266 CHCETOZONE ZETLANDICA. 



miniature scalpel, the blade of which has a curve backward. The direction of these crotchets 

 is at first slightly backward, but by-and-by they project transversely outward, and in four 

 or five of the terminal segments they are directed forward, doubtless in connection with 

 their functions in the mud or sandy mud. 



Two fragments of the anterior region of a form which does not appear to differ from 

 the foregoing were procured, probably by the tangles in Bono Bay, on the coast of 

 Algiers in the ' Porcupine ' expedition of 1870. As no crotchets are present, a certain 

 amount of doubt remains, the bristles at the posterior end of one fragment being 

 unusually long, and their bases of a deep brown hue. 



Cunningham and Ramage (1888) note that the anterior pair of brown nephridia 

 open at the base of the first pair of feet and extend backward through two or three 

 segments. The heart-body consists of three granular cords, as in Girratulus. 



Reproduction. — Partially developed eggs occurred in the perivisceral cavity of an 

 example captured in July. In Norwegian examples large ova were present during the 

 same month. 



Marenzeller (1889) thinks that the branchige are most frequently behind the tentacles. 

 The point at which the row of dorsal bristles joins the ventral, and the shorter and 

 stouter bristles in a half circle (Halbgurtel) is in the sixty-seventh or in some the seventy- 

 fifth bristled segment. 



2. Ohggtozonb zetlandioa, Mcintosh, 1911. Plate CVII, figs. 5 and5<x — bristle and hook. 



Specific Characters. — Head pointed in front, swollen behind, with a pair of kidney- 

 shaped ventral eyes, and externally the nuchal organs. 1 Dorsal tentacles in front of 

 first bristles. Body distinguished from that of Ghoetozone setosa by its flatness, 

 the more hirsute lateral regions, the button-shaped anus, and the absence of the 

 differentiated posterior region. Feet at the anterior part of the fragment have a 

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

 curved and faintly striated, and with tapered extremities. Ventral division with a few 

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

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

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

 cylindrical shaft inserted in the tissues, constricted before passing through the skin, after 

 which it curves forward and ends in the long, flattened, curved and tapering tip. The 

 ventral division has shorter capillary bristles of the same kind, and a series of stouter 

 crotchets with flattened shafts, and slightly narrowed curved tips with a blunt point. 



Synonyms. 



1911. Choetozone zetlandica, Mcintosh. Ann. Nat. Hist., ser. 8, vol. vii, p. 161. 



1914. ,, „ Southern. Proc. Roy. Irish Acad., vol. xxxi, no. 47, p. 115, pis. xii and 



xiii, fig. 29, a — k. 



1 The capture of perfect forms by Mr. Southern in the Clare Island district has enabled me 

 briefly to supplement the description. 



