T 



ELLOBIOPSIDAE 



By Dr H. Boschma, F.M.L.S., c.M.z.s. 



Rijksmuseum van Natuurlijke Historie, Leiden 



(Plates XXXVIII-XLI; Text-figs. 1-16) 

 INTRODUCTION 



HE material of the parasitic Protozoa, Ellobiopsidae, in the Discovery collections is interesting, as it 



- contains specimens of three of the larger species of the family, all belonging to the genus Amallocystis. 



As the material was in an excellent state of preservation, a comparative study could be made of the 

 organ of fixation and the parts of the organism which obviously serve for the absorption of food. The 

 rather complicated structure of these parts in two of the species found its explanation in the more 

 simple arrangement occurring in the third species. 



The collection contains abundant material of a parasite of various Euphausiacea, described in 

 a short preliminary note (Boschma, 1948) as A. fagei. There are previous records of this species, but 

 until recently it remained unnamed. 



The new species A. timbellatus described in the present paper is the first of the genus to become 

 known as a parasite of Caridea of the family Hoplophoridae. In the collection there are two specimens, 

 one of which was studied in more detail. 



Finally, the collection contains two specimens of A. capillosus Page, a parasite of Caridea of the 

 genus Pasiphaea, hitherto known from the Skagerrak only. The specimens described here are from 

 the Strait of Magellan. 



I am much obliged to Dr L. B. Holthuis for determining the sex of the specimens of Hophphoms 

 and of Pasiphaea infested with Amallocystis. Moreover, I am much indebted to Dr N. A. Mackintosh 

 for his care in editing the present paper. 



REVIEW OF THE LITERATURE OF THE ELLOBIOPSIDAE 



Sars (1868). Description and figure of parasitic bodies on the third maxiUipede and the two 

 preceding appendages of Pasiphaea midtidentata Esmark (P. norvegica M. Sars). Their shape was 

 reminiscent of the Gregarinids ; the smaller specimens consisted of a cylindrical sac with rounded free 

 extremity, and the larger specimens consisted of two sacs, one on the top of the other. The distal sac 

 was smaller and thinner than the proximal, the latter often being thicker in its upper than in its lower 

 part. It is not improbable that these parasitic bodies were Ellobiopsidae consisting of a trophomere 

 which could give rise to one gonomere. They remind one of Ellohiocystis tenuis Coutiere, 1911c, 

 parasitic on Pasiphaea sivado (Risso). 



Bate (1888). To the description of his new species P. cristata from St. 173 of the Challenger Expedi- 

 tion (off the Fiji Islands, 315 fathoms) this author adds: 'In our specimen, which I consider to be 

 a female, there is a mass of parasitic cell-growth (fig. 3) strung together in a bead-like arrangement and 

 suspended from a common centre' (loc. cit., p. 869). The figures (loc. cit., pi. cxl, figs, i, 3 and 3') 

 show that the parasite is attached to the ventral surface of the second abdominal segment; it consists 

 of groups of trophomeres, each bearing two or three gonomeres. In the most highly enlarged figure 

 there are visible the remains of recently detached gonomeres. 



