L.M.B.C. TURBELLAEIA. 68 



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 doul^tful. 

 Length .65 mm. Body truncate and slightly convex in 

 front with rounded projecting angles. Colour bright red, 

 due to the contents of the gut. The 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. Bijrsophlehs intermedia, v. Graff (PI. 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 hcdticus and 

 other forms in a coralline tide-pool near the Biological 

 Station, Port Erin. 



10. FroxenetesflahelUfer, Jens. (PI. 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 

 X^resent 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- 



