HAITCHIELLA TRIBULLATA. 201 



5. Polycirrus denticulatus, De St. Joseph, 1894. Plate CXXVII, figs. 7— 7 c— bristles 



and hooks. 



Specific Characters. — Cephalic region typical, but the tentacles are not phosphorescent. 

 Body 8 mm. or more in length, with fourteen setigerous and forty-six non-setigerous 

 segments. Bight pairs of ventral scutes, and six pairs of segmental organs of a greyish hue. 

 Bristles winged and serrate, commencing on the second segment. Hooks generally begin 

 on the ninth, and they number about five on the anterior (thoracic) region, though in one 

 none were present. 1 At the thirteenth setigerous segment the posterior series of hooks 

 commence. Their structure agrees with that of P. hdematodes. Ova roseate. 



Probably young of P. hdematodes. Hooks of the anterior region may drop out with 

 age and segmental organs may vary. 



Synonyms. 



1894. Polycirrus denticulatus, De St. Joseph. Ann. Sc. nat., 7 e ser., t. xvii, p. 242, pi. x, figs. 271—274. 

 1907. „ „ Soulier. Mem. Acad. Sc. Montpell., ser. 2, t. 3, p. 370. 



1914. „ „ Southern. Proc. Roy. Irish Acad., vol. xxxi, No. 47, p. 128. 



1915. „ „ Idem. Irish Sc. Invest., No. 3, p. 47. 



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



1917. „ „ Hessle. Zool. Bidr. Uppsala, Bd. v, p. 228. 



Habitat. — Blacksod Bay in roots of Laminarise on shore, and dredged in Ballynakill 

 Harbour (Southern). 



Abroad it occurs at Dinard, France (De St. Joseph). 



Southern (1914) attaches little importance to the serrate wings of the capillary 

 bristles as mentioned by De St. Joseph, since this may be due to abrasion. 



Genus CLVII. — Hatjchiella, Levinsen, 1893. 



Body anteriorly polycirrid in outline, often with an enlarged middle region, but 

 devoid of both bristles and hooks. Nephridiopores on disc-like processes on each side of 

 the anterior region. The anterior nephridia are longer than the posterior. 



1. Hatjchiella tribullata, Mcintosh, 1869. Plate CXXXVIII, figs. 13, 13 a and 13 b. 



Specific Characters. — Cephalic region as in Polycirrus. No eyes. The ventral 

 sides of the first segments form a lower lip. Body somewhat fusiform, 30 mm. long, 

 rounded dorsally and grooved ventrally, segments about eighty, two-ringed anteriorly. 

 Three elevated disc-like processes with a nephridial papilla in the centre on the sixth, 



1 An interesting fact in connection with Prof. Caullery's classification. 



195 



