s 
ON A NEW SPECIES OF ENTEROPNEUSTA, 
as yet in doubt. The large female with its attendant small males 
is usually found in a very prominent tubular enlargment of a part 
of the free edge of one of the genital wings. 
Anatomy. 
Proboscis : The epidermis of the proboscis (fig. 5, ep.) is some- 
what thicker than in the case of Pt. minuta measuring '11 mm. 
It is separated from the underlying musculature by the limiting 
membrane, composed of two layers, the outer attached to the 
nerve fibre layer of the epidermis, the inner to the circular 
muscular layer. Between these two layers run the capillaries of 
the vascular net of the proboscis (fig. 5, cnp.). Below the limiting 
membrane is the thin layer of circular muscle fibres, also some- 
what thicker than in the case of Pt. minuta, viz., -023 mm. The 
circular muscular layer gradually becomes thinner towards the 
neck of the proboscis, and finally thins out altogether. The 
delicate membrane limiting the circular muscular layer internally 
can readily be recognised especially in horizontal sections. On 
the inner side of the membrane, and at a little distance from it, 
there is an irregular cell layer, the nuclei of which are very 
distinct in hematoxylin preparations. 
From the outer side of this limiting membrane there pass 
through the circular muscular layer numerous fine fibres to the 
inner layer of the limiting membrane of the proboscis, while on 
its inner side the fibres of the longitudinal musculature are 
inserted. 
The fibres of the longitudinal musculature are related in their 
mode of origin from the proboscis base and in their course from 
there exactly as in Pt. minuta, and they show the same separation 
in preserved specimens into radial masses (fig. 5, lm.). The 
muscle fibres are embedded in a very fine connective tissue which 
anterior to the proboscis organs occupies the central region of the 
proboscis, muscle fibres being there absent. The connective tissue 
here presents a spongy appearance with a few very small nuclei 
situated in the course of the connecting strands or in the angles 
between the meshes. The splanchnic epithelium of the proboscis 
