AKT. 5 PARASITIC CRUSTACEA OF WEST INDIES BOSCHMA S 



Expedition from the East Indian Archipelago also, the greater part 

 of the Sacculinidae are sufficiently characterized by the peculiar struc- 

 ture of the excrescences on the external cuticle of the mantle (Van 

 Kampen and Boschma, 1925). In the paper cited we were able to 

 prove that a number of morphologically well defined species of 

 Sacculina occur in the East Indies. Two more striking facts were 

 observed, first, that a single species maj'^ occur as a parasite of several 

 species of crabs, and, second, that certain species of crabs may be 

 infested with two or more different species of Sacculina. Conse- 

 quently this paper proves conclusively that the opinions of Giard as 

 well as Smith can not be upheld. 



A comparative study of a great number of European representa- 

 tives of the genus Saccvlina (Boschma, 1927) yielded almost the 

 same results: Among the European forms one species of para- 

 site may infest different species of crabs, as in the case of Sacculina 

 carcini. In this region, however, two morphologically different 

 species have never been found as parasites on one species of host. 

 Previously Guerin-Ganivet (1911) published a paper in which notes 

 were given on the anatomy of many European Sacculinids, and this 

 author has already pointed out that a great number of the so-called 

 species of Giard's have no real systematic value. According to 

 Guerin-Ganivet we may regard a certain form as a definite species 

 only in those cases in which morphological differences from other 

 species can be demonstrated. In the paper cited I based my conclu- 

 sions on the same premises. 



In some cases a certain parasite infests exclusively crabs belonging 

 to a small systematic group, as Drepanorchis neglecta (Fraisse), 

 which is known to occur on the species of the genera Macropodia and 

 Inachus. Both of these genera belong to the subfamily Inachinae 

 (family Majidae) and the parasite, which is structurally very dif- 

 ferent from all other known European Sacculinids, is the only species 

 of the group which is known to infest these crabs. The parasite of 

 Dorynchus thomsoni^ another species of the same subfamily, belongs 

 to quite a different species {Sacculina atlantica) , which is not found 

 on any other crab. Another well defined species, Sacculina eriphiae, 

 also seems to occur on one species of crab only, namely, Eriphia 

 spinifrons. On the other hand Sacculina cwrcini infests a large 

 number of hosts belonging to different families of Brachyura. 



The West Indian species of Sacculinidae are very imperfectly 

 known. One species has been described as SaccuUna panopasi by 

 Gissler (1884) after its host Panopeus herbstii (Milne-Edwards). 

 The external form of this parasite is known, for the description is ac- 

 companied by two text-figures ; its internal anatomy and the structure 

 of its cuticle have not been described in the cited paper. Fortunately 



