ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 761 



anterior sucker, terminal or sub-terminal, leading into a vestibule or 

 pre-pharynx, into -which opens the pharynx. Posterior sucker relatively 

 small, and without radial thickenings or chitinous hooks. Intestine 

 with two branches, and without lateral diverticula. Genital opening 

 common, in the middle line immediately behind the pharynx. Vagina 

 single and unpaired, opening on the ventral surface to the left of the 

 common genital aperture. Testis single. One to two millimetres in 

 length." 



The author also records KoeUilceria filicolle (Rudolphi) from the 

 branchial arches of a Ray's Bream from the Menai Straits. The two 

 sexes occur together in one cyst, the males filiform, the females with a 

 filiform anterior portion and a kidney-shaped posterior portion. From 

 a very large Ray the leech Pontobdella Isevis (Blainville) is reported. 



Two-fold Function of Ovaries in some Polyclads.* — Paul Hallez 

 finds that many Antarctic Polyclads have no accessory glands on the 

 oviducts and a relatively small number of ovaries which are, however, 

 very large. Each ovary includes two portions, a ventral germinative 

 zone and a dorsal region which is secretory. The product of secretion 

 recalls that of the accessory glands of the oviducts and uterus in other 

 Polyclads. 



Regeneration in Short Head-pieces of Planaria.f — V. H. Keiller 

 has experimented with Planaria simplicissma. It seems impossible to 

 determine to what extent heteromorphic head-regeneration may occur. In 

 general, however, about 80 p.c. of the heads formed new heteromorphic 

 eyes and about as many new brains. 



The regenerating head-pieces often showed scattered pigment spots, 

 especially when no true eyes are regenerated. A pharynx may be re- 

 generated if the brain is cut near its posterior limit, and always if the 

 cut is made behind the brain. Unless the brain is cut no heteromorphic 

 brain nor eyes are found ; but head-pieces in which the brain is cut do 

 not necessarily form brain or eyes. 



The heteromorphic brain may be formed (1) by regeneration in close 

 connexion with the cut ends of the old brain, and probably under their 

 influence ; (2) by regeneration of a new brain separated from the old, 

 and connected with it by short cords ; and (3) by thickening of the 

 commissure nearest the cut ends. 



Heteromorphic eyes are usually paired if they develop at all. They 

 are rarely in the normal position. Heteromorphic brains of any of the 

 three types may occur in the absence of one or both eyes ; heteromorphic 

 eyes may occur in the absence of any trace of brain regeneration. Hetero- 

 morphic heads differ from normal heads in the extent and shape of the 

 digestive tract, which occupies almost the entire new region. 



Nemertines of Millport. J — J. Stephenson reports on these, de- 

 scribing Amphiporus elongatus sp.n., and Micrura scotica sp. n., and 

 adding useful notes on ten others, with particular reference to their 



* Comptes Rendus, cliii. (1911) pp. 142-3. 



t Arch. Entwickl., xxxi. (1910) pp. 131-44 (23 figs.). 



% Trans. R. Soc. Edinburgh, xlviii. (1911) pp. 1-29 (1 pi.). 



