ON A NKW Sl'KCIKS OK SCLI'-IH" 'II I-.I I.I >'. 



295 



slightly damaged ami no longer bear cirri. In tin 1 L8th ami 

 1'Jth cliR'tif'erous segment s t IK- neuropodia] cirrus is a short conical 

 process, '05-'08 inin. in length; lint those of the succeeding seg- 

 ments (lig. i;) rapidly increase in length, so that the cirri of the 

 3ord to -Kith segments arc linger-shaped ami ':2f>-':! nun. long 

 (rig. 5). There are no notopodial cirri. 



A lateral si- use-organ is present in each parapoiliuni imnie- 

 diatelv ventral to the base of the notopodium ; but as it is small, 

 ami usually hidden in a depression, it can be seen satisfactorily 

 only in sections. The surface of the organ which bears the sense- 

 hairs is oval in outline, and its longer diameter is not more than 

 about 40//. This area is sunk below the level of the surrounding 

 epidermis of the papilla on which the organ is situated. Ventral 

 to the papilla bearing the sense-organ is a larger eleva- 

 tion the epidermis of which is glandular (fig. <>) 



ChsetSB. 



The first notopodium bears ehfetse of three or 

 four different kinds, the relative positions and detailed 

 structure of which have been studied as far as has been 

 possible on the single intact notopodium available. 



(i) There is an anterior series of about ten almost 

 straight chretre (text-fig. 1, A), approximately '5 mm. 

 long and 9-HV in maximum diameter. Each of these 

 chretee tapers rapidly in its distal fourth to a fine 

 point, and the preparations indicate that the tips of 

 these chfetse project little beyond the lips of the 

 chietal sac. 



(ii) Close behind the cli;rt;e just described is a 

 series of about fifteen stronger chaetse, each bent in a 

 characteristic manner (te.xt-fig. 1. 15). These chretce 

 are '(>-'G5 mm. long, and their maximum diameter is 

 \n-\~2fjL. Kadi ch.-i'ta tapers somewhat abruptly at its 

 free end. and, when unworn, has along both sides, 

 tor a distance of ' I ."> mm. behind the fine-pointed tip, 

 a narrow and very delicate lamina which readilv 

 breaks up into a (dose-set scries of minute, pointed 

 processes, so that this region of the cli:t.-ta appears 

 to be finely spinctus. It is possible that these chaetse 

 arc really in two rmvs, an anterior row of about 



TKXT-KII:. 1. Cli.-i'tse fnnii tin 

 |iiliuni uf tlio specimen fnuu 

 (x200.) 



tirM. nolo- 

 S :otia l'.;iy. 



(ROY. 80C. EU1N. TRANS., VOL. 1., 10,.) 



