SPIO FILICORNIS. 175 



noted that Mesnil's drawing (Fig. 20) is not altogether clear; indeed, it might represent 

 a tail in process of regeneration. 



Mr. Southern l thinks his form agrees with Mesnil's 2 Spio martinensis. Between each 

 lateral pair is a patch of pigment formed of small and black grains resembling a third pair 

 of eyes. The ventral hooks are minutely bifid at the tip, and the bristles are frequently 

 covered with a red deposit, which, however, is not to be confounded with the granular or 

 dotted condition of other forms. This annelid needs further investigation. It may be a 

 variety of a known species. It was found at Sandy Mount Strand, Dublin Bay, and in 

 Blacksod Bay. 



No example 3 which could be identified with the Spio seticornis of 0. Fabricius 4 has been 

 met with, but this may be due less to its rarity than to imperfections in the original 

 description. It may be a common form. In order to render the task of identification 

 less difficult the following notes may be added. 



Linnasus (1767) considered S. seticornis identical with Baster's form (Opusc. sub- 

 secira 2, p. 134, Tab. 12, fig. 2). 



(Ersted 5 describes S. seticornis as from 8 — 10 lines long, and \ a line broad; two eyes 

 on each side in parallel series ; tentacles tapered at the tip ; segments devoid of black 

 points ; ligulate branchise in the middle of the body, vanishing at each extremity of the 

 series. He thinks that Spio crenaticomis, Mont. (' Trans. Linn. Soc.,' vol. xi, p. 14) and 

 Lumbricus cinatuloides, D. Chiaje ('Mem.,' Tab. 64, fig. 16) pertain to this genus. He 

 mentions the action of the tentacles from the mouth of the tube capturing small 

 " Naides " and Planarians which the annelid devours. The relationship to the species of 

 Fabricius is uncertain. 



De Quatrefages (1865) only quotes this form in his ' Anneles.' 6 



1 'Proc. Roy. Irish Acad./ vol. xxviii, p. 235, 1910. 



3 'Bull. sc. Fr. et Belg./ t. xxix, p. 122, pi. vii, figs. 1—20, 1896. 



3 The form described in the ' Annals Nat. Hist./ ser. 8, vol. iii, p. 163, is still sub judice. 



4 O. Fabricius (1780) gives his Spio seticornis a length of 3 in., the head broad behind and narrow 

 and rounded in front. Two black eyes on the vertex transversely elongated, having in front of them 

 two soft, long flexible tentacles with thin margins and almost the length of the body. The latter 

 (body) is flattened and grooved dorsally, rounded ventrally ; sixty-eight to seventy-six segments, much 

 attenuated posteriorly. Anteriorly in each segment is a cirrus, curved dorsally, pale with a red centre ; 

 beneath a papilla bearing several kinds of bristles. Thus the feet are directed dorsally for facility in 

 moving in its tube. Caudal segment with two short ovate cirri, whitish or reddish, suh-memhranous. 

 Colour of the body dark in front with whitish segment-junctions, whitish-green with the red dorsal 

 vessel in the middle ; posteriorly dull green with the transverse red branchiae (his cirri) . Mouth 

 below the snout, without an extruded proboscis. Tube two-thirds of a line broad, three times as long as 

 narrow, perpendicularly attached above the bottom, composed of secretion, sand-grains and silt 

 (argillaceis), and of the colour of its surroundings — ferruginous or brownish. Eats minute planarians, 

 which it captures with its tentacles. It is not fond of projecting from its tube or leaving it. It 

 sweeps the water with its tentacles, sometimes it projects its mouth — causing a turmoil in the water — 

 probably for food. Rarely it projects from the posterior end of the tube, but it withdraws instantly 

 on vibration of the water. 



5 'Arch. f. Naturges./ Bd. x, p. 106, 1844. 



6 T. ii, p. 307. 



