256 THE ANNELIDA POLYCHAETA. 



incomplete description of the latter, due to imperfection of the type, makes a 

 wholly satisfactory conclusion as to their relationship difficult to draw. An 

 important difference appears to be in the tentacles, which are whoUy smooth 

 in bilobata, but are jointed in nesiotes. L. muUipectinata differs in its shorter 

 tentacles, with the median and inner paired ones distinctly unequal, in lacking 

 a distinct subbasal tooth on the blade of the compound setae, etc. L. antennata, 

 so wide-spread in the Indo-Pacific region, and the Japanese L. microprion differ, 

 among other features, in having the branchiae begin farther forward. The 

 Philippine L. flavofasciata also differs in having the branchiae begin on somite 

 VII, in having the tentacles wholly smooth, etc. The Pacific Ocean species 

 having pectinate branchiae throughout the length of the body may be separated 

 by the following: 



Key. 



a. Branchiae beginning on somite IX. 



6. All branchiae distinctly shorter than the dorsal cirri L. contingens, sp. nov. 



66. At least the more posterior branchiae considerably longer than the dorsal cirri. 



c. Tentacles unjointed, wholly smooth L. bilobata (Treadwcll). 



cc. Tentacles jointed. 



d. Inner paired tentacles much shorter than the median, the latter reaching to somite VII; 

 appendage of compound setae with no distinct submedian tooth. 



L. mullibranchiala (Moore). 

 dd. Inner paired tentacles equalling the median in length and reaching to somite IX; append- 

 age of compound setae with a conspicuous submedian tooth L. nesiotes, sp. nov. 



aa. Branchiae beginning cephalad of somite IX. 

 6. Tentacles wholly smooth. 



Body covered with interrupted yellow bands L. flavofasciata (Grube). 



66. Tentacles annulated. 



c. Annulations strongly marked, and tentacles in part moniliform; the articles numerous and 



short; crochets tridentate L. antennata Sayigny. 



cc. Annulations of tentacles weak; crochets bidentate. 



d. Joints of tentacles long and few; first branchia with three filaments, on somite VI; right 

 maxilla II with five teeth, right maxilla III with seven. . , .L. microprion (Marenzeller). 

 dd. Joints of tentacles short and numerous; first branchia with but one filament, on somite 

 VII; right maxilla II witli eight teeth; right maxilla III with ten teeth. 



L. panamena, sp. nov. 



Leodice panamena, sp. nov. 



Plate 59, fig. 4-8; Plate 60, fig. 1-5. 



The type is incomplete, the posterior region being lost. The anterior 

 fragment, consisting of seventy-three somites, is 30 mm. long, with a maximimi 

 width, exclusive of parapodia, of 4 mm. The body is widest at the caudal end 

 of the fragment from where it narrows gradually cephalad, a Uttle more strongly 

 narrowing at the anterior end. 



