INVERTEBKATA, CRYPTOGAMIA, MICROSCOPY, ETC. 609 



a new species of Meaoderma — M. auchlandicimi — which is somewhat 

 similar to M. novce-zealandice. He fiu-ther points out that in its black 

 coloration Trochus nirjerrimus brings to mind allied species from the 

 South African and South American seas, while the green, at its base, 

 reminds one of the Chinese form, T. argyrostomus. 



Molluscoida. 



Marine Polyzoa.* — The Eev. T. Hincks has commenced a series 

 of papers in which he proposes to describe and figure a large number 

 of marine Polyzoa from various parts of the world which have 

 hitherto escaped notice, and thus to offer a contribution towards that 

 general history of the class which still remains to be ^Titten. 



It is not intended to be confined to bare diagnosis, and the follow- 

 ing points especially will receive elucidation : — (1) Geographical dis- 

 tribution — any new localities for known species will be recorded ; 

 (2) local variation — the differences exhibited by the same tyj)e under 

 differing circumstances will be noted whenever the opi^ortunity 

 presents itself of comparing specimens of the same species from 

 various parts of the world ; (3) the limits of variability in each case, 

 and the elements of structure most liable to variation ; (4) the true 

 principles of classification. With the descriptions of new forms will 

 be combined notes on such as are little known or misunderstood ; 

 and, so far as space will permit, in the case of each genus the number 

 of species already ranked under it will be indicated and its geogra- 

 phical range. These papers will therefore serve as an index to the 

 foreign species which have already been described, as well as an 

 introduction to many that are new. The classification employed will 

 be that of the author's ' History of the British Marine Polyzoa,' so 

 far as it apjilies, and with such modification as may be suggested by 

 an increased knowledge of the morphology of the tribe. A biblio- 

 graphical list will be appended containing the principal faunistic and 

 other works which deal with the foreign sjiecies. 



The series commences with some Madeiran Polyzoa collected by 

 Mr. J. Y. Johnson, and six new species are described and figured. 

 This is followed by descriptions and figures of other specimens from 

 Australia and elsewhere, including eleven new species and one now 

 genus (Sijihonoporella). 



Fresh-water Polyzoa.f — The ovum of Alcyonclla fungosa is com- 

 posed, according to W. Reinhardt, of transparent gi-anular protoplasm, 

 and has a largo clear nucleus and a nucleolus. Later, but while 

 the nucleus and nucleolus are still distinguishable, appear at the 

 periphery unifurm, refracting lumps — those described as cells by 

 Allinan. Generally only one of tlic ova in the ovary develops. The 

 nucleus enlarges so much as to touch the margin of the denser proto- 

 plasm ; it contains a delicate protoplasmic network. The sperma- 

 tozoon consists of a strongly i-efringcnt substance enveloped by a 

 membrane ; its head is round, but ends in a point, and is separated by 



* ' Ann. and Mag. Nat. Hi.st.,' vi. (1880) p. fiO. 

 t * Zool. Anzfip.,' iii. (1^80) pp. 208, 2M. 

 VOL. III. 2 R 



