List of the Holothurians in the collection of the Leyden Museum

The collection of Holothurians in the Leyden Museum was sent over to me with the request that I would subject them to a systematic revision. I undertook this task in the hope of being able at the same time by the aid of this material to make a step in advance with respect to their anatomy. Unfortunately in nearly all the specimens the intestines were so insufficiently preserved, that I was forced to limit myself to the identification of the species. This, however, was not superfluous, as the majority of the specimens were incorrectly named and as certain localities are not without interest for the question of geographical distribution. The collection of Holothurians in the Leyden Museum contains a total of 52 species (two of them being new), most of which were obtained from the Oriental and Moluccan regions.