50 DR J. STEPHENSON ON 
This species has a very distinctive appearance, and can be immediately recognised 
by its stout form, active, wriggling, nematode-like movements, and especially by its green 
colour. 
The position of this species with regard to the sete has been discussed above, 
where it was shown that it holds, in this respect, an intermediate position. The lobed 
testes and the large compact penial bulb, however, determine the decision to place 
it in the genus Lumbricillus. 'The importance of this last feature, the penial bulb, 
in classification, has lately been insisted on by Eisen (4), who distinguishes two sub- 
families, Lumbricilline and Enchytrxine, according to whether the penial glandular 
structures are or are not confined within a single bulb; in the Lumbricilline are 
included Lumbricillus, Marionina, Buchholaa, Stercutus, Bryodrilus, Henlea; in 
the Enchytreine, Hnchytreus, and Michaelsena. 
The ‘Bauchmarkdriisen’ are also a feature of the genus Lumbricillus. In the 
present species they are widely distributed, occurring throughout the whole of the 
anterior part of the body, but are small in size, and are only recognisable as such 
from the character of their cells as seen in sections. This comparatively undifferentiated 
condition may be contrasted with that which oceurs in Lumbricillus subterraneus, 
where the glands, though few in number, are individually large and prominent. 
In a number of species in which the aperture of the spermathecal duct is surrounded 
by gland-cells, the muscular layer of the body-wall is continued between these cells, in 
the manner described and figured for Lumbricillus tuba (v. ant.; also cf: Enchytreus 
albidus, post.) ; when, following the duct inwards, these gland-cells give place to the 
ordinary epithelium of the duct, we find, however, that the muscular layer is usually to 
be found outside the duct epithelium. In this species, however, the muscular layer is 
still to be found amongst and between the duct epithelium, having the same relations 
here as near the aperture. 
Enchytreus nodosus, n. sp. 
Found at Wemyss Bay, near high-water mark, where fresh water ran to the shore. 
Length 4 inch (8 mm.); small and thin, not tapering at either end. In colowr the 
animals are intensely white over part, especially the posterior part, of their extent, but 
clear and transparent for the rest ; there may be only irreeularly distributed white spots, 
or, as commonly, the posterior half of the body has intensely (opaque) white margins ; 
this opaque white coloration is due to ageregations of ccelomic corpuscles. Under the 
microscope the animal is, except for these aggregations, extremely transparent ; and the 
clitellum, which extends over segments xii. and half of xiii. (to the level of the sete of 
the latter), is hardly less transparent than the rest of the body. Segments thirty-two 
to thirty-nine. 
The set# are of the straight type, with proximal hook (fig. 8, a); the sharpness of 
this hook varies, and in certain cases there is a faint indication of a double ({-shaped) 
curvature (fig. 8,b). Sete are absent (both ventral and lateral) in segment xi1.; elsewhere 
