A NEW CASE OF D ROOD-CARING IN HOLOTI1URIANS. 123 



at the free end a single ripe ovum, which after liberation into the body- 

 - cavity, is fertilized by spermatozoa which may have entered there by 

 penetrating through the wall of respiratory trees. Gential tubes in maternal 

 body number about twenty-five pairs, i. e. about twice as many as the 

 number of youngs found in the body-cavity. Gential duct occurs in a 

 single number, opening externally by an orifice situated on a very incon- 

 spicuous prominence near the tentacular crown, as can be made out by 

 examination of sections. 



Numerous adult specimens other than the three referred to, were 

 found, in spite of careful searches, to contain no young in their body. 

 From the fact that the youngs discovered are in a quite advanced stage of 

 ■ development, it is probable that at the time of my stay at Ushibuka the 

 majority of the species have already finished discharging their youngs. 



After careful searches on the shore, I succeeded only once, on August 

 14th, in finding a young which seemed to have been born not very long 

 before. It was hidden in a dead Oyster-shell attached to the underside of 

 a large stone, at which spot several adult Pseudocucumis were also found. 

 It measured, when fresh, 14 mm. in length and 3 mm. in diameter. Color 

 deep grayish violet all over. Except in this coloring, the larger size of body 

 and the increased number of pedicels, the little specimen in question does 

 not differ in essential points from those youngs which were taken from 

 maternal bodies. It is still in possession of only ten tentacles, and the 

 respiratory trees remain in nearly the same state of development. The 

 stomach contains but a trace of plankton organisms taken in as food. 

 Remarkable is the exceedingly rare occurrence of newborn youngs in spots 

 where adult animals abound. This, I suppose, is due to the fact that, as 

 their power of attaching by means of pedicels is not yet very strong, they 

 are easily swept off by waves and current to deeper parts of the water, 

 where they start on their early lives. 



Up to date, so far as I am aware, similar cases of brooding habit in 

 • dendrochirotes have been recorded only twice, i. e., in Phyllophorus urna 

 v(Grube) 1 of the Mediterranean and in Thy one rubra Clark 2 of California. 



