164 LEPIDASTIIENIA SIBOGAE. 



u n d C i r r e n ist noch deutlich zu orkennon, insofern an 

 den vicrten Elytrenpaar die Endzapfen noch genau die 

 Beschaffenhoit der entsprcchenden Gebikle der Cirrenan- 

 lagen besitzen." 



However, Darboux thinks that Hacker's opinion about 

 the homology of both organs only should be based upon 

 „similitude de forme", whereas the german author after- 

 wards should have stated several important histological 

 differences between elytron and cirrus. Now, the only im- 

 portant point of difference that I could find mentioned 

 in Hacker's paper, is „flaschenförmigen Drüsen" making 

 their appearance in the ventral as well as in the dorsal 

 cirri. But Hacker demonstrated, that in the Ncctochaeta- 

 stade all the appendages show a short basal part and a 

 bottle-sliaped or scale-like distal part, that in all of them 

 there enters a muscle and a nerve, the branches of which 

 run to the terminal sense-organs. Also the phenomenon, 

 that in some Lepidasthenia-s^iioiQ^ the elytron and the 

 dorsal cirrus take any other's place, in my opinion pleads 

 for the homology of both organs ; Ehlers ') f. i. found, 

 that in a specimen of Lejndastheftia irregularis nine succee- 

 ding segments of the posterior body-region at the right 

 side possessed elytra, whereas at the left side there were 

 six elytra and three dorsal cirri ; also in Lejndasth. Digueti ^) 

 Grav. and convinensaUs Webst. similar phenomena have been 

 observed. As the Siboga-collection also contains some indi- 

 viduals of the rare Gastrolepidia davigera Schm., I could 

 corroborate Duncker's suggestion, that its ventral lamellae 

 have nothing to do with elytra and that they represent only a 

 lamellar enlargement of the epidermis; in this species 

 there are no dorsal tubercles and the cirriphores are situated 

 nearly in the same line with the elytrophores. 



II. Eulepis nialagana, n. sp. 



Station 204; Buton-strait, depth 75—94 M. ; Station 

 260, off Great Key island, depth 90 M. 



1) Die PolycLaeteu des Magellan, u. Chilen. Slrandes, 1901, p. 55. 



2) Bulletin du Muse'um d'llist. Nat. I. XI, 1906. p. 177. 



Notes from the Leyden Museum, Vol. XXXV. 



