46 ART. 7. — I. IJIMA : HEXACTINELLIDA, IV. 



cytoplasm always takes up stains well, a fact which renders the 

 limit of the inclosed nucleus indistinct. The use of the immer- 

 sion-system for the examination will make the matter clear, un- 

 less the cells are overstained, as is generally the case when 

 hsematoxylin is used. The nucleus contains from one to several 

 dark granules. It measures approximately I2 /', which is also 

 al)Out the size of the trabecular nuclei. 



TJie Larva. — In the study of the present species I have 

 been al)le to obtain a somewhat more definite knowled<re of the 

 larva, than was possible in the case of Leucopsacus orthodocus 

 {cfr., Contrib. III., pj). 42-46). And yet, many points certainly 

 remain to be settled in the future with a further supply of the 

 material. 



Of the larvie which I consider to l)e fully developed (PI. 

 III., figs. 20, 21), a single case was discovered in one of the two 

 mother-individuals constituting Sei. Coll. Mus. S]). No. 228, col- 

 lected in the month of April ; and no less than six cases, besides 

 a number of those representing earlier developmental stages, were 

 found in the third specimen obtained by myself during July. 

 The fourth sj)ecimen obtained in November seemed to contain 

 none, although it showed archœocyte-congeries developed in about 

 the same degree as in all other specimens. The above gives a 

 hint as to the season of the year in which the reproduction of 

 the species seems to take place most actively. 



In all probability the larvi^e arise outside of the chamber- 

 layer in the external trabecular spaces, which is the seat of all 

 archieocvte-cono-eries. However, I can not definitelv state that 

 all the ripe larvie I have found were invariably in that situa- 

 tion, — or that some of them were not situated in the inner system 



