194 POLYCIRRUS AURANTIACUS. 



Synonyms. 



1860. Poly cirrus aurantiacus, Grube. Arch. f. Naturges., Bd. xxvi, p. 110, Tab. iv, f. 8. 



1861. „ „ idem. Ausfl. Triest, pp. 78, 128, 149, Taf. iv, fig. 8. 



1864. „ „ idem. Insel Lussin, p. 89. 



„ Aphlebina pallida, Claparede. Glanures, p. 25, pi. ii, fig. 2. 



1865. Apneumea aurantiaca, De Quatrefages. Aimel., t. ii, p. 383. 



1869. Poly cirrus aurantiacus, Grube. Mitt. St. Vaast, etc., p. 38, Abhandl. Scliles. (resell., p. 105. 

 „ „ „ Mcintosh. Trans. Roy. Soc. Edin., vol. xxv, p. 424, pi. xv, figs. 18 



and 19. 

 1875. „ „ Panceri. Atti R. Accad. Sc. Napoli, p. 7, Tav. ii, figs. 4 — 7. 



1880. „ „ Langerhans. Zeitsch. f. wiss. Zool., Bd. xxxiv, p. 108, Tab. v, fig. 23. 



1884. „ „ idem. Ibid., Bd. 1, p. 266. 



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



1893. „ „ Marenzeller. Polych. Grund., p. 34. 



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



1894. „ „ De St. Joseph. Ann. Sc. nat., 7 e ser., t. xvii, p. 239. 



1897. „ „ Brumpt. Compt. Rend. Acad. Sc. Paris, 21 June, 1897 (Crust. Parasite). 



1904. „ „ Journ. M. B. A., vol. vii, p. 229. 



1909. „ „ Fauvel. Bull. Inst. Ocean., cxlii, p. 38. 



„ „ „ idem. Ann. Sc. nat., 9 e ser., t. x, p. 209. 



1916. „ „ Caullery. Bull. Soc. Zool. France, t. xl, p. 242. 



1917. „ „ Rioja. Anel. Poliq. Cantab., p. 60. 



„ „ „ Hessle. Zool. Bidr. Uppsala, Bd. v, p. 226. 



Habitat. — Abundant under stones and in crevices of rocks between tide-marks and 

 also dredged on the oyster-beds at St. Peter Port, Guernsey ; occasionally in a tube of 

 sand inside the valves of Tapes. It sometimes occurred in masses of Gellepora dredged in 

 15 fathoms in the same region, but it does not appear to bore. Not uncommon in similar 

 regions in Herm. Both this and P. hxmatodes haunt the mud under stones in the Channel 

 Islands. Dredged in the Minch off Lochmaddy, and abundantly amongst the tangle roots 

 obtained by the "dreg" in Bressay Sound, Shetland; St. Magnus Bay; Symbister 

 Harbour ; in 50 fathoms off Balta (J. G. Jeffreys). 



Mediterranean and the Adriatic (Grube) ; common in colonies amongst littoral Balani 

 at Naples (Lo Bianco) ; shores of Prance, De Quatrefages, De St. Joseph ; shores of 

 Cantabria (Rioja) ; Madeira (Langerhans). 



The cephalic region has even more voluminous folds than in P. medusa, the plate 

 being frilled anteriorly as well as forming the two broad folds posteriorly. Moreover 

 dorsally is an indication of a collar in the shape of a smoothly rounded ridge. The whole 

 is occasionally spread as a wide border to the oral region, which thus assumes the form of 

 a shallow funnel. When viewed from the dorsum the slight dorsal collar runs on each 

 side and bends downward behind the projecting fold of the anterior arch, and it 

 sometimes happens that a median fold in front divides the tentacles into two sym- 

 metrical series after the manner of Phoronis. The entire outer surface gives origin to 

 the dense series of dull yellow tentacles which form a seething mass of threads— slender, 

 flattened and fusiform. Each tentacle extends even to a greater degree than in 

 P. hdematodes, becoming paler when stretched though still retaining a trace of the 



