CIRRATULUS INCERTUS. 489 
they are a little less so, and the number is probably from seventy to one hundred, though 
no specimen is complete. 
Some had well-developed ova in July. 
The structure of the feet throughout is the same, viz., a dorsal and a ventral setigerous 
process, each having a tuft of translucent pale yellow capillary bristles (Plate CX XX, fig. 11a), 
the tips being slightly flattened at the somewhat narrow base, and tapering to delicate hair- 
like extremities. The dorsal are the longer, and they increase in length toward the middle 
of the body, and remain of considerable length posteriorly, where the distinction between 
the more slender and longer dorsal and the shorter and proportionally broader ventral is 
maintained. A curious series of coiled tubes (?) occurs posteriorly. 
It is interesting to find this Norwegian species in British waters. Truly the riches of 
the marine fauna of the West Coast of Ireland are by no means exhausted, especially in 
regard to the Marine Polycheets. 
CIRRATULUS CHIAJII, McIntosh, 1922. 
Crrratulus chraju, McIntosh, has been subsequently described as Cirratulus norvegicus, 
De Quatrefages, but Delle Chiaje had long before termed it Lwmbricus filugerus and Cirratulus 
filigerus, so that, if priority held, such would be its title. It is perhaps doing no injustice 
to De Quatrefages or other author by giving it the title C. chiajw after its early investigator. 
CIRRATULUS INCERTUS, McIntosh. Plate CXXXVII, fig. 9. 
In the Monograph of the British Marme Annelids! ambiguity was caused by the use 
of the specific name bioculatus for a Cirratulid dredged in the Zetlandic Seas by Dr. Gwyn 
Jeffreys, the name bioculatus having been applied by Keferstem? to another Cirratulid 
differing from this in several particulars. The species is small, and it is unknown whether 
it 1s a young or an adult form, only a single example having been obtained, and it measures 
about 2 of an inch in spirit, its diameter being about 1 mm. The general aspect (Plate 
CXXXVII, fig. 9) is indicated in the sketch, though the eyes have now disappeared. The 
segments are about fifty-five in number. The head shows less of a basal constriction than 
usual in examples of Cirratulus cirratus of the same size. The cirri from the fourth segment 
are of great length, probably reaching in life beyond the tip of the tail. The latter has a 
similar termination to that of C. cirratus, the ventral papilla being the more prominent. 
The caudal region thus diverges from Keferstein’s C. broculatus, which possesses two well- 
marked caudal cirri. 
The dorsal capillary bristles in front are of considerable length, and shorter forms are 
continued behind these. Thus at the tenth foot the long, slender tuft of finely tapered 
capillary bristles, with a slight curvature at the tip,* occupies the dorsal division, whilst the 
ventral series consists of bristles having short, cylindrical shafts, which expand into knife- 
1 Vol. ii, part i, Text, p. 253. 
* ¢Zeitschr. f. wiss. Zool.,’ Bd. xu, p. 121, Taf. x, figs. 23—27. 
> “Monograph, pl. citi, fig. 16. 
