I'ORIFERA. I. 



57 



The other genus of the supposed subfamily Plilceodiclyince is Ocranapia. Wlicu Plilaodictyin(c 

 is dissolved, and Phhrodictyon is referred to the Rnuerina-^ Ocranapia will have to pass to (icUiiiKr 

 where it belongs according to its spiculation, and then it must be nearly allied to Grlliodrs, from 

 which it is only distinguished by its form and the external la\-er of bark. The genus must be taken 

 to have its natural place here, and in this respect it is rather characteristic that Topsent lias de- 

 scribed loose fistula; of Ocranapia just as belonging to the genus Grlliodrs (G.cariconiis; see otherwise 

 for further partictilars under Ocranapia robusta). 



The result accordingly is that the hitherto admitted subfamily PliUeodictyincc^) is dissoh-ed, the 

 genus PhUcodictyon (=- Rliizoclialitia olim after the exclusion of olrracra and carotta) is referred to the 

 Rrnierincr close to Prfrosia, and the genus Ocranapia to the Gelliincr close to Grlliodrs. 



It may easily be understood that the subfamily Phl(Podictyi)ur has been kept up for some time, 

 as the forms comprised in it show some congruit\-. The three Plilfeodic/yon-sT^&ciGs enumerated here, 

 the two G(7//^/j.-species, Inridus and inicrotoxa to be described hereafter, and Ocranapia robusla thus 

 correspond in the presence of fistuke, and of an external, bark-like la\er, and some of them have the 

 mentioned lamellar skeletal structure. Moreover these forms show all the so-called Cellules .spheru- 

 leuses>, even if these cells are somewhat different. I think, however, that we cannot, at all events at 

 the present position of s}stematism, ascribe any importance to these characters. Thus fistulse and a 

 hard external layer of skin are also found in the genus Histodrrnia. — Lindgren (Zool. Jahrb. XI, 1898, 

 297, Tab. 19, Fig. 11 a— b) has also referred a / fisfodrrn/a-sTp&c\&?, to the genus Rliizochalina (the species 

 is wrough- determined 2.^ Rli-singaporoisix ^^xU. and if the lamellar skeletal structure is a phenomenon 

 of growth, no importance can be attached to it. Neither can au\- importance be attached to the occur- 

 rence of Cellules .spheruleuses , as long as their physiological .significance is not sufficiently known; 

 besides I have found quite similar forms of these cells in a llisfodrnna or a Desmacidonid-species 

 closeh- allied to Histodrrnia. vStrange to sa>-, these cells rtould thus seem to be especially developed 

 and conspicuous in forms with an external bark-layer. — Altered points of \ie\v in systematism may 

 possibly alter the collocation of the forms here mentioned, but at present I think the dissolution of 

 Carter's Phhcodirtxina that I here ha\-e made, to be necessar\-. 



I. Ph. tuber n. sp. 

 PL VI, Figs. II — 13, PI. XII, Fig. 6a, b. Fig. 7. 



The form roiindish, niorr or Ir.-is irrrgiilar ; only few fistulcr. Thr surface soninvhat rough from 

 Prajrcting spicules. Outermost a hard layer of skin with irregularly placed spicules parallel to the sur- 

 face. The inner skeleton is an irregular tissue of spicules zvithout fibres, in this tissue are found con- 

 centric layers of close-set spicules parallel to thr surface. Spongin present to a small degree. Spicula 

 curved oxea of a length of o-jS—o-js"""- 



This species mav be of a somewhat varying form; but it i.s, however, in all tlie specimens in 

 hand, more or less roundish or tuberous, and the sponge is pro\ided with one or a few fistulse. The 

 largest specimen is lengthv; it has a greatest length of 28'"- and a greatest breadth of ca. 13""". It 



') Carter for his Kfoup "^>^'l 'lif "•""'^ of Plilccodiciyina. 



S 



The Ingolf-Expedition. \ I. i. 



