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Prof. Michaelsen, Hamburg, — finally also some specimens of 
Bedford’s A. parvula , together with a pair of those, identified by 
the same author as H. difficilis Semper, were received through the 
kindness of Prof. Stanley Gardiner, Cambridge. — 1 beg to 
express my indebtedness to all these gentlemen for their exceed- 
ingly valuable assistance which has made it possible for me to 
reach a definite result in the rather intricate question about the 
synonomy of Actinopyga parvula (Sel.). 
As the first result of my researches I must maintain that the 
specimens from the Pacific are by no means identical with the 
Floridan type. The pacific form, at least that from Hawaii, is a 
separate species. According to Erwe, the M. aegyptiana of Hel fer 
is identical with the Pacific species. — However, the identification 
with M. aegyptiana is also wrong as I may assert after having had 
the opportunity of studying this species on the authentic material. 
Also the examination of the type of M. flavo-castanea has convinced 
me that this species is not a synonym of parvula from Florida and 
still less of the Pacific species. 
Further I was very surprised in finding, through the study 
of the type of M. parvula from Florida, that it could not be dis- 
tinguished from H. captiva Ludwig, in spite of the faet that they 
have been referred to different genera, the former to Actinopyga 
(Miilleria) the latter to Holothuria. This, however, is due simply 
to the faet that Ludwig and the following authors who mention 
this species have overlooked the presence of anal teeth in captiva. 
The examination of Bedford’s specimens of M. parvula led to the 
result that they were not the same as the species from the Pacific, 
identified as parvula by Fisher and Erwe. They represent a 
species which I shall designate as Actinopyga Bedfordi n. sp. 
I shall here shortly point out the differences between these 
species, especially between A. parvula and the form from the Pac¬ 
ific, hitherto wrongly designated by that name. 
Externally these two forms are differing both in colour and 
size. The Atlantic form grows only to half the size of the Ha- 
waiian, the former being only 4—5 cm, the latter 8—10 cm. That 
the difference in length is real is confirmed by examination of the 
generative organs. They are found well developed in the small 
Atlantic form at the said sizes 4—5 cm, while the Pacific form is 
