86 ART. II. — A. IZÜKA : 



U . CompouDcl bristles spiuigeioiis Leanira. 



h". „ ,, falcigerons Thalenessa. 



a". Median tentacle long, with ceiatophore. 



//. Compound bristles spinigorous SUienolejÀs. 



b". „ „ falcigerons Sthenelais. 



Gonus Thalenessa (Baircl), char, cmcnd. Mcintosh. 



Prcstomium with four largo oyes and threo tentacles ; of 

 the latter the median is very short. Elytra leaving the dorsum 

 uncovered anteriorly, furnished with ramose papillae on margin. 

 Parapodia with lamellar processes on tip ; ventral bristles 

 falcigerous and much stronger than in either Sthendais or Slgallon. 

 The ventral cirrus is also longer. It approaches Leanira in the 

 structure of the prostomium. 



Thalenessa ocalata Mcintosh. 

 PL X, figs. 1—2. 



1885. Thalenessa ocnlata, Mcintosh. " Challenger " Anuel., p. 112 ; PI. 



XXI, figs. 1, 2 ; PI. XXIIt, fig. 12 ; PI. XXV, fig. 3 ; PI. XIIIa, 



figs. 11, 12. 

 190o. Thalenessa oculata, Moore. Proc. x4.cad. Nat. 8c. Philad., Vol. LV, 



p. 42G. 



Body measures about 55 mm. in length, and Avith the bristles 

 6.5 mm. in breath. 



The eyes are very large and are situated close together on each 

 side, though widely separated transversely. Tliat of the anterior pair 

 is the larger, and shows a jjale area or " lens " of a considerable size. 

 I'rostoniium provided with a pair of short tentacles with somewhat 

 blunt end, and behind it with a median tentacle of nearly the same 



