322 SERPULIDA. 
Claparéde (1868) notes that the Serpulids have no proper ciliated groove ventrally, 
though that surface is partially ciliated as De Quatrefages first showed. These cilia probably 
effect the same purpose as the “ szllon coprogogue”’ of the Sabellids. The ciliated thoracic 
membrane is from its great vascularity probably an accessory respiratory organ. The author 
records fresh examples of hermaphroditism in Laonome, Salmacina and Pileolaria. He points 
out that the anterior region in the Serpulids is more or less solid from the filling up of the 
coelom in connection with the great development of the branchial apparatus. The circulation 
resembles that in the Sabellidee, and a vascular plexus exists round the gut. The blood is 
dichroic. In the nervous system the greatest development of the tubular fibres occurs, 
and the. cords are far apart. He was of opinion that only a pair of segmental organs were 
present, and that in those forming a calcareous tube the contents effervesced with acid. 
Fritz Miiller’ cites the case of a developing tubicolar worm in the earliest condition of 
which three pairs of branchial filaments occurred like Protula. A few days after one of 
these filaments became thickened at the extremity into a clavate operculum resembling 
Filograna. In three days more a new pair of branchial filaments had sprouted out, the 
opercular peduncle had lost its lateral filament and the worm appeared as a Serpula. 
Schenk’ (1874) gave a brief account of the structure of the body-wall in Serpula uncinata. 
In his transverse sections of the body-wall he appears to have overlooked the nerve-trunks, 
though traces of these occur in his figures. He further describes’ the early development of 
Serpula uncinata, Grube, or Serpula (Hupomatus) uncinatus, Philippi, which he found at 
Trieste. The adults had the ccelom filled with ova or spermatozoa as far forward as the 
sixth segment. The ova are round and 0°08 to 0:06 mm. in diameter. He describes the 
changes in the developing egg, the formation of polar globules, the retraction of the yolk, 
segmentation and nuclei, and the formation of the segmentation-cavity. He does not touch 
on the later stages. 
Huxley’s* view (1877) of the anterior region was that—“‘ In some (Serpulide) a tentacle 
is enlarged and its end secretes a shelly plate, which serves as an operculum, and shuts down 
over the mouth of the calcarous tube inhabited by the animal.” 
Grube (1878) placed the Serpulids along with Myzicola and the Sabellids, under his 
Family Serpulacea. He used the operculum largely iy his diagnosis of species. There is 
certainly much in common in the groups, such as the arrangement of the branchie, bristles 
and hooks in the anterior and posterior regions, though the nature of the tube generally 
difiers. 
Haswell’ (1889) found a curious Isopod, which he termed Hisothistos vermiformis, com- 
mensalistic or parasitic, in the tube of one of this family (viz., a Vermilia) from low water 
mark, Watson’s Bay, Australia. Later (1884) he made the interesting observation that 
in Eupomatus elegans of Port Jackson the ova were developed in the nephridia of the posterior 
region. 
Hicker (1896) observes that the early larval Serpulid is a monotrochous trochophore. 
1 «Pacts and Arguments for Darwin’ (1869), p. 112, figs. 65, 66 and 67. 
2 <Sitzb. K. Akad. Wiss. Wien,’ Bd. Ixx, pp. 1 and 2, pl. i. 
° Ibid., Bd. lxx, pp. 1—15. 
* “Tnverteb., p. 230. 
5 «Proc. Linn. Soc, N.S.W..,’ vol. ix, part 3, sep. copy, p. 1, pl. xxxvi. 
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