208 



THE SPONGES OF THE WEST-CENTRAL PACIFIC 



Text Figure No. 141. Spicules (tylostyles) of Ridlcia pelcia, X 182. 



The color in life was pinkish red, and the consistency was soft, easily 

 torn. 



The surface is smooth and lipostomous. The oscules, however, are prob- 

 ably represented by the large central hollow. 



The spicules in the wall of this sponge are chiefly in confusion, but a 

 very peculiar condition exists as to one end of each of the cylinders. Because 

 of the confusion in the above-mentioned storm, no record is available as to 

 which of the two ends of the specimens in the collecting jar had protruded 

 from the mud. In each case, however, one of these two ends is relatively 

 clean, and the other is very muddy; one, therefore, might conclude that the 

 muddy end was the region which had been buried. Furthermore, this muddy 

 end is adorned with conspicuous tufts, which look like rooting tufts and 

 may be rooting tufts. On the other hand, the spicules in these tufts have their 

 points directed away from the main mass of the sponge in a plumose fashion. 

 This would indicate that they were at the summit, not the base. These prob- 

 lematical root structures are about 65 /x in diameter and 500 /x to 1000 [x long. 

 Perhaps there was no large basal mass buried in the mud, and the entire 

 organism may have consisted of the hollow cylinder. More information is 

 desirable. 



The skeleton consists of peculiar tylostyles ; of these the central portion 

 is much swollen, giving the fusiform shape. A maximum size of 35 ll by 

 670 fi is reached, but in such a spicule the neck is only 15 ju, and the head 

 27 [x in diameter. 



All the other species now in the genus Ridlcia have smaller spicules than 

 peleia. Kieschnick, 1896, page 534, described Suberites oculatus from the 

 East Indies, unrecognizably. Thiele, 1900, page 175, redescribed the species 

 from new material and de Laubenfels, 1936, page 151, referred this to Ridlcia, 

 with hesitation. If this generic allocation is correct, this species is not only 

 the closest geographically but also has spicules the most nearly like those of 

 pelcia. However, whereas Thiele in one place refers to the spicules of his 

 sponge as being tylostyles, in all other places he calls them styles. His figures 

 are exclusively of styles. Therefore, it is decidedly possible that oculatus is 

 not a member of the genus Ridlcia at all. The type of the genus is Ridlcia 

 oviformis Dendy, 1888, page 515, and its spicules are the smallest of any in 



