APHBODITA. 241 



lining. Alimentary canal pinnately-branched, the glandular intestinal caeca being long 

 and complex. Dorsal fimbria small, alternating with the scales, or absent. First foot 

 bearing three dense tufts of bristles. Elytra fifteen pairs, occurring on the second, 

 fourth, fifth, thereafter on all alternate segments to the twenty-fifth, and then on every 

 third segment. Segmental organs (nephridia) opening by a well-marked papilla pointing 

 upwards between the feet. Nerve-cords median, between the ventral attachments of the 

 oblique muscles, or in a well-defined epidermal granular layer within the dense cuticle. 



Genus V. — Aphrodita, Linnxus, 1735. 



Eyes sessile ; dorsum covered with a thick, close felt of matted simple hair ; seta3 of 

 the ventral division of the foot very numerous, long, silky, and iridescent, and, like all the 

 other bristles, simple, not barbed or toothed. Intestine with eighteen long and 

 complex caeca (figs. 16 and 17, p. 250). Nerve-cords in a transversely elongated space 

 between the ventral attachments of the oblique muscles, and bounded externally by the 

 basement-tissue and the cuticle. 



Swammerdam's account of Physalus, as this form was then called (1758), contains a 

 notice of the three rows of bristles on the feet, which he considered only papillae. He 

 thought the scales the branchiae, and was of opinion that the animal was able to 

 " swell and bloat itself with air." He observed the ramifications of the alimentary canal 

 and the presence of blood-vessels. He criticised Rondelet for placing it amongst sea- 

 worms, and was inclined to relegate it to the proximity of the sea-urchins. His figures 

 are recognisable, though the whole dorsum is rough with tufts of bristles. 



Pallas, in his 'Miscellanea Zoologica ' (1766), showed the propriety of removing the 

 Aphroditae from the Mollusca, with which Linnaeus had grouped them. He indicated 

 that a more natural classification would be to conjoin the three genera, Aphrodita, Nereis, 

 and Serpula. He gave a general and fairly accurate description of the Aphroditidse, the 

 only feature requiring special notice being his observation that branchiae are present on 

 the dorsum, and that he included in the group Ghloeia and Amphinome (Pleione carun- 

 culata). 



0. F. Miiller, in his ' Zoologia Danica Prodromus ' (1776), included the Aphroditidae 

 and other Chaetopods under his Helminthica Setosa, the other group being his Helmin- 

 thica Mutica, in which were Gordius, Ascaris, and Hirudo. 



In Gmelin's edition of Linnaeus (1788) l the Aphroditaceans w r ere placed in the 

 Vermes Mollusca, after Doris, notwithstanding that there was little more than the 

 general ovoid outline to suggest the relationship. 



By Lamarck 3 the Aphroditidae were grouped under his second order of Annelides, 

 i. e. A. Antennata, along with Nereids, Eunicidae, and Amphinomidae. He simply followed 

 Savigny. 



1 ' Syst. Nat./ p. 3107. 



2 ' An. sans. Vert.,' 1818, tome v, p. 304. 



