Table 1.

Examples of the four major types of simple larval eyes we distinguished. The full list is in the electronic supplementary material, table S1. References: Tripedalia cystopora [31], Autolytus prolifera [32,33], Capitella sp. [34,35], Harmothoe imbricata [36,37], Lanice conchilega [32,38], Neanthes succinea [39], Odontosyllis ctenostoma [40], Pectinaria koreni [32], Phyllodoce maculate [41], Phyllodoce mucosa [42], Platynereis dumerilii [43–45], Polygordius appendiculatus [46,47], Serpula vermicularis [36,48], Spirobranchus giganteus [36,49–51], Spirobranchus polycerus [41,52,53], Spirorbis spirorbis [32], Syllis amica [40], Golfingia misakiana [54], Sipuncula larva [54], Aporrhais pespelecani [55], Aporrhais sp. [55], Atlanta peroni [56], Bittium reticulatum [57], Carinaria lamarckii [23], Hermissenda crassicornis [58], Ilyanassa obsolete [59,60], Lacuna divaricata [61], Rostanga pulchra [62], Smaragdia sp. [63], Strombus sp. [63], Trinchesia aurantia [64], Katharina tunicata [65], Lepidochiton cinereus [61], Terebratalia transversa [10], Loxosomatidae larva [66], Notoplana alcinoi [67], Pseudoceros canadensis [22], Stylochus mediterraneus [67,68], Thysanozoon brocchii [67], Kronborgia isopodicola [69], Diplozoon paradoxum [70], Entobdells soleae [71], Euzetrema knoepffleri [72], Merizocotyle sp. [73], Neodiplorchis scaphipodis [74], Neoheterocotyle rhinobatidis [75], Polystoma integerrium [76], Pseudodiplorchis americanus [74], Alloreadium lobatum [77], Fasciola hepatica [77,78], Heronimus chelidra [77], Heronimus mollis [79], Multicotyle purvisi [80], Philophtalmus megalurus [81], Spirorchis sp. [77], Bugula neritina [82,83], Bugula pacifica [11], Bugula simplex [11], Bugula stolonifera [11,83,84], Bugula turrita [11], Scrupocellaria bertholetti [11,85], Tricellaria occidentalis [11,86], Waterspora arcuata [87], Dactylopusia cf. tisboides [88], Balanus crenatus [89], Catalina sp. [90], Ptychodera flava [90], Glossobalanus marginatus [91], Amaroucium constellatum [92], Ascidia nigra [93], Ciona intestinalis [93–97], Distaplia occidentalis [95], Phallusia mammillata [93] and Branchiostoma floridae [98–100].

eye type
photoreceptor type	scanning photototactic eye	visual phototactic eye
ciliary photoreceptor	ascidian larval eyespot (Ciona); bryozoan larval eyespot	brachiopod larval cerebral eyes (Terebratalia); some mollusc veliger eyes
rhabdomeric photoreceptor	box jellyfish larval eyespots; annelid trochophore eyespot (Platynereis); amphioxus early larval Hesse eyecup; nemertean larval eyes (?); polyplacophoran eyespot (?)	annelid nectochaete adult eye (Platynereis), some mollusc veliger eyes; crustacean nauplius larval eye; some platyhelminths; hemichordate late larva (?)