356 STATTBOCEPHALtTS RUBROVITTATITS. 



The typical condition of the foot is assumed about the tenth and subsequent feet 

 (Plate LXXIII, fig. 4) toward the middle of the body. Dorsally is the stout dorsal 

 cirrus with the terminal articulation, its tip projecting considerably beyond the soft parts 

 of the foot beneath. The slender spine occurs internally as in the foregoing foot. 

 Claparede 1 describes the basal segment as having four parallel blood-vessels, which do not 

 enter the terminal piece, but anastomose with each other. He considers this the homo- 

 logue of the short ceratophore of the majority of Annelids. " The setigerous lobe is lar^e 

 and strong, its dorsal ridge richly ciliated, and the free border split into two conical 

 processes superiorly and convex edges inferiorly. The ventral cirrus projects beyond 

 the adjoining part of the setigerous lobe. The bristles of the dorsal part of the setigerous 

 lobe (Plate LXXXI, fig. 9) are transparent and elongated, gently widening upward and 

 forming a flattened blade with a finely serrated edge, the tip being curved and ending in 

 a slightly tapered point. Some of the bristles have a broader and shorter flattened 

 region at the tip than that figured. The serrations are elevated distally. Pruvot and 

 Racovitza describe them as having an irregular border. The bristles of the inferior 

 group are more numerous, but equally transparent, the shaft dilating into a somewhat 

 large distal region, which is bevelled and carries the rather elongated and minutely 

 serrated terminal piece, which is bifid (Plate LXXXI, fig. 9 a), the terminal hook 

 being separated by a considerable interval from the secondary process, and thus charac- 

 teristically differing from such types as Stawroceplialus Budolphii, from Naples, a 

 form in which the secondary process passes distally like a knife-blade and touches the 

 terminal hook. 



The presence of a spine in the dorsal cirrus, so called, raises the question as to 

 the composition of such a foot, De Quatrefages interpreting it as an indication of a 

 dorsal division, whilst Claparede thought differently. 



The feet retain the same structure to the posterior end of the animal, but they 

 diminish in size as in front. Claparede showed that the feet discharge many bacillary 

 bodies from follicles. 



In an example caught in a tow-net off Sark by Mrs. Collings in June, 1869, and 

 measuring about three quarters of an inch, the feet (Plate LXXIII, fig. 4 a) differed 

 considerably from those of the foregoing ripe male. Thus the dorsal cirrus was less 

 massive, the inferior processes of the setigerous region were more acute in lateral 

 view, and the bristles, both simple and compound, were more attenuated. The terminal 

 pieces of these, however, maintained the character of the species, the terminal hook 

 and the secondary process being separated by a considerable curved interval, though 

 the process was somewhat shorter (Plate LXXXI, fig. 9&). 



Reproduction, — Most of the examples procured in July at Herm were males in which 

 the body-cavity was distended with sperms. These also invaded the feet, almost to the 

 tip, and a column of them passed along the centre of the dorsal cirrus. Pruvot and 

 Racovitza give July as the breeding period, and add that most of the young have a single 

 pigment-band on each segment. In transverse section the body of the male shows 

 greatly stretched muscular layers, whilst the alimentary canal forms an elliptical 

 central slit, apparently without food. 



1 ( Annel. Chet. Nap./ i ; p. 118, pi. vii, fig. 2 b, f. 



