PIONOSYLLIS (?) DIVARIOATA. 165 



1863. Syllis normannica, Claparede. Beobach. u. Anat., p. 40, Taf. xiii, f. 24. 



1879. Pionosyllis divaricata, Langerhans. Zeitsch. f. w. ZooL, Bd. xxxiii, p. 545. 



1886. „ longocirrata, De St. Joseph. Ann. Sc. Nat., 7 e ser., t. 1, p. 160, pi. viii, f. 21 — 29. 



Habitat. — -Under a stone in a rock-pool at Herm, and nnder stones between tide- 

 marks at St. Peter Port, Guernsey. 



St. Vaast-la-Hongue (Kef erstein) ; Madeira, at some depth (Langerhans) ; Bochardien, 

 France (De St. Joseph). 



Head (Plate LIX, fig. 12) like that of Syllis, with two large palpi, which thus 

 conspicuously differ from those of Gastalia fusca ; eyes red, and the pairs of each side 

 are close together, besides a small pair at the base of the lateral tentacles. A median 

 tentacle of considerable length occurs just in front of the eyes, and there are two on the 

 anterior border of the snout. 



Body about an inch in length, and it has a considerable number of segments. It 

 tapers a little anteriorly and still more so posteriorly. It is of a dull brownish or pale 

 fawn hue, somewhat paler in the centre, which has a few dark brown specks. The first 

 fourth of the body is paler than the succeeding (probably from the pharynx), and is of a 

 pale brownish hue. From this a dull, brownish-yellow, median stripe proceeds to the tail, 

 having on each side a brownish stripe which, by sending a spur outwards at every 

 segment- junction, cuts the brown of the dorsum into segments. The bases of the feet 

 are occasionally paler than the inner region. The under surface is pale brownish. 



The proboscis is extruded as a short, firm process with a smooth distal edge, and 

 a brown interior with a prominent dorsal tooth, which, according to De St. Joseph, has a 

 poison-canal at its base, the issue of the organ being preceded by a ring of ten papillae, 

 each being continued posteriorly (behind the ring) by an elongated caecal process, the 

 function of which is unknown. 



The foot (Plate LXX, fig. 7) has a long pale dorsal cirrus — longer than that of 

 Gastalia, indeed it resembles a mobile hair which is now gently extended, and again 

 drawn in numerous screw-coils close to the body of the worm. The dorsal division of the 

 foot is represented in the mature female by a single stout spine which scarcely projects 

 beyond the integument, such probably being the precursor of the swimming-bristles, yet 

 its occurrence at first caused the specific separation of the example. The inferior lobe is 

 of moderate length in the ripe form, longer in the others, and slightly bevelled at the tip. 

 It has several spines and a series of slender bristles (Plate LXXVIII, figs. 17 a and 17 b), 

 which have a short dilatation at the tip with a few serrations on the convex edge. The 

 terminal blade is flattened, narrow, diminishing very little towards the tip, which is 

 rather abruptly hooked and has a slender secondary process beneath. The terminal pieces 

 of these bristles diminish in length from the upper to the lower border of the fan 

 projecting from the foot. The ventral cirrus is somewhat lanceolate, curved, carried far 

 outward, and does not reach the tip of the fleshy setigerous lobe. The foot in the immature 

 form is apparently considerably longer than in the mature, the ova, in the example 

 under examination, distending the base. 



Reproduction. — De St. Joseph observes that this species produces directly without 

 alternation of generations. In the ripe forms the segmental organs from the eighteenth 



