4 I. IJI3IA : HEXACTINELLIDA. I. 



my material was also furnished by tbe splendid collection of 

 Mr. Alan Owston, of Yokohama, which collection I understand 

 has since been transferred to the British Museum. It was some 

 of the beautiful specimens in his possession that instigated me 

 in 1894 to the study of the Hexactinellida. 



Here I beg leave to fulfil the pleasant duty of returning 

 my grateful thanks to all those who have rendered me assistance 

 in one way or another during the progress of my investigations. 



The authorities of the Imperial University of Tokyo, and 

 the Publishing Committee of this Journal, have given me their 

 most liberal support, the former in affording me all the material 

 facilities needed and the latter in allowing carte-hlanche the 

 printing of my numerous plates. 



Prof. F. E. Schulze of Berlin has favored me with much 

 advice and information, which could not fail to be invaluable to 

 me as coming from an authority of such profound experience in 

 the same field of investigation. 



From Prof. K. Mitsukuri I have always received the 

 attentive assistance of a most symi^athetic colleague. 



Mr. Alan Owston not only placed at my disposal the whole 

 of his Hexactinellid collection already referred to, but also made 

 a gracious gift of numerous valuable specimens to the Science 

 College. I am under special obligations to him lor the free use 

 I was allowed to make of his gallant yacht, the * Golden 

 Hind,' on the many occasions of my collecting trips to the 

 Sagami Sea. 



In the execution of many of the drawings of spicules I have 

 been ably helped at first by Mr. K. Nagahara and afterwards by 

 Mr. Y. Nag AS A WA, assistants in the Zoological Institute. An 



