338 FILOGRANA. 
muscles in P. infundibulum. In this species the intestinal sinus is lodged between the 
epithelial coat and the circular muscular fibres. Guiant-fibres occur in its nerve-cord and 
cesophageal commissures. 
Jaquet’ (1886) gives an account of the circulation in Protula intestinum. 
Lo Bianco (1893) describes two species of Protula from Naples, viz., P. protula, Cuvier, 
and P. tubularia, Montagu, the former having four pairs of eye-specks on the branchie, the 
latter with twenty to twenty-four simple eyes in double series on these organs. Moreover, 
P. protula is said to have no hooks on the thoracic region, whilst in P. tubularia they begin 
on the third segment. Further investigations of the two forms are necessary, especially 
in view of the variability of certain members of the Serpulidee. 
Fauvel’ (1909) has shown that the young examples possess the bristles of Apomatus in 
the last two thoracic segments, but that they disappear in the adult. Further (1910), he 
has given a critical revision of this species, and finds that Protula Meilhaci, at Marseilles 
and Cette, of Marion, is the same form (Protula tubularia), as also is Psygmobranchus simplex, 
De Quatrefages, and P. intermedius, Marion. Moreover, he deems it possible that the young 
Protula tubularva, which has lost its operculum, may have been confounded with Apomatus 
(e.g., A. similis), especially as young examples of Protula have Apomatus-like bristles in the 
posterior region of the thorax, these disappearmg in the larger forms. Fauvel had 
examples from Killarey Harbour. It is possible that several foreign species, at present 
separated, may yet be linked on to the British form. There is a close resemblance in both 
bristles and hooks. 
Genus CLXXVII.—Fimocrana, Oken, 1815. 
Reticulatum, Raius, ‘Hist. Plant., 1, p. 65; Tubularva, Plancus, “de Conch.’; Tubercu- 
laria, Blainville, “ Dict. Sc.,’ t. xlvii, p. 556 (errore typ.); Zubspora, Kohlreuter, * Act. 
Petrop., vil, p. 374; Tubipora, Gmelin, ‘ Syst. Nat.,’ p. 3754; Fuligrana, Oken, ‘N.G.,’ 
1815, p. 379, og Register VI; Filigrana, Agassiz, “ Nomenclat.,’ p. 155 ; Filograna, Berkeley, 
‘Zool. Journ., 1832; Filipora, Flem., * Brit. An.,’ 1828, p. 536; Fulograna, Philippi, 1844, 
‘ Arch. f. Naturges.,’ p. 196. 
Cephalic plate with a collar open dorsally, a lateral fan-shaped flap on each side, and a 
broad ventral flap split except at the lamellee. Four branchie at each side, the dorsal filament 
in each tuft bearing a thin ovate operculum or none. Body with seven or eight bristled 
segments anteriorly from the third backward, then a bare region, followed by another with 
slender bristles, lastly a bare region in front of the anus. Anterior bristles of two kinds, 
one with tapered knife-like tips, the other with broader, curved tips, having a serrated differ- 
entiation at the base.* Anterior hooks (which, like the posterior, are in a single row) have a 
nearly straight anterior edge serrated throughout, and ending below in a main fang beneath 
which is a sulcus. The posterior hooks are smaller, but similar in structure. Multiplies by 
1 Op. cit., p. 362, pl. xxi, figs. 71—74. 
* “Assoc. Francaise,’ 1909, Lille, p. 130. 
® Posterior bristles capillary falciform (Carus). 
