REPORT ON THE ANNELIDA. 
63 
less than the great stalked rotate kinds which occur in an irregular, and sometimes very- 
prominent, transverse row across the middle of the scale, and behind the minute papillae 
which are overlapped by the preceding scale. AVith the exception of the anterior curve, 
the margin of the scale is furnished with cilia, of considerable length and with slightly 
rounded or bulbous extremities. The first scale is quite encircled by cilia. The cicatrix 
for the attachment of the scales is long, but it is less firm, and does not show the ad- 
ditional external process as in I]jhione muricata. 
In vertical section these scales present a dense series of vertical fibres running from 
the homogeneous and translucent inner surface to the outer (dorsal). The upper surface 
presents the granular papillae, the large rotate kinds being hollow. All possess a similar 
structure, even the apparently smooth surface being covered, under a high power, by 
minute papillae. 
The dorsal division of the foot has a dense tuft of pale yellowish silky hairs which 
differ from those of Iphione muricata in being much more slender, and in having a very 
attenuate tip (PL VIIIa. fig. 3). The comparison of the extremities in the respective 
species is characteristic. The spines toward the tip are needle-like or capillary ; lower 
down they assume the form of pinnae (as seen laterally in PI. VIIIa. fig. 4) ; moreover, 
the pinnae agree with the arrangement in Iphione in being opj^osite, whereas in the 
Polynoidae proper they are alternate. Inferiorly the spines diminish and disappear, the 
shaft being striated longitudinally as in Iphione muricata. 
The inferior division of the foot bears a strong group of dull yellow bristles with 
simple slightly hooked tips (PI. VIIIa. fig. 5), the rows of spines beneath being so 
developed as to form a densely bearded tip, the general arrangement being well seen in 
an antero-posterior view (PI. VIIIa. fig. 6, which represents a smaller example). The 
superior bristles have longer tips than those figured, but their spines are somewhat 
shorter. Developing bristles, or at least those unworn, show a long tapering translucent 
process beyond the hook. 
An elevated cuticular protuberance occurs behind and partly overlaps the head, and is 
most pronounced in the young animal. A double row of low papillae runs backward from 
the foregoing on each side of the middle line. In neither is the development so great as 
in Iphione. A series of wart-like papillae occur along the superior and posterior border of 
each foot, the processes being best developed in those carrying cirri, which are not present 
in Iphione muricata. The cuticle on the ventral surface is covered with minute papillae. 
The area between the insertions of the oblique muscles is of moderate length in the 
anterior third, and the nerve-cords are fairly developed. They are less flattened than in 
Iphionella cimex. 
There is nothing remarkable in the extruded proboscis except that the basal process 
of the maxilla has an obscure elevation or two exterior to the teeth. In the alimentary 
canal of one example were fragments of amphipodous Crustaceans. 
