L.M.B.C. TURBELLARIA. aS 7/ 
Schmidt’s description did not include the genital organs, 
and since these afford the most distinctive features, the 
systematic position of this species has long been doubtful. 
Length .65 mm. Body truncate and slightly convex in 
front with rounded projecting angles. Colour bright red, 
due to the contents of the gut. ‘Phe eyes are very striking 
owing to the comparatively large size of the lens. The 
pharynx is sub-central. The copulatory organ has the 
form of the tool known as a ‘“‘ rose-bit”’ or ‘‘ countersink.” 
For further description of this and other species included 
in this paper, see my memoir on “ British Marine Tur- 
bellaria,’’ in the forthcoming number of the “‘ Quarterly 
Journal of Microscopical Science.” 
9. Byrsophlebs intermedia, v. Graff (Pl. XII, figs. 17, 18.) 
Length 5 mm. Body flattened, yellowish-white, rounded 
in front, bluntly pointed behind. The feature which dis- 
tinguishes this species from the closely allied B. graffi, 
Jensen, is the elongate form of the penis, the basal part 
of which is composed of the granule-vesicle strengthened 
by spiral muscles. The distal part is enclosed in a funnel- 
shaped copulatory-organ ending in a rounded aperture, 
from the margin of which a chitinous spur is given off. 
This species occurred along with Provortex balticus and 
other forms in a coralline tide-pool near the Biological 
Station, Port Krin. 
10. Proxenetes flabellifer, Jens. (Pl. XII, figs. 14, 15, 16.) 
This species has the form of a fine white thread the 
advancing end of which is kept in continual, sensitive 
motion above the substratum. The hinder end is provided . 
with well-developed adhesive papillae which are speedily 
used at the slightest provocation. The rhabdites are 
present in large numbers in this genus, forming a pair of 
extensive and well-marked tracts converging between the 
eyes to the anterior end. The copulatory-organ is retort- 
