SONATSA MERIDIONALIS. 417 



tral band between and in front of the parapodia, a similar but smaller one on the 

 seventh, and also cross-bands on some succeeding somites. On the sixth and 

 succeeding somites the uncini are borne on distinctly elevated glandular tori; 

 and connecting the tori of these somites a narrow, thickened, and transversely 

 wTinkled or folded longitudinal band on each side. In the type the diameter 

 of the first somite is nearly 3 mm. ; that of the seventh only 2 mm. 



The tip of the head is narrow and pointed, much narrower than it is, e.g., 

 in Maldane sarsi. Lateral free border high and continuous from anterior end 

 to the caudal limbus, the edge smooth. Caudal limbus with the edge forming 

 at the middle a reentrant angle which is a little greater than 90°. Keel extending 

 as a low ridge on tip of head, transversely depressed near base of latter and then 

 continuing as a conspicuously high ridge to the caudal end of the plate. Nuchal 

 organs narrow and short, bowed mesad. Behind the middle of the cephalic 

 plate along inner base of free border there is a deep fiu-row on each side which 

 continues about the caudal end. There is a broad but low elevation about the 

 caudal end of mouth, this elevation radially crossed by mmierous fine sulci. 

 In front of the mouth two narrow low ridges which meet at an angle at the median 

 line, these being also transversely wrinkled. 



The uncini of the second setigerous eomite in the type near nine on each 

 side; those of the third and fourth, fifteen to eighteen; of the fifth, one hundred 

 or more; and those of the sixth about forty-five or fifty. The uncini of the 

 anterior somites are conspicuously narrowed at the neck, producing a distinct 

 shoulder, the exposed portion ha\ang an even or nearly even curve with the 

 rest of the seta. Head bearing two teeth or hooks, or sometimes a weak third 

 one present, a large straight one and a smaller one back of this, and also bearing 

 across the free end transversely a series of slender, closely appressed teeth, or 

 spines, which extend over and partially ensheath the base of the larger hook. 

 Subrostral hairs arising from a moderately sahent angle close to base of the larger 

 tooth. Hooks fibrous. The fully developed uncini of more posterior somites 

 are larger and have the crown broader, with three and sometimes four hooks, 

 and the subrostral hairs six or more in number. The posterior or major capillary 

 setae with a long, slender, acute tip, which on the most anterior segments appears 

 smooth, but on the others bears numerous fine and closely arranged teeth; on 

 the gradually widening part below the tip there is on one side a very narrow 

 limbus, the limbus of the other side being obsolete. Anterior, or minor, capillary 

 setae much finer and shorter than the posteriors, as usual. 



Caudal end of type missing. 



