60 DR J. STEPHENSON ON 
ante-clitellial, and two or three post-clitellial. Im length the sete of the posterior 
part of the body appear to be, on the average, rather longer than those of the 
anterior ; the longest may measure up to ‘1 mm. The bundles are replaced during 
the life of the animal (fig. 13); thus there may appear to be eight setee in a bundle, 
but of these one group of four will be immature, wanting the proximal hooked 
end. 
The alimentary tract (Pl. IL. fig. 16), with its appendages (septal glands, pepto- 
nephridia), corresponds with previous descriptions, except that I have not found, as 
GoopricH states for his form, the last pair of septal glands smaller than the others. 
The dorsal vessel may take its origin from the intestinal sinus in segments Xiv., xv., 
Xvi, Xvii., or xviil; the lateral commisswres may be four in number, in segments ii., iil., 
iv., and v., but I am not satisfied that this number and arrangement are constant. 
The blood is colourless. | 
One kind of lymph corpuscles only is mentioned by MicHaELs—EN—flat, oval, or 
pear-shaped cells, nucleated, with a large nucleolus ; GoopRiIcH mentions three kinds, 
and gives a detailed description of each. In my specimens I noted two forms of 
ccelomic corpuscles—one granular, flat, irreeularly pear-shaped or oval, and nucleated, 
corresponding to MicHAELSEN’s description ; the other spherical or irregular, not 
flattened, homogeneous, more refractile than the first type, apparently not nucleated 
and not so numerous as the first kind. These may perhaps correspond to the first type 
of coelomic corpuscle described by GoopricuH. 
The cerebral ganglion lies in segment 1., attached to the dorsal wall of the buccal 
cavity ; it is one-and-a-half times as long as broad when the head is extended ; its 
posterior border is convex or flattened. The two authors already quoted both found 
it to be slightly dented behind. A pair of spots occur near the posterior margin of the 
ganglion, dark by transmitted light. They were often very large and conspicuous, 
and sometimes contained a few refractile particles besides the usual granular matter 
of which they seemed to be made up. They were not always quite symmetrically 
placed (Pl. II. fig. 16). 
There is a well-marked tubular cavity dorsally in the substance of the ventral 
nerve-cord all through the clitellar region, and for some distance in front of this ; 
it splits up into several smaller tubes in the region of the last septal glands, and 
some of these tubes can be followed for some distance farther towards the head. 
The funnels of the vasa deferentia vary much in shape; when the animal stretches 
itself out, they may be seven or eight times as long as broad ; ordinarily they are perhaps 
about five times, and sometimes may appear as little as three times as long as broad. 
The vasa deferentia may extend backwards as far as seement xxi. The vesiculx seminales 
are constituted by a bulging forwards of septum +2; thus masses of spermatozoa are 
seen to surround the cesophagus in segments x. and x1,, or ix., x., and xi. 
The shape of the spermathecxw deserves mention, since it differs from that described 
by the two authors previously quoted. Thus MicHantsen’s figure shows the cavity of 
