.L2ETMAT0NICE FILICORNIS. 261 



which taper to a fine hair-like point. Their outline seems to be smooth, though sandy 

 debris lodges readily amongst them. The anterior tuft is directed forwards and inwards 

 as an expanded fan, while the compact posterior one goes inwards and backwards. A 

 strong spine supports the foot. The bristles are similar but somewhat stronger dorsally 

 in the second foot. In the third foot a more slender series of bristles occurs to the 

 exterior of the cirrus, while a stronger series is dorsal. This and the next have 

 pinnate bristles in the ventral division. 



The fourth foot, which is provided with a ventral cirrus, has in the inferior division 

 a tuft of pale pinnate bristles, like those of Aphrodita. The same pinnate bristles occur 

 in the fifth foot, adjoining the ventral cirrus, while above them are a few of the ordinary 

 kind with feathered tip and hook. In the sixth only the latter are present. The typical 

 forms are shown in Plate XXXVI, figs. 5 and 7. 



In the same way the last foot or two have a modification of the ventral bristles, for 

 the spikes above the hook are short and distinctly separate. Moreover the last foot has 

 pinnate bristles as in front, along with an ordinary form or two. 



The feet appear to be about thirty-four, the dorsal division alternately bearing cirri 

 and long bristles. 



The dorsal cirri spring from the centre of a fringe of the more slender bristles, their 

 places being taken in the scale-bearing segments by the long hooked spines. In the 

 case of the cirrigerous feet a group of stout, short, brownish bristles occurs in front of the 

 cirrus, and a somewhat longer and stronger series springs in the scale-bearing feet on 

 the dorsal side of the long spines. All are densely covered with a muddy and sandy 

 investment, but their surface appears to be smooth. 



A typical foot, e. g. one bearing the long dorsal spines, has dorsally (from within 

 outward) the slender hairs which form the felt, then a group of short stiff bristles, fol- 

 lowed by the papilla carrying the long brown spines, which have a distinct curve. A 

 tuft of delicate bristles occurs beneath. The scale is fixed posteriorly. After an 

 interval the ventral branch of the foot bears the semi-pinnate bristles and the ventral 

 cirrus. 



The last pair of feet are rudimentary, and lie in ordinary positions behind the anus 

 which is dorsal. 



The segmental organs (nephridia) point upward between the feet, and are as well 

 developed as in Aphrodita aculeata. 



A Norwegian example, sent by Dr. Merle Norman, 1 shows guards to the front of the 

 dorsal spines, and a slightly hastate tip beyond the barbs. The ventral bristles seem to 

 have shorter tips. 



A series of small specimens occur from North Unst — from 55 mm. upwards. These 

 have pale spines and bristles, yet all the bristles and the dorsum are densely coated with 

 sand-grains. They were captured in July, and probably represent the growth since the 

 previous spawning season. 



Loxosoma3 are common in this species on the feet, ventral surface, and on the 

 dorsum under the scales. 



1 Op. cit., p. 171. 



