46 DR J. STEPHENSON ON 
characteristic appearance of the spermathecz in the fresh specimen, by which this form 
is easily identified, has been alluded to. 
Since the form and relations of the spermathece and their ducts are among the 
most valuable characters for the discrimination of species in this group, it would seem 
advisable to separate this form under a special name ; the designation tuba is meant to 
refer to the trumpet-like appearance noted above. 
Iumbricillus viridis, n. sp. 
Found at Wemyss Bay, under stones below high-water mark, where fresh water was 
running to the shore. 
Length 1 inch; the worm is stout, with a tapering anterior end. All but the 
anterior part of the body is of a green colowr, due to the alimentary canal. They are 
active animals, and exhibit nematode-like contortions. Segments forty-five to forty-nine. 
The prostomium is bluntly conical. Numbers of hyaline cells are found in the 
superficial epithelium, arranged in fairly regular transverse rows over the whole extent 
of the body, most regular in its posterior part. 
The setz are in the usual four rows, two ventral and two lateral. They are straight, 
or almost straight, with a slight and usually gentle curve at their proximal end. Their 
points, especially on the anterior part of the body, are often blunt; indeed the ends 
may be almost square, with rounded corners; posteriorly sharper points are common. 
They are arranged fan-wise in the bundles; all the setee of a bundle are not of the same 
length, but while in the ventral bundles the.imner (ventral) are shortest, in the lateral 
bundles the shorter setze are those on the dorsal side of the bundle. Thus in a bundle 
of seven ventral sete, in the anterior part of the body, the lengths of the individual 
setee, from the outer to the inner, were ‘105, °105, °105, (09, °085, °078, ‘066 mm. ; 
in another bundle, similarly, ‘112, -112, :105, ‘10, 095; ina lateral bundle situated more 
posteriorly, the lengths of the setee, beginning with the ventralmost seta of the bundle, 
were ‘090, ‘08, ‘075. 
The average leneth of the setee is therefore about one-tenth of a millimetre, longer 
ones occurring in the anterior part of the body ; their thickness is about ‘005 to 0045 
mm. The number of sete per bundle is five, six, or seven in the ventral series in front 
of the clitellum, three or four posterior to this; there are no ventral sete on segment 
xii. The lateral setee are four or five, exceptionally three, in a bundle in front of the 
clitellum, two or three behind this. 
Notwithstanding the fact that the setee have been described above as straight or 
almost straight, | believe that the majority of them are to be considered as slightly, 
though very slightly, {-shaped. It is perhaps allowable to dwell for a moment on this 
point, since the genus Lumbricillus, in which the present form must, I think, be in- 
cluded, has {-shaped setee, and straight setee would be a curious anomaly. 
Fig. 6, a, representing a bundle of seven setze from an anterior segment, and drawn 
