ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 395 



spinulates and spined acuates. The Myxospongice are regarded as 

 the ancestors of allies of the Spongiidce (s. str,), which have given 

 rise to the Aplysinidce and Hirclniidce. Throughout the Monactinellid 

 series there is a tendency to form flesh-spicules, which are divisible 

 into (1) Monactinellid, e. g. anchorates, &c., and (2) Polyadinellid, as 

 stellates. They remain insignificant when a fibrous skeleton was 

 already in existence, but where this is wanting they assume its 

 functions and form continuous skeletons. 



The boldness of attempting to construct a fresh classification of 

 sponges, and to describe 500 Australasian species when separated 

 by some thousands of miles from the only sound basis for systematic 

 work in this group — viz. collections of authentic types of previous 

 writers — seems scarcely justified by this sample of the results, 

 and must, it is to be feared, lead to the further complication rather 

 than the elucidation of this difficult subject. 



Japanese Litliistidse.* — L. Doderlein describes some new Lithistid 

 sponges from Enoshima : — Seliscothon chonelleides, Discodermia 

 japonica, D. calyx, and D. vermicularis. In the description of these 

 latter he has avoided the use of the expressions individual and 

 colony, but it has been difficult not to use them, for while D. japonica 

 has in its simplest condition the form of an individual, it may by 

 budding give rise to other individuals, and to the whole mass the 

 word colony might be properly applied. D. calyx has not a single 

 large osculum, but a number of smaller ones, so that here the limits 

 of individuality are at once passed, and D. vermicularis has the oscula 

 appearing quite independently of the division, so that the buds that 

 are formed have no individuality. This last, indeed, is neither a 

 simple sponge nor a sponge-colony, but rather a branched sponge. 



After an account of the siliceous spicules and of the sarcode, the 

 author refers to the difficulty raised by the fact that, while some of 

 his sjDonges contained very few embryonic corpuscles, others had a 

 great many ; this is to be explained by the periods of vegetation, to 

 which these sponges are subject, and from which is due the maximal 

 and minimal conditions of their growth ; they do not live in such 

 deep water as to be free from the influence of the surrounding medium. 



After briefly noting the characters of the now twelve known species 

 of this genus, and discussing various points in their physiology, the 

 author passes to the affinities of the Lithistidse, of which he gives the 

 accompanying phylogenetic table. 



Megamorina Ammocladina 



Khizomorina 



Tetracladina Geodinidas 



StellettidEe. 

 * Zeitscbr. f. Wiss. ZooL, xl. (1884) pp. 62-104 (3 pis.). 



