as sunken knobs seen as ciliated pits, and probably only visible in sectioned specimens; or as dorsal prostomial protrusions on the posterior region of the prostomium. This character is probably important in describing phylogenetic relationships among phyllodocid genera, but is difficult to observe in some taxa and best omitted from routine identification procedures unless clearly visible (Pleijel, 1991: 226–229).

The nuchal organs may be separate structures, or may be fused to the cirrophores at the base of the first pair of tentacular cirri (Pleijel, 1991: 226–229).

A fifth, median antenna is present in some phyllodocid genera. Even if this antenna is broken, the scar on the prostomium is often visible. The median antenna may be present as a small papilla or as a distinct, elongate antenna (Pleijel, 1991: 226–229).

The length of the median antenna, if present, is recorded as a multiple of the length of the prostomium.

The structure of the proboscis is vital for accurate identification of phyllodocid genera and species. If the proboscis is not everted (which is often the case), a ventral incision will need to be reveal the structure on the interior of the inverted proboscis. Phyllodocids in which the proboscis is "uniform" (especially species of Eumida) often have the basal part more smooth than the slightly wrinkled distal region; this seems to be an artefact of preservation, and probosces in these taxa are uniformly covered with papillae. Other genera, e.g. Phyllodoce spp., have a very distinct separation of the proboscis into two regions, each of which has different surface structures and papillation. Austrophyllum is here coded as having a proboscis divided into 2 regions since the arrangement of papillae differs proximally and distally; this is a practical judgement, not the phylogenetic interpretation of this genus given by Pleijel (1991).

The length of the distal region of the proboscis (in taxa with divided probosces), is recorded as a multiple of the length of the basal region.

The basal region of the divided proboscis may be bare of papillae; large approximately conical or rounded papillae may be present (e.g. in Phyllodoce); or small approximately spherical granules termed micropapillae may be present (as in Eumida and Sige).

If papillae are present, it is important to observe whether they are densely distributed (in no obvious pattern), or to count the number of rows of papillae if they are arranged in distinct longitudinal rows.

The number of papillae in each longitudinal row on the basal region of the proboscis is useful in distinguishing some species, e.g. in the genus Phyllodoce.

The distal region of the divided proboscis may be bare of papillae; or large approximately conical or rounded papillae may be present. Note that the distal region of the divided proboscis may also be tuberculated, which is recorded in the next character.

The presence and arrangement of tubercles (rugose longitudinal ridges) and papillae distinguishes species of Phyllodoce and other genera.

The undivided proboscis may be bare of papillae; large approximately conical or rounded papillae may be present (e.g. in Phyllodoce); small approximately spherical granules termed micropapillae may be present (as in Eumida and Sige); or elongate, densely-packed filiform papillae unique to the genus Pterocirrus may be present (Pleijel, 1991: 226–229).

The arrangement of papillae on the undivided proboscis is a character that is most useful at the species level.

The proboscis of phyllodocids may have a terminal ring of papillae at the oral opening, but note that the proboscis must be fully everted (or fully dissected) to determine if a terminal ring of papillae is present.

The number of papillae in the terminal ring is easily counted on good specimens; most species with a terminal ring have about 17 papillae but may range between 15–18 or up to 21 due to intraspecific variability, especially in species of Eumida. This character may only become useful when intraspecific variability is better documented.

Fusion of anterior segments occurs to varying degrees in different phyllodocid genera and is among the most phylogenetically informative characters in the family. In order to reduce confusion and make routine identifications easier, in this treatment segment 1 means "first visible segment", and this may not be homologous with the first visible segment in other phyllodocid taxa.

Fusion and/or reduction of anterior segments in phyllodocids makes identification of homologous segments difficult. In order to reduce confusion and make routine identifications easier, in this treatment segment 1 means "first visible segment", and this may not be homologous with the first visible segment in other phyllodocid taxa.

Fusion of anterior segments occurs to varying degrees in different phyllodocid genera and is among the most phylogenetically informative characters in the family. In order to reduce confusion and make routine identifications easier, in this treatment segment 1 means "first visible segment", and this may not be homologous with the first visible segment in other phyllodocid taxa.

In order to reduce confusion and make routine identifications easier, in this treatment tentacular cirri of segment 1 means "tentacular cirri arising from the first visible segment", and may not be homologous with the cirri arising from the first visible segment in other phyllodocid taxa.

Due to reductions and loss of anterior segments, the second visible segment may not be homologous in all phyllodocid taxa.

