430 SIGALION MATHILDA. 



lower border, and dorsally having a papilla for the scale. The inferior lobe is irregularly 

 conical, the upper slope ending in a rounded process pierced by the spine, and the margin 

 trending downward and slightly backward from this to the abrupt angle inferiorly. The 

 upper bristles have slender shafts with slightly dilated extremities and an oblique edge, and 

 present only traces of rough processes, the long tapering distal region having numerous 



Fig. 33.— Papilla of scale of Sigalion MatJdldce, Aud. and Ed. x 280. 



segments, the tip apparently being simple. The group below the spine is similar, except 

 that the ventral series show a distinct spine or two towards the end of the shaft. The 

 ventral cirrus is subulate, and projects beyond the tip of the fleshy part of the foot. 



The third foot has a similar form, but papillas occur dorsally (a conical upper and 

 two boss-like inferior), and ventrally is a rounded papilla internal to the cirrus. The 

 ventral bristles now present a claw at the tip, 



A typical foot (Plate XXXI, fig. 10) shows dorsally three ciliated pads (ctenidia) 

 along the dorsal edge. The dorsal lobe projects somewhat further outward than the 

 ventral, is club-shaped, with a sinus superiorly, and a long, slightly tapered papilla a 

 little below the dorsal bristles. The normal extremity of the division seems to be tilted 

 upwards, the bristles standing obliquely upwards and backwards from the dorsal edge. 

 Internally they commence as extremely fine hair-like forms, with very minute spikes. 

 Towards the outer edge these simple bristles become much stronger, show slight longi- 

 tudinal striations of the shaft, and a curvature where the spinous distal region commences. 

 They then taper to a very slender extremity. De Saint- Joseph 1 states that these bristles 

 end in a bifid point, an error of interpretation probably due to imperfect specimens. The 

 minute spikes project upwards and outwards when the bristle is in position (Plate XLII, 

 figs. 11 and 12). Fine transverse or oblique lines indicate the rows of spines. The spine 

 passes out below the bristles and above the papilla. 



The inferior division of the foot presents superiorly a small papilla internal to the 

 bristles, a somewhat short series of bristles (Plate XLII, fig. 13), the tips having 

 proximally a series of longer spines in whorls, five or six of which are very distinct, and 



1 Op. cit., 1898, p. 239. 



