Figure 8. A, armature of the four posterior trunk limbs as seen in an individual in which they are fortuitously twisted towards the mid line. Proximally the four gnathobases are seen close together, that of limb 11 being jammed between those of limbs 10 and 12. The more distal armature of this limb is largely obscured by that of adjoining limbs. Being the last of the series, with nothing to obscure it posteriorly, trunk limb 12 clearly displays its gnathobase and endites 2–5. Its endopodite is largely obscured by endite 5 but some of its spinous armature can be seen arising from behind that endite. The arrangement of the armature of the endites of this limb facilitates understanding of that of the three more anterior limbs where, especially in limbs 9 and 10, it is seen 'full face' and it is difficult to see where that of one endite ends and that of the next begins. That the more proximal armature of all these limbs consists largely of stout spines, sometimes curved near their tips to enable them to drag material towards the food groove, is readily seen. More distally, especially on limbs 9 and 10, the armature of endite 4 includes many stout hook-like spines (for details see Fig. 8B). The posterior limits of the grid setae, which do not cover the apparatus seen here, are seen to the left (anterior) of the illustration. Scale bar 100 Mm. B, details of the distal endites of trunk limbs 9 and 10 seen at greater magnification. The fifth and fourth endites of limbs 9 and 10, seen face on, have a broad posterior 'margin', in each case provided with an armature of highly specialized spines of great diversity. On endite 5 the spines extend somewhat obliquely to facilitate the 'embracing' of masses of food material. Those of the anterior margin of limb 9 are scrapers that differ somewhat from orthodox scrapers and have hook-like tips. These perhaps serve to sweep and push rather than scrape surfaces, to which access is less easy than for anterior limbs, but their exact role cannot be defined. More distally and posteriorly are hook-like spines of various types and sizes that clearly drag in collected material or, in the case of very large distal hooks, retain it, and there are more hook-like spines internal to the scrapers. On endite 4, a dense and diverse array of hook-like spines and a few small denticulate spines are well suited to passing material proximally. The distal armature of endite 5 of trunk limb 10, while extending outwards so that the entire ensemble forms a scoop, is quite different. Whereas the distalmost spines can clearly scrape and sweep, their close companions bear diverging marginal rows of denticles, well suited to scooping and sweeping masses of material proximally to a region functionally continuous with endite 4, like which it is armed with a profusion of hooks. The large spiniform spines seen on the extreme right are of trunk limb 12. Much of limb 11 is here hidden between this limb and limb 10. These limbs also pass material proximally. Scale bar 50 Mm.