52 SUMMARY OF CURRENT RESEARCHES RELATING TO 



ago in the spiral valve of the hammerhead shark (Sphyrna sygcena) 

 which eats the Teleosts. Practical considerations are discussed at 

 some length. 



Egg-making in a Trematode.* — Edwin Linton gives a vivid de- 

 scription of the process of egg-making in Epibdella bumpusii, an 

 ectoparasite of the sting-ray (Basi/atis centrura). A mass of yolk leaves 

 the yolk-reservoir ; as it passes the germ-duct a germ is drawn out by 

 the suction ; yolk-mass and germ together pass along the common duct 

 to the ootype : an egg is moulded into a tetrahedral shape by a kind of 

 hammering action of the walls of the ootype, and a shell is formed from 

 substance secreted by the shell-forming gland ; a slowing-up of the 

 action of the ootype is followed by the appearance of a minute cluster of 

 sperms in the common duct ; this cluster of sperms comes from the 

 seminal duct, and passes along the common duct to the ootype ; a 

 momentary pause marks the arrival of the sperm at the ootype ; powerful 

 contractions of the walls of the ootype eject the egg from the uterus 

 into the water. 



Incertae Sedis. 



Nutritive Process in Tornaria.f — A. T. Masterman finds that 

 ingestion is effected by ciliary currents, the extra-stomial ingestion 

 being due to the circum-oral band and the ciliated walls of the vestibule, 

 the intra-stomial ingestion being effected by the cilia lining the pharynx. 

 The water of the ciliary currents is probably returned along the lateral 

 grooves of the pharynx, and then by the corners of the mouth to the 

 exterior. Digestion is intra-cellular in the stomach (digestive area), but 

 may also be inter-cellular — in the stomach, and in the intestine also. 

 Currents in the stomach and intestine are ciliary. The pylorus and 

 anus are worked by the rhythmic contractility of the surrounding walls. 



Swimming Habit of Japanese Enteropneust. J — Iwaji Ikeda 



observed in the Inland Sea, 50 miles east of Hiroshima, a sheet of 

 swarming Enteropneusts (Glandiccps haclcsii Marion), about a hundred 

 in a cubic foot, on an average about 8 cm. in length. The swarming on 

 the surface is said by the fishermen to occur on calm nights from 

 August to the beginning of September, but not every year. The post- 

 hepatic region is flattened, and the gut contained miicro-organisms 

 without sand. This species is probably a swimmer and a creeper, but 

 not a burrower. Perhaps it comes to the surface after micro-plankton, 

 for the swarming does not seem to have to do with sexual maturity. 



New. Genus of Fresh-water Bryozoa from Japan. § — Asajiro Oka 

 describes Stephanella Tiina g. et sp. n, which seems to be referable to the 

 Plumatellidae. There is a thin, branched, creeping stolon ; the zocecia 

 are cylindrical and upright ; the ectocyst is gelatinous and transparent ; 

 there is an epistome ; the lophophore has very short arms ; there are 



* Biol. Bull., xiv. (1908) .pp. 19-2G (5 figs.). 



t Quart. Journ. Micr. Sci., lii. (1908) pp. 481-93 (1 p\). 



% Armot. Zool. Japon., vi. (1908) pp. 255-7. 



§ Tom. cit., pp. 277-85 (1 pi.). 



s 



