256 ART. 7. r. IJIMA : HEXACTINELLIDA, IV. 



but are more generally situated at the end of tubular outbulgings 

 or buds of the sponge-wall. These are at first csecum-like but 

 after a time an osculum opens at the blind end of each ; they, 

 as also the simple secondary oscula, should be considered to repre- 

 sent daughter-persons formed by the mother-person, ill- defined and 

 persistently continuous with the latter though they are. The bud 

 may grow to conspicuous dimensions and thus may give to the 

 sponge a very peculiar and characteristic shape. It seems to be 

 invariably the rule that the simple secondary osculum or the 

 tubular daughter-person, whichever be the case, arises at some 

 point on one of the median edges— not on the broad lateral sides 

 — of the laterally compressed mother-sponge, and that, when two 

 or more secondary oscula or daughter-persons coexist, these are 

 all situated in a row on the same body-edge. 



My material comprises a series of specimens varying in the 

 number of daughter-persons from one up to five. 



The two specimens of PI. XX., figs. 1 and 2, show each a 

 single daughter-person. In the one (fig. 1) the wall is somewhat 

 bulged out sagitally in the upper half of one of its obtuse edges. 

 At the lower end of this out-bulging is an artificial gap in the 

 wall, produced without doubt by the severing off of a daughter- 

 person which had grown there. Assumably the upper part of 

 the same out-bulging is in an inceptional stage of giving rise to 

 a second daughter-person. The other specimen (fig. 2), a strongly 

 laterally compressed individual, shows a conspicuous tubular 

 daughter-person, 183 mm. long and springing from the upper 

 part of the mother-wall in an obliquely upward direction. In 

 this case we may presume, from the circumstances of space, that 

 a second daughter-person, were it ever to arise, would be formed 

 below the one already present. In the third specimen I have 



