124 Transactions of the South African Philosophical Society. 
reticulations of the same colour. The disposal of the patches are some- 
what similar on each side of the body, and this similarity is further 
increased by the presence of two white lines, due to the absence of 
pigment, running longitudinally and parallel to each other along 
each side of the body. The upper begins at the anterior margin of 
the pleuropodia on a level with the rhinophora and runs parallel 
with the margin of the foot. The lower begins just behind the 
anterior tentacles, runs parallel with the upper line, and ends on the 
margin of the foot at a point a little in advance of the ending of 
the upper line. 
On the inside of the pleuropodia the colouration consists of dark 
dots forming a small margin which merges into reticulate markings 
towards the body where, at the base of the pleuropodia and on the 
region between the mantle and the rhinophora, it consists of a 
number of separate dots. The mantle is closely covered with such 
dots merging into short lines, the whole forming a general appearance 
of radiation from the shell aperture as a centre. On the siphon 
these take the form of dark patches and lines running longitudinally 
to it. The mantle cavity is devoid of colour, as is also the region 
opposite the gills in which the opaline gland lies. 
Systematic position.—The three species of the proposed genus 
agree in the peculiar position of the rhinophora, but they present 
several differences. P. piperata and P. Mouhoti differ from P. Lowzi 
in the much more posterior position of the mantle region, more 
oval body, and in having the genital aperture under the mantle. 
That all three agree in the free pleuropodia is not a fact of much 
significance, and P. Lowi differs from the other two in having the 
pleuropodia much more developed in a vertical direction. 
There is, then, only this one distinct point, viz., the position of the 
rhinophora, and that, though peculiar to the group, does not, in my 
opinion, justify the definite establishment of a new genus, though it 
may be convenient to retain it till some new light may be thrown 
upon this interesting group by further material for anatomical 
examination. 
Only one specimen has as yet been secured, and for this as well as 
other new specimens of marine life we are indebted to the members 
of the East London Angling Society, the president of which, Mr. 
Low, takes an active interest in the scientific aspect of the Society’s 
work. 