In order to reduce confusion and make routine identifications easier, in this treatment dorsal cirri of segment 2 means "dorsal cirri of second visible segment", and this may not be homologous with the cirri of the second visible segment in other phyllodocid taxa.

Text descriptions of the shape of the dorsal cirri of segment 2 (the second visible segment) may be entered here.

The ventral cirri of segment 2 (the second visible segment) may be strongly flattened (and usually asymmetrical about the long axis) in some genera, while other genera have tentacular cirri that are approximately circular in cross-section (Pleijel, 1991: 226–229). Unfortunately, these cirri are often broken.

Segment 2 means the "second visible segment"; due to reductions and loss the second visible segment may not be homologous in all phyllodocid taxa. The length of the tentacular cirri (measured against their reach posteriorly along the body segments) is a useful species-level character in many phyllodocids.

Segment 3 means the "third visible segment"; due to reductions and loss the third visible segment may not be homologous in all phyllodocid taxa. Fusion of anterior segments occurs to varying degrees in different phyllodocid genera and is among the most phylogenetically informative characters in the family. Careful observation of well-preserved specimens under low incident light and in dorsal, lateral and ventral views is necessary to determine the degree of fusion of segments and the arrangement of accompanaying tentacular cirri (Pleijel, 1991: 226–229). Scars will usually be visible even if tentacular cirri are broken.

Segment 3 means the "third visible segment"; due to reductions and loss the third visible segment may not be homologous in all phyllodocid taxa. The length of the tentacular cirri (measured against their reach posteriorly along the body segments) is a useful species-level character in many phyllodocids.

Aciculae may support tentacular cirri, but these can usually only be seen (as short projecting chaetae) if the tentacular cirrus is broken off at the base (Pleijel, 1991: 226–229). If it is necessary to do this, it should be done on one side only, so as to leave at least one tentacular cirrus in each position intact.

The segment at which chaetae first occur is useful in some phyllodicids, but some intraspecific variability has been observed for this character (Pleijel, 1987).

Biramous parapodia, i.e. notopodia with aciculae, do not occur in most phyllodocid genera, and are present only in Australophyllum, Notophyllum and Zverlinum. Even in these genera the first 15–30 parapodia are uniramous, dorsal aciculae being present after these anterior segments (Pleijel, 1991: 226–229). Notopodial aciculae may be visible under low magnification on whole specimens where a dorsal cirrus is broken off.

Notopodial capillary chaetae are absent in most phyllodocid genera, and occur only in Australophyllum and Notophyllum and only after the first 15–30 parapodia which are uniramous (Pleijel, 1991: 226–229).

Shape of dorsal cirri is useful at the species level, but categorising the various shapes is difficult. Accurate use of this character will depend heavily on comparison with the figures of character states and of individual species incorporated into this database.

Most phyllodocids have a neuropodium that divided into dorsal and ventral lobes (which may be equal or unequal in size; this information is recorded in the next character). One species of Eumida recorded in this database has an entire neuropodium without any evidence of division.

The relative proportions of the dorsal and ventral neuropodial lobes separate some genera, while other genera are polymorphic for this character (Pleijel, 1991: 226–229).

The ventral cirri in most phyllodocids is oriented horizontally, i.e. with long axis parallel with the long axis of the neuropodium. However, 4 genera have the long axis of the ventral cirri distinctly oblique (pointing up) compared with the neuropodium (Pleijel, 1991: 226–229).

The relative length of the ventral cirri compared with the neuropodial lobe may be a useful species level character.

Some species of Phyllodoce possess ventral cirri with distinctly extended and narrow tips, and this character is a useful specific character in that genus.

Chaetal morphology appears to vary little among phyllodocid genera and species (although Eibye-Jacobsen (1991) provides some exceptions). Because of this, and because the difficulty in making comparable observations of phyllodocid chaetae is greater than in many other polychaete families, little use is made of phyllodocid chaetal morphology in this interactive key. Any useful descriptions of chaetae may be entered here as text.

The presence of long, cirriform anal cirri tapering to a fine tip readily distinguishes the genus Hypereteone (as defined by Wilson, 1988) from all other phyllodocids. Pleijel (1991) showed that Hypereteone as so defined leaves Eteone as a paraphyletic taxon not defined by a derived character state, but the form of the anal cirri remains a useful character if entire specimens are available.

General comments on this species, including ecological or biological notes, may be included here as text.

Comparative notes on related taxa and the characters that best distinguish similar species may be included here as text.