268 CIRRATULISPIO CAULLERYI. 



Genus CX. — Cirratulispio, Mcintosh, 1911. 



Elongated filiform annelids with conical prostomium. Two long tentacles from the 

 first bristled segment. Body of an anterior region of nine narrow bristled segments with 

 capillary bristles, followed by a second region of wide segments and rows of crotchets 

 with interspersed capillary bristles. 



1. Cirratulispio Caulleryi, 1 Mcintosh. Plate CI, fig. 1— head; Plate CVII, figs. 14 and 



14 a — bristles and hook. 



Specific Characters. — Head bluntly conical, and the sides of the cone slightly hollowed. 

 Pair of slender tentacles from the buccal segment, which bears bristles. Body elongated 

 and filiform, probably 2 to 3 in. long, of two regions, the anterior with nine pairs of 

 golden bristles, and a succeeding region with broader segments. 



Anterior foot with a dorsal and a ventral tuft of moderately long, golden capillary 

 bristles with a convergent curve, the dorsal being longer than the ventral. The foot of 

 the second region has dorsally two smooth capillary bristles, followed by five or six 

 crotchets with the tips produced into slender processes, and then a series of strong, curved 

 crotchets, with stout, pointed tips, bristles being interposed. 



Tubicolous ? 



Synonym. 

 1911. Cirratulispto, Mcintosh. Ann. Nat. Hist., ser. 8, vol. vii, p. 167, pi. vi, fig. 7, pi. vii, figs. 7 a, lb. 



Habitat. — Dredged in the ' Porcupine ' expedition of 1869 in 378 fathoms in sticky 

 mud off the coast of Ireland. The mud contained fragments of Foraminifera, Coccoliths, 

 and sandy debris. 



The head (Plate CI, fig. I) is bluntly conical and the sides of the cone are slightly 

 hollowed. A pair of slender tentacles pass from the bristled segment immediately behind 

 and therefore apparently posterior to the buccal ring, though fusion may exist. 



The body is filiform and elongated, probably 2 to 3 in. in length, apparently 

 tubicolous, and it is imperfect posteriorly; but at least two regions are recognisable — 

 namely, the anterior with nine pairs of well-marked pale golden bristles, and the succeeding 

 division. 



The first region agrees with the Chastopterids in the number of the segments (nine), 

 and each foot has a dorsal and a ventral tuft of moderately long capillary, pale golden 

 bristles (Plate CVII, fig. 14) which have a slight convergent curve — that is, the dorsal 

 bending downward and the ventral upward. Both arise close together in the tissues, then 

 slant from each other so that a flat cone in the middle of the foot lies between them. 

 The dorsal tuft is considerably longer than the ventral, but the structure of the bristles 

 is the same in both. Each bristle has a long cylindrical shaft not differentiated from the 

 tip, and gradually tapers to a fine point from its middle, though in the shorter ventral 

 forms there are differences in this respect. 



1 Named after the distinguished Professor of Evolution in the Sorbonne, who lias advanced our 

 knowledge of the group in a noteworthy manner. 



