ATLANT. DEEP-SEA EXPED. 1910. VOL. III]. 



SPONGIA. 



Malacosaccus floricomatus Topsent. 



PI. I, fig. 2. 



Vide litter: 41 pag. 33. 



St. 10. One specimen. 



At stat. 10 one specimen of a subcylindrical, stalked 

 sponge of a very loose consistency was procured. The 

 body of this sponge is 7 cm. long and has in the middle 

 a diameter of 3 cm. diminishing towards the base to 2 

 cm. The subcylindrical somewhat twisted stalk is 8 cm. 

 long and of 4 mm. in diameter with a basal bulb 6 mm. 

 in diameter. The surface is finely hispid owing to the 

 projection of the distal rays of the sword-like dermal 

 hexacts, to be described later. Orifices, about 1 mm. in 

 diameter, are rather densely spread over it. Whether 

 there was an opening at the summit cannot be decided, 

 as the upper part was cut off. There is no gastral cavity 

 though a cut certainly appears on one side at the summit, 

 about 1 cm. deep and 0.7 cm. in diameter. But as the 

 walls of this cut exhibit no special spiculation, which is 

 similar to that in the parenchyme I do not think it can 

 be regarded as a rudimentary cloacal cavity. 



The specimen thus exhibits a striking resemblance to 

 Malacosaccus floricomatus Topsent (op. cit. pi. I, fig. 10). 

 The spiculation also shows more affinity to this species 

 than to the closely allied, M. unguiculatus Schulze, though 

 it has not been possible after careful examination to find 

 either the hypodermal spined hexacts (op. cit. pi. VII, 

 fig. 3 c), or the floricomes with numerous secondary rays, 

 like those found by Topsent under the superficial encrust- 



ment at the top of the stalk. But all the other forms of 

 spicules have been observed: Thus in the dermal surface 

 there is a layer af swordlike hexacts (like those figured 

 op. cit. 3 a, 3 b), and between them small onychasters, 

 0.07 mm. in diameter (op. cit. fig. 3 g), together with a 

 few, very slender floricomes. In the parenchyme between 

 the large, flexible, absolutely smooth hexacts there are 

 many robust floricomes (op. cit. fig. 3 f), with a diameter 

 between 0.190—0.300 mm. These are specially large and 

 abundant in the wall of the above mentioned cut. Further 

 there were onychasters, discohexasters and oxyhexasters 

 of the same forms as figured by Topsent in respectively 

 (fig. 3 h, 3 i, 3 k op. cit.). 



The rather flexible stalk has a peripheral coating of 

 smaller, slenderer spicules and a central rigid part of 

 rather robust ones. The spicules in both places are 

 hexacts, differently transformed, mostly reduced to triactins 

 (like fig. 3 d op. cit.). In the remaining patches of the 

 skin the same spiculation has been observed as in the der- 

 mal skeleton of the body. Besides this there was in the 

 coating of the basal hulb a dense felt, consisting of rather 

 slender hexacts with rays of most variable length and 

 beset with few exeedingly fine prongs — much like those 

 described by Topsent (p. 38) in the "revetement parti- 

 culier" from the upper part of the stalk. 



I think I am justified in referring at least provisionally 

 the specimen at my disposal to Malacosaccus floricomatus 

 Topsent, in spite of the absence of the hypodermal spined 

 hexacts and the floricomes with numerous rays. 



Geographical 

 the Azores: 



distribution. Malacosaccus floricomatus Topsent has been recorded from the east of 



St. 749 Lat. 38° 55' N., long 21° 18' 45" W. Depth: 5005 m. 



Bottom: "vase blanche et 

 globigerines" 



3 specimens and 2 stalks 



The "Michael Sars" specimen came from the Bay of Biscay: 



St. 10 



Lat. 45" 26' N., long 9" 20' W. Depth: 4700 m. Bottom: yellow mud 



1 speci men 



Regadrella phoenix O. Schmidt. 



PI. I, fig. 3. 



Vide litter: 41 p. 39, 30 p. 22. 



St. 23. Seven specimens and several basal cups. 



Of this species the "Michael Sars" obtained at 

 stat. 23 seven or eight tolerably well preserved specimens, 

 though all without basal cups. About double the number 

 of basal cups were, however, taken at the same station. 

 But as they were found in a separate bottle (together 

 with Aphrocallistes) it is impossible to decide, whether 

 they belong to the upper parts of the above mentioned 

 specimens. 



The basal cups were generally separated, but often 

 they were attached very close to each other. Some of 

 the cups had inside a coating of Hamacantha bowerbankii, 

 and at the common base of fixation a small Characella 

 pachastrelloides was attached. 



All the specimens seem to have been torn off very 

 close to the base. The largest one is 17 cm. long with 

 a diameter at the middle of about 8.5 cm. and the smaller 

 ones 12 cm. long with a diameter of 5 cm. The sieve- 

 plate, the skeleton of which is pretty well preserved on 

 nearly all the specimens, resembling exactly Topsent's 

 fig. 3 pi. VI 41, has a diameter of 3 to 5 cm. The 



