162 
MR. H. N. MOSELEY ON THE ANATOMY AND 
to this zone is a broader zone darkly shaded, as being deeply stained with 
carmine, and consisting of dense circular muscular fibres. Externally to this 
the black dots represent a zone of longitudinal muscular fibres seen in section. 
Eollowing on this is a broad zone occupied by loose radiating fibres, then two 
irregular darkish lines, corresponding with a large quantity of glandular 
matter present in this region, and some slight circular fibres, succeeded by a 
zone (A) occupied by fine dots, representing longitudinal muscular fibres in 
section, which fibres lie in meshes formed by radiating and circular fibres. 
The structure of the extreme verge will best be comprehended by reference 
to fig. 9, in which this is represented much enlarged. 
A. Muscular zone referred to in the description of fig. 9. 
Fig. 9. Portion of the periphery of the foregoing section, much enlarged. Drawn with 
the camera. To the right hand is seen the external epithelium of the pharynx. 
A light line (A) follows this to the left, representing an apparently structure- 
less membrane, succeeded by a single row of very stout muscular fibres (L. m ). 
The remainder of the drawing represents the broad muscular zone (A) of the 
last figure, which is here seen to consist of a meshwork of radiating and 
circular fibres, in the interstices of which are stout longitudinal fibres in 
section. The circular fibres are more densely aggregated at the outer margin 
of the zone, and form a sort of special zone (i. c. m.). 
e. Epithelium. 
A. Structureless layer. 
L. m. Longitudinal muscular layer. 
i. c. m. Circular muscular layer. 
PLATE XIII. 
Fig. 1. Penis of Bipaliurn Diana within its proper cavity or sheath, as exposed in a lon- 
gitudinal section and in the plane of the body ; drawn with the camera. The 
penis (p) is seen to be conical in form; it is bent upon itself. Towards its 
pointed extremity may he seen the termination of its central canal, lettered d. 
Strong muscular fibres are seen passing into the organ from above to form its 
longitudinal muscular system ; between the interlacement of these fibres are 
spaces ( s ) which are lightly stained in carmine preparations, and are transverse 
sections of branched retractor muscles of the penis. 
The external circular fibres of the penis are faintly indicated. 
C. Cavity of sheath of penis. 
jp. Penis. 
d. Spermatic duct. 
s. Branched retractor muscles seen in transverse section. 
u. The same muscles seen in their longitudinal section. 
