TRYPANOSYLLIS ZEBRA. 171 



segment- junctions, and the dorsal cirri are violet from corpuscles. An alternation of 

 longer and shorter cirri is noted by De St. Joseph, and they are present anteriorly in 

 the example figured. 



The proboscis occupies the area from the sixth to the eighteenth segment, and the 

 proventriculus the following eighteen (De St. Joseph). 1 The stomach has no lateral ca?ca. 

 Anteriorly the proboscis has ten soft papilla?, and ten hook-like horny denticulations, 

 accompanied by a single large conical tooth on the dorsal arch. 



The foot (Plate LXX, fig. 8) anteriorly has dorsally the long and large cirrus alternately 

 with a shorter one after the first few segments, the longer cirri having about forty and 

 the shorter about twenty articulations. As transparent objects the cirri show a median 

 groove towards the base. 



The setigerous region forms a blunt or truncated bilobed process only slightly 

 rounded at the inferior angle. Dorsally the upper angle is pierced by two of the three 

 spines, and below them are two flat, conical papilla?, the bristles closely following — to the 

 number of a dozen or thereabout — in the groove beneath. They extend to the margin 

 beyond the rounded ventral angle. Each (Plate LXXVIII, fig. IS) has a translucent shaft 

 with the usual dorsal convexity, a few longitudinal stria? in the middle, and a more distinct 

 series of slightly oblique striations in the enlarged distal region which has traces of 

 serrations on its convex margin. The terminal piece is rather shorter and broader than 

 in Pionosyllis, with a few oblique striations on the blade, boldly bifid at the tip and 

 spinous along the free (upper) edge. 



The ventral cirrus is ovato -lanceolate, and extends a little beyond the setigerous 

 region. 



The feet in front of the tail become much less, but they preserve a similar shape. 

 The bristles are more slender, and the ventral cirrus is somewhat longer and more 

 tapered at the tip. The simple bifid bristle mentioned by De St. Joseph as occurring 

 in this region has not been seen. 



In a form procured in August at Herm the eyes were larger, and the pigment-bars 

 occurred — the one in the middle of the segment and the other at the segment- junction. 

 The dorsal cirrus was somewhat shorter than in the type. 



The foot presents a long and often gracefully coiled dorsal cirrus of about twenty 

 segments, best marked towards the tip. The conical setigerous region has an irregular 

 outline at the tip. Superiorly the sharp tips of the two spines project, then a 

 prominent papilla appears, below which is the fascicle of bristles in their furrow ; the 

 translucent shafts have the usual curvature towards the tip, which is dilated and bevelled 

 to an acute point. Oblique stria? occur in this region of the bristle, and its front edge 

 shows a trace of serrations. The terminal piece agrees with the type. 



This beautiful species was first found by Grube (1860), and his description and 

 figures are good. 



Claparede (1864) described it as a new species, and instituted for it the genus 

 Tri/panosylUs. This acute and enthusiastic zoologist first found the species budding, 

 the nurse-stock having seventy-two segments and the stolon twenty-two. He gives a 



1 This has not been verified. 



