30 A C. OUDEMANS. 
directed upwards ; a few sections further backwards this little 
arch becomes larger, sending two horns downwards; again, a 
few sections further and the circular muscular layer is closed. 
Meanwhile we see within the little arch the beginnings of the 
lacune, for there are more than one, all situated against the 
circular layer, so that when this is closed there is also a circular 
arrangement of the lacunz, which of course are all more or 
less triangular, with their bases against the circular layer and 
with their tops turned towards the centre (fig. 53). The 
lacunz are separated from one another by transverse muscular 
fibres, which not only take their course from the one side of 
the circular layer to the other, so that they form in the centre 
a median chord, transversing each other in all directions, but 
which also extend further outwards than the circular layer, so 
that they appear to run radially from the centre to the skin. 
I seldom saw any communication between the lacunee whenever 
a transverse band was partly absent. As in Carinoma longi- 
tudinal muscular fibres also took part in the limitation of these 
lacune, being placed both against the circular layer and against 
the transverse muscular bands, and also in the angles of the 
triangular lacune. Even between the transverse fibres of 
the bands, as in Carinoma, longitudinal fibres occurred. 
However, the blood did not directly bathe these fibres, but was 
separated from them by a richly developed beautiful epithelium 
of small round cells with relatively large granular nuclei as in 
Carinoma. On a sagittal section (fig. 67) going from above 
downwards we find the circular muscular layer (not indicated 
in the figure), a few longitudinal fibres, epithelium, lacuna, 
epithelium, longitudinal fibres, then the chord or cylinder of 
transverse fibres, and then the same arrangement in inverse 
order. 
Where the epithelium cells were present in large numbers, 
the very thin and nearly colourless hyaline basal layer was 
not visible. It was clearly seen where the epithelium was 
torn off. 
Though we cannot say that in Carinoma the opening of 
the proboscidian sheath is not wholly terminal, yet in Valen- 
