SIGALION BUSKII. 431 



a tapering tip with finer spines. The bristles below these have larger shafts — dilated 

 and slightly curved towards the extremity (Plate XLII, fig. 14), with numerous rows of 

 spines on the convex edge. The distal region is jointed, and terminates in a beak or 

 claw. Then follows a dense tuft of similar compound bristles without spines at the tip 

 of the shaft, and a long, jointed, tapering, terminal region with a minute claw (Plate 

 XLII, fig. 15). They become more slender at the ventral margin (as in Plate XLII, 

 fig. 16). 



Besides these slender forms there are, below the spine, one or two somewhat stouter 

 bristles, which show a single segment in the terminal bifid region (Plate XLII, fig. 17). 

 The ventral cirrus is long and slender — reaching to the tip of the fleshy part of the foot 

 — in spirit. 



The foot at the posterior end retains much of the foregoing structure, both as 

 regards the fleshy parts and the bristles. Those at and above the spine of the ventral 

 division are somewhat stronger, and the ventral cirrus is proportionally longer than in 

 front. 



The branchiae commence on the fourth foot, and occur apparently on every foot. 

 The statement of Carus, therefore, that in Sigalion the branchiae alternate with the 

 scales anteriorly is not borne out in this species. 



Reproduction. — A fragmentary specimen procured off the Algerian coast had well- 

 developed ova on August 27th (' Porcupine,' 1870). 



Habits. — In confinement its habits are similar to those of Sthenelais boa. 



This Annelid, which formed the type of the family, was found by Audouin and 

 Milne Edwards at the islands of Chausey, and measured about five inches long by three 

 or four lines broad, and with 180 segments. 



The scales of this species and the general characters approach very closely the 

 Sigalion squamatum of Delle Chiaje, even closer than Claparede — the able interpreter of 

 some of the more doubtful Annelids described by the Italian naturalist — supposed, 

 especially since the difference in regard to the eyes has now been removed. Neither 

 Delle Chiaje nor Claparede, however, show the ciliated mammillae on the dorsal edge of 

 the foot, so that this doubtful distinction alone remains. In his supplemental volume 

 Claparede specially refers to the distribution of the nerves in the papillae for the scales, 

 and also in the periphery of these organs, thus giving them extreme sensibility. He 

 mentions the occurrence of certain spicules or rod-like bodies on the pinnae of the 

 papillae, probably of a parasitic nature ; but such have not occurred in the British 

 species. The males of S. squamatum were whitish, the females of a fine rosy hue — due 

 to the eggs. Leidy's 1 8. Mathildas from New Jersey is a Sthenelais. 



2. Sigalion Buskii, Mcintosh, 1869. 



Specific Characters. — Head somewhat pear-shaped, broad in front and narrow 

 posteriorly. Body stouter than in S. Mathildas, pale greyish in spirit. Scales more or 



1 ' Marine Invert./ &c, p. 148, pi. ii, f. 53. 



56 



