Cysticercus from a rare Dolphin. 421 
forming a shallow cup. At the anterior end of each 
bothridium there is a small rounded muscular « accessory 
sucker” (tig. 3, S.). The apex of the scolex bears a slight 
papilla (“ myzorhynehus’ *) (fig. 3, P.), but there are no 
hooks of any kind. ‘The scolex measures about 0°5 mm. in 
length and about 0°25 mm. in width at the level of the 
accessory suckers. ‘lhe bothridia, including the accessory 
suckers, are about 0°3 mm. long, the diameter ‘of the accessory 
suckers themselves being 0° Imm. The neck, in a well- 
advanced specimen, measures 0*2 mm. in thickness and is of 
very nearly the same diameter throughout its length, though 
slightly widened here and there. 
The histological structure of the animal presents some 
features of interest, ‘Ihe wall of the external “ bladder,” as 
has been mentioned, is greatly thickened, especially on two 
opposite sides. ‘The groundwork of this thick envelope con- 
sists of loose parenchymatous tissue, with a few scattered 
muscle-fibres. There is a slight concentration of these 
towards the periphery, as seen in transverse sections, forming 
a vague circular layer. Externally the surface is covered 
with a delicate cuticle, immediately below which there is a 
thin coat of circular muscle-fibres, followed again by a thin 
coat of longitudinal muscles. 
The parenchyme i is densely crowded with calcareous bodies, 
showing the usual concentric structure. In addition to these 
there are immense numbers of. fat-cells, each enclosing a 
large globule of fat. This fat is so abundant that it at first 
hindered the preparation of satisfactory serial sections, as it 
was found that a layer of it, partially dissolved out of the 
tissues by the xylol used in ‘the process, was formed round 
the object when embedded in paraffin in the usual way. 
This difficulty was found to be easily overcome by a short 
immersion in ether before clearing. The fat-cells were very 
beautifully demonstrated by staining thin shavings of the 
parenchyme with Sudan IIT. and mounting in glycerine. 
The parenchyme of the bladder-wall also contains numerous 
branching excretory vessels with delicate walls. These 
empty eventually into.a wide and sinuous excretory canal, 
opening to the exterior by a minute pore at the posterior end 
of the bladder, This pore is, in some cases, just visible to 
the naked eye. 
The structure of the long “ neck” shows the same layers 
as have been described for the bladder, but in the reverse 
order, and they may be seen to pass over from one to the 
Ave & Mag. N. Hist. Ser. 9. Vol. iii. 28 
