ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 25 



Structure of Asymmetron bassanum Gunther.* — Esther R. Morris 

 and Janet Raff describe this species of lancelet which is not uncommonly 

 met with at depths up to twenty fathoms in certain rather restricted 

 areas along the Victorian coast. The average myotome formula is 

 44, 17, 14 ; at the anterior end there is always an incomplete ring of 

 pigment, the oral cirri are 24 to 26 in number, and bear sense-papillae, 

 the ventral fin is divided into fin-chambers, the gonads are in a single 

 series on the right side and vary in number from 25 to 30. Beyond the 

 atriopore the atrial cavity is continued back and divides into two caeca 

 surrounding the intestine, and separating the ccelom from the body-wall 

 except on the ventral surface. This paired post-atrioporal caecum is 

 distinctive. 



Relation of Entozoa to Bacterial Disease.f — A. E. Shipley dis- 

 cusses a case of the Nematode CystidicoJa farionis in the swim-bladder 

 of some rainbow trout, where it seems clear that the Nematode, in 

 piercing through the intestinal wall, traversing the intermediate tissues, 

 and entering the swim-bladder, had inoculated that organ with bacterial 

 disease. He cites other cases of a similar sort, which suggest that the 

 Entozoa in our digestive organs may be playing a part similar to the 

 biting and piercing Ectozoa, as disseminators of microbes. 



Tunicata. 



Australian Tunica tes.J — H. Leigh ton Kesteven describes a number 

 of new forms. A new genus Sidneioides combines the characters of 

 Sidnyum and Polyclinwn ; in general features it closely resembles both, 

 differing from the former and resembling the latter in having the wall 

 of the stomach smooth ; and resembling the former and differing from 

 the latter in the absence of an atrial languet. 



INVERTEBRATA. 



Mollusca. 

 a. Cephalopoda. 



Beaks of Fossil Cephalopods.§ — Alfred Till finds that it is possi- 

 ble to distinguish fossil Nautilus-beaks from others which are " not- 

 Nciidilm,' 1 ' 1 and even to distinguish a few " genera " of beaks. 



/3. Gastropoda. 



Development of Pulmonary Cavity in Slug.|| — Paul Heyder has 

 studied the development of Avion empiricorum Fer. var. rufus, with 

 special reference to the pulmonary cavity. He also discusses the primi- 

 tive kidney, the definitive kidney, the heart, and the pericardium. The 

 primordium of the pulmonary cavity appears before there is any hint of 

 the mantle fold. The branchial cavity of Prosobranchs is a deep 

 insinking of the mantle groove ; branchial cavity and pallia! cavity are 



* Proc. R. Soc. Victoria, xxii. (1909) pp. 85-90 (3 pis.). 



t Journ. Econ. Biol., iv. (1909) pp. 61-71 (1 fig.). 



X Proc. Linn. Soc. N.S. Wales, xxxiv. (1909) pp. 276-95 (3 pis.). 



§ Vein. Zool. Bot. Ges. Wien, lix. (1909) pp. 123-9. 



|| Zeitschr. wiss. Zool., xciii. (1909) pp. 90-156 (3 pis. and 6 figs.). 



