BRITISH MARINE TURBELLABIA. 511 



in the latter. The granule-gland and copulatory organ 

 agree exactly in both species. Claparede figures large rounded 

 bodies which may possibly prove to be the accessory uterine 

 glands (Lang). 



Habitat. — On Laminaria, Lamlash Bay, Arran (Claparede). 



A more exact description of this species is necessary before 

 the specific identity or difference of Oligocladus sanguino- 

 leutus and auritus can be regarded as proved. It appears 

 fairly clear that they both possess the same generic characters 

 — the subterminal mouth, position of the genital pores, and 

 multiple uterine glands. No satisfactory points of difference 

 can at present be determined. On the contrary, it is notice- 

 able that it is just those organs which Claparede describes 

 accurately — the mouth, pharynx, and intestine, and the male 

 copulatory organ — which agree exactly with the corresponding 

 structures in O. sanguinolentus. 



Genus 34. — Stylostomum, Lang (1884). 



Body smooth. Tentacles rudimentary. Oral and 

 genital apertures open on acommon depression im- 

 mediately behind the brain. Main-gut with 5 — 6 

 pairs of secondary non-anastomosing branches. 

 The median anterior branch is absent over the 

 pharyngeal region. Male copulatory organ lies 

 under the anterior part, the female organ under 

 and behind the hinder part of the pharyngeal 

 sheath. Two uterine glands. Cephalic eyes few 

 in number. 



71. Stylostomum variabile, Lang. PI. XXXIX, fig. 1. 



? 1853. Planaria ellipsis, Daly ell (29). 



? 1865. Leptoplana ellipsis, Johnston (38). 



? 1875. „ „ Mcintosh (45). 



1884. Stylostomum variabile, Lang (54). 



1884. Stylostomum ? ellipsis, Lang (54). 



Length 5 — 9 ram. Body elliptical, broadly rounded 



