10 Annelida Ghcetopoda 
Elytra numerous, completely covering the body, or leav- 
ing a naked median space of variable width; along the 
posterior part of the body not always in pairs. Setae of 
dorsal ramus, few, delicate : of the ventral ramus for the 
most part bidentate, but with a few, stouter than the others, 
pointed. 
This genus is closely related to Halosydna Knbg. but 
differs in the number and arrangement of the elytra, in 
having pointed setse in the lower ramus, and in having a 
distinct facial tubercle. In many respects it agrees with 
Lepidasthenia Mgrn., but is excluded from that genus by 
having setse in the dorsal rami. 
Lepidametria commensalis n. sp. 
PL. Ill, PIGS. 23-31, 
Bead (f. 23), convex, sides rounded, widest and highest 
at posterior third, posterior margin slightly concave. 
Eyes circular, black, lateral, all small, and in alcoholic 
specimens seen with difficulty. Anterior pair largest, 
situated at the widest part of the head. Posterior pair 
mere specks, half way between the front pair and the 
hind margin of the head. 
Lateral antennae, bases forming about one-third the 
length of the entire head ; antennae a little longer than the 
head. Base of median antenna stout, cylindrical, project- 
ing a little beyond the origin of the lateral antennae. 
Middle antenna one-third longer than the lateral. All the 
antennae, together with the tentacular cirri and dorsal 
cirri are cylindrical to near the end, where there is a very 
slight swelling, after which they taper rapidly, having a 
filiform termination. 
Palpi, stout, extending beyond the middle antenna, 
decreasing regularly to near the end, where they become 
suddenly filiform ; covered with minute cylindrical papillae. 
