372 Br. R. von Lendenfeld on the Nervous and 



gland are identical nephridia tlian that they represent those of 

 different segments. 



VII. Lastly, I wish briefly to point out that Frotessor 

 Edouard Van Beneden of Li^ge was the first naturalist since 

 Straus-Diirckheim to insist upon the necessity of regardnig 

 Limulus as an Arachnid. In 1871 (Socit^te Entomologique 

 de Belgique) he briefly expressed this view as the result of an 

 examination of the embryos of Limulus-, but he did not 

 attempt to support it by any detailed comparison of the 

 organization of the Xiphosura, Eurypterina, and Arachmda. 



Had Professor Clans done justice to his predecessors m the 

 discussion of the classification of the Arthropoda, he would 

 have cited the views of the professor of Liege as well as my 

 own detailed observations and speculations, which, I am glad 

 to acknowledge, owe their existence to the brief but suggestive 

 publication of my friend Edouard Van Beneden. 



XXXU.— Contributions towards the Knowledge of the Nervous 

 and Muscular Systems of the Horny Sponges. By Dr. R. 

 VON Lendenfeld*. 



One of the Australian species of Euspongia, which is identical 

 with Euspongia anfractuosa, Carter f, shows in many respects 

 remarkable diflerences from the known structure:): of the common 

 bath-sponge, Euspongia officinalis. The sponge is massive, 

 and has short, rounded, finger-like processes. Each of the 

 latter contains a wide cylindrical cavity running in the direc- 

 tion of its length, and which externally looks very like a wide 

 oscular tube. These wide tubes open below into a system of 

 anastomosing lacuna. Ihe whole dermis is rich in pores. 

 A very elegant sand-net is diftused between the regularly 

 distributed pore-sieves. On closer examination it is seen that 

 the tubes in the digitiform processes are lined with a 

 membrane of exactly the same structure. This applies also 

 to the lining of the lacunose cavities in the interior of the 

 sponge. The tubes and lacunas are not oscular tubes, and do 

 not belong to the true sponge-body, but form a vestibular 



* Translated by W. S. Dallas, F.L.S., from the ' Sitzungsbericbte der 

 kcinigl. preu.*siscbeu Akademie der Wissenscbafteu zu Berlin/ 1886, 

 pp. 1015-1020. 



t Ann. & Mag. Nat. Hist. ser. 5, vol. xv. p. 316. 



\ r. E. Sehnlze, " Untersuchungen iiber den Bau und die Entwicke- 

 lung der Spongien. — VII. Mittheilung. Die Fanjilie der Spongidas" 

 (Zeitscbr. f. wiss. Zool. Bd. xxxii, pp. 591 et seqq.). 



