394 SUMMAEY OF CUBRENT RESEARCHES RELATING TO 



on the presence of subdermal cavities, such as are found in siliceous 

 sponges. 



Fam. Teichonidce : Teichonella Carter, and Mlhardia n. gen., the 

 latter distinguished by a cup-like form, the oscular and pore-surfaces 

 respectively bearing spicules of a different character. 



The general histology is not overlooked. In two species the 

 mesoderm was found to contain some large flattened cells whose 

 protoplasm forms a network upon large spicules, and perhaps contri- 

 butes to their formation. Ova were found abundantly only in two 

 species. The author's former observations on the spermospores of 

 Calcarea are confirmed ; they are undoubtedly of mesodermic origin. 



Australian Monactinellida.* — E. v. Lendenfeld has chosen a 

 rich and comparatively unworked field for systematic work among the 

 sponges, viz. Australia and New Zealand, from which he claims to 

 have specimens of about 500 species at his command. He gives a pre- 

 liminary account of his classification, with genealogical and structural 

 considerations suggested by the study of this large collection, but 

 appears, unfortunately, not to have attached sufficient importance to the 

 work of previous labourers in this field, for although he refers frequently 

 to the work of Schmidt and F. E. Schulze, whose generalizations are 

 based almost exclusively on the Mediterranean and Atlantic faunas, 

 we find no allusion (as such) to Mr. Carter's very full and carefully 

 constructed system, which embodies the results of the examination 

 of, inter alia, very large Australian collections, such as his eminent 

 German colleagues have probably never had access to. Von Lendenfeld 

 derives the Monactinellida from the Horny sponges ; the two funda- 

 mental families of his system are obtained by the subdivision of the 

 older family Chalinidce, viz. into (1) Clialarcliidce, characterized by a 

 horny network with scanty and very slender biradiate (acerate) axial 

 spicules. (2) Chalcoenidce, by a horny network with dense masses of 

 large biradiates. From (2) he derives, on one side, (3) Benieridce, 

 containing biradiate spicules, but devoid of perceptible horny sub- 

 stance, and on the other, (4) Echispidce, distinguished by spined spicules 

 projecting from the horny fibre from between them (co-extensive with 

 Ectyonida Carter). (5) GhlatJiridcB, with horny network, containing 

 acuate spicules (almost co-extensive with Axinellida Carter). From (5) 

 is derived, (6) Suheritidce, with uni-radiates, and without horny sub- 

 stance. 



He denies to the flesh-spicules any share in the demarcation of 

 the large groups, but reserves them for generic distinctions; hence 

 Schmidt's and Vosmaer's family DesmacidinidcB does not appear. 

 These spicules he regards as of common origin, but as quite distinct 

 from the skeletal spicules. He has, however, been induced to lay less 

 weight on them from having found them in sponges otherwise very 

 distinct from each other — a fact probably due (as his discovery of 

 them in a Hircinia shows) to their occurrence as foreign bodies in 

 some of the sponges in question. 



The skeleton spicules commence with a biradiate form, and pro- 

 ceed by reduction of a ray to the formation of (i.) acuates, and (ii.) 



* Zool. Anzeig., vii. (1884) pp. 201-6. 



