ON A NEW SPECIKS OF APHKODITA — JOHNSTON 243 



firm structures, dark brown in the adult but much lighter in 

 colour in young specimens. They seem to be arranged in three 

 rows on the neuropodium. The uppermost consists of two very 

 strong, dark seta? ; the next, of three or four smaller and lighter 

 coloured ones ; ami the lowest, of several still smaller bristles. 

 This division is not as well marked posteriorly, the two lower 

 rows becoming one, the uppermost remaining fairly distinct. All 

 of these setse are similar in shape (PI. xlix., tig JS). They taper 

 rather rapidly at the end, which is bent slightly and has a 

 rounded extremity. There are no processes present, but longi- 

 tudinal striations occur. A. australis has ventral seta? of two or 

 three kinds, one ends in a rather broad point and bears minute 

 processes, whilst the others may be either dart-shaped or else 

 slightly hairy. There seems to he only one seta present in each 

 peristomial neuropodium. It is short and thick, very little of it 

 projecting beyond the foot. The next segment bears two on 

 each side, these representing the uppermost of the three rows 

 visible in segments situated more posteriorly. The aciculum of 

 each division of the foot is a short, dark, slightly curved, sharp- 

 pointed body, which does not project. The parapodia are ringed 

 and like the ventral surface of the animal, hear numerous 

 tubercles. 



The ventral cirri are short, the majority being only two mm. 

 long. They are rather thicker at the base than the dorsal cirri. 

 Each tapers towards the end, becoming swollen some distance 

 from it, so as to become rather spatulate (PI. xlix., tigs. 1,2.) 

 This may be caused by the preserving fluid. There is a ringed 

 appearance externally. A strand of tissue is visible in the 

 middle. The dorsal and ventral cirri of the peristomium are 

 very long compared with those of other segments, and lie close 

 behind the palps, constituting the peristomial tentacles. They 

 are long in the next segment also, but decrease in size rapidly in 

 succeeding segments. Near the base of each ventral cirrus there 

 is situated a small whitish tubercle, probably representing the 

 segmental papilla. 5 



The dorsal cirri alternate with the elytra, the peristomium 

 bearing cirri. Excepting those which are borne on the most 

 anterior segments and are relatively long, these organs are about 

 nine millimetres long. They are rounded and tapering, ending 

 in a slightly enlarged tip. Like the ventral cirri, they are 

 ringed and possess a median strand of tissue. The peculiar net- 



5 Haswell — Note on Segmental Organs of Aphrodita (Proc. Linn. Soc. 

 N. S. Wales, vii., 1S82, p. 610). 



