14 SABELLARIA SPINULQSA. 



1915. Sabellaria spinulosa, Allen. Journ. M. B. A., vol. x, p. 645. 

 1917. „ „ Rioja. AnneL Poliq. Cantabrico, p. 43. 



1919. „ „ var. Inboshi, Fauvel. Arch. Zool. Expei-., t. lviii, p. 449. 



„ » „ idem. Bull. Mus. Hist. Nat., No. 6, p. 477. 



Habitat. — Masses of the tubes cover rocks and shale about half -tide-mark near the 

 commencement of the East Rocks, St. Andrews, and elsewhere. They also occur on the 

 roots of tangles and on shells and stones from deep water. Berwick Bay (Dr. Johnston) ; 

 Southport (Dr. Carrington) ; Luccomb Chine, Isle of Wight, between tide-marks; 

 occasionally on oysters off St. Peter Port, Guernsey; Lochmaddy, North Uist, under 

 stones near low water-mark, not common (W.C.M.) ; Plymouth (Allen and Orawshay) ; 

 Dublin Bay (Southern). Whereas at St. Andrews it forms large spreading masses 

 between tide-marks, its place is taken at Hilbre Island by 8. alveolata, and S. spinulosa 

 there is said to be a form from deep water. Southern states that it also is usually found 

 in deeper water in Dublin Bay, whilst on the West Coast it is littoral as well as 

 laminarian in distribution. 



Abroad it is found in Sweden (Loven), Heligoland (Leuckart), French coast (De 

 St. Joseph), St. Thomas and Madagascar (Fauvel). 



The cephalic region in Sabellaria spinulosa (Plate CXVIII, fig. 3 a) is divided 

 dorsally into two great lateral lobes bearing the palese on pillars, the dorsal edge of the 

 mouth being in the centre, whilst the lips slope obliquely backward ventrally ; the two 

 lobes, which appear to be homologous with the operculum of the Serpulidas, can be widely 

 separated ventrally, where they merge into the mouth and its tentacles. Arnold Watson 

 found three sets of cilia on the tentacles : (1) A series of long cilia, arranged at intervals 

 in pairs, driving particles into the longitudinal groove ; (2) with these are palpocils which 

 remain extended after the former cease l ; (3) a shorter series of cilia in the tentacular 

 groove. Each lobe forms a semicircle, which by apposition with its neighbour constitutes 

 the opercular crown on the dorsal arch of the mouth, and between the tentacles is a 

 tongue-shaped fold or process — richly ciliated. 



The external series of golden palea3 which form a fringe to the crown are about 

 twenty-five in number, the typical palea3 (Plate CXXIII, fig. 2) having a shaft, 

 which tapers from the junction of the tip to the pointed base. The tip forms a broad, 

 flattened, and somewhat spatulate process, one side of which bulges more than the other 

 immediately on expanding above the shaft, whilst the tip is symmetrically narrowed to a 

 blunt point, which is cut into three spikes on each side, the centre being produced as a 

 long process with three lateral spikes directed distally. In the examples from Luccomb 

 Chine, Isle of Wight, these lateral spikes are smaller and more numerous, and the 

 process is larger. Strias cross the flattened tip from side to side, and are slightly curved 

 upward at each end, the bulged base of the tip often showing a differentiation of these 

 and a more marked curvature. The paleaB at the extreme ends dorsally and ventrally 

 are less neatly formed than those in the centre of the semicircle, the inner lateral 

 spikes being long and powerful, whilst the central elongated process is more or less 



1 The cilia themselves often remain quiescent, so that it might be difficult to distinguish the one 

 from the other. 



