GEODIA VARIOSPICULOSA. 55 



The agreement between the specimens described above as Sidonops bicolor 

 is so great that there cannot be any doubt as to their identity; in fact not 

 even varieties or forms can be estabhshed. 



Since the spiculation is geodine in character, the afferent cortical canals 

 cribriporal, and the efferents uniporal, this sponge must be placed in Sidonops. 

 For the reasons given in the description of Geodia agassizii, I have compared it 

 not only with the known species of Sidonops but also with those of Geodia. 

 The species of these genera which seems to be most closely allied to it is the 

 one described in this report as Sidonops angulata. This differs from S. bicolor 

 by the possession of anatriaenes and angularly bent amphioxes, by the smaller 

 size of the sterrasters, and by the oxyasters and oxysphaerasters always having 

 perfectly smooth rays. These differences are certainly sufficient for specific 

 distinction. 



GEODIA Lamarck. 



Among the megascleres are regular triaenes. The tetraxon megascleres 

 arc confined to the superficial part and arranged radially. The dermal micro- 

 sdercs are asters. The afferents and efferents are both cribriporal. 



There are sixty-two specimens of Geodia in the collection made by the 

 "Albatross." These belong to thirteen species, t«n of which are new. Two 

 species, one previously known and one now described for the first time, are 

 further divided into seven varieties, five of which are new. 



Geodia variospiculosa Thiele. 

 Zoologica, 1898, 24, p. 10, taf. 0, figs. (5-7. Undenfeld, Tierreich, 190.3, 19, p. 107. 



intermedia, var. nov. 

 Plate 17, figs. 23-26, 34-40, 49; Plate 18, figs. S, 10, 13-20, 22, 27; Plate 19, figs. 9-11, 19, 20, 22, 24, 31. 



micraster, \ar. nov. 



Plate 17, figs. 27-33, 41-48, 50; Plate 18, figs. 1-7, 9, 11, 12, 21, 23-26; Plate 19, figs. 1-8, 12-18, 21, 



23, 25-.30, 32. 



Two specimens collected by the "Albatross" off Honshu Island, Japan, 

 differ from the typical G. variospiculosa Thiele, from the var. clavigera Thiele, 

 and from each other, sufficiently to rank as new varieties. In both these new 

 varieties the choanosomal oxyasters are considerably smaller than in the type, 

 and in one of them they are not so large as in the other. The variety in which 

 they are smallest I name micraster, the one in which they are not so small 

 intermedia. 



