466 WwW. A. HASWELL. 
PLATE 26. 
Fie. 13.—Horizontal section of Heterocherus showing a considerable 
part of the ventral nerve-plexus. Facsimile of photograph. 
Fie. 14.—Part of a similar section to that represented in Fig. 12, more 
highly magnified. 
Fic. 15 a.—Small sperm. x 1500. 
Fie. 15 6.—Head end of giant sperm. x 1500. 
Fic. 16.—Horizontal section in the plane of the ovaries, the burse, and 
their ducts. Facsimile of photograph. 
Fic. 17.—General view (semidiagrammatic) of the left bursa seminalis with 
its duct and the antrum femininum. 
Fig. 18.—Section through one of the chitinous mouth-pieces with its bulb 
and the wall of the bursa seminalis. From a horizontal section of the animal. 
x 700. 
Fic. 19.—Lateral view of some of the chitinous elements of the mouth- 
piece in their natural relations. 
Fig. 20.—Isolated chitinous elements of the mouth-piece. 
Fig. 21.—Approximately sagittal section, showing Laurer’s canal (2). 
Facsimile of photograph. 
Fie. 22.—Sagittal section, showing the relation of Laurer’s canal in another 
specimen. Here the canal shows no distinct lumen, but its course is clearly 
indicated by the arrangement of the histological elements between the dorsal 
aperture (w) and the antrum femininum (azé). 
Fig. 23.—Section through the fertilised ovum passing somewhat obliquely 
through the first cleavage spindle and through one of the polar bodies. 
xX 330. 
Fic. 24.—Portion of a section through unfertilised ovum, showing appear- 
ance of chromatin elements after formation of polar bodies. x 600. 
PLATE 27. 
Vig. 25.—General view of the organisation of Anomaloceelus, seen from 
the ventral aspect. ‘Lhe testes and the vitelline glands are not represented. 
Xx 45. 
Fic. 26.—Vertical section of the integument, showing transverse sections 
of some of the epidermal capillaries. Facsimile of photograph. 
Fie. 27.—Vertical section through the epidermis. x 1500. 
Fig. 28.—Portion of a horizontal section of the epidermis. Facsimile of 
photograph. : 
