110 FLABELLIGERA AFFIOTS. 



globate glands and De Quatrefages hairs. De St. Joseph again was of opinion they 

 might perform both functions (sensory and glandular). The living animal is certainly 

 endowed with great sensibility, and apparently these organs are largely connected 

 therewith. 



This form likewise has a heart-body, Cunningham 1 figuring it in sections as a 

 fimbriated cellular process. 



The body, which is about three inches long, and has from thirty to forty-five bristled 

 segments, is somewhat fusiform, tapered a little anteriorly to the base of the fan of 

 bristles, and much more gradually posteriorly where it ends in a vent at the conical tip, 

 the bristles and papillse in the most perfect examples projecting slightly beyond it. In 

 life it appears to be enveloped in a transparent and slightly milky gelatinous investment 

 which just allows the tips of the bristles to protrude beyond it, and this is studded with 

 minute oval specks— the papilla. The colour is brownish-green anteriorly with a central 

 streak of reddish-brown in some, darker brown in others, the margin being greenish or 

 bluish, then pale green in the central line with a similar margin on each side posteriorly. 

 On every segment for three-fourths of the length are several groups of white grains. 

 Some have a fine translucent bluish shade— due to the bluish specks in the gelatinous 

 investment. The branchiae are green, and the palpi yellowish or orange (yellow or 

 roseate, De St. Joseph) and when the annelid is immersed in spirit it gives the fluid a 

 rich brownish tint. 



In life, when the anterior fan or collar is expanded, a series of ciliated green branchiae 

 appear dorsally in two groups (twenty to twenty-five in each) and the two crenated palpi 

 with their ventral groove, both fixed to the central process, which has the dark mouth in 

 the centre. A broad collar from the dorsal margin of the process gives origin to the 

 branchiae, that is, they spring from its edge, whilst in the middle line the tongue-shaped 

 process passes dorsally between the dense lateral groups of branchise, the other or broad 

 end joining the fillet around the mouth in the centre ventrally. This tongue-shaped 

 process has a narrow lateral band which runs from the base to the tip on each side, and a 

 median band in 8. diplochaitos, which, as De St. Joseph states, shows differences, probably 

 the " two levres ventrales retractiles " of this author. Two ovoid elevations occur below 

 the mouth, one on each side, and then, ventrally and externally, are the palpi with their 

 deep ventral grooves. The whole apparatus recalls the complex oral region of Phoronis, 

 and probably similar functions are performed by the various parts, especially by the 

 palpi. 



The mouth itself is surrounded by a dark brown pigment-ring, apparently a rudi- 

 mentary dental apparatus, the brown deposit being arranged in semicircles and isolated 

 patches. 



Anteriorly the dorsal and ventral bristles of the first foot are modified to form on 

 each side a beautiful vertical fan of pale resplendent bristles which support a granular 

 membrane like a web, the whole now and then assuming the form of a horse-shoe. They 

 are so arranged that the longer bristles in each are lateral, the groups ending in a 

 gradually diminishing series dorsally and ventrally, yet the longest are beneath the 

 middle of the series. A long, acutely triangular gap on each side as far forward as the 

 1 'Quart. Journ. Micr. Sci./ vol. xxviii, N.s., pi. xix, fig. 20, 1888. 



