CHCETOZONE Z. 267 



Habitat. — Dredged in 100 fathoms, St. Magnus Bay, Shetland, in July, 1867, by Dr. 

 Q-wyn Jeffreys; between tide-marks, in clear sand, Clare Island district (Southern). 



The original example was a fragment, about half an inch in length, of the middle and 

 posterior regions, including more than sixty bristled segments, which differs from G. setosa 

 by the flattened body, longer lateral bristles, the button-shaped anus, and the absence of 

 the differentiated posterior region so characteristic of the species just mentioned. 



The broad, flattened body, 44 mm. long in the complete form, has 150 very distinct 

 segments, with setigerous papilte projecting as conical eminences. The posterior end 

 seems to have been reproduced, about fifteen segments being thus added, with the large 

 button-shaped pygidium ; but the general structure of the feet remains as in front, and 

 it differs from the condition in G. setosa. in which the modification of the crotchets in the 

 posterior region is characteristic. 



The feet at the anterior part of the fragment (Plate CVII, fig. 5) have dorsally a 

 few finely-tapered capillary bristles and a series of broad, flattened bristles, curved and 

 faintly striated, and with tapered extremities. They represent the intermediate forms 

 ushering in the anterior crotchets of G. setosa. The ventral division consists of a few 

 shorter capillary bristles and a still shorter series of the same curved, flattened, faintly 

 striated bristles, with tapering tips as in the dorsal division. In front of the reproduced 

 tail the dorsal division has a few long, tapering, capillary bristles, the main series, 

 however, consisting of long, stiff, curved, and striated forms, with a nearly cylindrical 

 shaft inserted in the tissues, a constriction being evident before passing through the 

 skin, after which it curves forward, and ends in the long, flattened, curved, and tapering 

 tip. The ventral division, again, has shorter bristles of the same kind as the foregoing, 

 besides a series of stouter crotchets, which have flattened shafts inserted in the tissues, 

 and slightly narrowed curved tips tapering to a blunt point (Plate CVII, fig. 5 a). 



This form, therefore, appears to pertain to De St. Joseph's second series, viz. those 

 with capillary bristles in the dorsal throughout, and crotchets in a certain number of the 

 ventral divisions of the feet, but the absence of reliable figures in known forms makes its 

 relationship uncertain. 



Reproduction. — The fragment pertained to a female with ova of uniform size in the 

 perivisceral space, besides many smaller in the ovaries. It was procured in July. 

 Southern found the young pelagic in March and August. 



3. Chcbtozone Z. Plate CIII, fig. 17 — bristles. 



1911. Choetozone Z, Mcintosh. Ann. Nat. Hist., ser. 8, vol. vii, p. 167, pi. vi, fig. 6 a. 



As no locality is given in the case of a fragment dredged in the ' Porcupine ' 

 expedition of 1870, it may be noted that it has a gradually widening and spatulate tail, 

 which is bluntly rounded, with a median ridge dorsally and ventrally, the former curving 

 downward to terminate in the ventral anus, which has a peak anteriorly. The region in 

 front is considerably narrower, the dorsal surface being rounded, the ventral flattened. 

 The segments are numerous and narrow, and have dorsal and ventral tufts of slender 

 capillary bristles (Plate CIII, fig. 17) of a pale yellow colour and nearly straight. 



