1904.] rOLYCHJETA OP THE MALDIVE AllCHIPELAGO. 275 



The neuropodium of the last segment of A is a low straight 

 ridge, thus diffeinng from the semicircular flap found in C. vario- 

 pedatus. Each extends about one-third across the body (as in 

 C. variopedatus), and its uncini are conspicuous by their brown 

 colour. 



The parapodia of the regions B and C are exactly similar to 

 those of C. variopedatus. 



I have examined in detail the setse of C. variopedatus, but, in 

 preference to repeating what is there stated, refer to Maren- 

 zeller's description, which applies equally w-ell to C. vario2yedatus 

 and to C. cautus. 



In C. longimanus the long setse of A correspond exactly to 

 those of C. variopedatics, which differ from those figured by 

 Marenzeller in C. cautus only in that the more slender-bladed 

 setje of the last notopodium are less bent at the junction of the 

 leaf-like expansion and the shaft. This difterence, as explained 

 above, is probably accidental. Their shafts are striated longi- 

 tudinally, and their thin expansions transversely by two sets of 

 fine lines, as described by Marenzeller and Schmarda. 



The long setse of the hind body are more slender than those of 

 C variopedatus, and whereas those of the latter terminate in a 

 definite, more or less blunt point, those of the former have slender 

 flexible prolongations as in text-fig. 39 (p. 274). Though at 

 first sight this flexible ending appears likely to be accidental, I 

 find it to be a constant distinction. It is figured clearly by 

 Schmarda in both his C. macropus and C. hamatus, though in 

 the text he describes the sette as hooked. This is not so, the 

 flexibility of the ending causing it usually to be bent in a 

 preparation. 



In all three species these sette are of two kinds (a fact not 

 hitherto noted in C. variopedatus) : the first sort, with blunt 

 proximal ends, extending from the body into the notopodium ; the 

 second, much thinner, with pointed proximal ends which overlap 

 the tips of the first kind, and extend into the very point of the 

 notopodium. 



The strong setse of the fourth segment of A number 1 6 on each 

 side. They difier slightly in shape from those of C. variopedatus 

 (see Plate XYIII. fig. 1 a, h). In both species, however, these 

 setae difier among themselves. Their number in my specimens of 

 C. variopedatus is from 18 to 20, while Joyeux-Lafi'uie gives 15 

 as the number most frequently met with*. 



The variation of the uncini is as described by Marenzeller in 

 C. cautus and as I have found it in C variopedatus. In C longi- 

 tnanus they are remarkably conspicuous owing to their dark 

 colour, except in the ventral halves of the neuropodia of 0, where, 

 as in G. variopedatus, they are invisible to the unaided eye t. 



* It does not seem to have been noticed by eai'lier authors that the sette of para- 

 podium 4 A are not merely strengthened but that shafts as well as heads are flattened 

 in C. variopedatus, as also in C. longimanus and C. longipes. 



f In Joyeux-Laffuie's monograph it is not stated that uncini occur in the neuro- 

 podium of the last segment of A. Mcxrenzeller describes them in C. cautus and I 

 find them in C. variopedatus. In C. longimanus they are visible to the naked eye. 



18* 



