454 THE ANNELIDA POLYCHAETA. 



On the ventral side there is a wide lower Hp, the anterior margin of which 

 is widely concave. The anterior border may be raised, with the median area 

 depressed across the entire width. 



In the thoracic region there are fifteen setigerous somites. The dorsum 

 of this region is evenly convex and smooth, with no distinct intersegmental 

 furrows excepting a few at the anterior end, the furrow between the third and 

 fourth setigerous somites being especially distinct, the border on the caudal 

 side of this furrow representing the nuchal fold of Melinna, etc. It is depressed 

 on each side below the level of the sides, the parapodia being attached along the 

 line of depression and becoming more dorsal and approaching nearer to each 

 other at the anterior end, as usual in species of related genera. Ventrally and 

 laterally the somites are separated clearly by deep intersegmental furrows. 

 Somites undivided. Just caudad of the labial lobe a very obhque furrow on 

 each side meets on the fifth somite the one from the opposite side at a very 

 obtuse angle, forming a widely V-shaped mark, in which the arms become less 

 deeply impressed away from the angle. Toward the caudal end of the thorax 

 the somites become much longer than the anterior ones. The somites of the 

 anterior region of the abdomen are long ; but they become very short in com- 

 parison with their width and closely crowded in the posterior region, those 

 inmiediately preceding the caudal end being exceedingly short. The caudal 

 end of the body flares out in campanulate manner much as in some maldanids, 

 with the free border divided by radial furrows and with projections Uke short 

 papillae. The poor preservation of the jjart prevents more detailed description. 



The notopodia of the first few setigerous somites are very small, the first 

 ones scarcely obvious as distinct elevations. In the other parts of the thorax 

 they are distinct and well developed. They are very stout in comparison with 

 length, and distally are compressed to an edge through which the setae emerge. 

 The uncinigerous thoracic lobes project from the caudal edge of the somites 

 just ventrad of the notopodia. The most anterior of these lobes are very 

 broad dorspventrally in comparison with the anterocaudal length, the free edge 

 straight. Caudad the width decreases regularly and strongly, the lobes in 

 the posterior part of the thorax being very small. The uncinigerous tori of 

 the abdominal region are very narrow dorsoventrally, short, and moderately 

 compressed in the anterocaudal direction. 



The notopodial setae of the most anterior and of the most posterior setig- 

 erous somites are very short and fine. Those of the typical fascicles are moder- 

 ate or short. The setae are narrowed distad and drawn out into fine, curving 



