PORIFERA III. 



J 9 



the specimens previously described are of similar sizes. The papillae vary in length from 1*5 to 4""". 

 The colour (in spirit) is in one specimen green, but otherwise whitish, presumably on account of de- 

 colouration. The consistency is bladdery, the dermal layer being firm and solid, while the inner body 

 is soft and strongly contracted. The surface is smooth. The dermal layer is a rather thin, firm mem- 

 brane, provided with close-lying spicules. Pores and oscula . The pores are certainly found at the 

 summit of certain papillae, as in one of the papillae 1 found a very distinct, sieve-like pore-membrane 

 with close-lying, circular pores, but as my material is somewhat damaged and only shows few papillae, 

 I can say nothing further, but there are no pores found otherwise on the surface. Some others of the 

 papillae are oscular papillae with a simple opening at the summit. That the papillae are partly oscular, 

 partly pore-papillae is also confirmed by what is found in the following species /. viridis. 



The skeleton. The skeleton of the dermal layer consists of close-lying, tangential spicules, inter- 

 crossing each other in all directions; they lie rather closely, but not more closely however than that 

 the membrane ma) - be seen everywhere between them. In the peduncle they lie quite closely and 

 here they are all arranged parallel to the longitudinal direction; the layer is also here considerably 

 thicker, and the spicules lie in several layers; the peduncle, however, is not compact, but the inner 

 cavity continues down through it. In the wall of the papillae the spicules likewise lie quite close to 

 each other and all parallel to the longitudinal direction with one end towards the opening of the pa- 

 pilla. The skeleton of the inner body I have only been able to examine somewhat incompletely, as 

 the specimens in my material for the most part want the inner body; it is however not at all 

 devoid of a skeleton; there are bundles and loose fibres present which seem mainly to have a course 

 along the surface, but whether there is otherwise any definite arrangement I have not been able to 

 see. Spongin is not present in the skeleton. 



Spicula: a. Megasclera; these are of one form, strongyla; they are slightly, generally somewhat 

 irregularly curved; they are thickest in the middle and taper a little towards the ends; these latter 

 are sometimes, either one or both, slightly swollen; there is often a little difference between the ends, 

 one being slightly thinner than the other, but most frequently such a difference is not observable. 

 The length is 0-42 — 0-64™'", most frequently about intermediate between these sizes, the thickness is 

 o-oio— o-oi28 mm . Fine developmental stages were found singly, they are monactinal, and they are especially 

 found in the inner body. Microsclera not present. 



As I have examined the type-specimen of the Reniera inflata Arm. Hans, the identification of 

 this with the present species is certain. — While the Joyeuxia viridis Tops. (1. c. 1904) must be the 

 present species, the two specimens which this author described in 1892 for the first time (I.e. Fasc. II, 

 94.), and on which he founded the genus Joyeuxia and the species viridis, are on the contrary probably 

 a distinct species and identical with the species described below. 



Locality: The Ingolf-Expedition has taken three specimens of this species on the following 

 localities: station 32, 66° 35' Lat. N, 56 38' Long. W, depth 318 fathoms; station 81, 6i = 44' Lat. N., 27° 00' 

 Long. W., depth 485 fathoms, and station 97, 65 28' Lat. N., 27 39' Long. W., depth 450 fathoms. The 

 localities lie in the Davis and the Denmark Straits. 



Gcogr. distr. The species has earlier been taken South-west of Bukenfjord, Norway, depth 106 

 fathoms (Schmidt 1. c.) and at 38 31' Lat. N., 26 50' Long. W., depth 449 fathoms. The species is thus 



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