tO" ON THE ANATOMY OF MEGASCOLIDES AUSTRALIS, 
clear spaces surrounded by a granular non-staininge material; towards the base of 
each can usually be detected a nucleus pushed to one side. These goblet cells push 
aside the others, only parts of which are hence sometimes cut in section. The 
internal ends of the columnar cells cannot generally be clearly made out, as they 
appear to run into a kind of thick basement membrane, in which nuclei (n.) are often 
seen. Into this membrane, and thus amongst the bases of the columnar and goblet 
cells penetrate numerous branches of blood-vessels (bv.) These vessels actually 
penetrate between the epidermis cells, and, though unfortunately not shown in the 
figure, form small coils amongst the cells reaching nearly to the surface. Internally 
to the epidermis is the usual layer of circular muscle fibres (Plate 2, fig. 6, and plate 
4, fig. 18.) On its external aspect, the fibres are thinner and more loosely arranged 
than internally, as they are also in sections of Lumbricus ; they are also thrown into 
much more strongly marked folds than is the case with the internal fibres, which are 
thicker and somewhat closely packed together. Great numbers of blood-vessels — 
branch amongst the fibres. 
The layer of longitudinal muscles is, seen in transverse section, much deeper 
than that of the circular ones, and is again much more strongly developed ventrally 
than dorsally. The fibres differ considerably from those of Lwmbricus, not presenting 
that definite arrangement of the strands resembling branches on each side of a series 
of radially placed stems of connecting tissue, which is so characteristic of Zwmbricus. 
In Microcheta rappi* there is apparently no gathering of the longitudinal fibres 
into groups, whilst in Megascolides we meet with a form intermediate between the 
two extremes seen in Microcheta and Lumbricus. The strands (musc., long.) are 
first of all gathered into smaller groups of 3-12, surrounded by connective tissue 
(ct.), and these smaller groups are again gathered into much larger and irregular 
ones, separated from each other by radial strands of connective tissue passing from 
the circular muscles, inwards to the body cavity. Along these breaks, between the 
muscles, pass blood-vessels and the ducts of the numerous nephridia to be described 
later on. 
The strands are also, as in Zumbricus, angular and not rounded in section. 
Internally again to the muscle layers is a distinct layer of connective tissue, from 
which strands of tissue of a homogeneous appearance may be seen radiating into the 
body wall amongst the muscles (ct.), and within this is the epithelium, the irregularly 
shaped cells of which line the body cavity, becoming modified in various parts. 
In the second—the clitellar region—the skin is much modified as usual, but 
differs in structure from that in Lumbricus or in Microchetat as recently figured by 
BENHAM. 
* BennamM. Q.J.M.S. (Plate 16, bis., fig. 39.) 
+ Op. Cit.—For the description of that in Zwmbricus I have not been able to consult the original paper 
of CLAPAREDE, and so have taken advantage of the description quoted by Mr. Benuam. 
