ACOETID^. 399 



tapering. They do not reach the tip of the fleshy part of the foot (in spirit), though 

 they pass beyond the bases of the bristles. 



Nerve-cords. — At the sides of the nerve-cords are numerous nucleated cells, and the 

 cords themselves in section present a peculiar areolar or reticulated appearance — a 

 feature, however, which may be due to the mode of preparation. The granular epidermic 

 layer seems to be largely developed. 



Habits. — The late Dr. Carrington, of Eccles, found it at Southport in considerable 

 numbers, along with Harmothoe lunulata, in the ambulacra! grooves of Astropecten 

 irregularis, his attention having been attracted by the bluish phosphorescence when the 

 star-fishes were put in fresh water. It is very fragile, so that it is difficult to obtain an 

 entire example ; yet it is sluggish. Claparede, again, procured it on the same star-fish at 

 Naples in company with another Annelid, Stephania flexuosa. 



Reproduction. — Dr. Carrington observed ova in his examples from Southport, but no 

 date is given, though it is probable that they were obtained during the storms of winter. 

 The ova were seen through the dorsal papillse. M. Claparede procured those with ova 

 and sperms at Naples in the winter of 1868-9. 



Delle Chiaje first found this species in the ambulacral grooves of Astropecten 

 cmrantiacus and pent acanthus at Naples, and gives a figure of the entire animal, which is 

 of a pinkish hue. 



Amongst allied forms, Webster, in his 'Annelids of the Virginian Coast,' describes 

 Lepidametria commensalis with scales extending the whole length of the body, viz. 50 to 

 90 mm., and living in the tube of Amphitrite ornata (Verrill). Moreover he also describes 

 a minute form (which he terms " Antinoe parasitica") parasitic under the scales. It 

 has peculiar hooks in the posterior segments (ventral series) — he thinks for holding on. 



This species is apparently that referred to and figured by Delle Chiaje in 1823, but 

 his reference to the previous note by Baster could not be verified. It has been thought 

 best to retain the specific name astericola subsequently given to it by the Italian author, 

 the original one of squamosa being less characteristic. 



Family IV.— ACOETIDiE, Kinberg, 1857. 



Head without a facial tubercle. Median tentacle arising from the middle of the 

 anterior lobe ; bases of the lateral tentacles covered by the ocular peduncles. Palpi long 

 and tapering. Body elongate, flattened. Scales numerous. Scale-bearing segments 

 alternating with those bearing cirri. Pharynx exsertile, with numerous papilke on the 

 margin — the median dorsal and ventral tentaculiform. No pregastric caeca. A 

 segmental eminence, but no distinct papilla. 



52 



