Appendix. 



Since the foregoing was delivered for printing-, I have seen a 

 new work by Hérouaed (1902). In this book he gives a detailed de- 

 scription of his Stichojms richardi^ which description seems in every 

 respect to confirm my supposition, as expressed on page 6, that this 

 „n. sp." is the same as Stichopus tremulus, which, under the name 

 of Holothuria tremula, was described so early as 135 years ago. 



HÉROUAED estabhshes a new genus Allantis, to which he refers 

 Mesothuria intestinalis and M. verrilli^ which two species he unites 

 into one, as Koehler and Ludwig also do. Hérouard regards, 

 however, M. verrilli as a variety of M. intestinalis, but sometimes 

 he writes only intestinalis even when the specimens in question 

 are verrilli. The genus Allantis is said to be distinguished from Meso- 

 thuria by the 5 pairs of tentacles, which he close to the radh, 

 being smaller than the 5 pairs, which he right in the interradh; 

 another distinguishing feature should be that the feet are distri- 

 buted over the whole of the body, with the exception of the fore- 

 most part of the median ventral radius.'") 



Neither of these distinguishing features holds good for the 

 genuine Mesothuria intestinalis. In this latter species, the tentac- 

 les are just as large in the radii as in the interradii; and the feet 

 are, as I have particularly emphasized (1896), distributed over the 

 whole of the body, but those belonging to the median ventral radius 

 are very small, so that at first sight the median portion of the ven- 

 tral side appears to be quite bare from the one end to the 



1) Hérouard mentions „Dix paires de tentacules petits" and „dix paires de 

 tentacules plus gros". This expression must have slipped in unawares, for there 

 are, as is well known, only 20, not 40, tentacles. 



