( 37 ) 



The results are still much higher than for the ordinary tempera- 

 ture, a very favourable result for measurements at low temperature. 



Lastly a single determination in liquid hydrogen was made. Fifteen 

 minutes after the thread had adopted the temperature of the hath 

 it was pulled asunder. The total weight was 3013 grams, the 

 diameter 0.271 m.m., hence the maximum strain in KG / mm s=52.1 

 again much higher than at the temperature of liquid air. The structure 

 of the section was striated, unridged and no smooth part occurred. 



Zoology. — "Poterion a Boring Sponge" By Prof. G. C. J. Vosmaer. 

 (Communicated in the meeting of May 30, 1908). 



In 1822 Hardwicke published l ) a short notice on a remarkable 

 "Zoophyte, commonly found about the Coasts of Singapore Island." 

 The author stated that it belonged to the Sponges, and called it 

 Spongia patera. Evidently not acquainted with this publication 

 Schlegel 1858 -) proposed the name Poterion neptuni for a sponge, 

 which universally is considered to be identical with Hardwicke's 

 sponge. According to the rules of nomenclature the object has, conse- 

 quently, to be called Poterion patera (Hardw.), as first pointed out 

 by Sollas 3 ). 



Both Hardwicke and Schlegel state that the sponge is fairly 

 common. No wonder that this object, which presents itself as a 

 gigantic cup, with a height of more than 1 M. and an aperture of 

 30 cm. or more, drew the attention of sailors. It is also found in 

 many museums, especially in Holland. The Leyden Museum of Natural 

 History, the Museum of the Utrecht University and the Museum 

 of the Amsterdam Zoological Gardens ("Artis") possess beautiful 

 specimens, together more than 30. This rich material induced Harting 



1 ) Asiatic Researches XIV, p. 180. 



2 ) Handleid. Dierkunde II, p. 542. 



3 ) Ann. en Mag. Nat. Hist. (5) VI, p. 441 (1880). 



