ZOOLOGY AND BOTANY, MICEOSCOPY, ETC. 223 



epidermis that plays the chief genetic r61e. The whole process of bud- 

 ding and scissiparity is discussed in detail. 



Individuals which are becoming sexual continue to bud and to re- 

 produce by scissiparity until they are mature. In Chaetogaster the 

 asexual process continues during the reproductive period. Every zooid 

 separated by budding from a sexual individual is also sexual, and the 

 genital primordia in the zooid are developed in proportion to the state 

 of gonadial development in the parent. The reproductive period does 

 not end in death ; the gonads retrogress, and the posterior end of the 

 body begins or continues to bud off new segments. Epigamic pheno- 

 mena are most marked in those Naidomorphs that live in favourable 

 conditions of life. 



Structure of New Species of Branchellion.* — W. Harold Leigh- 

 Sharpe describes Branchellion australis sp. n., from a skate caught at 

 Port Victor, South Australia. There are thirty-one pairs of gills, instead 

 of thirty-three in B. iorpedinis, the pigmentation is different, and there 

 seem to be no eyes, whereas B. torpedinis has six. It may be noticed 

 that respiration is carried on not only by the foliaceous branchise, but 

 also by rounded vesicles protruding from the abdominal portion of the 

 body. " Vesicles are common in other genera, and I have seen them 

 rise and fall by pulsation in CalUohdella lophii. They receive lymph, 

 which after aeration is returned to the lateral sinus, so that respu'ation 

 is lymphatic." The author contributes some interesting sections. 



New Ichthyobdellid Parasite.f — Charles Badham describes Austroh- 

 della translucens g. et sp. n., a small transparent leech, a fatal parasite 

 on the fins of the sand-whiting (Sillago ciliata) in New South Wales. 

 There are well-defined neck and body regions ; the body is cylindrical 

 in the young, much flattened in the adult ; the lateral parts of the body 

 below the clitellum bulge out and form a shoulder-like appearance ; a 

 somite has six annuli ; there are no pulsating vesicles, their place being 

 taken by a continuous contractile lacuna placed on either side outside 

 the body musculature ; there are dorsal and ventral median lacunae, 

 communicating by segmental lacunar ; there are three pairs of pouches 

 in the thick-walled intestine, and a fourth pair is represented by a 

 flexure of the gut ; there are five pairs of testes ; there is one pair 

 of eyes. 



Platyhelminthes. 



Bilharziosis.l — R. T. Leiper makes another contribution to his 

 study of vesical and intestinal bilharziosis. Haamaturia occurs in not 

 less than half of the total population of Lower Egypt. The bleeding is 

 due to erosion of the mucous membrane by innumerable minute hard- 

 shelled eggs, which are made to move by the contractions of the 



* Trans. R. Soc. South Australia, xl. (1916) pp. 42-55 (9 figs.), 

 t Quart. Journ. Micr. Sci., Ixii. (1916) pp. 1-41 (2 pis. and 6 figs.), 

 i Proc. Roy. Soc. Med., ix. (1916) pp. 145-72 (25 figs.). See also Bull. Inst. 

 Egyptien, x. (1916) pp. 217-27. 



