POTTS — POLYCH^TA. 351 



33. Sthenelais foliosa, sp. n. (Plate 21. fig. 64.) 



A small anterior piece of this well-marked species was obtained, with a breadth of 

 4 mm. 



Head with somewhat short tentacles, provided with large and rather expanded ctenidia 

 hiding anterior pair of eyes. Palps rather shorter than in S. variabilis. Elytra large, 

 transparent, and foliaceous, possessing smooth borders save for two or three small scattered 

 cilia on outer margins of each. In anterior segments small equal spinose tubercles cover 

 most of surface, but not posterior border ; in posterior confined to middle part, elytra 

 having mai'ginal zone nearly free from tubercles. 



Parapodium distinguished by entire absence of spinose setse in upper part of neuro- 

 podium. Second type of sette (fig. 64) represented by stout setae, not slender as in 

 tS. variabilis, wavy oblique lines running across shaft just beneath articulation. Ventral- 

 most setse of usual type, few in number and very slender. 



Locality. Saya de Mallia, Seychelles, C 12, 47 fathoms, in company with Fsammolyce 

 gracilis, Panthalis edriophthalma, and Lepidonotii,s carinulata ; " bottom was muddy 

 with a little shell material." This species is at once recognised by the characteristic 

 elytra, which, owing to their delicacy, have a ruffled appearance in spirit. 



Genus THALANESSA. 



34. Thalanessa digitata, Mcintosh. 



Mclutosh, Polycliseta, 'Challenger' Reports, vol. xii., 1885, p. 140 [Admiralty Islands, 16-25 



fathoms] . 

 Willey, in Herdman, Ceylon Pearl Oyster Report, pt. iv., Polychseta, p. 260. 



Measurements. Length 68 mm., breadth 4 mm. (with setse) ; no. of segments 144. 



As far as can be judged without comparison of specimens, this species is to be identified 

 by the difference in the arrangement of the setse in the five anterior setigerous parapodia, 

 compared to that in the rest of the body. 



The eyes are reddish in colour, small and rather indistinct ; the elytra are more 

 elongated antero-posteriorly than appears in Mcintosh's figure. In all other respects the 

 animal corresponds exactly to the descriptions quoted above. 



Locality. Hulule, Male Atoll, Maldives, with Sthenelais variabilis. 



EXPLANATION OP THE PLATES. 



Plate 18. 



Fig. 1. Lepidonotus carinatus : edge of elytron, x 340. 



,, pustulatus : sixth elytron. 



„ purpureas: surface of elytron, showing honeycomb arrangement, x 340. 



„ cristatus, var. echinata : second elytron. 



„ „ „ varieties of ornament on second elytron. 



„ ,, var. ornata : sixth elytron. 



„ „ „ varieties of ornament on sixth elytron. 



