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diadema Costa infested with a species of Spheronella (S. diadema Giard and Bonnier, without 
description) and two other specimens of the same Amphipod with Podascon Della Valle: Giard 
and Bonnier. Of Decapoda there have only been found as yet Choniostomatide on Hippolyte 
Gaimardii M.-Edw. and on Hipp. polaris (Sab.); both these species, we know, are not 
unfrequently infested, either with Hemiarthrus abdominalis (ky.) under the abdomen, or with 
Gyge Hippolytes (Kr.) in the branchial] cavity. In a specimen infested with Choniostoma J. Sparre 
Schneider has observed a specimen of Hemiarthrus, and on a specimen of Hipp. Garmardii, 
under a large swelling on the right side of the animal, I have found eleven ovisacs and an 
adult female of Chon. Hansenii, as well as an adult male and a tiny female (smaller than 
the male) of Gyge Hippolytes, and besides, under the apparently normal left side of the 
carapace, a male of Gyge. In the species of the genus Erythrops (order Mysidacea), G. O. Sars 
has found the Epicarid Aspidophryxus peltatus G.O.8., and Giard and Bonnier have reserved 
this name for the form found on Ey. erythrophthalmus (Goes) (£. Goésii G. O. 8.), and 
established a new species, A. Sarsii G. and B., for the form which lives on L. microphthalmus 
G.O.S. Giard and Bonnier have found their type specimens of the latter species (the value 
of which future examination will have to decide) on the same specimen as their type 
specimens of Aspidoecia Normani, and I have found a specimen of Aspidophryxus on an 
Er. erythrophthalmus sent to me by Prof. Sars as infested with Aspidoecia, but this parasite 
must have fallen off before the animals were sent to me, if it was ever there at all. 
The genus Sylon Kr., belonging to Rhizocephala, lives, as we know, on the ventral 
side of the abdomen in some species of Hippolyte, but I have not found it on any specimen 
infested with Choniostoma. The remaining species belonging to Rhizocephala and Copepoda, 
which are parasitic on Malacostraca, have all been taken on forms on which no Choniostomatidee 
have been found. 
Together with Spheronella paradoxa I have found repeatedly in the marsupium of 
Bathyporeia several specimens of a species belonging to the family Tyroglyphide (the 
order Acarida). 
Of other parasites I have only detected some Protozoa on the branchize and the 
marsupial plates in the material of Malacostraca with Choniostomatidz examined by me. 
So I have arrived at the result that there exists no connection at all between 
Choniostomatidee and any of the other parasites of different orders found on the same 
species of hosts. 
g. Nourishment. 
T cut a bit of skin of an Hrythrops in the place where an Aspidoecia had been 
attached, cleaned it with caustic potash from muscles and viscous substance, and discovered 
a small hole, where the mouth of the parasite had its place. And this seems very natural 
indeed; in the first place, the mandibles appear quite well qualified for producing such a 
hole; secondly, the mouth is doubtless suctorial, and lastly, the female, which is permanently 
