AMPHARETE HOMA. 445 



body, from which it slants steeply. In outline, as seen from above, it is roughly 

 trapeziform, but with a median triangular lobe projecting forward from the middle 

 of the anterior border. From the caudal end of each edge of this lobe a deep 

 sulcus runs back on the peristomium a little ectad of caudad, the two sulci being 

 connected across the caudal end by two transverse furrows. Scars seem to 

 indicate that some tentacular processes in life arise above these longitudinal 

 sulci, but none are now present in the type. The prostomium ventrally is con- 

 cave, there being a concavity for each of the three lobes, the three fusing into 

 the large general concavity of the main prostomial lobe. From this concave 

 surface arise slender, cylindrical tentacles, of which most are lost in the type. 



The lower Up is a large transverse lobe distinctly separated off laterally 

 and caudally by a deep furrow. The lobe is wide, with both anterior and poste- 

 rior border convex at the middle, arcuate. It is crossed by two sulci, the more 

 caudal of which extends entirely across, while the anterior one extends only across 

 the caudal part of the convex mesal region. 



The paleae are not flattened, being capillary setae less coarse than usual and 

 with fine tips which are straight, or but slightly curved. They are colorless, or 

 nearly so, lacking the usual golden lustre. In each series there are eleven paleae, 

 which decrease in length caudad, the most caudal very short. 



There are four pairs of branchiae. Of the branchiae on each side, three 

 form an anterior transverse series continuous with the three of the other side, 

 all in the series being contiguous at base. The fourth branchia on each side is 

 caudad of the interval between the second and third branchiae from the ectal end 

 of the series and lies in close contact with these two branchiae. It has its base 

 prolonged caudoectad. All branchiae in the type are broken off close to the 

 base. 



The first two setigerous somites are not separated dorsally by an inter- 

 segmental furrow. The oblique furrows from the posterior tentacles, one on each 

 side, set off a large, smooth, triangular arc, with apex between the median tentacles 

 of the transverse series, the apical region of the area being set off by a transverse 

 furrow, this anterior piece corresponding apparently to a distinct ventral band 

 of the presetigerous somite, on which the paleae are borne. This ventral piece 

 is incised anteriorly at each end, leaving a rounded lobe just beneath the paleae. 

 Laterally this somite is fused with the succeeding one and this in turn, but more 

 weakly, with the third. There is in the type a small scar just caudad of the 

 paleae on each side, from which possibly a cirriform process has been lost. The 

 first two setigerous somites are clearly separated ventrally, the first one being 



