ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 633 



Australian Bryozoa.* — In the new decade, wliicli completes tlie 

 first volume of the ' Prodromus of the Zoology of Victoria,' Professor 

 P. H. MacGillivray continues his valuable contributions on the Polyzoa 

 of Victoria. The present number deals with Retepora, a genus better 

 represented in the southern hemisphere than in the northern. Twelve 

 species are described and three varieties of the well-known Setepora 

 monilifera MacG., and besides the figures of these, one plate is 

 devoted to dra wings of the opercula, which in Professor MacGillivray 's 

 hands have proved of great value for specific determination. 



The preface is dated 1883, and the paper having been written 

 nearly two years, there is consequently some overlapping with this 

 and Ml". Busk's work on the ' Challenger ' Polyzoa. 



7- Brachiopoda. 



Anatomy of Crania.t — In continuation of a previous paper,| 

 M. Joubin describes further points in the anatomy of Crania. 



The shell is formed of extremely fine calcareous fibres ; it is 

 traversed by perforations spreading out, in the upper valve, in 

 arborescent ramifications, of which the final branches are attenuated 

 filaments terminating on the external surface. In the ventral valve 

 the perforations are only at the points where there are no muscular 

 insertions. The mantle is composed of two portions — an interior and 

 an exterior. There are three principal pairs of muscles, two of which 

 are adductors ; the less important muscles sustain the arms and 

 perform other functions. The arms are not supported by any calca- 

 reous loop. Eespiration is not eff"ected by any special organs, and 

 there is no circulatory system. The nervous system, as in Lingula, is 

 very poorly developed. 



Arthropoda. 



a. Insecta. 



Eye and Optic Tract of Insects.§ — Dr. S. J. Hickson, in the first 

 portion of his paper, gives a detailed account of the eye and optic 

 tract of Musca vomitoria, and afterwards discusses and attempts to 

 clear up the difierences between his results and those of other 

 investigators. 



The account of the eye of Musca is only intelligible when studied 

 with the aid of the accompanying illustrations ; in it the following 

 new terms are used : the opiicon is the ganglionic swelling which is 

 separated from the cerebral by a narrow constriction, which is, as 

 Beyer has shown, the homologuo of the optic nerve of other arthro- 

 pods : tbe second swelling, which is separated from the opticon by 

 a tract of fine nerve-fibrils, is called the epi-oplicun ; while the tliird, 

 or peri-opticon, is separated by a bundle of long optic nerve-fibrils. 

 The term neurospongium is given to the fine mesh work of minute 



• Prodromus of tlie Zool. of Victoria, decade x., 1885. 



t CornpteM Kendus, c. (188."); pp. 4G4-G. 



X Ibid., xcix. (1884) pp. 985-7. See this Journal, ante, pp. 235-4. 



§ Quart. Journ. Micr. Hci., xxv. (1885) pp. 215-51 (3 pl».). 



