SOME LITTORAL OLIGOCHATA OF THE CLYDE. 35 
It may be mentioned that it is about as long as broad, is somewhat narrower behind 
than in front, and is slightly indented posteriorly. It is contained in segment 1. 
With regard to the genital organs, only certain points in connection with the 
atrium and spermatheca need be considered. ‘The atrium, according to Bennam, shows 
a division into two parts, which he distinguishes as glandular and non-glandular, of almost 
equal extent, the lining cells of the first part being cubical and vacuolated, as if a 
secretion had been discharged, while the cells of the second part are flat. In my 
specimens also, two regions are to be distinguished; but the first region is very much 
less extensive than described by Benuam, and extends only for a very short distance 
on both sides of the entrance of the prostate; the prostate enters the atrium almost 
immediately beyond the ending of the vas deferens (cf. Bennawm’s fig. 18), and the 
glandular cells extend about equally on both sides of this point. In character these 
cells are tall and filled with deeply staining granules, but not vacuolated. 
The spermathecee present an external portion, narrowing gradually towards the 
aperture, with a vertical position in the segment, and a long, more dilated, sausage- 
shaped cavity, bent into a number of curves; the whole being either confined to 
seoment x., or extending forwards into ix., or backwards to the level of xii. This second 
internal and far more extensive portion is, in my specimens, lined by tall columnar cells 
of large size, extensively vacuolated ; the vertical portion, or duct, in extent about half 
the vertical diameter of the segment, is lined by more solid-looking smaller columnar 
cells, the outlines of the individual cells being often indistinguishable. 
Marionina senufusca (Clap.). 
This worm was first described in 1861 by CuaparépE (3), who discovered it in the 
Hebrides. His account deals almost entirely with the reproductive organs; beyond 
this it includes only a few short statements as to size, colour, nephridia, and coelomic 
corpuscles. SOUTHERN (13, 14) has recently recorded the same species in both Ireland 
(Dublin Bay) and Scotland (Dalmeny, where the specimens were collected by Evans), 
and has given (14) further particulars of its anatomy. The following account deals 
principally with points which have not yet received detailed attention. 
The worms were found at Fintry Bay, about high-water mark, under moist stones, 
at a place where fresh water was running to the shore; and subsequently at Balloch, in 
a similar locality. 
Length 16 mm. Segments forty-two. Colow light red, whiter in front of the 
clitellum. Both ends blunt; head-pore at the junction of prostomium and segment i. ; 
clitellum embracing segments xii. and xii. 
The setx are of the same character throughout, in both dorsal and ventral bundles. 
They are slightly curved in a J-shape, the distal curve, however, being much less in 
extent than the proximal, which is a long, gentle sweep ; they are comparatively slender, - 
and pointed at both ends (fig. 2). In number they are, in front of the clitellum, 
