POLYCIRRUS NEMATODES. 199 



smaller more widely separated. Setigerous processes (22) have the posterior papilla 

 larger than in P. aurantiacus. Bristles simple, capillary or slightly winged, and they 

 begin on the second segment. Uncinigerous processes commence about the ninth 

 segment (thirteenth, Canllery), have few hooks in a single row, and they are smaller than 

 in P. aurantiacus, have a wedge-shaped base tapering abruptly forward to the prow, a 

 marked process at the junction of the base with the posterior outline, and a small process 

 beneath the main fang on the anterior outline. At least two teeth on the crown above 

 the main fang. The anterior hooks slightly differ from the posterior. Colour blood-red. 

 Tube of fine sand attached to shells, or in crevices of rocks. 



Synonyms. 



1864. Aphlebina hsematodes, Claparede. Grlaimres, p. 25, pi. ii, figs, la to ^. 



1865. Apneumsea leoncina, De Quatrefages. Amiel., t. ii, p. 414, pi, xiv, figs. 10 — 11. 



1884. Poly cirrus hsematodes, Langerhans. Zeitschr. f. wiss. Zool., Bd. xl, p. 265, pi. xvi, fig. 26. 



1885. „ „ Cams. Fauna Medit., i, p. 267. 

 „ Cuenot. Archiv Zool. Exper., 2 e ser., t. ix, p. 414. 

 „ Lo Bianco. Atti. R. Accad. Sc. Nap., vol. v, No. 11, p. 60. 

 „ De St. Joseph. Ann. Sc. nat., 7 e ser., t. xvii, p. 241, pi. x, fig. 270. 

 „ Fauvel. Bull. Inst. Oceanogr., p. 39. 

 „ Southern. Proc. Eoy. Irish Acad., vol. xxxi, No. 47, p. 128. 



elisabethse, Mcintosh. Ann. Nat. Hist., ser. 8, vol. xv, p. 35. 

 hsematodes, Southern. Irish. Sc. Invest., No. 3, p. 47. 



„ Allen. Journ. M. B. A., vol. x, p. 636. 



„ Caullery. Bull. Soc. Zool. France, t. xl, p. 242. 



,, Bioja. Anel. Poliq. Cantab., p. 60. 



,, Hessle. Zool. Bidr. Uppsala, Bd. v, p. 227. 



1891. 

 1893. 

 1894. 

 1909. 

 1914. 

 1915. 



1916 

 1917 



Habitat. — From the deeper water off the Bay of St. Andrews {debris of fishing boats 

 (E. M.) In tube on egg-capsule of skate, Lochmaddy; Fairlie Channel, Scotland; 

 dredged in 50 fathoms off Balta, Shetland ; in 100 fathoms, St. Magnus Bay, Shetland ; 

 in a sandy tube on a Pecten, Shetland (J. G. J.). Procured between tide-marks, under 

 stones in rock-pools, Herm ; in a hole in a thick form of Flustra beside Potamilla 

 reniformis off Fermain Bay, Guernsey ; on old shell along with Polydora, Guernsey ; in 

 cracks of rocks in the same locality. Plymouth (Allen). Blacksod Bay and Clew Bay 

 (Southern). 



The Mediterranean (Claparede). Shores of France (De St. Joseph). Shores of 

 Cantabria (Rioja). Madeira (Langerhans). 



Dorsally the cephalic plate arises in front of a prominent ring somewhat crescentic 

 anteriorly and apparently continuous with the post-oral segment. The supra-oral frill is 

 similar to that of P. aurantiacus, but its lateral folds differ, the boss or projection caused 

 by them being further forward and more conspicuous, and in the preparation the median 

 fissure runs to the anterior border and forms "a spout-like projection there. The tentacles 

 have a similar structure and form a mass like that of the common species. When 

 extended the cephalic plate makes a wide, frilled margin to the funnel-shaped oral 

 region, and the median scute is smoothly rounded ventrally. 



